[Closed] Belt drive. It may be time to admit defeat.

People talk about watts/kg when referring to road cyclists. I've heard it a few times (most in depth in Tyler hamilton's book) that to win the TdF you need a power output of 6.5watts/kg body weight. He reckons the easiest way to achieve this is simply to lose weight.

Interestingly, and perhaps pertinent to molgrips/aracer's discussion, two riders could have the same winning specific power output (6.5watts/kg) but if one was 80kg, they'd put more force through their bike/ drivetrain than a 70kg rider.

Does anyone know when the new 108 and 111 tooth Gates belts are coming out?
I want to get in the game but need a shorter belt. Come on Gates!

CBA to read most of pages 2 & 3... but, IME of belts (4 years and perhaps 4000km, so not up there with some of the distances discussed earlier) I'm on my second belt on a singlespeed commuter. It's geared so that hills are a pain but the torque I'm putting through the drivetrain on steeper stuff must be quite high (and I don't meant that I'm ace, just that in those situations, to move the bike along the rider needs to really get some leverage on the cranks).

I too have experienced the increased frequency of replacing BBs (perhaps one every 6-8 months).

My main reason for purchase was the low maintenance aspect. Apart from whole bike cleaning I never touch the belt in normal service - no oiling, degreasing or anything.

When the belt failed I actually thought my rear cog was stripping the splines off the freehub so I tested it by riding up a steep hill one evening and ended up stripping half the teeth off the belt. On inspection the remaining ones were worn to a triangular profile, and the creaking noise I thought was my freehub was actually the teeth shearing at their base.

I love my belt drive but I can see that in conditions where there's debris getting into it, or where its being loaded from the side, then a belt would fail a lot more quickly than I've experienced.

Just to veer slightly OT (this is STW after all). One of the advantages of a belt is its lightness.

If we had a fully enclosed chain, how light could that be made? Maybe smaller pitch, etc. Didn't Shimano have a crack at a 10mm pitch a few years back?

One of the advantages of a belt is its lightness.

That's one of the things that first got me interested but now Gates have had to change the rear carrier to steel, they want you ideally to fit a snubber and you need a stiffer rear triangle that can be split which again adds weight. I'm not sure the weight savings are that great.

avdave2 - Member
That's one of the things that first got me interested but now Gates have had to change the rear carrier to steel, they want you ideally to fit a snubber and you need a stiffer rear triangle that can be split which again adds weight. I'm not sure the weight savings are that great.

Good point. My experiments have all been on the ordinary belt and cogs. The stiffer rear triangle and split need not add more than a few grams of weight. If they do, it's bad design.

However a rear cog made of steel is going to be considerably heavier than the same thing in aluminium and also than its equivalent for a chain. As for a snubber, that's tantamount to admitting the system doesn't work without a bodge... 🙂

A somewhat trivial point after all the heavy-hitting physics going on, someone earlier on mentioned the motorbike industry had given up on belt drive. Harley Davidson however didn't and have it taped.

someone earlier on mentioned the motorbike industry had given up on belt drive. Harley Davidson however didn't

BMW still use belts too.

Physics arguments aside, this is a very insightful thread. Thanks for sharing, OP.

wilko1999 - Member
A somewhat trivial point after all the heavy-hitting physics going on, someone earlier on mentioned the motorbike industry had given up on belt drive. Harley Davidson however didn't and have it taped.

It was the thousands of miles I did on my HD in outback Queensland on dirt roads that convinced me belt drives were more than up to the job.

Is anyone else disappointed this thread is not about turntables?

epicyclo, I have thought of using bmx microdrive,and encasing it,might be doable with removable spider cranks.
would cost a fair bit tho.

emanuel - Member
epicyclo, I have thought of using bmx microdrive,and encasing it,might be doable with removable spider cranks.
would cost a fair bit tho.

But do it right and you'd never have to buy another chain or chainring for your drivetrain.

Well maybe "never" is a slight exaggeration - probably once every 50 years.

I don't use a snubber and I've never had the belt ride up over the rear pulley. I really don't know what the point of them is.
The rear pulley is steel, but then, so are the rear sprockets on my SS & Rohloff.

