5 ms·
> we already have consumer bicycle gears that deliver 97% efficiency: a Dura Ace groupset is expensive compared to the stuff you'll get at Wall-Mart, but they'r
by davidgould 8y ago
> we already have consumer bicycle gears that deliver 97% efficiency: a Dura Ace groupset is expensive compared to the stuff you'll get at Wall-Mart, but they're sold at pretty much every cycling store. I wouldn't be surprised if the Ultegra and 105 (Shimano's next two groupsets by price) were nearly as efficient as well.
There isn't really much difference in efficiency with price in group sets until you get into the really bad cheap stuff. Most of the differences are cosmetic or ergonomic and status related. Chains and bearing and cogs are the only items that affect efficiency and they are all pretty good. Good chain line and proper maintenance and lubrication make more of a difference.
Internal hubs are slightly less efficient overall and this depends a lot on the internal design and which gears are in use. But even these are something like 94% - 97% efficient.
Shaft drives have been the "next thing" since the end of the 19th century but have never managed to combine reliability and efficiency well. I doubt an exposed mesh 90 degree gear set with what look like teeny tiny exposed ball bearings are going to be as efficient after a good splash of water laden with brake dust and road grit. It might work if they enclose the whole system.
- rienbdj 8y agoweight is a big factor between cheap and expensive groupsets
- magicalhippo 8y agoOverheard at a popular stop for bikers near me: "Yeah, I could have gotten the model above it which is 500g lighter, but it would have cost me another $3500." It should be noted that the guy who said it could have easily lost 500g by a minuscule adjustment to his daily snack intake...
- whafro 8y agoNo, it should not have been noted.
- magicalhippo 8y agoMaybe it's a local thing, but a considerable number of the guys stopping there (it's pretty much the midpoint on a quite nice and highly popular round trip) are middle-aged, and clearly quite well off. So they eat well and ride expensive bikes...
- whafro 8y agoI'll just leave it at this: this particular guy's eating habits, whether you're privy to the details of them or not (and I suspect you aren't), were totally not germane to the discussion. The first sentence was legit, and the second was entirely unnecessary.
- AceyMan 8y agoTo be fair, this is in fact a very common observation among cyclists, with no snark intended. Obviously, mass is mass, it matters not one whit if it's meat or space-age metal. It's just funny how many wannabee Eddy Merckxs seem immune to that truth, and we who grok it like to snicker when we hear discussions like the one cited.
- rienbdj 8y agoNot quite. rotating mass (e.g. tyres) is more important to bike handling and efficiency.
- magicalhippo 8y agoI said snack intake because most people do eat some snack, and it's the easiest area to cut calories. Of course, he could alternatively have cut down his dinner portion by a slight amount for the same effect. 500 grams is ~10 calories per day for a year, and 10 calories is 1/25th of a Snickers bar or about one eight of a potato. Either way, he'd get the same effect has the extra $3500 would have, which was what I found amusing and why I mentioned it.
- devjam 8y agoAs the cycling component equivalent of the CAP theorem goes: light, cheap, strong - pick any 2.
- microcolonel 8y agoHow light, how cheap, and how strong, though? Seems like an incomplete theorem.
- kodis 8y agoI had a similar experience: I could buy a steel water bottle cage for $12, or a nearly identical model made of titanium for a savings of a few dozen grams at the cost of an extra $60 or so. This seems like an exceptionally silly expense for a device which is designed to carry two pounds of water around!
- gomox 8y agoThe "classic" Mobikes have enclosed shaft drives. But they also have airless tires, a tiny frame and crank size and a frontwheel powered LED system. It's hard to say where their perceived huge inefficiency comes from.
- akvadrako 8y ago> Internal hubs are slightly less efficient overall and this depends a lot on the internal design and which gears are in use. But even these are something like 94% - 97% efficient. This isn't true. Rolhoff hubs can approach that for some gears, but bikes with them start at $2K. Nothing else except derailleurs are even close: http://bikeshed.johnhoogstrate.nl/bicycle/drivetrain/shimano_alfine_inter_11/#efficiency http://bikeshed.johnhoogstrate.nl/bicycle/drivetrain/shimano... https://www.cyclingabout.com/speed-difference-testing-gearbox-systems/ https://www.cyclingabout.com/speed-difference-testing-gearbo... Also, current shafts and bands reduce speed another few percent.
- jdietrich 8y agoA well maintained Sturmey Archer three-speed will match the efficiency of the Rohloff, albeit with a far narrower range of ratios. They're an excellent choice for utility bikes in relatively flat areas.