Class 3 belt drives bikes with throttle?

[lionman]

I have never seen a belt driven mountain bike.

Belt drives are limited to a single sprocket front and rear obviously, so are popular with fixies and internal geared rear hubs. There are a few companies around that do them. One of the cheaper, most widely available ones is the Lekker range although these are commuter style bikes, wrong geometry for off road.

They have internal rear hubs. You could potentially install a BBSHD on one and have a 1000W 3/7/8 speed but not sure how durable it would be.

There is a company locally to me that builds custom bikes and specializes in belt drives. They are pretty pricey with each bike being hand made here in Australia but they are pretty solid machines. They do mostly fixie style bikes but might be willing to help you out.

http://www.flyingmachine.com.au/

 

[Chalo]

I'm probably going to go to Rodriguez bikes and get a custom frame made.

If you're normal sized and you want a normalish bike, it would be much cheaper to buy a commercial chromoly frame and have a framebuilder install a joint in the seat stay for you.

I think the Rohloff plus mid drive (or NuVinci plus mid drive) is better option than Pinion with a hub motor. You get to shift the motor's power to optimize for torque or speed. You get to use a normal bike frame that can be reconfigured later if you want.

With Pinion, you can have lots of gears at the pedals, but only one ratio for the motor (so only one best speed range, and fixed wheel torque). On the plus side, with Pinion you don't have to accommodate motor torque within the gearbox's maximum capacity.

Rohloff is a couple of pounds lighter than Pinion.

With NuVinci, you don't have to worry about shifting under load, because the transmission is always fully engaged. That's a plus especially in an electric assist application. There can be no violent crashing shifts.

 

[Diarmuid]

I have never seen a belt driven mountain bike. [...]

Doesn't have to be a mountain bike. I don't think I ever wrote that it had to be one.

I'm probably going to go to Rodriguez bikes and get a custom frame made.

If you're normal sized and you want a normalish bike, it would be much cheaper to buy a commercial chromoly frame and have a framebuilder install a joint in the seat stay for you.

I think the Rohloff plus mid drive (or NuVinci plus mid drive) is better option than Pinion with a hub motor. You get to shift the motor's power to optimize for torque or speed. You get to use a normal bike frame that can be reconfigured later if you want.

With Pinion, you can have lots of gears at the pedals, but only one ratio for the motor (so only one best speed range, and fixed wheel torque). On the plus side, with Pinion you don't have to accommodate motor torque within the gearbox's maximum capacity.

Rohloff is a couple of pounds lighter than Pinion.

With NuVinci, you don't have to worry about shifting under load, because the transmission is always fully engaged. That's a plus especially in an electric assist application. There can be no violent crashing shifts.

I'm not normal sized as I covered in my first post. The benefit of a Pinion + rear hub is that I can have a "regular" bike frame that isn't married to a single mid-drive motor like the Bafang Max. I can always swap out the rear hub motor for something else.

 

[Chalo]

If you're normal sized and you want a normalish bike, it would be much cheaper to buy a commercial chromoly frame and have a framebuilder install a joint in the seat stay for you.

I'm not normal sized as I covered in my first post.

No you didn't. What's your special size concern?

If you get a Pinion compatible frame, you're stuck with the Pinion gearbox and crank. Rohloff and NuVinci fit pretty much any conventional frame, so you can revise the bike later as desired.

 

[Diarmuid]

If you're normal sized and you want a normalish bike, it would be much cheaper to buy a commercial chromoly frame and have a framebuilder install a joint in the seat stay for you.

I'm not normal sized as I covered in my first post.

No you didn't. What's your special size concern?

If you get a Pinion compatible frame, you're stuck with the Pinion gearbox and crank. Rohloff and NuVinci fit pretty much any conventional frame, so you can revise the bike later as desired.

I'm 6'6", 270 lbs with a 34" inseam. Nothing really ever fits me so having something custom fit for me is just par for the course.

Here are some examples from Rodriguez bikes.

 

[fechter]

That last one looks pretty nice.

 

[Chalo]

I'm 6'6", 270 lbs with a 34" inseam. Nothing really ever fits me so having something custom fit for me is just par for the course.

I hear you. I'm 6'8" and about 350 lbs. I have only ever had one tailor-made frame, by David Bohm of Tucson. Here are a couple of older photos showing its original configuration with 26" wheels:


It is fitted with 29x2.5" wheels and tires now.

Mostly I've gotten by with retrofitting 68cm frames and other large bikes with sturdier cranks and bigger cockpit parts. My current e-bike is one I built myself from the rear triangle of a 68cm road bike plus some chromoly tubing:
.

There are a handful of commercial frames that would be big enough for you, like the XXL Surly offerings. They aren't as nice as a Rodriguez. But nicer than a scrappy homebuild, most likely.