12 ms·

A word of warning. I started looking a little into motor assist bike mods a few years ago, and very quickly you find that the biggest mistake people make in thi

A word of warning. I started looking a little into motor assist bike mods a few years ago, and very quickly you find that the biggest mistake people make in this area is not altering any of the other systems of the bike. That is, they'll put in the motor, and then just ride. Which works, but then you find that your brakes aren't quite good enough to stop quickly at the new higher speeds. Shocks are no longer good enough to prevent certain issues as well. Maybe the frame needs reinforcing... I don't quite remember the whole laundry list. I don't know how important some of these improvements are, I just remember reading this advice more than once, and safety is important. So be smart and do your research.

treis 5y ago
I think ebike is a misnomer. These things are really e-(motor)cycles. This confusion is making it really hard for me to search for what I need. All I want is an assist to take the edge off of hills. Don't need to cruise at 30mph for an hour.
- germinalphrase 5y ago
  Search for a 750 watt motor. That is the upper limit in many countries for a standard commercial ebike. Bafang and Tongsheng both produce popular motors.
  - treis 5y ago
    Google says those cruise at ~30mph.
    - 1-more 5y ago
      You can get really nerdy and calculate this the way triathletes/time trialists do with a tool like this[0]. I plugged in what I think my numbers are for mass and my relaxed ride CdA and on my road bike and you're on the money. [0] http://www.aeroweenie.com/calc.html http://www.aeroweenie.com/calc.html
      - morganw 5y ago
        That's really helpful. It predicts 534 Watts to get me (110kg, 0.4 CdA) to the 45kph limit for Class 3 California bikes. The Grin Technologies motor simulator https://ebikes.ca/tools/simulator.html https://ebikes.ca/tools/simulator.html predicts (the "Load Line") 837 Watts for "MTB upright", 648W for "MTB, Tuck" and 570W for "Road, Tuck". I do find that in an upright position it takes 100-200W of human power in addition to 750W power measured at the input to the motor controller. The controller's pretty efficient, but the motor (GMAC) is only 85% max, so there's maybe 570W at the axle. The US CPSC and California laws aren't clear whether the 750W/1 horsepower limit is power in or power out, but power in is what shows on the display, so I limit it to that. Also, even a mild grade will cause the motor to approach the 70 deg C limit I chose after 1 minute. I live in the flattish Santa Clara County, but I'd definitely want a mid-drive if I lived in a hilly area. A 250 or 350W Riese & Müller Delite https://www.r-m.de/en-us/bikes/delite/ https://www.r-m.de/en-us/bikes/delite/ I test rode needed a lot of human power to hit the 45 kph max, but it climbed hills in Larkspur like a goat. 750W will have no problem getting a recumbent bike to 30MPH, but don't count on it for an upright.
      - morganw 5y ago
        Oh, and to see what 700W from a human looks like, an Olympic track cyclist toasts a piece of bread: https://www.youtube.com/watch?v=S4O5voOCqAQ https://www.youtube.com/watch?v=S4O5voOCqAQ
        1-more 5y ago
        Yep. Bradley Wiggins's 2015 velodrome hour world record was 440W (since eclipsed in distance but not power). This puts into perspective how cheap power is in the industrial age. His hour record was the equivalent power of 35 grams of gasoline. Or it's about 5 not great power tool batteries (eyeballing eBay listings). It's gonna be tough when we have a world built for nearly free energy and we don't have the free energy anymore.
    - dzhiurgis 5y ago
      I had guy in lycra overtake me at that speed (slight downhill). He smiled and took off.
    - loeg 5y ago
      It's plausible. Pro riders put out 400-500W to do ~30 mph, but are likely in a more aerodynamic position than most ebike riders (or drafting).
      - shiftpgdn 5y ago
        Pro riders can do 30mph at around 270-300W on a flat surface as they’re typically very skinny. I need about 350-450W to do 30mph as an 88kg/1.88M male.
    - germinalphrase 5y ago
      Hm. You’re right. Bad suggestion. Overkill.
- bootlooped 5y ago
  I think the phrase e-bike generally refers to a bicycle, with operable pedals, that also has an electric motor to assist when peddling, and possibly a throttle. When I think electric motorcycle, I think of something that does not have pedals at all.
  - analog31 5y ago
    One issue is that the pedals could be practically cosmetic, if the power added by the motor is such that pedaling is unnecessary. This was true with some early mopeds too -- the pedals were pretty much good for starting the motor and nothing else. I'm seeing more of this as e-bikes evolve towards smaller diameter, wider tires and heavier frames. The US "class" system seems useful, inasmuch as it more or less specifies the capability of the bike with and without pedaling. I'm all for adding a new transportation / recreation option, and have adopted a wait-and-see attitude for how the technology and its use will evolve. So far, e-bikes have not affected my use of a conventional bike, except for people asking me when I'm going to get an e-bike.
    - mastax 5y ago
      Huh, I've never seen a moped that you could pedal like a bike even in a photo. Apparently the "ped" is from "pedal," not "pedestrian." I wonder if eBikes will follow the same path? I don't think they will, a gas motor is already disruptive enough that you may as well become a motorcycle.
      - throwaway_se099 5y ago