As we seem to going off on all sorts of tangents, here's another one; Pinion Gearboxes.
If we are agreed that it's rider power that is wrecking belts, then surely putting the reduction gears before the belt will increase the torque load or top run tension on the belt*. Has anyone got any long term experiences with a belt drive Pinion bike ?

*I'm a mechanic, not an engineer. I've probably used the wrong term, but you know what I mean.

MidlandTrailquestsGraham - Member
I don't use a snubber and I've never had the belt ride up over the rear pulley. I really don't know what the point of them is...

It's really to compensate for lateral flex in the chainstays. On one bike I have, the chainstays are suitably stiff, so a snubber is not needed.

On another the chainstays are like noodles, and the only way to keep the belt on is by using a snubber. What is happening is that the teeth on the belt are arriving at the rear cog out of parallel because of the flex. The snubber forces them down. A snubber is a bodge IMO.

MTG you probably have just made the durability of the belts eureka moment in that obviously motorbike drives are from a gearbox! I would imagine by adding a pinion gearbox to the equation on a bike will enhance the lifespan of a gates drive on a bike as any torque applied through the belt is a lot more constant than direct pedal power.
I know the thread went off at a bit of a tangent but it's actually all relevant to the durability of a gates belt drive set up.

we're just exploring different paths to get the same answer.

epicyclo, I'll have a go.

476km on the new belt and front pulley and it needs adjusting.
Don't believe what Gates tell you about it being maintenance free.

I noticed it was getting a bit slack over the past few days.
I was going to adjust it yesterday, but after a very muddy ride home, the belt tension was OK again.
It hadn't magically adjusted itself, it was the mud packed in between the belt and pulleys tightening everything up.
I jet washed it at work yesterday and it went back to being slack again.

Pictures showing the wear on the belt at less than 500km.

[img] [/img]

[img] [/img]

This is all very disappointing - I have been waiting to fit a Gates for a while now.

But thinking about it - why would you expect anything to be more durable than a steel chain?

I ran belt drive bike on my commuter for about a year. It creaked a bit under heavy load - I also snapped two belts within a year (covered by warranty but still)

It required constant tensioning despite the bike being a complete with belt drive and not a bodge.

I sold it and went back to a chain. No problems in 3 years...

[img] ?w=705[/img]
[url= http://revanchebikeco.wordpress.com/2014/05/09/belt-drive-bicycle/ ]clicky[/url]
weights, the splitter is 116g, an equivalent length of seatstay is 12g.

will write a few words, plus weight pics, later.

the other style of splitter, shown elsewhere in the thread, is the same weight as the dropout it replaces.

Further updates for those who are interested;
I entered Erlestoke 12 last Saturday on the belt drive Rohloff.
On my third lap, about 22km in, the belt came off.
It looked like the same problem I had at Sleepless In The Saddle when it was really muddy in the woods there, the belt and pulleys are pretty good at clearing wet or gritty mud, but leaf and twig fibres get trapped in the narrow slot of the Centre Track belt until it's forced away from the pulley and jumps off.
I found a big puddle and did my best to wash the mud off and poke the fibres out with a pointy twig, finished the lap, then swapped to my single speed chain drive Lynskey.

I'm racing single speed at Bristol Bike Fest in two weeks time, so I fitted a SS rear wheel with a part worn steel pulley, a new SS belt and kept the same 50t front pulley with 700km wear on it.
With the bike updside down, I gave the cranks half a turn and noticed it didn't sound quite right.
A closer look showed the sharp edges on the part worn rear pulley were cutting in to the belt.
You can see the difference between the damaged and undamaged parts as I stopped turning.

[img] [/img]

[img] [/img]

[img] [/img]

I don't think it's done any serious damage. I've swapped to another less worn rear pulley and it's running smoothly now, although it does make me wonder what I'm going to do about a spare rear wheel for Bristol.

@ MTG - your patience and stubbornness(!) to continue with the system must be applauded.

I've been following your posts re belts for some time and remain "belt curious".

The worry point for me is the frame stiffness seemingly required for the system to work effectively.

If I've missed you mention it apologies but is your ti frame particularly stiff?

The Skookum I have is nicely compliant at the back but this must equate to flex, which is bad for a belt drive - yes.

Keen to avoid needing a snubber.

