Shaymo

Strida was one of the first bikes to use a belt drive system producing both weight savings and a greaseless solution.

One of the negative features of this system being banded about was slippage in wet conditions. But we know now that the motorbike manufacturers are using it successfully on many models.

I also understand that many of the major bicycle manufacturers have full frame belt drive systems designs in the pipeline.

Has anybody any experience with belt systems on their bicycles? I think it’s a pretty major direction in bike design in relation to weight saving and a cleaner slicker bikes.

Bacciagalupe

Belts are slightly less efficient than chains; plus you either have to go SS/fixed (i.e. one gear only) or use an internal hub, which also reduces efficiency. Chains are also easier to repair, whereas a belt can only be replaced. If you opt for gears, any weight savings are more than offset by the increase in weight of an IH over derailleurs.

Ergo, you're compromising performance and one aspect of maintenance for a cleaner drive train. Although I'm sure better belts will be made moving forward, belt drives make sense for some applications but not for others. I doubt it will end up as the "wave of the future."

Simple Simon

Anyone who experiences the silence and smoothness of a belt drive will be won over. Efficiencies are well up there and there are now loads of bike companies now offering them (admittedly small companies - bigger companies are always slower to catch up). Chains are good for that last 0.05% performance that racers demand, but for the rest of us, I predict belts will become more and popular. Except that is for people who LIKE to have a tribal chain tattoo, on their legs/trousers/pants

EvilV

I doubt that belt drives will become more efficient. The technology should be pretty mature since it features in most engine camshaft drives these days. I saw a strida advert which said the belt was good for 50,000 miles the other day.

I'd be interested to see the engineering figures on belt efficiency. Also, remember that bike chains become radically less efficient than the oft quoted ideal numbers once they become dirty, dry of lubricant or slightly out of line as in most derailieur gears.

cyclistjohn

Hello EvilV, I trust your "kickstart" leg has mended now?

Take a look here for some info':

https://www.gates.com/news/index.cfm?...ocation_id=752

I can probably dig out more if you're *really* interested ;-)

EvilV

OK John - thanks. I read that, but it doesn't say how efficient the belt is with numbers. It would have to be installed in a particular setup for that anyway.

I'm wondering why strida don't have a hub gear setup with their bikes. Their two speed ones I think are using the schlump thing.


Oh - and yes my leg's ok now thanks. I lost a good amount of fitness during the winter though when I couldn't walk.

cyclistjohn

I'll go find another disc drive tonight with some research on it, & see if I can find you some useful links with efficiency values :-)

Me too. "Somnatash" was fortunate enough to have met Mark Sanders, the Strida designer, at a show recently. I was hoping he would be at Spezi earlier this year, but no, as I'd like to ask him a few questions about Strida's design. He's going to be in Singapore in a week or two, but it's a bit far to go (although I imagine much warmer than here!) & I haven't been invited, so I'll have to wait until he appears at one of the European shows :-)

You're right, the "new" Strida will have a Schlumpf 2 speed drive, but that takes the price a bit out of my league presently. I saw Florian Schlumpf at Spezi, but didn't chat with him, as he was busy with others, & I hadn't formulated enough sensible, coherent, questions to ask. His engineering though, is very impressive.



I rode a 500cc Triumph in the TA (UK volunteer reserves) & occasionally that backfired (not much money in the UK armed forces ;-)) which really hurt me a couple of times, but nowhere near as badly as you suffered - ouch!

Your posts made me wonder if you were ever going to ride again!

I almost bought a motorcycle again recently, but the day before I was going to phone to order a bike, I tripped over some metalwork outside our house, & really hurt my left foot (too much German white wine I think ;-))

Whilst recovering, it occurred to me that I'd actually be able to carry less on the Honda bike than I would on a bicycle! I'd have trouble parking it, wouldn't become any fitter, etc., etc. so in fact abandoned the idea!

It's interesting you should write about fitness!

I started cycling again seriously just before I joined BF about 2 years ago, & after that 2 year period, I'm back to a proper weight & fitness :-)

However, I've noticed that if I don't ride for say, 2 or 3 days, I "seize up" & it takes several more days of riding before I become "supple". So, I can imagine you were pretty upset during winter!?

datako

I have been experimenting with belt drive for a number of years and I have a belt drive bike. It's homebrewed - uses a Thun & Pirelli set up.

The belt is nice and quiet. It certainly improves the sensation of cycling because it is quiet. I do not notice any difference in efficiency between it and a chain.

Belt drive has a lot of pluses going for it. Combined with a hub gear it is the obvious way forward.

Bikes will need some redesign before belt drive can become popular. Chainstays will have to be redesigned so there is absolutely no lateral flex, and also so that they separate at the dropout to allow the belt to be fitted.

Solsticejk

I ride my Strida pretty much every day and I have to agree that the belt drive is what makes an already great design really shine. The grab-and-go simplicity (not being careful of where you put your hands, no need to roll up a pant leg) is what this bike is all about. I've ruined two pairs of favorite pants over the years when forgetting to roll up the leg on my regular bike, but on the Strida, it's no problem. Also, the lack of the potential for rust is another plus. I can't imagine the difference in effeciency is so great that the cons outweigh the pro's for the use of belt drives in commuter-type applications such as folding bikes and cruisers.