        I've never seen a moped that you could pedal like a bike even in a photo. As an example, https://en.wikipedia.org/wiki/Puch_Maxi https://en.wikipedia.org/wiki/Puch_Maxi
      - analog31 5y ago
        I wonder if electric starters killed the pedals. I grew up in an area that was pretty heavily car-centric, so we didn't see a lot of alternatives. The Schwinn store got the Solex Horse, which had pedals, but they were really only useful for starting as there was one gear with a low ratio. The only next thing we saw was the Honda Spree, which as I recall had an electric starter and whatever qualified as an "automatic transmission," and I think that class of scooter is still more or less the standard today. It seemed like a big step forward in terms of ease of use.
- ZeroGravitas 5y ago
  EPAC or Pedelec is a term used for bikes that meet the EU regulations, assist should cut off beyond 25kph (15.5mph) and you only get power when you cycle. I think there's a motor wattage maximum too so that might help your search.
  - treis 5y ago
    Those seem to be the magic words to find what I'm looking for, thanks!
  - kylegordon 5y ago
    yup, and 250W continuous And the great bit is that if you are ignorant of these laws and get caught on an electric bike doing higher speeds then you get a penalty as if you are riding a motorbike without insurance or a license - aka penalty points on your regular driving license, plus all the other court shenanigans.
  - dzhiurgis 5y ago
    I'm all in for sensible regulation, but don't structure in a way that it's impossible to buy mid-speed ebike because no one knows how to certify or suddenly it costs 4x more for no apparent reason.
    - aaronblohowiak 5y ago
      We call it a class 1 ebike and they are easy to buy in USA.
- analog31 5y ago
  This could be a market problem, like trying to buy a small car these days. People are demanding bigger, faster, more range. I know several people with e-bikes, and most of them are on their second or third bike in pursuit of more speed and power, fatter tires, shocks, etc. A used bike might fit your bill. Or the DIY route. The friction motor might be a bit iffy, but you might be able to buy an electric front or rear wheel for not too much and use the same electronics.
  - swader999 5y ago
    Friction motors are not great in the rain. The tire tread type and width, the pressure on the tire and the material of the friction drive surface are all difficult to get right. These kinds of motors are very noisy too.
- PragmaticPulp 5y ago
  This distinction is becoming a big problem in our local mountain biking community. Most of us really wouldn’t mind if people who needed a little extra help (older people, injured people, people new to the sport) were riding bikes that provided a small assist to help out with the hills. It’s actually great to see older people being able to ride again with some help from a motor, for example. But instead, we’re seeing a lot of e-bike builders abusing the concept to hack or build bikes that are basically electric motorcycles. It gets old fast when your local mountain bike trail is now crowded with kids motoring up the mountain on their modified e-bikes without even pretending to pedal. It’s even worse when they end up deep into trails they’re not qualified to ride with a dead battery and no natural ability to pedal back out. The end result has been a blanket ban on e-bikes on most trails and a lot of animosity toward e-bikes. I wish there was a better compromise, but after watching all of the dumb outcomes play out on my local trails from a small handful of people abusing the concept, I understand why it had come to this.
  - swader999 5y ago
    Do bans work? I could probably build a bike that you really couldn't tell unless you took it apart.
    - PragmaticPulp 5y ago
      Partially. My local trail bans e-bikes and off-leash dogs, but I still run into both on a regular basis. Occasionally there will be someone waiting at the trailhead writing tickets to people who come off the trail with an e-bike or an off-leash dog. This seems to work as word spreads through Facebook groups and people stay away. Also generates some decent revenue when someone can write tickets for an hour and hand out a couple thousand dollars in fines for blatant violations (they stand right next to the very clear signage at the trailhead)
    - ip26 5y ago
      If it's indistinguishable from a regular bike, it's probably not one of the 1500kW bikes their organization had a problem with.
calvinmorrison 5y ago
#1 rule people forget is: how fast can you stop. You see it with young car guys vs old ones. Old dudes upgrade the brakes before the turbo and visa versa
- tyingq 5y ago
  Some of that may be because brakes on old cars (drum brakes, undersized discs, etc) were often terrible. I think stock brakes have been quite good on most cars in the last 15 years or so. For example, a 2021 Chevy Surburban is a HUGE SUV, but does 70mph-0 in 166 feet. Better than a 1999 Camaro Z28 or Mustang GT, at 184 and 182 feet, respectively.
  - mrfusion 5y ago
    Are those numbers with threshold braking or engaging the ABS?
    - tyingq 5y ago
      Not sure, but here's the sources: The article with the Suburban data: https://www.caranddriver.com/features/a35048882/tahoe-yukon-escalade-braking-performance/ https://www.caranddriver.com/features/a35048882/tahoe-yukon-... Mustang and Camaro: https://www.caranddriver.com/reviews/comparison-test/a15140859/1999-chevrolet-camaro-z28-vs-ford-mustang-gt-archived-comparison/ https://www.caranddriver.com/reviews/comparison-test/a151408...
  - sokoloff 5y ago
    I wonder how the 20 year old GT cars would do on modern tire construction and compounds?
    - throwaway0a5e 5y ago