It's a mixture of sandy trails and claggy clay fields around here.

How have the belts faired with sandy use?

My belt is on a Kona A and due to the linkage pivots I initially had a massive problem with keeping the belt on due to lack of stiffness. Repeated slipping of the belt damaged it enough that it snapped, defeated by the sheer size of the Leicestershire Alps.
So, replaced it with a Centretrack belt and using the bolt in option on the Pro2 hub. Running it at "conventional chain" tension and I've had no problems since.
The belt came off once when my front wheel flicked up a massive branch which got caught in the chainstay but that would have pulled a chain off too (or snapped it, the chain that is)
Ridden on gloopy mud with no problems. At the moment its getting ridden weekly on Tentsmuir Forest which is on the beach so very sandy. Had the first issue of the dry dusty squeak that aflicts american riders the other day. Doubt it will be a problem tonight. ...

I went for a Qoroz because they already made a [url= http://www.qoroz.com/expedition-one/ ]belt drive expedition bike[/url] which has passed the [url= http://www.qoroz.com/docs/msg_bikes-stiffness_test.pdf ]Gates/Rohloff frame stiffness test[/url].
Mine is a custom built cross between that bike and a their [url= http://www.qoroz.com/mountain-won-29er/ ]regular mountain bike[/url].

The one thing I really regret about all this is not keeping proper records of wear, both of chains & sprockets and belts & pulleys.
I've started being a bit more methodical about it all now, which is how I know the new front pulley has done 700km.
What I'll do now is run belt drive till it's worn out, then run chain drive until that's worn out, so I can properly compare wear rates.

It's very sandy round here, parts of Kinver Edge are literally like riding on a beach.
Normal mud, no matter how wet, sticky, sandy or deep, doesn't seem to be a problem, the open design of the pulleys works well. It's the leaf mould that clogs up the belt, where a metal chain would just chop through it.

[img] ?w=705&h=528[/img]
[img] ?w=705&h=528[/img]
http://revanchebikeco.wordpress.com/2014/05/31/the-weight-debate-chains-or-belts/

as you can see, the splitter adds 100g.

wow, admire your patience, but what a waste of time!

I have to say that all of this ois helping to convince me that gates belts are a faff and a waste of money.

I had toyed vaguely with the idea of a belt drive commuting fixie or SS road bike but I think I can live with the weight for the cost and apparent maintenance savings...

Shame really as I sort of want it to be the perfect SS drive solution, but the t ain't really is it...

Emanuel, that's a steel splitter. My frame is titanium and instead of a removable section with two lap joints, has only single lap joint, meaning I have to spring the two halves apart to create a gap for the belt, so I guess mine would be a bit lighter than that.

but what a waste of time!

There still isn't much in the way of real world experience out there.
Gates have got lots of publicity shots of commuter bikes and the occasional mountain bike on a dry, dusty trail.

STW have done their usual Copy & Paste of press releases without actually finding out if the product is fit for purpose or not.
http://singletrackmag.com/wp-content/uploads/2014/05/cavalerie-full-sussers-built-for-effigear-internal-gearboxes/
http://singletrackmag.com/wp-content/uploads/2014/02/nicolai-fat-pinion/

As far as I can tell, I am the only person in the whole world to have attempted to ride a Gates Carbon Drive through leafy mud and proved that it doesn't work.

MTG

Serious question, have you sent pictures and mileage details to Gates to see if you can get their thoughts on the amount of wear you are suffering?

mtq-true, it's what I had on hand: the difference in weight is for steel frames using that method.

I had one belt replaced FOC by Gates. I haven't bothered chasing them about the others. Maybe I should have.

I'll be at Bristol Bike Fest at the weekend if anyone wants to have a look at the belt drive. I've only ever seen two others in real life myself, both on display, not being ridden.

I do wonder whether companies might pay you for destruction testing of kit, Graham!

Orange had a belt + Alfine bike a good few years back. I wonder if the fact that they didn't offer it as OE spec says that they also found it didn't work so well on MTBs. There was certainly interest and some demand.