FoldingCyclist

Well the Strida was hardly "one of the first bikes to use a belt drive system". In the folding bike realm,
the MicroBike from Sweden and the Picnica from Japan come immediately to mind as having it before the
Strida, I think there were a few others as well. As for regular bikes, I remember seeing belt drives in the
early 80's and a bike mechanic friend had an experimental bike he built in the mid 70's with a belt drive. I
rode it once and was impressed with its smooth quiet ride. So belt drives are not a particularly new
wave of bicycle innovation that companies are just itching to jump on. However, I do think they are a
reasonable option on a folder with a hub gear for folks that travel with their bikes a lot and want to
avoid spreading the chain grease around.

Simple Simon

Not convinced ? .. check out this Moulton https://flickr.com/photos/57997293@N0...in/photostream

Also Kudos to Strida for backing belts for over 20yrs, even in the face of much flack from all the traditionalists

datako

The reason belt drives have not been adopted in the bike industry is the need to make frame modifications to do it, and so it is not an easy retrofit job.

capsicum

belts are subject to more debris damage than chains. I know a couple people who have been stranded by broken motorcycle belts, in both cases some road bit got between the belt and pulley, punched a hole and very shortly there after it snapped. Otherwise they are clean and low maintenance, rather pricey compared to chain though and a pain to change.

...and the first use of belts on bikes was over a hundred years ago, they may actually predate the use of chain drive.

EvilV

I had an ancient moped when I was a lad around 1967 that had belt drive between the crankshaft and the primary drive sprocket. It was a v belt of the sort car's used to use for driving fans and dynamos at the time. The moped was made in 1959. It had 1.3 BHP and seemed pretty quick to me at the time. LOL.

downtube

Actually Spot makes a dropout with a slit in it to allow a belt to pass through. I think may companies will implement this dropout in the future. Currently the dropout wholesales for $55/ea, hence I do not think the future will come to the market very quickly.

Thanks,
Yan

datako

I've seen that. It seems unnecessarily cumbersome to me.

All that's needed is a bolted joint at the dropout like the old bikes used to have. It's a triangulated structure so it would be strong enough and not need any fancy proprietary part. Similarly, many carbon bikes use a pinned joint at the junction of the seat stay to the dropout, and if this was replaced by a fitted bolt, it would probably do the job.

All that would then be required would be to remove the bolt, slightly spring the stays apart and slip in the belt.

I'm not convinced that is any greater risk than the same thing happening on a chain.

I used to ride my belt drive motorcycles offroad a fair bit (didn't live near a surfaced road) and the few times rocks got caught in the belt they were pulverised with no apparent damage to the belt.

FoldingCyclist

I remember seeing the Spot bikes at Interbike last year, I assumed the dropouts they were using came
from the Carbon Drive folks as part of the framebuilder kit they were selling. I thought the dropouts
were clever but had the exact same thought datako had about a less cumbersome solution, which
given the Spot's harsh pricing, makes even more sense.

griftereck

belts should be easy to fit to bikes that have swing arms.
even better if the stay was made into a case to enclose the belt.
so theres no chance of damage or catching your clothes.
be good if it was single sided wheels with the bearing in the side of the belt case.

mconlonx

Retrofitting belts should be relatively easy* on bikes with elevated chainstays like the Dahon Curve, Mu, and Glide models with IGHs... gee, many of the newer "utility" Dahon designs could accept belts... probably coincidence...

Another easily adaptable class of bikes would be mountain bikes from the 90s with e-chainstays, like the Nishiki Alien.

*Assuming there are cog/ring/belt specs that would fit existing chainstay dimensions.

brakemeister

*Assuming there are cog/ring/belt specs that would fit existing chainstay dimensions.[/QUOTE]

and also gearing for 20 inch wheels as the front and rear cog is truly only available at this time for 26 inch ers

thor

jur

Early Birdys came with a belt drive but it was ditched, why I don't know.

oboeterry

and also gearing for 20 inch wheels as the front and rear cog is truly only available at this time for 26 inch ers

thor[/QUOTE]

Not quite true... see www.abiobikes.com

ShinyBiker

My .02:

1. Just because a Strida has a belt drive doesn't mean that your pants can't get caught or ripped between the front ring and the belt. You'll still need a pants clip.

2. I suspect that in a medium sized town you'd be lucky to find a mechanic that would be able to service them.

datako

What servicing are we talking about? I can't think of anything that would cause any problem for a proper bike mechanic.

EvilV

I suppose we have all changed a few car fan belts, and a lot more besides.

The writer above was dead on about the Dahon curve and other single chain stay bikes. I suspect that the main problem might be in getting suitable pulleys and a range of sizes to suit personal gearing tastes.

On the point about the chaincase (beltcase?) above, if we still had full chain cases on our bikes like on the old Raleigh Superbes, the whole discussion about belts and chains would be redundant. Those chain cases systems allowed the chain to run clean and in oil. The chains virtually never wore out in normal use. A straight running chain, well oiled and protected from dirt and water is virtually everlasting as far as cycling loading and mileage is concerned. We could easily go back to that in many designs of hub geared folders. The technology works fine and is cheap and available.

There was a photo on here a few weeks ago of a chain case system that used tubes to protect the chain. There was a cover at either end over the cog and chain wheel and tubes of about an inch diameter covering the chain. Light and modern looking. oil it once a month and never look at it again.