      Probably pretty good but not better than modern cars. In the 2000s one of the car magazines tested top trim (big engine, race package, etc) classic muscle cars on modern tires and they put down respectable numbers, not better than 00s cars, but respectable. Suspension and chassis stuff hasn't come all that far since the 90s so high end cars of that era should be able to handle very respectably compared to modern stuff. The differences are more apparent at the low end. Modern crossovers handle very respectably for what they are. Obviously modern stuff will always win in a straight line because power levels increased massively over the past 20yr.
asdff 5y ago
If you limit yourself to like 25mph thats a nonissue though, all bikes are built to handle that speed.
- swader999 5y ago
  You'll add approx 20-30 pounds with the battery and a hub motor to the frame and that can make stopping more difficult, it's not the same as a heavier rider.
  - loeg 5y ago
    Not sure what you mean. The range of weights on any given adult bike beyond, say, extra small, are much wider than 20-30 lbs. It's exactly the same as a heavier rider as far as stopping distance.
    - swader999 5y ago
      The handling of the bike with weight added on the frame (especially if it is high) is quite different under a hard stop than just adding a heavier rider with the same weight. You can shift towards the back of the bike with your body for instance.
      - parineum 5y ago
        > especially if it is high Like the body of a larger person or a person wearing a backpack?
        swader999 5y ago
        I mean where you mount the battery pack on the bike. On a rear rack above the tire is probably the easiest but its not great for stopping or handling, especially if its more than ten pounds. On the down tube is better. Carrying the batteries in a back pack can be done. I did that for a few months.
  - adrianN 5y ago
bambax 5y ago
I made an ebike from a brand new Decathlon "rockrider" MTB 3 years ago, and have ridden about 10k km on it since. I changed brake pads often, and tires a couple of times, etc. but the frame is fine. It's really life changing. I used to ride a motorcycle, and I still own one, but I seldom use it anymore; the ebike is absolutely perfect for short commutes (under 20 km each way). That said, complete ebikes are more available now, and at good prices, so conversion kits are becoming less relevant.
- Aerroon 5y ago
  Don't complete ebikes cost as much as used cars?
  - jdboyd 5y ago
    An Ancheer ebike from Amazon cost around $1k, and while possible, it would be hard to get a car for that price. It seems pretty well made for the price, but it doesn't include the best quality shifters. I can set the saddle high enough for my 6'5" self, but I do want the handle bars raised as well. I suspect that for people 6' and under, it would be fine as is.
  - acomjean 5y ago
    I bought a decent e-bike for $1800. It’s got good components (shimano) and disc brakes. I’ve put about 2000 miles on it so far and use the pedal assist 30% of the time, turn it off to get more of a workout when riding home. You can get cheaper and way more expensive but I think this is the sweet spot. (For comparison My non ebike is a hybrid commuter which was about 600)
  - dmix 5y ago
    Not if you factor in insurance (especially for young males) and budget ebikes start at $1000 and even at entry level they are still very capable. Plus car repairs and gas. Besides people always get suckered into getting way nicer/newer cars than they really need (myself included). Financing is a difficult thing to keep at the low end. So in practice it’s not really comparable. But cars obviously have plenty of other benefits.
NathanielK 5y ago
The shocks on most cheap bikes are questionable at best. Lots of stiction and you're lucky if there's any dampening at all. Downhill mountainbikes are popular conversions. They are designed with high speeds and impacts in mind. The cost may be prohibitive to many DIYers though. For high speed (50km/h), adequate tires are also necessary. E50 rated tires are now widely available that can handle the speeds and loads.
- dzhiurgis 5y ago
  DIY downhill ebike is around $4000 NZD, while the cheapest, lowest spec downhill ebike from manufacturer is $6000 or so. There's a sizeable savings to be made.
  - swader999 5y ago
    Yeah I think you don't need to do this to an expensive bike. Mechanical disc brakes and just a front shock are probably fine if you want to go 50km/hr. A heavier sturdier frame and burlier tires are ok because it is powered. I wouldn't recommend converting a road bike as they are more fragile.
    - dzhiurgis 5y ago
      I’d love a utility ebike but afaik they just don’t have enough weight and hence - the grip at high speeds to be safe. I’d guess e-scooter/moped is next best thing tho parking is an issue in some places.
      - NathanielK 5y ago
        Mechanical grip is entirely a function of tire compounds. In fact, ebikes can have even more tractive grip because you can make them AWD! This makes them much safer in snow and ice compared to other two wheeled vehicles.
      - swader999 5y ago
        They are fine at 45-50 km/hr. That keeps pace with car speed on residential roads fairly well. Any faster and I agree you could look at scooter or moped.
BoxOfRain 5y ago
Another big issue is stealability - as a cycle commuter I considered an electric conversion right up until I remembered my office is in one of Oxford's black spots for bike thefts (the whole area is bad to be honest, but I'm in one of the worst places for it). The key to preventing your bike from being stolen by some fifth generation product of inbreeding isn't to have the best lock, it's to make it less worthwhile to steal than the bikes around it. The crappier your bike looks the less likely it's going to be stolen, an obvious electric bike parked with any regularity is going to vanish pretty quickly to a thief with a bolt cutter no matter how good your lock is.