Personally I don't see enough reason to even try it off road in the long-term (not meant as a dismissive view of your experience and these posts MTG, quite the opposite, if I had more time I'd like to know from experience not just building some city bikes - so this thread is appreciated), mainly as benefits over a chain were almost non-existent. For someone like me who changes ratios and wheels etc fairly regularly it would prove more faff than I could live with. Great for a clean city bike, but so is a chain-guard and wax lube : )

[i]You only know that from my experience[/i]

not entirely. Look at the history of bicycles and look at how much has changed in drive-train technology, and every single "advance" be that belt, gearbox, shaft, 2WD, whatever has failed the remove the chain and sprocket as the lightest, most versatile, most long lived, most robust, and most cost effective way of propelling a bicycle forward short of strapping a motor into the frame.

Could have told you that from the get-go. But I don't need to, you've just found out for yourself 😀

Latest news;
I stripped a load of teeth off the belt last night "just riding along".
I'm a bit behind with uploading my rides, I'm adding the last month or so now. I'll report back when I've finished, but I reckon the belt lasted less than 3000km

3098km

[img] ?oh=3ebf64b80bfe4c8691492ceb42248f3f&oe=548E5559&__gda__=1421831264_23804c63756fbe24d08512e1d185fc85[/img]

[img] ?oh=6dc80c779e5a2470d7dca060f40a1aa5&oe=548AFE4E&__gda__=1422773445_f8537010ed2763e794ad4d4ce8032512[/img]

I hate all these "It doesn't work threads / pictures" as I built up a bike specifically for running belt but is still running a chain as I can't decide whether to try it out or not.

I do like the idea of having a truly hosepipe clean bike with no oily drive train to pick up gunk...... and Gates have finally produced the 111T belt I would need to make it all work.

My set up includes an Alfine - do you think I would get better mileage by having gears (i.e. putting less power through the belt)?

I believe MTG has also destroyed all the same bits while running a Rohloff so I think the answer is no - it is unfortunately crap for off road use however you set it up.
I'm also very disappointed as I'd also had ideas of running one with my Rohloff rigid bike for even less maintenance and a little weight saving. The weight saving though went out of the widow when gates were forced to move to steel carriers. Now it looks like the maintenance is a non starter too.

I'd replace with a traditional chain/sprocket/chainring set up.

The money you save on not buying replacement belts you can put towards the jacket fund to get something less pish than those you had highlighted.

😉

Ndthornton, that one above is on a Rohloff, so no, it doesn't seem to make a difference.
I'm still not convinced one way or the other about the cost of belt over chain.
I've just fitted almost new second hand chainring, sprocket and chain, so I'll log the miles on that and see how long it all lasts.

It's not just the cost though, it's the sudden catastrophic failure.
Apart from the one with the stone punched through, which lasted a few weeks with a hole in it before breaking, they have all failed without warning.

"they have all failed without warning"

No they haven't. Plenty of people have warned you that they would break.:-)

I don't think that's too bad, given that it's entirely feasible that a chain and sprocket arrangement can also be killed off in that distance quite easily ( there was a thread this week on the 1x11 set ups,showing significant wear after several hundred miles) how much are the rings and belts? Given that you don't have to spend money on lube and time cleaning them that well I'd view it as evens between chain and belt.

there was a thread this week on the 1x11 set ups,showing significant wear after several hundred miles

But that's not a valid comparison, the belt replaces a chain only in a single speed or hub gear set up. I get around 3 years on my all year round off road commuter from a chain. It doesn't get cleaned just more oil added. One chain and sprocket every 3 years and a new chainring every 6 is pretty cheap.

there was a thread this week on the 1x11 set ups,showing significant wear after several hundred miles

And whilst pics on that thread showed cassettes looking a little ropey actually they didn't have any 'significant wear'.

An £8 KMC X9 chain bites the dust with just over a month's use.

[img] ?oh=2e2986792769bcea4934009b25457d8e&oe=54DC9C62[/img]

Yes, some of the rollers are missing. It had been making odd noises the past few days. 😕
I'll fit a new one and keep a log of how long it lasts.
Even if a chain does work out more expensive per mile than a belt per mile, the fact that I had plenty of warning and the opportunity to replace it before it failed makes the chain a better option for a mountain bike.

I just don't get how you do it.

[quote=njee20 said]I just don't get how you do it.

