Anyone done a belt drive conversion?

ballsofcottonwool
All this talk of broken chains, has anyone ever snapped a chain on a singlespeed with a proper chain line?

Twice. Once very 40 years, regular as clockwork. 🙂

My belt has been plenty robust, after about 2500 miles of everything from desert to horrible mud the most wear has been to the aluminium front sprocket then the belt and least worn is the steel rear sprocket.  Mine may benefit from having a sprung tensioner (it’s a Nicolai full suspension bike) so there is some give.  But my feeling is the belt is way too expensive and so much less readily available compared to a chain set up that I can’t see any point in it beyond being cleaner.  Even the cleaner bit loses some of it’s value when I have to squirt a bit of silicone spray on the belt to keep it quiet in the dry

@molgrips don’t worry, I’ll keep disagreeing with you if it helps🤣

I can’t really see the point in them, if you use one you have to be single speed or hub gear and chains in those situations are dirt cheap, stupidly reliable and need next to no maintenance anyway. If they could replace a chain used on a cassette that would be nice but I don’t think that would ever happen.
Solution looking for a problem in my opinion.

They’re lighter than a chain though once you add up the sprockets there probably isn’t much in it. It’s niche for sure and definitely not forgiving of bad maintenance but I wouldn’t say it doesn’t have advantages.

If you’re interested in hub gears and singlespeed then you’re probably already sold on the low (no) maintenance aspect and the belt just takes it a stage further. The belts won’t ‘just’ snap on their own. It’s impossible. They may degrade over time as elements break down through accidental damage until they reach the tipping point then snap. As has already been said, a quick check every once in a while will alert you to anything wrong. I had someone call me once saying he’d noticed a crack in his belt about 150km back and it didn’t seem to have gotten any worse but could he order a spare belt anyway just in case!

Of course there are occasions when they’ll experience load in a direction they weren’t designed for (sideways), perhaps a stick or a rock gets trapped and distorts the whole drivetrain but that really is an extreme example. If you’re anywhere that would be difficult to get back to if you had to push/freewheel, then taking a spare belt is just good sense.

Choosing a chain over a belt because it’s more likely to break but easier to fix is just a stupid argument.

I’ve been riding belts regularly for about 8 years and I’ve never broken a belt. I’ve seen broken belts so I know it happens. In that time, I’ve broken 1 pair of bars, 1 saddle, cracked 1 seatpost, ripped a pedal out of a crank and broken a brake lever. Most of those were from crashes and I’d never consider taking a spare of any of those things with me when riding. The fact that most people (me included) will take spare quick links and gear hangers with them on trips tells me all I need to know about reliability.

Ton’s comment about soft peddling (sic) because he thought it was going to snap is just stupid.

The main weakness in the belt system is that to work reliably, it really needs to be run in a very straight line. A chain will tolerate a really angled chainline, a belt system won’t. In the early days of home conversions, it seemed like people weren’t paying any attention to this and so the belt was constantly running at an angle and putting stress on the outside of the belt. When you realise that the strength of the belt comes from carbon strands running the length of the belt and when distortion happens that places more load on single strands on the outside, making them more likely to break on their own, weakening the belt as a whole, then it becomes obvious why perfect chainline and proper handling (fitting/removel) is key.

You also need to pay attention to the chainline and how straight it remains while you’re putting power down through the pedals. It’s no use if the bike has perfect chainline when stationary but is so flexy under power that the belt is constantly being pulled from side to side. This is why some partner brands working with Gates, want you to test your frame for stiffness before fitting a belt system.

Belts work and chains work, it’s all good (I also have derailleur bikes with chains). However, if we were to start from scratch today and build a geared drivetrain for a bicycle, I doubt we’d end up with a chain, a bunch of exposed to the elements cogs and a big lever that forced the chain to jump from one cog to the other. If the same amount of R&D was put into making belts and internal gear hubs than was put into developing derailleur systems work despite their obvious flaws, the derailleur (and chains) would die pretty quickly.