- swader999 5y ago
  So true. I spray painted my bike a flat black and put crappy looking fenders on it for wet riding. It looked like hell on the bike rack.
- mycall 5y ago
  Put a lojack into the frame and have fun catching them.
  - culopatin 5y ago
    Yeah so fun to have to figure out a way home, how to get to work the next day, having to deal with the police, retrieving the bike, hours spent on fun
  - mastax 5y ago
    The police don't want to help retrieve your bike, even if you know exactly where it is.
  - UI_at_80x24 5y ago
    Or AirTags.
jbay808 5y ago
Hopefully your motor will also work as a regenerative brake. But perhaps not every controller offers that?
- analog31 5y ago
  As I understand it, that's actually rare.
  - Baeocystin 5y ago
    It is. Motors that can regen also 'cog' if you're out of power, which sucks. It turns out it's a lot more comfortable to just have a freewheel system that can coast without any extra friction. The extra energy recoverable otherwise just isn't worth the tradeoff.
    - jbay808 5y ago
      It should scarcely cost any power to cancel the cogging torque though, wouldn't it? Can't you just keep a small percentage of the battery in reserve for that purpose?
      - Baeocystin 5y ago
        No matter what you do, you still have the ultimate potential endpoint of being stuck out somewhere with a dead battery pack and an annoying ride home compared to a freewheel system. (It's worth mentioning that the other main reason you don't see regen used much on bikes is that freewheel systems allow the use of gearing, which greatly improves starting torque, which really is what matters for ebiking comfort. Direct drive systems are less efficient, so they are already starting from behind the curve with regards to making regen worthwhile.) https://www.bikeberry.com/pages/direct-drive-vs-geared https://www.bikeberry.com/pages/direct-drive-vs-geared
  - sudosysgen 5y ago
    Not rare at all. Most direct drive motors, which is almost all over 750w, can do it, and their associated controllers generally have a setting for that.
twoslide 5y ago
This is a good point. I bought a used bike for about $100 online and have now done about 5K KM using a cheap conversion kit online, with minimal maintenance. However, I was lucky and also bought a low power kit (250W, while 1000W kits are available). It is a great way to get around but some caution is required. In the wost cases, front wheel drive motors can bend/break the front fork on a ride - not a good situation.
Johnny555 5y ago
I think the biggest mistake people make with eBike conversions is putting in too powerful of a motor. If your motor lets you bike faster than the brakes or other components can handle, then it's too much motor. Get an electric moped/scooter/motorcycle if you want to ride faster than you can pedal.
- thunfischbrot 5y ago
  Yes, also include the added weight though. The converted bike will take longer to stop at the same speed just because you added a motor and battery.
sundvor 5y ago
Absolutely. The weight of batteries and increase speed will quickly tell you you need hydraulic brakes, and not a crap system either. I was thinking, the one in the linked article uses friction against the back wheel. What happens the moment you get a good chunk of debris in there? It could get painful very quickly.
_0ffh 5y ago
Yes, another important one is the chain, if used for transmitting motor power. The additional torque can severely shorten it's life span if it is not adequately strong.
bananapear 5y ago
Also, at least in the UK, unless the e-bike meets certain conditions it is legally a motorcycle - which comes with the requirement for a licence, insurance, vehicle approval etc. https://www.bbc.co.uk/news/uk-england-london-51707616 https://www.bbc.co.uk/news/uk-england-london-51707616
- uncleScrumpy 5y ago
  Yes this is a better link. https://www.gov.uk/electric-bike-rules https://www.gov.uk/electric-bike-rules
notjes 5y ago
I did a couple of conversions but mostly just replaced the rear wheel with a built in motor. It is a dirt cheap mod and it is very modest optics wise. Unlike other options. In general it is very advisable to look for spots on the frame where the power of the motor will be attacking. Most parts are designed to handle stress just from one direction only. That is why I am not a fan of conversions that utilize front wheel motors and/or big guns like 500W+ motors - even for the rear wheel.
CaptainZapp 5y ago
It can actually be much worse and void your insurance. There are kits available to convert a low performance e-bike into a high performance one, which runs much faster and needs a registration and a number plate. But cause an accident, which doesn't even needs to be your own fault with such a revamped bike and your insurance will tell you that you're shit out of luck and you will have to pay for the whole damage. Potentially ruining your life.
iamthepieman 5y ago
Safety is definitely important but I have a hard time lining up this advice with how I ride my current bike. I ride downhill at up to 40 mph and my brakes, frame and shock work fine. On my mountain bike, I jump off 6 foot drops regularly. Maybe it's a matter of wear and tear over time being greater because your average speed is higher? I have a hard believing it's the added weight of the motor and battery either since I'm 50 pounds heavier than my brother in law and we have swapped biked a few times with neither bike having issues.

