Belt drive fixed

I have missed lots of this thread. Are you running it fixed? Can you run them fixed?

Yep. Gates released a threaded rear fixed cog with the new centertrack system. Running 55/21.

Can you skid with beltdrive or is it with brakes only ?

Not had any issues with the belt slipping at all in either direction. I don't really skid though, front-brake only. So far it's behaving really nicely, feels like a brand new chain every single ride.

Yesterday outside the QMC, I saw a bad-ass home belt-converted charge plug.
If its there today I'll try and get a picture.

Yep. Gates released a threaded rear fixed cog with the new centertrack system. Running 55/21.

Did you use the sugino lockring in the end?

Did you use the sugino lockring in the end?

I have the sugino one, but I was impatient waiting for it to arrive so I just used a mallet and a drive punch tool to bodge a normal lockring on there.

Been experimenting with belt drives for a while now. Currently rather happy with my Parlee. Have been getting rather obsessive with trying to get this as light as possible without going to crazy on the parts. Currently sitting just under the 4 kilo mark I believe. Happy to answer any questions people have on belt drives! Skidding-wise, I haven't had an issue on my bike as of yet...

http://www.lfgss.com/picture.php?albumid=2181&pictureid=16572

4kg! surely that's light enough as it is? you've bitten the drug son.

Been experimenting with belt drives for a while now. Currently rather happy with my Parlee. Have been getting rather obsessive with trying to get this as light as possible without going to crazy on the parts. Currently sitting just under the 4 kilo mark I believe. Happy to answer any questions people have on belt drives! Skidding-wise, I haven't had an issue on my bike as of yet...

http://www.lfgss.com/picture.php?albumid=2181&pictureid=16572

Nice bike. Are you using the thread-on cog, or something like the halo fix-g as scoble suggested? In hindsight I would have gone for halo hub. I was pretty lucky that everything fit quite easily with a retrofit.

Friend have stripped the Halo Fixed-G hubs, he now have ordered the threaded belt cog to be used with normal fixed hubs.

how do you strip a Fix-G hub? Is the belt drive sprocket particularly thin?

(I have been using a Fix G for a year, brakeless, with a 7mm base cog and it still looks like new)

Have no idea, but it happened to him, and he's one of those spinny kind with three brakes.

I've been using the thread on gates belt cog with no issue what so ever. That said I do have two small spacers on in-between my hub (Mack superlight) and the cog to ensure the belt has a dead on straight chain line.

I'm using a standard lock ring to keep the cog in place. You can find lock ring tools that look kind of like pincers that can be used to fit it on properly. Useful when trying to tighten a lock ring that is in a recessed place.

I had to space my threaded cog out a little too. 2 x 1mm spacers. Didn't lost quite that much thread as the bit right next to the hub isn't threaded.

Also had to flip the front sprocket over to line it up with the rear and give it enough clearance from the chainstay.

Other than that mine all fit perfectly into an All City Big Block. Wheel is right in the center of the track-ends with the belt tensioned and I can get the belt off easily enough at the front.

Definitely need to make some careful measurements if you are retrofitting it to avoid an expensive mistake.

how do you strip a Fix-G hub? Is the belt drive sprocket particularly thin?

(I have been using a Fix G for a year, brakeless, with a 7mm base cog and it still looks like new)

In respond to this, I've gathered more information from my friend whom was servicing his belter.

The sprocket wasn't exactly thin but it did managed to cause damage to the spindle, creating a play which get worse, the problem is that the spindle is aluminium, so like those high end road hubs, the sprocket will dig in the spindle.

Here's some photos;

As you can see the sprocket have cause damage to the body, which is a shame as the Fixed-G hubs is a great idea let down by the fact it use an alu spindle.

We replaced his entire drivetrain with the aforementioned new threaded centertrack fixed sprocket (+ belt and beltring), which mean he can able to run a conventional hubs with the new system.

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The HG spline was designed to be made from steel and driven only one way. The load reversal of fixed gear use highlights that it provides provides plenty of backlash, which will be destructive pretty quickly. In fact, all sliding fit splines will have some backlash, although you can reduce it by making the mating parts precisely to minimise the clearances, and then reduce the negative consequences by making the flanks larger and more steeply angles (closer to radial)

Given the size of that belt pulley, it seems that 6-bolt ISO would be a far more sensible way to attach it to the hub, if the aim is to have a drive which can be fitted to cheap and easily available hubs. The properly tarty way to join a sprocket to a hub is with a Hirth joint, but that might look a bit pricey even to people who are ready to waste their money on belt drives :-)

His cheap £450 belt drive bicycle have become very expensive quickly when realised you can't just buy a fixed cog.

We were talking about the 6 bolt system which would have been ideas.

The splines of that pulley don't look as square as a standard toothed cog (or the ones I use anyway) which may not have helped and maybe less suited to using fixed?

I've seen a Sugino lock ring that uses the same tool as external BB cups (16 drive grooves), and you can get a socket to drive that.

Is there any other lockring that mate well with a BB tools out there?

I don't think there is ed, i've been thinking it might be better to modify a tool to work with the lockring. As you'll need a special lockring tool to get inside the space and have a hole for the axle to go through. Something like this park one.

I've been thinking about Belt drive recently so have been doing a bit of research. I found a picture of en excel calculator with some archive digging i found the file, i've modified it and put it here for people to download.

EDIT: The socket tool will only work if you can remove the axle, so for allen bolted hubs, the hole is for a 3/8" = ~ 9.5mm so too small for a 10mm rear axle.

If you're going to modify the tool anyway, you could just bore it out to clear a 10mm axle, 3/8" square drive should still engage, or use the hexagonal flats on the tool boss to drive it.

good thinking

I mangled one with a file so that the axle fits through. Didn't bother making it pretty as an adjustable spanner works fine for driving it. Satisfying to make, but never bothered to use it

The Pedros one has a ½" square drive, solving the problem without recourse to modification