+1

I think a large part of it is the Worcestershire sandstone.
The stone itself is not as abrasive as the grit you get in other areas, but it seems to be held in suspension in water easily, turning the puddles orange.
I commute mostly off road, even if half of it is just canal towpath, and I oil the chain every day, sometimes twice, at home and at work, but I can hear the chain grinding within seconds of riding through a puddle.

I've not had much luck with KMC chains, I'd break them fairly frequently, but since I switched to shimano I havent had a breakage yet in about 750 miles.

A quick look on Strava suggests you've done about 310 miles in 4 weeks? All on that bike?

No chain should fail in that time, irrespective of grit! Mental.

How can the rollers go missing, or erode like that? I don't buy this unique mud argument.

I oil the chain every day,

you tried a dry lube and clean chain. Oil tends to attract and hold dirt. A dry clean chain maybe a solution

I've found KMC chains to be dire, despite the love on here.

That chain is on the Lynskey and was already part worn when the belt stripped on the Qoroz. I've got no record of when I originally fitted it.
I'm currently running the Qoroz Rohloff and the Lynskey SS. I just happen to have been riding mostly SS recently.
I'll fit a new chain today on the old sprockets as they both look OK and keep an accurate record of how long it lasts this time.

julians - Member

I've not had much luck with KMC chains, I'd break them fairly frequently, but since I switched to shimano I havent had a breakage yet in about 750 miles.

Don't KMC manufacture Shimano chains?

I reckon it's luck of the draw for the most part.

Seems weird, I've had 10x your miles out of chains, the one on my meta lasted 2000+ miles before a rock killed it

I've found KMC chains to be dire, despite the love on here.

9000km on a x10sl dlc road chain - well past the 1.0mm wear marker on my chain checker, fitted a new cassette at 5000km, shifted perfect on old cassette, still perfect on new cassette

I don't get how people to claim to do years with a singlespeed chain. I have recently gone Rohloff on my mountainbike and even of mostly try trails I find chain strech quite bad. Chain binned at just over 1000k second one not gonna last more then 1500 it seems.

MTG, (at the risk of sounding condescending) are you leaving enough slack in that chain?

Rohloff, chainstretch, HA!

If it's still attached, keep pedalling mate.

MTG does seem to be beating on the drivetrain impressively. I took a Rohloff-equipped bike to Oz and NZ with a shitton of luggage and the chain didn't break. Hell I rode up the world's steepest street* with around 40KGs on, pushing so hard in the bottom gear that I was puffing like a powelifter. The strain on the drivetrain was [i]exceptional[/i].

Nothing broke. I only changed my chain affter the trip because I felt like it. XTR 771 spec, Thorn Ally Chainring, Rohloff Rear Sprocket. It did thousands of miles afterwards.

[IMG] [/IMG]

If I didn't wear it out with this lunacy, I fail to see why a belt is worth the effort.

*Yeah, OK offroad can be steeper, but not by much. I was forced to zig-zag to stop the front lifting off. Bear in mind I'd couriered for a few months and then been riding around the south of NZ for 3 months, I was probably able to generate about as much drivetrain force as as TdF racer [though I didnt have the endurance. Hell I rode so hard into the wind giving my Ex a slipstream my damn Achilles frayed/strained. That sucked.]

EDIT: NB my chain was never tight.

EDIT EDIT:

cynic-al - Member
Is anyone else disappointed this thread is not about turntables?

NO. Belt drive FTW.

PS - when riding up that street I was around 85kg of almost only muscle, and pulling down on the bars so hard they damn near bent. With 175mm Cranks the torque was enough to make the whole gorram frame wind up!

That chain is on the Lynskey and was already part worn when the belt stripped on the Qoroz. I've got no record of when I originally fitted it.

So your statement about a chain biting the dust with 'just over a months use' is actually bobbins, and you have no clue about how old it is...? Have you considered a career writing headlines for tabloids? 🙄

Just to be clear, chain snapping is a different issue to chain wear.

Graham, why not trynone of those floating fully enclosed chain guards? Saw one on a bike in Germany, look very good.