treis 5y ago

I think ebike is a misnomer. These things are really e-(motor)cycles. This confusion is making it really hard for me to search for what I need. All I want is an assist to take the edge off of hills. Don't need to cruise at 30mph for an hour.

germinalphrase 5y ago
Search for a 750 watt motor. That is the upper limit in many countries for a standard commercial ebike. Bafang and Tongsheng both produce popular motors.
- treis 5y ago
  Google says those cruise at ~30mph.
  - 1-more 5y ago
    You can get really nerdy and calculate this the way triathletes/time trialists do with a tool like this[0]. I plugged in what I think my numbers are for mass and my relaxed ride CdA and on my road bike and you're on the money. [0] http://www.aeroweenie.com/calc.html http://www.aeroweenie.com/calc.html
    - morganw 5y ago
      That's really helpful. It predicts 534 Watts to get me (110kg, 0.4 CdA) to the 45kph limit for Class 3 California bikes. The Grin Technologies motor simulator https://ebikes.ca/tools/simulator.html https://ebikes.ca/tools/simulator.html predicts (the "Load Line") 837 Watts for "MTB upright", 648W for "MTB, Tuck" and 570W for "Road, Tuck". I do find that in an upright position it takes 100-200W of human power in addition to 750W power measured at the input to the motor controller. The controller's pretty efficient, but the motor (GMAC) is only 85% max, so there's maybe 570W at the axle. The US CPSC and California laws aren't clear whether the 750W/1 horsepower limit is power in or power out, but power in is what shows on the display, so I limit it to that. Also, even a mild grade will cause the motor to approach the 70 deg C limit I chose after 1 minute. I live in the flattish Santa Clara County, but I'd definitely want a mid-drive if I lived in a hilly area. A 250 or 350W Riese & Müller Delite https://www.r-m.de/en-us/bikes/delite/ https://www.r-m.de/en-us/bikes/delite/ I test rode needed a lot of human power to hit the 45 kph max, but it climbed hills in Larkspur like a goat. 750W will have no problem getting a recumbent bike to 30MPH, but don't count on it for an upright.
    - morganw 5y ago
      Oh, and to see what 700W from a human looks like, an Olympic track cyclist toasts a piece of bread: https://www.youtube.com/watch?v=S4O5voOCqAQ https://www.youtube.com/watch?v=S4O5voOCqAQ
      - 1-more 5y ago
        Yep. Bradley Wiggins's 2015 velodrome hour world record was 440W (since eclipsed in distance but not power). This puts into perspective how cheap power is in the industrial age. His hour record was the equivalent power of 35 grams of gasoline. Or it's about 5 not great power tool batteries (eyeballing eBay listings). It's gonna be tough when we have a world built for nearly free energy and we don't have the free energy anymore.
  - dzhiurgis 5y ago
    I had guy in lycra overtake me at that speed (slight downhill). He smiled and took off.
  - loeg 5y ago
    It's plausible. Pro riders put out 400-500W to do ~30 mph, but are likely in a more aerodynamic position than most ebike riders (or drafting).
    - shiftpgdn 5y ago
      Pro riders can do 30mph at around 270-300W on a flat surface as they’re typically very skinny. I need about 350-450W to do 30mph as an 88kg/1.88M male.
  - germinalphrase 5y ago
    Hm. You’re right. Bad suggestion. Overkill.
bootlooped 5y ago
I think the phrase e-bike generally refers to a bicycle, with operable pedals, that also has an electric motor to assist when peddling, and possibly a throttle. When I think electric motorcycle, I think of something that does not have pedals at all.
- analog31 5y ago
  One issue is that the pedals could be practically cosmetic, if the power added by the motor is such that pedaling is unnecessary. This was true with some early mopeds too -- the pedals were pretty much good for starting the motor and nothing else. I'm seeing more of this as e-bikes evolve towards smaller diameter, wider tires and heavier frames. The US "class" system seems useful, inasmuch as it more or less specifies the capability of the bike with and without pedaling. I'm all for adding a new transportation / recreation option, and have adopted a wait-and-see attitude for how the technology and its use will evolve. So far, e-bikes have not affected my use of a conventional bike, except for people asking me when I'm going to get an e-bike.
  - mastax 5y ago
    Huh, I've never seen a moped that you could pedal like a bike even in a photo. Apparently the "ped" is from "pedal," not "pedestrian." I wonder if eBikes will follow the same path? I don't think they will, a gas motor is already disruptive enough that you may as well become a motorcycle.
    - throwaway_se099 5y ago
      I've never seen a moped that you could pedal like a bike even in a photo. As an example, https://en.wikipedia.org/wiki/Puch_Maxi https://en.wikipedia.org/wiki/Puch_Maxi
    - analog31 5y ago
      I wonder if electric starters killed the pedals. I grew up in an area that was pretty heavily car-centric, so we didn't see a lot of alternatives. The Schwinn store got the Solex Horse, which had pedals, but they were really only useful for starting as there was one gear with a low ratio. The only next thing we saw was the Honda Spree, which as I recall had an electric starter and whatever qualified as an "automatic transmission," and I think that class of scooter is still more or less the standard today. It seemed like a big step forward in terms of ease of use.
ZeroGravitas 5y ago
EPAC or Pedelec is a term used for bikes that meet the EU regulations, assist should cut off beyond 25kph (15.5mph) and you only get power when you cycle. I think there's a motor wattage maximum too so that might help your search.
- treis 5y ago
  Those seem to be the magic words to find what I'm looking for, thanks!
- kylegordon 5y ago
  yup, and 250W continuous And the great bit is that if you are ignorant of these laws and get caught on an electric bike doing higher speeds then you get a penalty as if you are riding a motorbike without insurance or a license - aka penalty points on your regular driving license, plus all the other court shenanigans.
- dzhiurgis 5y ago
  I'm all in for sensible regulation, but don't structure in a way that it's impossible to buy mid-speed ebike because no one knows how to certify or suddenly it costs 4x more for no apparent reason.
  - aaronblohowiak 5y ago
    We call it a class 1 ebike and they are easy to buy in USA.
analog31 5y ago
This could be a market problem, like trying to buy a small car these days. People are demanding bigger, faster, more range. I know several people with e-bikes, and most of them are on their second or third bike in pursuit of more speed and power, fatter tires, shocks, etc. A used bike might fit your bill. Or the DIY route. The friction motor might be a bit iffy, but you might be able to buy an electric front or rear wheel for not too much and use the same electronics.
- swader999 5y ago
  Friction motors are not great in the rain. The tire tread type and width, the pressure on the tire and the material of the friction drive surface are all difficult to get right. These kinds of motors are very noisy too.
PragmaticPulp 5y ago
This distinction is becoming a big problem in our local mountain biking community. Most of us really wouldn’t mind if people who needed a little extra help (older people, injured people, people new to the sport) were riding bikes that provided a small assist to help out with the hills. It’s actually great to see older people being able to ride again with some help from a motor, for example. But instead, we’re seeing a lot of e-bike builders abusing the concept to hack or build bikes that are basically electric motorcycles. It gets old fast when your local mountain bike trail is now crowded with kids motoring up the mountain on their modified e-bikes without even pretending to pedal. It’s even worse when they end up deep into trails they’re not qualified to ride with a dead battery and no natural ability to pedal back out. The end result has been a blanket ban on e-bikes on most trails and a lot of animosity toward e-bikes. I wish there was a better compromise, but after watching all of the dumb outcomes play out on my local trails from a small handful of people abusing the concept, I understand why it had come to this.
- swader999 5y ago
  Do bans work? I could probably build a bike that you really couldn't tell unless you took it apart.
  - PragmaticPulp 5y ago
    Partially. My local trail bans e-bikes and off-leash dogs, but I still run into both on a regular basis. Occasionally there will be someone waiting at the trailhead writing tickets to people who come off the trail with an e-bike or an off-leash dog. This seems to work as word spreads through Facebook groups and people stay away. Also generates some decent revenue when someone can write tickets for an hour and hand out a couple thousand dollars in fines for blatant violations (they stand right next to the very clear signage at the trailhead)
  - ip26 5y ago
    If it's indistinguishable from a regular bike, it's probably not one of the 1500kW bikes their organization had a problem with.

