Class 3 belt drives bikes with throttle?

Diarmuid

100 µW
Joined
May 27, 2018
Messages
9
Does anyone know of any class 3 (or higher) bikes that have a throttle and a belt drive? In case someone doesn't know, a class 3 is defined by being able to go to 28 MPH. Something like the Juiced Cross Current S but in a belt drive.

I have a lot of property that I can ride off road on and would like to take advantage of that.

Thanks!
 
What about a Sur-ron? Belt primary and chain (real chain) secondary. I can't think of any belt drive bicycles. Belts might not be the best for off road too. It's bad if little rocks get between the belt and the sprocket. If your property is pretty flat, a big hub motor might work OK.
 
What's your objective? Belt drive doesn't work as well as chain overall. It's cleaner and quieter, but also much more expensive, generally less durable, and less efficient. You have to be able to split the frame to install it, which usually makes your frame janky.

If you want belt drive with multiple gear ratios, you have to use an internally geared hub. Those don't usually prosper when you feed them enough power for 28mph. Rohloff and NuVinci are capable exceptions. The former is insanely expensive; the latter is out of business.

Bikes are very mature technology. When "regular" bikes never have a feature that seems desirable to you, it's a good idea to find out why before you buy a bike with that feature.
 
fechter said:
Voltron said:
In California anyway, class 3 can't have a throttle.

I don't think that's correct, but on private property it wouldn't matter.


Correct about private property, which is why I was wondering why he cared about classes, but it is written in that class 3 can only be actuated by pedaling. Class 2 can have a throttle and PAS. ( In Cali anyway)

312.5. (a) An “electric bicycle” is a bicycle equipped with fully operable pedals and an electric motor of less than 750 watts.
(1) A “class 1 electric bicycle,” or “low-speed pedal-assisted electric bicycle,” is a bicycle equipped with a motor that provides assistance only when the rider is pedaling, and that ceases to provide assistance when the bicycle reaches the speed of 20 miles per hour.
(2) A “class 2 electric bicycle,” or “low-speed throttle-assisted electric bicycle,” is a bicycle equipped with a motor that may be used exclusively to propel the bicycle, and that is not capable of providing assistance when the bicycle reaches the speed of 20 miles per hour.
(3) A “class 3 electric bicycle,” or “speed pedal-assisted electric bicycle,” is a bicycle equipped with a motor that provides assistance only when the rider is pedaling, and that ceases to provide assistance when the bicycle reaches the speed of 28 miles per hour, and equipped with a speedometer.
 
And I'm totally with him on some throttle twisting... it was more just to point out that he won't find the two together much on a stock Class 3.
 
Voltron said:
312.5. (a) An “electric bicycle” is a bicycle equipped with fully operable pedals and an electric motor of less than 750 watts.
(1) A “class 1 electric bicycle,” or “low-speed pedal-assisted electric bicycle,” is a bicycle equipped with a motor that provides assistance only when the rider is pedaling, and that ceases to provide assistance when the bicycle reaches the speed of 20 miles per hour.
(2) A “class 2 electric bicycle,” or “low-speed throttle-assisted electric bicycle,” is a bicycle equipped with a motor that may be used exclusively to propel the bicycle, and that is not capable of providing assistance when the bicycle reaches the speed of 20 miles per hour.
(3) A “class 3 electric bicycle,” or “speed pedal-assisted electric bicycle,” is a bicycle equipped with a motor that provides assistance only when the rider is pedaling, and that ceases to provide assistance when the bicycle reaches the speed of 28 miles per hour, and equipped with a speedometer.

To be clear, Class 1 and Class 3 do not prohibit the use of a hand throttle. They merely prohibit the hand throttle from providing any input for the motor to run if the rider is not also pedaling.

I understand that this may not have been their intent. But the law they passed clearly does not preclude the use of a hand throttle. It merely precludes the exclusive use of a hand throttle.
 
Chalo said:
What's your objective? Belt drive doesn't work as well as chain overall. It's cleaner and quieter, but also much more expensive, generally less durable, and less efficient. You have to be able to split the frame to install it, which usually makes your frame janky.