Bobbins is a strong word, I'd prefer guesstimate. 😛
Although I'll admit that claiming it was a KMC X9 was bobbins; turns out it was a Shimano. 😳

I always thought of my Qoroz as my main bike and my Lynskey as my spare.
If I was racing, I'd set the Qoroz up as either Rohloff or SS and the Lynskey the same to take as a spare bike.
I'm not planning on doing any more races, so when I removed the belt drive from the Qoroz, I thought I'd leave it more or less permanently as Rohloff and the Lynskey as SS.
I also took the opportunity to use up some odd size chainrings and sprockets I had by swapping bits around between both my bikes, Mrs MTG's bike and the tandem.
Somewhere in the confusion, the Lynskey ended up with the old chain off the rear of the tandem, or possibly the 'cross bike, which I thought was KMC, but now turns out it wasn't.
Anyway, I've now fitted the Lynskey with the old Shimano chain off the 'cross bike, or possibly the tandem.

Anyway, it's got another part worn chain on it, so when that one wears out, I'll fit a new one and keep a record of how long it lasts.

Well that's cleared that up then...

[url= http://www.hebie.de/schutz/kettenschuetzer/chainglider/350/?&L=1 ]Hebie Chainglider[/url]

[img] [/img]

I'd find a different route to work while you're at it, or try to ride around the puddles.

Well that's cleared that up then

I've seen those Chaingliders before, but always thought of them as a commuter thing to keep chain oil off your smart trousers.
They look like they would just fill up with mud on a mountain bike.

I don't know, but I've always thought that most of the mud gets on the chain from the back tyre and most water from the front tyre.
I've thought about making some sort of snow plough shaped attachment, on the set tube where the front derailleur mounts, to divert any mud stuck to the rear tyre off to one side or the other, over the top of the chain and away from the chain stay bridge where it normally collects. A sort of metal rear Neoguard.
I don't know if that would help or if it's been tried before.

Have a look at Geoff Apps' bike - there's a plate to keep the tyre mud from the chain and the chain is running inside some kind of tubes. If you made a BB mount thing out of aluminium sheet it could act as a flat guard between tyre and chain and a curved guard in front of the chain ring to keep the water off.

They look like they would just fill up with mud on a mountain bike.

Worth a try though? I have a feeling it'd help a lot. I'd use one if I had a SS or hub geared bike.

If I'm honest I think you're just exposing your drivetrain to the sorts of wear that it would take most folk a year or more to do.

Katz FTW:

[img] [/img]
Fully sealed chain drive in the swing-arm, to Rohloff wheel. Shame they've gone bust. Got to be scope for a similar design with a gearbox up front.

After 350 or so dry miles, after going through it's first bit of gloopy mud when down in Dorset I now have a nice ornament hanging in my garage to remind me how useless it is.

[img] [/img]

Clocked up 1500+ miles on it's replacement chain and cogs with a slight chain stretch and EEB tightening.
If in mud avoid, great for commuting on tarmac

"If in mud avoid, great for commuting on tarmac"

my experiance dealing with trek district warrenty claims from the till side of the desk says otherwise- even with the propper deflection measurement tool for set up - one for the history books.

MTG

Why not run a track chain, surely you won't kill that?

I may have asked this before but does the frame flex a lot in use?

Could it be subtle enough that on a SS/IGH chains alignment its enough to add more, than can be tolerated, lateral force causing premature wear?

letmetalktomark - Member

I may have asked this before but does the frame flex a lot in use?

For the use of a Gates Belt drive the frame has to be passed by Gates for stiffness to make sure the flex doesn't cause the problem, so I believe

[img] [/img]

[img] [/img]

For the use of a Gates Belt drive the frame has to be passed by Gates for stiffness to make sure the flex doesn't cause the problem, so I believe

For the use of a Gates Belt drive the frame has to be passed by Gates for stiffness to make sure the flex doesn't cause the problem, so I believe

That's not really true. There's nothing to stop you buying gates beltdrive parts and fitting them to any old thing. And yes, if the frame isn't suited (too flexy/inaccurate chainline) then the experience you'll have with the system will be poor.

The Gates test exists to make sure designers/builders have access to data to make sure their design will work as expected.

Some vendors want you to submit some of this data before they sell you parts to work with the beltdrive. This is to ensure you don't build a bike to use the system that then proves to be a bit shonky, giving the whole system a bad name.