calvinmorrison 5y ago

#1 rule people forget is: how fast can you stop. You see it with young car guys vs old ones. Old dudes upgrade the brakes before the turbo and visa versa

tyingq 5y ago
Some of that may be because brakes on old cars (drum brakes, undersized discs, etc) were often terrible. I think stock brakes have been quite good on most cars in the last 15 years or so. For example, a 2021 Chevy Surburban is a HUGE SUV, but does 70mph-0 in 166 feet. Better than a 1999 Camaro Z28 or Mustang GT, at 184 and 182 feet, respectively.
- mrfusion 5y ago
  Are those numbers with threshold braking or engaging the ABS?
  - tyingq 5y ago
    Not sure, but here's the sources: The article with the Suburban data: https://www.caranddriver.com/features/a35048882/tahoe-yukon-escalade-braking-performance/ https://www.caranddriver.com/features/a35048882/tahoe-yukon-... Mustang and Camaro: https://www.caranddriver.com/reviews/comparison-test/a15140859/1999-chevrolet-camaro-z28-vs-ford-mustang-gt-archived-comparison/ https://www.caranddriver.com/reviews/comparison-test/a151408...
- sokoloff 5y ago
  I wonder how the 20 year old GT cars would do on modern tire construction and compounds?
  - throwaway0a5e 5y ago
    Probably pretty good but not better than modern cars. In the 2000s one of the car magazines tested top trim (big engine, race package, etc) classic muscle cars on modern tires and they put down respectable numbers, not better than 00s cars, but respectable. Suspension and chassis stuff hasn't come all that far since the 90s so high end cars of that era should be able to handle very respectably compared to modern stuff. The differences are more apparent at the low end. Modern crossovers handle very respectably for what they are. Obviously modern stuff will always win in a straight line because power levels increased massively over the past 20yr.

