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I often wonder about this while hiking or riding my dirt bike out on the trails. Gas powered dirt bikes are prohibited almost everywhere due to risk of fire and

I often wonder about this while hiking or riding my dirt bike out on the trails. Gas powered dirt bikes are prohibited almost everywhere due to risk of fire and chemical contamination. However, more and more I am seeing e-bikes ripping around on hiking trails that would get me and my dirt bikes a hefty fine and impound. The risk of fire and contamination is practically the same. And these e-bikes are typically driven by the same people who would call the cops on a gas powered bike on the same trail. The irony is they ride and do peaceful yoga on trails that were made by motor vehicles whose owners were probably gentrified out of their homes. Go figure.

almost_usual 4y ago
I’m surprised e-bikes are allowed, they’re also prohibited on the trails here and considered OHV. Regarding fire I’d be worried about the hot exhaust on a dry 100+ day.
- zelon88 4y ago
  Most trail bikes come from the factory with spark arrestors with the major exception being cheap Chinese branded bikes. And I don't think the temperature of the exhaust stream would be enough to light a match 6" away from the tip of the muffler. You'd have to reef on the bike and park it in a pile of dry leaves up to the exhaust header for temperature alone to start a fire. The problem is when you dump the bike. If you dump it on a tree or a rock you can fracture the gas tank (releasing fuel) or the crankcase (releasing oil). Or if you tip the bike completely over the fuel will eventually be released. Releasing these doesn't imply fire is inevitable. You still need ignition. If a fire starts you can try to smother it. On an electric bike the same situation applies. If you dump the bike and fracture the battery (that is often attached to the downtube of the frame) then you will have a catastrophic chemical reaction. Thermal runaway is almost guaranteed. You can't even put it out by smothering it. Furthermore, most lithium battery controllers in consumer devices are proprietary and most consumers have no idea what their true capabilities and thresholds are. Some batteries might be inherently safer than others due to simple firmware that they don't know exists and have no visibility into. There's really no hiding the capabilities of an analog machine.
  - SoftTalker 4y ago
    > Most trail bikes come from the factory with spark arrestors And most riders immediately remove them because they gunk up with soot and restrict the exhaust.
scythe 4y ago
It's my understanding that e-bikes which can ride on traditional "bike" trails (I'm used to this rule for bike lanes) are limited to a relatively human-accessible speed, usually 15 or 20 mph in the US. Are these e-bike riders going faster than that? If so, they might be breaking the law. I had assumed dirt bikes were banned on these trails due to weight and speed, leading to damage to the trail, risks to other trail users and potential structural failure of the often wooden bridges. The risk of fire with a modern gasoline engine is quite small, though air quality effects are significant.
- prmoustache 4y ago
  There are many people bypassing the limit using hacks or on some cheap chinese kits just by going in the settings (usually a button combo, knowledge widely available on the internet). Yes it is illegal but in the same way the 50cc mopeds are supposed to be limited at 45kph (27mph) and all the kids always modified them to go faster. I believe there has always been more unrestricted 50cc mopeds than legal ones in the street. Only some old people kept them restricted. Most people are willing to take the risk of not getting insurance coverage and a fine once in a while to gain a few minutes per day and be the king of the road. Most only have third party insurance anyway and a bicycle or a moped don't usually create that much physical damage to other vehicules. It only becomes ugly when people hit pedestrians but thankfully and for obvious reasons it is a much rarer event than car drivers doing it.
  - ClumsyPilot 4y ago
    50cc moped is over 2000W, thats almost 10 times the power of a typical ebike at 250W
audunw 4y ago
> The risk of fire and contamination is practically the same. Source? There's very little risk of an e-bike catching fire unless you're charging the battery. Most of the risk will be at home. Battery fires gets a lot of attention because they're a new thing, but they're far safer than ICE alternatives in almost all circumstances. At least that's what the fire department here in Norway says, and they have pretty good experience with EVs by now.
- zelon88 4y ago
  You obviously don't trail ride. When you ride trails you sometimes fall down. Sometimes you catch a branch with your bars. Sometimes your bike lands on rocks or logs. The down tube of an ebike frame is often where the batteries are located. This area takes a lot of abuse from the front wheel and is in perfect position to take damage during frontal impact. Look up my YT @Platinum_Racing to see an example of terrain that could very easily destroy an ebike or gas bike.
lm28469 4y ago
> Gas powered dirt bikes are prohibited almost everywhere due to risk of fire and chemical contamination. All gas powered bikes generate heat and pollution. (dry grass + hot pipes for example) Only defective ebikes will generate heat and pollution

almost_usual 4y ago

I’m surprised e-bikes are allowed, they’re also prohibited on the trails here and considered OHV. Regarding fire I’d be worried about the hot exhaust on a dry 100+ day.

