Ok- I’ve now done about 160km on my new tubeless Coker. It’s great!
I was most impressed with Stan from Stans no-tubes who emailed me back personally. Stan makes the most popular tubeless kit for mountainbikes. He also made me a custom 36" rim strip for my Coker. They sent my package from the US to NZ- I got it within 10 days of placing my order.
I can’t tell you much about the conversion itself, since I left my bike mechanic to do it. It was pretty straigtforward apparently. The 36" rim strip goes around the rim and the tyre goes on top. Then it’s a couple of scoops of Stans sealant to seal up any holes. Apparently it was also holding air pretty well even before the sealant was put in. It would have been nice to have tried it without any sealant in there. But anyway, Blair (the mechanic) chucked in about 3 scoops of sealant.
My main reason for the conversion was to lighten the wheel. All up it saved about 200g.
A Coker inner tube weights 480-500g
The 36" rim strip (120g) and 3 scoops sealang (3x60g=180g).
When you consider the fact that this is rotating weight right at furthest point on your wheel, it feels quite significant. I’d previously converted my standard Coker Spokes (600g) to much thinner Unicycle Factory Stainless Spokes (don’t have the weight- does anyone know?). I estimate this saved about 200g. So in total the Coker wheel is about 400g lighter after both conversions.
Well- the main thing you notice with the wheel is how lively it feels. Although it’s not as big a jump as dropping all 400g at once, it still felt faster than just having the Stainless steel spoke conversion alone. It accelerates much faster and, more significantly, it seems to decelerate faster. I dont’ use brakes on my coker, yet I was able to slow from about 30km/h to a stop (with 102mm cranks) in just a few metres. With less momentum- the tubeless/SS Coker seemed to track around corners in a tighter circle also.
I think some users on this forum questioned the loss of flywheel effect a while back. Basically, a Coker Wheel is so heavy anyway that you can afford to lose a lot of it before it feels as jittery as a 28’er. You can compensate by using shorter cranks, which is in fact the best thing about this. It’s like moving up a gear- from Tubed to Tubeless is like going from 125mm cranks to 110mm cranks. Once you factor in the SS conversion and a stiff carbon seat you can almost ride 100mm cranks with the same ease as 125mm cranks on the standard Coker.
Off-road is probably where the tubeless Coker really shines. Without the fear of pinch flats (which you hardly ever get on a Coker anyway, but still), you can lower the pressure right down for better traction. Even at the same pressure, I think it rides nicer than a tubed Coker. The tyre is more compliant as there is no friction between the tyre and an inner tube. This thing hums on gravel.
There is another option of lightening the Coker wheel, which I’m hoping Tony Melton will try this week so that I can compare the two. That is to use a 29’er inner tube in a Coker- you’d be surprised how much it stretches. This should probably save even more weight than the Coker conversion, especially if your bike mechanic chucks in three scoops of sealant.
Anyway, I think this is the way Cokering should go. It’s still a pretty heavy wheel so any method of lightening it is a good thing!