asdff 5y ago

If you limit yourself to like 25mph thats a nonissue though, all bikes are built to handle that speed.

swader999 5y ago
You'll add approx 20-30 pounds with the battery and a hub motor to the frame and that can make stopping more difficult, it's not the same as a heavier rider.
- loeg 5y ago
  Not sure what you mean. The range of weights on any given adult bike beyond, say, extra small, are much wider than 20-30 lbs. It's exactly the same as a heavier rider as far as stopping distance.
  - swader999 5y ago
    The handling of the bike with weight added on the frame (especially if it is high) is quite different under a hard stop than just adding a heavier rider with the same weight. You can shift towards the back of the bike with your body for instance.
    - parineum 5y ago
      > especially if it is high Like the body of a larger person or a person wearing a backpack?
      - swader999 5y ago
        I mean where you mount the battery pack on the bike. On a rear rack above the tire is probably the easiest but its not great for stopping or handling, especially if its more than ten pounds. On the down tube is better. Carrying the batteries in a back pack can be done. I did that for a few months.
- adrianN 5y ago

bambax 5y ago

I made an ebike from a brand new Decathlon "rockrider" MTB 3 years ago, and have ridden about 10k km on it since. I changed brake pads often, and tires a couple of times, etc. but the frame is fine. It's really life changing. I used to ride a motorcycle, and I still own one, but I seldom use it anymore; the ebike is absolutely perfect for short commutes (under 20 km each way). That said, complete ebikes are more available now, and at good prices, so conversion kits are becoming less relevant.

Aerroon 5y ago
Don't complete ebikes cost as much as used cars?
- jdboyd 5y ago
  An Ancheer ebike from Amazon cost around $1k, and while possible, it would be hard to get a car for that price. It seems pretty well made for the price, but it doesn't include the best quality shifters. I can set the saddle high enough for my 6'5" self, but I do want the handle bars raised as well. I suspect that for people 6' and under, it would be fine as is.
- acomjean 5y ago
  I bought a decent e-bike for $1800. It’s got good components (shimano) and disc brakes. I’ve put about 2000 miles on it so far and use the pedal assist 30% of the time, turn it off to get more of a workout when riding home. You can get cheaper and way more expensive but I think this is the sweet spot. (For comparison My non ebike is a hybrid commuter which was about 600)
- dmix 5y ago
  Not if you factor in insurance (especially for young males) and budget ebikes start at $1000 and even at entry level they are still very capable. Plus car repairs and gas. Besides people always get suckered into getting way nicer/newer cars than they really need (myself included). Financing is a difficult thing to keep at the low end. So in practice it’s not really comparable. But cars obviously have plenty of other benefits.

NathanielK 5y ago

The shocks on most cheap bikes are questionable at best. Lots of stiction and you're lucky if there's any dampening at all. Downhill mountainbikes are popular conversions. They are designed with high speeds and impacts in mind. The cost may be prohibitive to many DIYers though. For high speed (50km/h), adequate tires are also necessary. E50 rated tires are now widely available that can handle the speeds and loads.

dzhiurgis 5y ago
DIY downhill ebike is around $4000 NZD, while the cheapest, lowest spec downhill ebike from manufacturer is $6000 or so. There's a sizeable savings to be made.
- swader999 5y ago
  Yeah I think you don't need to do this to an expensive bike. Mechanical disc brakes and just a front shock are probably fine if you want to go 50km/hr. A heavier sturdier frame and burlier tires are ok because it is powered. I wouldn't recommend converting a road bike as they are more fragile.
  - dzhiurgis 5y ago
    I’d love a utility ebike but afaik they just don’t have enough weight and hence - the grip at high speeds to be safe. I’d guess e-scooter/moped is next best thing tho parking is an issue in some places.
    - NathanielK 5y ago
      Mechanical grip is entirely a function of tire compounds. In fact, ebikes can have even more tractive grip because you can make them AWD! This makes them much safer in snow and ice compared to other two wheeled vehicles.
    - swader999 5y ago
      They are fine at 45-50 km/hr. That keeps pace with car speed on residential roads fairly well. Any faster and I agree you could look at scooter or moped.

