belt vs chain drive for E-MTB

Pedrohlt

10 mW
Joined
Dec 13, 2009
Messages
24
Location
São Bernardo do Campo / SP - Brazil
So I'm building a dual drive E-MTB and I'm not sure if I use chain/sprokets or belt/pulley for drive. Here are some of the pros that I could think of each one:

BELT:
- Quieter
- Smoother
- Less prone to fall off
- Less maintenance ?
- Lighter ?
- Less sensitive to misalignment

CHAIN:
- Cheaper
- Narrower
- No slip
- More resistant to rocks, debris

Now the biggest cons of belt drive is little rocks getting in the pulley, which can jam the drive or damage the pulley and belt. That's my biggest concern on belt drives. I have had a few rocks stuck in my e-longboard belt drive, but maybe that's because the pulley is very close to the floor. But on the other hand, I'll ride on dirt, grass, gravel roads on an E-MTB, not just on asphalt like a longboard.
I learned to hate chain drives with my current E-MTB, I still have a hard time trying to properly align the chain. I have to admit it has some design mistakes :lol: , but I think it would not happen with a belt drive.

So what you guys think?
 
Yes, that was my first tought, but I searched here on ES and there is a lot of belt driven MTBs. I wonder if they're having problems with dirt, rocks etc.
 
Hey.

Builded different drivetrains for Mtb´s the last years.

Chain was the first and is the right drivetrain for use in bad conditions with low to medium strong setups.
Like 6S or 8S Hobbywing Setups, or 10S Vesc.

Belt is stronger( ok i only tested HTD5-25mm Belts) sounds nicer.
No to little problems with dry debris, stones or dust is not a problem at all.
But wet mud and grass is really bad for it, in autum riding through forrest? No it was never possible for me.

Direct Drive with Spur Gears, sealed with a gearbox is the boss IMO.
Ultra compact, super low drag, strong as hell.
No Probs with any kind of Dirt

Feel free to ask

Hang Loose
Jenso
 
Belt eats up power. Belt overworks axle and bottom bracket bearings with high static tension. Belt doesn't last as long as chain, but costs more. And the frame must be designed to split so that the belt can be installed.
 
Yes, it sounds like chain drive is the way to go for off-road use. I prefer belt drives, but I think it will limit my use. Thanks everybody for the help!
I think I'm gonna use #25 chain and 6.3:1 ratio.
I'll post some pics of my board when it's complete.
 
Chalo said:
Belt eats up power. Belt overworks axle and bottom bracket bearings with high static tension. Belt doesn't last as long as chain, but costs more. And the frame must be designed to split so that the belt can be installed.

V-belts eat lots of power. Gates carbon polychain is about a draw for efficiency with a good chain setup, and should last life of vehicle.

Concerns about the belt taking damage or wearing out seem a bit strange to me, as my 70hp DSR uses the same size gates poly-chain and I got 23,000miles with at least 10,000 of it being >75mph speeds. I ride it through a hell of mud and sand and tall grass and everything in between and amazingly have no issues even putting 70hp and 120ft-lbs through the belt.

Conversely, on my human-only powered road bicycle, I would snap pedal chain every other month or so just from being a pedal masher.
 
I haven't used a Gates toothed belt on my own bike, but in my observation of other people's bikes, they begin to shed teeth by the time they rack up enough miles to wear out a reasonably well-maintained chain. I'm sure it helps to use large sprockets so drive forces are distributed over plenty of teeth. Of course, special attention to sprocket alignment surely helps, as does fitting them to a rigid frame that doesn't flex out of alignment under load.

Bike chains seem to snap mainly from shifting under load, which belts don't (can't) do. Otherwise they wear out from elongation but rarely break.

The added friction in a toothed belt is easy to feel if the belt is tightened to spec. It may not amount to much percentage loss at high power, but at low power it's significant.
 
[youtube]4Fzg_y3pp5A[/youtube]

Thats >70hp spinning up the tire of my DSR to >80mph and catching traction again down to 30-40mph in a chirp. Never poppeda tooth off this belt or had it skip or do anything other than perform silently and maintenance free. Same exact belt material and tooth pitch and profile as the modern gates bicycle drive (but 8mm wider)

If human pedaling can rip teeth off, IMHO its 100% due to frame flex letting the center to center distances decrease and tip-loading the belt.

At motorcycle power levels, the belt yeilds more than a 3whp advantage to in dynoing power to the rear wheel vs 520 roller chain on a 70hp bike. Obviously 520 chain is way bigger and more lossy than pedal bike chain, but IMHO a belt feels amazing to pedal a bike. No backlash and silent and smooth and direct feeling. As someone who enjoys silent riding its fantasic not to have a jingling chain.
 
So I was just given a cr80 Frame and Im thinking of doing a belt because the back sprocket needs to be replaced anyway. Where would I find a sprocket and belt that will work for it? a 14t front and 49t rear sprocket is what the bike comes with. running a 21" rear tire and a motor spinning at 4,000 rpm that shoud put me at a top speed of about 70 mph if I'm doing my math right. I might want to do a little more speed like 80 mph but it all depends on what I can find that will work with my bike.

Any help would be great.
 
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