Interested in Hub Gears & Belt Drive & read German ?

Then could you let us know what Phil (boss of Simpel bikes) has to say about them in his velo blog ?

https://phil.veloblog.ch/post/7/859

You like a translation? Here you are (please note: I am german and this is a kind of "word for word translation". I did my best but I am neither a translator nor bike specialist nor grew up double tongue and if phil or anyone does not agree with translation or that his words - in green colour - are posted here, please let me know and I delete or correct):

Optimists live longer!
written by phil 5 march 2008

The carbon belt toothed drive has, according to Gates a mileage of about 20.000 km. The tooth belt itself should not suffer substantial wear, the drivetrain wheels will suffer minimal wear due to dirt (sand, little stones...). Not even ones hands will get dirty when changing the belt. Our "optimist" prototype-wheel should really live long!
Anyway, attention in press and publicity is huge. In an online article the german magazin "aktiv radfahren" cant stop raving.


We have new pics from the "optimist" which I like to publish here:

Pics here

Also interesting is weight saving: with a Shimano hub 230 gramm are saved in comparision to using a chain. The toothbeltwheels are admittedly a little bit heavier but with the belt one saves about 280 gramms in comparison to a standard chain.

Further below he answers a poster who states that chain efficiency is still the best:

"...the gates drivebelts level of efficiency is nearly identical to a chain, actually slightly above in some tests. In a chain the level of efficiency descends due to wear, the drivebelt stay much longer at the same level.

Hope that helps

Hmmm not so sure about the bike part

Thank you for your time and trouble, Somnatash, much appreciated. I had hoped that Simpel were working on a conversion kit to turn chain driven hub geared bikes into belt drive, but it doesn't look like it, not yet at least. I read somewhere that the Birdy Green was available on mainland europe at one time with belt drive, does anyone know if this is so ?

Likewise, very useful somnatash, thanks.

Interestingly, one of the fellow "origami" riders mentioned a Birdy with belt drive some time ago, & a Moulton rider also has belt drive. I'll try to find out more at our next attendance.

We like belt drives best in heavy rain - no rust afterwards ;-)

You are very welcome! No, you are right, Phil is not talking about a conversion and yes, you are right again, a birdy with beltdrive was available but was stopped since it did not turn out to be successful.

somnatash, do you know what the problems were?

Not exactly, I will find out and be back.

https://www.pdeleuw.de/fahrrad/birdye.html

looks like he's testing

https://www.carbondrivesystems.com
https://www.carbondrive.net/

and I think that Strida uses the same supplier.

I wonder if the tensioner was a factor in the belt wear. The chain drive Green has a tensioner in the ususal plce below and in front of the axle line, but the photo on page two of the birdye report doesn't show a tensioner there, but it does seem to show the drive line coming in very high over the axle, perhaps there was some tensioning mechanism directly sitting on top of the sprocket, making the final contact angle quite steep, and causing wear.

I've seen the belt drive stainless steel framed Moulton, a beautiful machine, the only problem with the belt came if you stood on the pedals, then the belt sometimes snapped. They also showed a Moulton Bentley model at a show in Japan that had a belt drive arrangement, but i dont think it ever went on sale.

A belt with a twisted steel wire inside it might be able to withstand standing-on-pedals stresses, and an eccentric bottom bracket might work better than a tensioner.

Regards
T

Thanks for those links, & the Birdy one; very interesting.

"The sprockets contain Mud Ports™ that shed even the worst types of debris. This system works as well in wet, snowy, or muddy conditions as it does when conditions are perfect. It is the only drive system that is completely lubricant-free as well."

Heavy mud is about the only condition where we don't use our Stridas, as our 3's don't like it, so those "Mud Ports" sound promising for a future version.

I read a note by Mark Sanders a while ago which I think mentioned Gates' belts are used on the 3's, & probably also the 5's.

I have both Stridas (3.2 & 5) and I'd say that the belt drive is the same on both.

test rode the gates system on a spotbrand bike last year ....
felt good but when wet it made very loud squeaking noises ....
tried to get some answers from them after the show, but never received any emails ... too bad ...
will see i f I can find them again this year at the tradeshow
thor

According to the Colorado office, a wider range of sprockets should become available in the US sometime in October 2008. Ballpark price: $300 for, say, a 55T and a 22T sprocket and belt, with replacement belts costing around $65.

The belts are rated at 5000 psi ... and to temperatures as low as -65° F (-54° C.)

Regards
T

(I've been waiting for a chance to use that emoticon, it being very hot and humid here)