Which throttle for mountain biking?

[ferret]

A question for off road riders (single track, downhill etc.).

I am concerned about getting unwanted throttle inputs from bumps, landings, pulling on the handlebars etc.

So, which kind of throttle is best for the rough stuff?

Avner.

[zlagger]

I've been using a full twist and it works fine, but there have been a few bumps of a throttle here and there. I'm thinking of trying a thumb throttle next.

[MadRhino]

Half twist.

[The fingers]

My thumb throttle is very twitchy with any subtle movement of the hands on the handlebars such as when going over rough areas. Half twist grip would get my vote.

[Drunkskunk]

Half Twist.

[d8veh]

Definitely not a full throttle. You can't grip the bars properly, and they break if you hit a bump while holding full throttle. Half-throttle gets my vote.

[ferret]

What about torque sensing (using Cycle assist V3)?
Anyone tried it?

Avner.

[MadRhino]

What about torque sensing (using Cycle assist V3)?
Anyone tried it?

Avner.

A pedal assist is definitely for the streets, and low power.

[iperov]

thumb throttle, reversed, on left hand

[dogman dan]

If you ride a thumb throttle over big bumps while at WOT, you break it off every time. Full throttle sounds good, and would be if it was a motorcycle throttle and cable. But an ebike full throttle turns too easy, and you get the bucking bronco effect if you aren't super careful. Not such a big deal, till you build your 3000w trail bike. Then it throws you for a loop. Where the hell did that shoe go?

It's a no doubt about it deal, half throttle.

Lots of quads have thumb throttles, but the thumb tab on those doesn't snap off like cheap bike throttles.

If they built a better throttle, and charged what it cost, we'd all whine like babies at the cost of it. Except for a few hard core riders. Thumb would be fine, if you didn't break em so easy. Real nylon would do it, but they use cheap pvc.

[ferret]

What about torque sensing (using Cycle assist V3)?
Anyone tried it?

Avner.

A pedal assist is definitely for the streets, and low power.

Are you talking a on/off pedal assist or the kind that senses the torque applied by the rider and gives proportional signal to the controller?

[iperov]

If you ride a thumb throttle over big bumps while at WOT.

i told reversed thumb throttle,
pushing by forefinger

[MadRhino]

What about torque sensing (using Cycle assist V3)?
Anyone tried it?

Avner.

A pedal assist is definitely for the streets, and low power.

Are you talking a on/off pedal assist or the kind that senses the torque applied by the rider and gives proportional signal to the controller?

Any pedal assist will be very tricky in mountain trails. Even on the street, it works fine only with low power.

[xenodius]

A pedal assist is definitely for the streets, and low power.

Are you talking a on/off pedal assist or the kind that senses the torque applied by the rider and gives proportional signal to the controller?

Any pedal assist will be very tricky in mountain trails. Even on the street, it works fine only with low power.

We might have different ideas of what's "low power"...

I would think that a DD hub and torque BB would be perfect for tricky trails. On my (human only) 29'er I have to be in a really low gear to get up the 18-22% grades, but that also makes it super easy to spin out even on ~8% grades. With a torque BB, you could use a much higher gear and apply power on the flats, but with the added help of the motor have enough parallel torque to get up the grades. And you wouldn't have to worry about throttling perfectly-- or at all. You'd just go. Couldn't be more natural! Easily the best choice unless you're super lazy, but definitely the most expensive too.

[ferret]

I'm glad to hear it , because I am planning a setup with a torque sensor and a CA V3.

BTW it will use a GNG V1 motor, not very high powered.

Avner.

[MadRhino]

With my bikes, I just twist the throttle and climb. No need to pedal or shift gears. Any throttle applied by the crank cadence or torque would make unpredictable jerks caused by the bumps and drops when riding standing on the pedals.
Can you imagine your bike suddenly jerking 10Kw and flipping upside down because you just hit a pothole or a bump while standing on the pedals.

[lbz5mc12]

I'm using thumb but wishing my half twist didn't get destroyed in my gnarly bike accident a few months ago. I'm going with half twist on this one.

[xenodius]

With my bikes, I just twist the throttle and climb. No need to pedal or shift gears. Any throttle applied by the crank cadence or torque would make unpredictable jerks caused by the bumps and drops when riding standing on the pedals.
Can you imagine your bike suddenly jerking 10Kw and flipping upside down because you just hit a pothole or a bump while standing on the pedals.

I'd think a reasonable ramp rate would prevent stuttering variations in torque from causing any trouble. Can't say from experience, though it sounds like you might be able to =)

[lollandster]

I have the thun/CA3 setup on two of my bikes and while it works very good 99% of the time I have found that when you need to do some tricky trail maneuvers you want that torque sensor disabled and use throttle instead. The reason is that the Thun doesn't detect torque more than once every revolution so you wont get power until you get the pedal all the way around, and if you are in a high gear form stop the torque reading is very high when the CA finally gets a reading and you get too much power. If you got a slow up ramping it gets hard to do hill starts imo. I'm sure this problem is less evident with better gear selecting, I tend to use only a few gears and often a too high one.

The second problem i have experienced with the thun is when you need to apply lots of power to get up a very short crest with a twisty flat or down hill on the top. When you get to the top and you start pedaling lighter it takes a second for the CA to register the new much lower torque and you continue to get full power after getting over the crest and that isn't always what you want.

Luckily I got Justin to listen to me and get PAS as part of the presets so now I can just select 1 on my three speed button to disable PAS and have throttle only.

My bike is modest powered at 1300 watts, I haven't tried the thun with higher power yet since the 10v DC-DC converter in the CA3 doesn't do 72v.

As for the original question: I recommend half twist for all the same reasons as stated in above posts. I use thumb throttle in one of my bikes and that is because the gear selector is too close to the handlebar so I can't change gears if I install a twist throttle. The thumb throttle is possible to mount on the left side of the gear selector.

[dogman dan]

That's easily cured by using a long enough bar, to move the throttle down enough to clear the trigger shifters. Generally, about 3/8 inch is all I need.

One trick for lengthening the right side bar is to pound in a broomstick, and add an inch to it.

[zombiess]

I developed an electronic interface that solves this issue by implementing a buffer.

[kfong]

Half twist. I was thinking of getting a Thun. The fact that it was square taper turned me off on it. Technical sections are also an issue that I think a good throttle response does better. Lots of times I'm balancing rather than pedaling while hitting the throttle to get me over a particularly hard section.