If you want belt drive with multiple gear ratios, you have to use an internally geared hub. Those don't usually prosper when you feed them enough power for 28mph. Rohloff and NuVinci are capable exceptions. The former is insanely expensive; the latter is out of business.

Bikes are very mature technology. When "regular" bikes never have a feature that seems desirable to you, it's a good idea to find out why before you buy a bike with that feature.

Are there any resources you can share with me about the bolded? I thought the whole point of something like a belt drive system was that it was more durable and less maintenance. The gates drive in particular seems to have a service life of something like 10k miles before you would need to replace the belt.
 
wturber said:
Voltron said:
312.5. (a) An “electric bicycle” is a bicycle equipped with fully operable pedals and an electric motor of less than 750 watts.
(1) A “class 1 electric bicycle,” or “low-speed pedal-assisted electric bicycle,” is a bicycle equipped with a motor that provides assistance only when the rider is pedaling, and that ceases to provide assistance when the bicycle reaches the speed of 20 miles per hour.
(2) A “class 2 electric bicycle,” or “low-speed throttle-assisted electric bicycle,” is a bicycle equipped with a motor that may be used exclusively to propel the bicycle, and that is not capable of providing assistance when the bicycle reaches the speed of 20 miles per hour.
(3) A “class 3 electric bicycle,” or “speed pedal-assisted electric bicycle,” is a bicycle equipped with a motor that provides assistance only when the rider is pedaling, and that ceases to provide assistance when the bicycle reaches the speed of 28 miles per hour, and equipped with a speedometer.

To be clear, Class 1 and Class 3 do not prohibit the use of a hand throttle. They merely prohibit the hand throttle from providing any input for the motor to run if the rider is not also pedaling.

I understand that this may not have been their intent. But the law they passed clearly does not preclude the use of a hand throttle. It merely precludes the exclusive use of a hand throttle.

I've seen some jurisdictions and products where the bike is a class 3 via PAS, but the throttle cuts out after 20 MPH like on a class 2.
 
Diarmuid said:
Chalo said:
Belt drive doesn't work as well as chain overall. It's cleaner and quieter, but also much more expensive, generally less durable, and less efficient.

Are there any resources you can share with me about the bolded? I thought the whole point of something like a belt drive system was that it was more durable and less maintenance.

Less maintenance is definitely true, to the degree that keeping your chain oiled is maintenance. And a drive belt is probably more durable than a chain that never gets oiled. But historically (and there have been a number of bicycle drive belts to sample from) a drive belt wears out and begins to shed teeth at a lower mileage than you can get from a regularly oiled chain.

Also, chains are tolerant of several times normal human pedal power, but belts tend to crap out at slightly more than their intended power.

The efficiency of toothed drive belts falls in between that of a chain and that of a double bevel gear drive shaft.
 
At bicycle power levels you may be right about efficiency.

From dynoing the same motorcycle back to back chain and gates toothed belt, a 520 size chain cost about 1.5hp in friction losses over a gates toothed belt (70whp power level).

I personally love the direct connection with no backlash and silence a belt offers.

It's true if you are going to hit your drivetrain with big shock loads then a chain is perhaps the best option.
 
Motorcycles have O-ring chains that exact a friction penalty in return for keeping the lubricant inside. Lubricating those is more about keeping the seals healthy than for the pins and bushings.

Bike chains are pretty much defenseless against contamination, moisture, and loss of lubricant. But they are lightweight and very efficient.
 
Chalo said:
<snip>
Bike chains are pretty much defenseless against contamination, moisture, and loss of lubricant. But they are lightweight and very efficient.

And apparently particularly so if lubricated with paraffin wax, run without much side flex (straight chain line), and run to avoid using the smallest gears on the rear cluster.
 
I like belt drives and have built many motorcycles using them. Yet I don’t believe bicycle size belt drives are up to the task to build an off road ebike. I may be wrong, since I have not seen the later developments about them, but those that were available 10 years ago didn’t make me feel I should use them.

Then, small mid drives are problematic enough already, that you should not add the trouble of using components that may be hard to quickly find replacement parts.