zelon88 4y ago
Most trail bikes come from the factory with spark arrestors with the major exception being cheap Chinese branded bikes. And I don't think the temperature of the exhaust stream would be enough to light a match 6" away from the tip of the muffler. You'd have to reef on the bike and park it in a pile of dry leaves up to the exhaust header for temperature alone to start a fire. The problem is when you dump the bike. If you dump it on a tree or a rock you can fracture the gas tank (releasing fuel) or the crankcase (releasing oil). Or if you tip the bike completely over the fuel will eventually be released. Releasing these doesn't imply fire is inevitable. You still need ignition. If a fire starts you can try to smother it. On an electric bike the same situation applies. If you dump the bike and fracture the battery (that is often attached to the downtube of the frame) then you will have a catastrophic chemical reaction. Thermal runaway is almost guaranteed. You can't even put it out by smothering it. Furthermore, most lithium battery controllers in consumer devices are proprietary and most consumers have no idea what their true capabilities and thresholds are. Some batteries might be inherently safer than others due to simple firmware that they don't know exists and have no visibility into. There's really no hiding the capabilities of an analog machine.
- SoftTalker 4y ago
  > Most trail bikes come from the factory with spark arrestors And most riders immediately remove them because they gunk up with soot and restrict the exhaust.

scythe 4y ago

It's my understanding that e-bikes which can ride on traditional "bike" trails (I'm used to this rule for bike lanes) are limited to a relatively human-accessible speed, usually 15 or 20 mph in the US. Are these e-bike riders going faster than that? If so, they might be breaking the law. I had assumed dirt bikes were banned on these trails due to weight and speed, leading to damage to the trail, risks to other trail users and potential structural failure of the often wooden bridges. The risk of fire with a modern gasoline engine is quite small, though air quality effects are significant.

prmoustache 4y ago
There are many people bypassing the limit using hacks or on some cheap chinese kits just by going in the settings (usually a button combo, knowledge widely available on the internet). Yes it is illegal but in the same way the 50cc mopeds are supposed to be limited at 45kph (27mph) and all the kids always modified them to go faster. I believe there has always been more unrestricted 50cc mopeds than legal ones in the street. Only some old people kept them restricted. Most people are willing to take the risk of not getting insurance coverage and a fine once in a while to gain a few minutes per day and be the king of the road. Most only have third party insurance anyway and a bicycle or a moped don't usually create that much physical damage to other vehicules. It only becomes ugly when people hit pedestrians but thankfully and for obvious reasons it is a much rarer event than car drivers doing it.
- ClumsyPilot 4y ago
  50cc moped is over 2000W, thats almost 10 times the power of a typical ebike at 250W

audunw 4y ago

> The risk of fire and contamination is practically the same. Source? There's very little risk of an e-bike catching fire unless you're charging the battery. Most of the risk will be at home. Battery fires gets a lot of attention because they're a new thing, but they're far safer than ICE alternatives in almost all circumstances. At least that's what the fire department here in Norway says, and they have pretty good experience with EVs by now.

zelon88 4y ago
You obviously don't trail ride. When you ride trails you sometimes fall down. Sometimes you catch a branch with your bars. Sometimes your bike lands on rocks or logs. The down tube of an ebike frame is often where the batteries are located. This area takes a lot of abuse from the front wheel and is in perfect position to take damage during frontal impact. Look up my YT @Platinum_Racing to see an example of terrain that could very easily destroy an ebike or gas bike.

lm28469 4y ago

> Gas powered dirt bikes are prohibited almost everywhere due to risk of fire and chemical contamination. All gas powered bikes generate heat and pollution. (dry grass + hot pipes for example) Only defective ebikes will generate heat and pollution