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Shane’s Belt Drive Titanium Commuter by XACD

Shane dropped me a line recently saying he was just thinking about his third XACD frame – and would I like to hear more about the belt drive commuting bike he’d had made? When I took a look I knew it would be rude not to find out more!

Shane's belt drive, hub geared, disk braked commuter - excellent job!

Shane’s belt drive, hub geared, disk braked commuter – excellent job!

Shane based his whole frame around the Gates belt drive system, the mini S&S coupler on the right hand seat stay is to allow the rear triangle to be split to put the belt in place. I noticed that it was using the first generation Gates drive…

Yes, that’s the original CDX belt drive system, the CenterTrack came out not long after I finished it up. I never had any issues with the belt drive on this frame, but I actually built it because of a bad experience with an off the shelf belt drive bike! It was based on a very poor steel frame which couldn’t handle the torque and torsion of the belt drive drivetrain (belt slippage!) from day one. That was enough for me to never buy an off the shelf bike again, so I built my own via XACD.

I used to run it either singlespeed or with the Alfine 8spd hub depending on how I felt; it was a sweet ride. I put a lot of thought and research into it as the belt drive system needs certain requirements for alignment and strength. It was basically designed to be a pure commuter and that’s all it was used for.

Belt drive system looking good - neat internal cable routing guide in frame too.

Belt drive system looking good – S&S coupler splits the seat stay and neat internal cable routing guide in frame too.

I asked Shane about the ordering process and how he’d got on with Porter:

I never had any issues with Porter, as you know you just have to be as clear, simple, and basic as possible so nothing is lost in translation, even to the point where I just send images of exactly what I want to get my message across. This was my 2nd custom frame and just like the first it was spot on!

I like a more traditional (horizontal top tube) frame, just with modern tweaks like internal cabling where I can. All the tubing was upsized and the rear triangle tubing was thicker than stock to reduce flex which can cause belt drive slippage on CDX systems. The S&S coupler worked just great.

Nice close up showing dropout detail with tensioner, S&S coupler to split the stay and mechanical disk.

Nice close up showing dropout detail with tensioner, S&S coupler to split the stay and mechanical disk.

And finally, of course, what would he do differently next time?

There is nothing I would really change if I built again. I do find the XACD inserts for internal cable routing a bit finicky though, they never seem to want to stay seated, my next frame will just have port holes with no inserts.

My designs for the next frame are pretty much finalised. It will be used for commuting again, but will also be my training bike, so it will need to be comfy as well as stiff & responsive when I need to put out some watts. Featuring full mudguards, disc brakes with internal Di2… basically a no excuses, all weather, go anywhere roadie. Really excited about this one!

Notice the thicker tubing that Shane's used on the stays to keep the backend really solid for the belt drive.

Notice the thicker tubing that Shane’s used on the stays to keep the backend really solid for the belt drive.

You’ve got to admire the clean lines there; Shane’s done an excellent job! It’s interesting to see how thick the tubing has become to make sure the stiffness is there for the belt drive. Standard frames would have a wall thickness of 0.9mm all over but this frame uses extra chunky 1.6mm tubing for the ‘stays and 1.2mm for the down tube.

This sort of beefing up will definately result in a stronger frame, although it could give a slightly more ‘dead’ ride feeling compared to the thinner tubing. An alternative approach, at least for the down tube, would be to increase the overall diameter of the tube. I’m going to split off my calculations into another post as it bears some looking at but roughly speaking you could replace the 38.1mm x 1.2mm tube with a 50mm x 0.9mm tube and have something which is both stiffer and lighter!

The stays would be trickier to beef up but it’s interesting to note that Van Nicholas run a stock 0.9mm wall thickness all over on their belt drive compatible frame. Part of the reason, according to some sources, might well be that the CenterTrack system appears to need less tension to keep it on the straight and narrow. One day curiosity will overtake me and I’ll get a belt drive frame made so I can test that theory out – to see if you can have a light frame that’s stiff enough to run a belt drive with.

XACD’s internal cable inserts look much neater than the welded inserts that Waltly (for example) use, I’d be tempted to bond them into the frame with a bit of epoxy and see if they can be tempted to stay in place.

I’m certainly liking Shane’s work so far, it’ll be interesting to see how frame number three turns out…

Have you had a frame made in the Far East? If so I’d love to hear about it and maybe feature it in the Gallery so drop me a line via the contacts page.