I believe mid drives are best for riding the nountain teails, but I use big DD hubs for reliability. This had proved a good choice so many times, that I abandoned the idea to build a mid drive dirt bike. If I ever need one, I would buy a ready made E-Trial motorcycle.
 
liveforphysics said:
....
From dynoing the same motorcycle back to back chain and gates toothed belt, a 520 size chain cost about 1.5hp in friction losses over a gates toothed belt (70whp power level).
...

Thanks for posting test results.
Few people have access to free Dyno time like that.

...

As to the posts about bike chains...
I can attest to the fact - my tadpole chain (long bastard) went completely to shit after sitting for a few years. If not tended to the bike chains rust solid.

Based on that lesson I started oiling and greasing different chains on different bikes to see how they stand up. Never considered using wax.

...

Belt drive sure sounds sexy to me.
I am looking at hooking up Zero Motors to different existing Boat transmissions... And proper spacing with a Belt just ends up so much cleaner.

(Yea... My boat still ain't in the water. Its outfitted with Stevo's gear (lol) which I need to return... Then I need to get a manager job at Starbucks so I can afford to buy my own Zero Pull-Down equipment)

-methods
 
There's another issue with belts that I didn't address earlier. Belts have to be tight to function properly. Chains don't.

The bearings in a bicycle's bottom bracket and rear hub are happier and run with less friction when they aren't under static load. But more than that, internal gears are your only option for variable gearing when you use a belt, and gearhubs react poorly to static chain or belt tension.

I have had to replace entire hub cores that were wrecked by being used with belt drives that were tight all the time. And I've had to replace belts that got chewed up from not having enough tension. It's a delicate balance that can't always be struck.
 
methods said:
Never considered using wax.

-methods

It's an old method. I use it cuz I'm tired of dealing with chain tattoos and the like. But it apparently is one of the top performers when it comes to reducing chain friction.
 
Yes...
I a quite unhappy with how my "grease job" came out on the StumpJumper.
I imagine that all the dust is going to clump up soon as well

We want to stop oxidation for one
Maybe lubricate for another
I do not know if the wax reflows and wets into the friction interfaces?

I know that a lot of folks use fancy anodized looking chains around here and they look dry to me.

...

Chalo has a good point about static tension with belts. I had not considered that a chain gives you a lot more margin in that department.

...

I have some experience using PTFT infused gun oil. Upon first application it has little affect. After using it 30 or 40 times I can say that on "gun steel" (blued steel) the result is a surface which is slicker than shit but totally dry and collects not dust. The surfaces appear to be pretty resistant to rust - tho even with blue + PTFT - I still break out in rust spots if left untended for months on end.

I refer only to the external surfaces and not the internal wear parts. On wear parts we still apply very small quantities of grease.

-methods
 
methods said:
We want to stop oxidation for one
Maybe lubricate for another
I do not know if the wax reflows and wets into the friction interfaces?

Reflow? Surely not. The only flowing that occurs is when I soak the chain in hot wax in my crock pot.

There's plenty of online info if you want to try wax and check out the pros and cons.
 
Thanks for the tip... I may look into that.

I certainly hope this is not the same pot you cook your rice and beans in :shock:

-methods
 
methods said:
Thanks for the tip... I may look into that.

I certainly hope this is not the same pot you cook your rice and beans in :shock:

-methods

Nope. Got a cheap used one at Goodwill.
 
Guess it depends on the kind of wax--if it's paraffin, normal Phoenix temperatures can begin to melt it. ;)

Road surface temperatures, especially if sitting in the middle of a bunch of cars/etc at a traffic light, can be 130-140F or higher (on a 120F+ day at zenith I once measured 150F a few inches above the road surface, sitting there on Crazybike2 waiting for the light to change; almost passed out in the completely still air before it went green. :(

(I used to have a temp sensor down near the motor, when it was a powerchair motor under teh BB./frame)
 
I haven't really found anything since starting this thread that are available in the US. There are a few different models available in the EU though. I'm probably going to go to Rodriguez bikes and get a custom frame made.

http://www.rodbikes.com/catalog/makeshift/makeshift-main.html

What I haven't decided on is a Pinion + rear hub, or mid drive + rohloff.
 
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