Belt Drive Slippage…Bull$hit!

Belt Drive

I stopped in to the Spot booth to take a look at how the Belt drive works. I talked with one of the guys about the rumor that belt drives slip. I think that in some cases it might be true, but not this one. Getting a belt to slip is damn near impossible with the Polycarb teeth mated to the belt. Getting the belt on and off is really the only drawback that I see since it will require a gap in the drive side rear triangle.

If you are considering a trouble-free commuter that doesn’t leave you greasy - a single speed belt drive might be the way to go. A belt drive on an internally geared hub?! That would be killer.

<a href=”http://www.flickr.com/photos/45335443@N00/2897005333/>Belt Drive



15 Comments

And has Spot ridden their system in a Seattle rainstorm up a 17% grade hill? Are they sending it to us to test it that way? Remember when Shimano denied that the shifting action was too light? And then later they made it less light; or how Speedplay didn’t acknowledge their cleats slipped until a new design eliminated that slip; or how twin-paired spokes make absolutely zero difference in the wind tunnel, but I digress.

Am I missing something, what’s wrong with a good old fashioned chain.  Lube it up, let it dry, wipe it off - ride for 1000K, repeat??

The merits of belts are worthwhile and I hope someone does make one reliable; especially for the plain-clothes cyclists, cargo, or just “won’t make your pants dirty.” If Spot has done it, “rock on.” We (or rather me) just needs to see it work.

I saw/rode one of these in Asheville at BioWheels.  Very nice setup and super quiet.  Advantages of the drive system are the belt lasts 3-5x longer than chain; little to no stretch, a major plus for the SS crowd so you don’t have to adjust your eccentric BB or readjust your drops.  And for the carbon junkies, the Spot brand uses the Gates carbon belts.  I haven’t ridden the Delta CDrive systems so I have no idea how they ride.

The rep was definitely apprehensive when asked about how important belt tension was.  I don’t know how many of you have put your own fan belt on your car before but it’s not super easy.  Seems like it could be a little tricky for roadside fixes, but other than that I was pretty impresses by the belt.  I also thought that nuvinci infinitely variable gear hub on the bike with the belt was slick.

I’m sure, like any product, there are evagenlists both ways.  I’m personally still out on whether it’s the way to go or not, but a friend of mine had some serious problems with the spot belt drive at the dirt demo.

The tension wasn’t quite right and so he started dropping the belt off every 100 yards or so (it seems to be a lot more sensitive than a chain to tension), and then finally, on a very small grade hill (he was just trying to make it back at this point) the belt shattered into 3 pieces sending his stomach into the stem. 

I’ve heard that once the belt starts slipping off, the individual fibers are loaded unevenly and start to break apart internally, and then you get catastrophic failure. 

Seems like it needs a little work still.

Also should set the tone here that Bike Hugger wants these to do well and not just rip on a manufacturer for bringing something to market. Discussing it is one thing, snarky comments and all, but we’re not here to just flame them.

@ Nathan,

The reports I heard from Dirt Demo may have been your friend.

Is building a disconnectable belt completely impossible with today’s technology?  This problem seems difficult but possible, especially if someone could put in some money and engineering expertise.

Thanks for sharing information on the belt-drive.  I am very interested in a singlespeed mtn bike with this set-up and have been wondering if it would be the correct application for what i want.  thanks for the info on this.  i’m still a little undecided, perhaps we can hope for more articles about this subject from Bike Hugger in the future?

It was only yesterday that I googled “belt drive Alfine” just to make sure I wouldn’t take false credit for starting the meme, and I found this year-old-to-the-date post about the very same thing:
Shimano Alfine goes Off Road or new Shimano Alfine Interpretation

The impression I get is that we’d all like a ruggedized road bike.  It’s got nearly all the characteristics of our road bikes, except we can just throw a leg over and go just about anywhere, on/off road, regardless of the time or season.  Putting the shifter on a drop bar is part of that, eliminating the chain is another, and let me also just add that it would be nice to have a cleaner system for running the shift cable and housing on a bike with normal derailleur stops.  That goes for discs, too, but that’s really a frame/fork thing.  Zipties are for computers, not cabling.

I snap a lot of chains. Almost every season. I snap them because I do terrible things to them and I intend to continue this abuse. therefore, a belt-drive is a god-sent solution. No more catapulting over the bars when a link blows. Belt with i-motion or alfine, (see Trek ‘District’ and ‘Soho’.

Byron, I’ve put a few miles on the Spot 29er belt drive on steep hills—no slippage and absolutely reliable. I haven’t tried the Gates belt in the rain. I rode a Strida (with a Kevlar belt, not Gates) all last winter (constant rain) without any problems.

My main concern with drive belts is that once they break you’re prety much screwed.  A chain can be repeaired temporarily, at least to end the ride but nobody will carry a spare belt and therefore as a MTBer, being stuck 10 miles afar in the woods with a broken belt would be a real pita.

I have a Geurchiotti that has a press fit attachment in the seat stay for a belt drive.

Perhaps Spot would like to have a veteran messenger test ride the crap out of one for them?

Around town, working, and used during serious Bike Polo games…

Anyone? Bueller?

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