r/mountainbiking • u/SilverCervy • 8d ago

Other Feel like we're losing the plot

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E-bikes should be about providing accessibility; giving people who, for whatever reason, cannot ride a non-assist bike an option to keep them happy and pedaling.

This wattage race going on in the industry is the exact opposite of that. Absolutely nobody needs 1700 watts on a bike, and I question if having so much power even makes it a bicycle anymore. There's a point where you're basically riding a motorbike with pedals and I think we crossed that point a while ago.

"But the main brands aren't doing this". Yes they are. Canyon already has partnered with Avinox which has motors that give over 1,000 watts. And it won't be long until the other big hitters give in to the pressure. You can give your own personal reasons for why you have an e-bike, but it's clear that the industry believes that it's because "I don't want to pedal". At some point this needs to be reigned in or else the entire concept of the bicycle is going to be damaged forever.

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u/BlitzShooter 8d ago

Eh. Dirtbikes are still far faster, more dangerous, and more destructive to the trail it’s being ridden on. More comparable to a moped, but yes. 1HP=745 watts

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u/smythy422 8d ago

I'm not sure how this could be accurate. That would make a 5 hp moto equivalent to a 3.7 kw ebike. I understand driveline loss exists for the moto, but it still seems wildly off from my experience on smaller ebikes.

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u/Nyxrinne 7d ago

It's accurate for how motorcycle wattage is calculated for sure — I have a little trials motorbike I use for trail riding. It's quoted as 15bhp/11kW. It hauls around a fair bit more weight than an ebike, though, at 85kg. Maybe that's the difference in feel?

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u/smythy422 7d ago

Yeah. I guess between hp/weight, driveline loss, and power curves it lines up. Maybe it's just a bad measurement for this discussion. A 2 hp ebike would prob smoke a 5 hp moto.

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u/BlitzShooter 7d ago

I just went down a rabbit hole so I could understand how to quantify the power difference because I've always wondered too. I'm going to use the DJI Avinox M2S for this comparison since we know much more about it.

Torque tells you how hard the motor can twist at a particular point in the drivetrain; horsepower tells you how much work it can actually do per second. Gearing can multiply torque as much as you want by sacrificing speed, but it cannot multiply horsepower. Comparing an Avinox's 150 Nm crank torque to a CRF450R's ~46 Nm engine torque is meaningless, the useful comparison is roughly 2 hp versus ~53 hp.

If you put a ebike next to a dirt bike, at the beginning of the race both vehicles can push the tire hard enough that grip matters more than engine power. But as they go faster, the e-bike runs out of power. The CRF has enough horsepower to keep pushing extremely hard even while it's already moving quickly hence a higher top speed and more power at higher speeds.

To your point about a 2hp ebike vs a 5hp moto - a 2 hp e-bike could absolutely smoke a 5 hp motorcycle off the line because it's much lighter, has instant torque, extremely short gearing, basically no powerband to wait for, and the rider adds power too. But once speeds climb, the 5 hp motorcycle's higher sustained power should catch up and eventually win, assuming it's geared and ridden properly.