BoxOfRain 5y ago

Another big issue is stealability - as a cycle commuter I considered an electric conversion right up until I remembered my office is in one of Oxford's black spots for bike thefts (the whole area is bad to be honest, but I'm in one of the worst places for it). The key to preventing your bike from being stolen by some fifth generation product of inbreeding isn't to have the best lock, it's to make it less worthwhile to steal than the bikes around it. The crappier your bike looks the less likely it's going to be stolen, an obvious electric bike parked with any regularity is going to vanish pretty quickly to a thief with a bolt cutter no matter how good your lock is.

swader999 5y ago
So true. I spray painted my bike a flat black and put crappy looking fenders on it for wet riding. It looked like hell on the bike rack.
mycall 5y ago
Put a lojack into the frame and have fun catching them.
- culopatin 5y ago
  Yeah so fun to have to figure out a way home, how to get to work the next day, having to deal with the police, retrieving the bike, hours spent on fun
- mastax 5y ago
  The police don't want to help retrieve your bike, even if you know exactly where it is.
- UI_at_80x24 5y ago
  Or AirTags.

jbay808 5y ago

Hopefully your motor will also work as a regenerative brake. But perhaps not every controller offers that?

analog31 5y ago
As I understand it, that's actually rare.
- Baeocystin 5y ago
  It is. Motors that can regen also 'cog' if you're out of power, which sucks. It turns out it's a lot more comfortable to just have a freewheel system that can coast without any extra friction. The extra energy recoverable otherwise just isn't worth the tradeoff.
  - jbay808 5y ago
    It should scarcely cost any power to cancel the cogging torque though, wouldn't it? Can't you just keep a small percentage of the battery in reserve for that purpose?
    - Baeocystin 5y ago
      No matter what you do, you still have the ultimate potential endpoint of being stuck out somewhere with a dead battery pack and an annoying ride home compared to a freewheel system. (It's worth mentioning that the other main reason you don't see regen used much on bikes is that freewheel systems allow the use of gearing, which greatly improves starting torque, which really is what matters for ebiking comfort. Direct drive systems are less efficient, so they are already starting from behind the curve with regards to making regen worthwhile.) https://www.bikeberry.com/pages/direct-drive-vs-geared https://www.bikeberry.com/pages/direct-drive-vs-geared
- sudosysgen 5y ago
  Not rare at all. Most direct drive motors, which is almost all over 750w, can do it, and their associated controllers generally have a setting for that.

twoslide 5y ago

This is a good point. I bought a used bike for about $100 online and have now done about 5K KM using a cheap conversion kit online, with minimal maintenance. However, I was lucky and also bought a low power kit (250W, while 1000W kits are available). It is a great way to get around but some caution is required. In the wost cases, front wheel drive motors can bend/break the front fork on a ride - not a good situation.

Johnny555 5y ago

I think the biggest mistake people make with eBike conversions is putting in too powerful of a motor. If your motor lets you bike faster than the brakes or other components can handle, then it's too much motor. Get an electric moped/scooter/motorcycle if you want to ride faster than you can pedal.

thunfischbrot 5y ago
Yes, also include the added weight though. The converted bike will take longer to stop at the same speed just because you added a motor and battery.

sundvor 5y ago

Absolutely. The weight of batteries and increase speed will quickly tell you you need hydraulic brakes, and not a crap system either. I was thinking, the one in the linked article uses friction against the back wheel. What happens the moment you get a good chunk of debris in there? It could get painful very quickly.

_0ffh 5y ago

Yes, another important one is the chain, if used for transmitting motor power. The additional torque can severely shorten it's life span if it is not adequately strong.

bananapear 5y ago

Also, at least in the UK, unless the e-bike meets certain conditions it is legally a motorcycle - which comes with the requirement for a licence, insurance, vehicle approval etc. https://www.bbc.co.uk/news/uk-england-london-51707616 https://www.bbc.co.uk/news/uk-england-london-51707616

uncleScrumpy 5y ago
Yes this is a better link. https://www.gov.uk/electric-bike-rules https://www.gov.uk/electric-bike-rules

notjes 5y ago

I did a couple of conversions but mostly just replaced the rear wheel with a built in motor. It is a dirt cheap mod and it is very modest optics wise. Unlike other options. In general it is very advisable to look for spots on the frame where the power of the motor will be attacking. Most parts are designed to handle stress just from one direction only. That is why I am not a fan of conversions that utilize front wheel motors and/or big guns like 500W+ motors - even for the rear wheel.

CaptainZapp 5y ago

It can actually be much worse and void your insurance. There are kits available to convert a low performance e-bike into a high performance one, which runs much faster and needs a registration and a number plate. But cause an accident, which doesn't even needs to be your own fault with such a revamped bike and your insurance will tell you that you're shit out of luck and you will have to pay for the whole damage. Potentially ruining your life.

iamthepieman 5y ago

Safety is definitely important but I have a hard time lining up this advice with how I ride my current bike. I ride downhill at up to 40 mph and my brakes, frame and shock work fine. On my mountain bike, I jump off 6 foot drops regularly. Maybe it's a matter of wear and tear over time being greater because your average speed is higher? I have a hard believing it's the added weight of the motor and battery either since I'm 50 pounds heavier than my brother in law and we have swapped biked a few times with neither bike having issues.