Belt drive instead of chain..why? why not?

[Cyril Haearn]

Saw a cycle with belt drive in an LBS, plusminus?

The belt lasts longer than a chain and stretches less (not at all?)
No oil to gather muck!
It is quieter than a chain
It is smoother taking up drive (does it give a bit?)

Disadvantages: needs a special frame because the belt cannot be split like a chain
Special chainset and sprocket/mounting, non-standard parts, might be troublesome for a blacksmith in Kazakhstan

I think the disadvantages outweigh the advantages but there seem to be a few about. Might chain drive become rare in a few decades? What are belts made of, what properties do they have, what do they cost?

[fastpedaller]

Why not? - a low efficiency compared with a chain?

[colin54]

viewtopic.php?t=93776
viewtopic.php?t=27877
viewtopic.php?f=5&t=71505
Some previous go rounds on the subject.

[scottg]

Split-able drive belt, available here.

https://www.veercycle.com/products/spli ... 4666125390

Now all I need is a 12 spline Sturmey cog for belts.
Saving me having to reinvent the "Little oil bath chaincase" of Sunbeam fame.

[MarcusT]

Today, the disadvantages outweigh the advantages because I would need to purchase a new bike to have belt drive. Purchase price pretty much double from a chain drive.
I would like to get one, but...

[simonhill]

I always thought In Hub Gears with belt drive bikes were an expensive niche product. Thinking Rolhoff and Gates at about 3 grand.

A couple of weeks ago I was riding Japan's most popular cycle route, the Shimanami Kaido (Google it, parts are very impressive). On the ferry at the start, I saw a couple on IHG belt bikes. The bikes were very tatty and I thought maybe they had been intentionally distressed, which is a bit unlikely in Japan as theft is very rare.

Anyway, a bit later I had a coffee stop and met a Spanish tourist who was also riding one. I had a look and it was 8 speed, belt, hybrid style. He said he chose it because it was the cheapest of the hire bikes. The other components were entry level-ish and it obviously wasn't an expensive bike.

I wondered if maybe the rental company had got a job lot because of ease of maintenance. Then in another town, I saw one belonging to a woman, it was a Firestone make. It was an alu mixte frame with coaster brake. Again, the components were fairly basic and it certainly didn't look expensive. I googled Firestone bikes, but I think it was more branding than the actual manufacturer.

Given that derailleur or IHG chain bikes like these go for about £250 upwards in Japan, I can't believe the belt version could have cost much, if any more.

Has anyone seen cheap IHG belt bikes for sale in the UK (or anywhere else). If not, then why not.

[DNC123]

We saw this in Telford back in 2015...

[reohn2]

Some thoughts:-
For
Cleanliness
Low maintenance
Long life

Against
Possible efficiency losses.Question for engineers amongst us,what are the mechanical losses of a belt to a chain on and IGH bike?
Specialist frame design
Cost of belts

Obviously it has to be IGH gearing,

On an IGH bike chains are cheap and can be protected from the ravages of weather by way of regularly maintenance or partial or total coverage/protection,but they do last a long time unprotected anyway unless left totally unmaintained.

[Marcus Aurelius]

Pro, belts are cleaner. Cons, they tend to slip under big efforts, they are more of a pain to sort out if they break.

[pliptrot]

We saw this in Telford back in 2015...

Looks very expensive - and very attractive. I have never seen composite rims on a tandem - this indicates they are, perhaps, stronger and more durable than some of us imagine(?).

[reohn2]

Pro, belts are cleaner. Cons, they tend to slip under big efforts, they are more of a pain to sort out if they break.

I don't think they slip this chap claims to have zero issues with his belt,even when runs slack:- https://youtu.be/djw2ZDim_cM the video is about his sponsored Koga but he begins to talk about the Rohloff and Gates Belt drive at around 8.15 in.I watched a few of his touring videos with and he does some serious offroad touring.

[pjclinch]

My wife's Gazelle has a belt, it's only been a year so far, but zero issues. With a hub gear I'd get one myself if I was getting a new bike for the simple reason that around here the road salt kills a chain every year, seemingly no matter how often I clean and lube it.

Pete.

[DNC123]

We saw this in Telford back in 2015...

Looks very expensive - and very attractive. I have never seen composite rims on a tandem - this indicates they are, perhaps, stronger and more durable than some of us imagine(?).

I can't remember the full story. The bike seems to come from Shropshire, but the guy was telling me about going to France for large parts of the drivetrain. Can't remember if this was the belt drive, wheels or gears. Maybe it was all of them. He'd gone into a lot of research about the belt drive and claimed to have no issues.

Picture doesn't show it, but there was quite a crowd gathered round the bike. It caused quite a stir.

And yes...it was very attractive.

[foxyrider]

We saw this in Telford back in 2015...

Looks very expensive - and very attractive. I have never seen composite rims on a tandem - this indicates they are, perhaps, stronger and more durable than some of us imagine(?).

It sure is purdy!

carbon rims, wheels and even discs have been used on tandems for decades we used a trispoke front, solid rear to race on @ 1990 when it was all still pretty new - those same wheels are still in use on a solo now.

As regards the belt drive question, Ikea were selling their own brand 3s belt drive bikes for @ £500 until 2018 when they were withdrawn due to issues with the belts snapping - i have a strong suspicion the fault was user rather than component, the reports all seemed to be related to the US market much like the Q/r/lawyers lips issue.

The ideal use of belt drive would be on a folder where any downsides are negated in the plus of having a clean drivetrain.

[Brucey]

Pro, belts are cleaner. Cons, they tend to slip under big efforts, they are more of a pain to sort out if they break.

I don't think they slip this chap claims to have zero issues with his belt,even when runs slack:- https://youtu.be/djw2ZDim_cM the video is about his sponsored Koga but he begins to talk about the Rohloff and Gates Belt drive at around 8.15 in.I watched a few of his touring videos with and he does some serious offroad touring.

belts are not all the same by any means but they certainly can/do slip if not correctly tensioned. Some folk run a thing called 'a snubber' which is intended to provide increased wrap-round for the belt and the snubber practically forces the belt into engagement with the hub pulley. You can run with less tension this way.

With many belts if they are not to slip or derail they need to be run with a preload (tension) which is about the same as (or more than) the service loads. The alignment needs to be perfect with a belt drive; typical IGH chainlines are simply not good enough.

Obviously not everyone pushes as hard on the pedals or is as sensitive to variations in performance. But most of the belt drive bikes I have ridden feel kind of spongy when you pedal hard. This almost certainly makes an utter nonsense of claimed/measured efficiency measurements; they might work OK at constant torque but cyclists produce anything but constant torque/power.

You have sod-all choice of gearing with belts; you may effectively have only one choice of belt length/pulley sizes that might be practical on your bike

The final kick in the nuts for cheap (?) belt drives is that the sprocket fitting onto a typical IGH is not designed for use under high preload and problems are depressingly commonplace as a result. IME belt drive sprockets cost between £50 and £100 each and are often 'special order' items which you have to wait for.

So belts have their place for sure but (IMHO) you have to value cleanliness very highly, be allergic to chain oil or something and (probably) push not very hard on the pedals and/or be rather unfussy about how the bike feels.

If there was room in the market for an inefficient, inflexible drive system, needing a special frame , then shaft drive would be more popular than it is....

cheers