Blog: Tubeless

25 Jun 2013

Road tubeless conclusions

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If you follow my blog and/or Twitter you’ll know road tubeless has been on my mind this season. After a brief hiccup my feelings have clarified: road tubeless is a winner. With the conclusion out of the way I want to share a few unvarnished thoughts on the pros and cons as I see them. Read more →

For a long time it seemed standard 19mm rims were the only option for road wheels. That’s changed a lot in the last few years. Now we’re seeing very good rims 23mm and wider.

To some extent wide rims are a product of racing technology. A wider rim increases the roundness of the tire profile compared to the lightbulb shape on a narrower rim. When tire width closely matches rim width there’s an aerodynamic advantage — aerodynamics are key for pro racers.

In many cases race-oriented technologies don’t translate to the recreational market but wide rims offer benefits everyone can appreciate. You are less likely to experience pinch flats with wider rims; larger air volume allows for lower pressures, which can increase comfort; cornering is improved since tires experience less flop in response to lateral forces; and wide rims are typically stronger with better durability. There are downsides to consider too. You may require brake adjustment when switching between wide and narrow rims; and brake modulation may suffer.

Two excellent wide rims I have in stock at the moment are the H Plus Son Archetype and the Pacenti SL23. The choice is a matter of taste and specific application. Get in touch to see which rim is best for you. Here are some photos of a recent build using the Pacenti rim laced to White Industries hubs for singlespeed use. These are comfortable wheels that handle well and look terrific.

26 May 2013

Road tubeless not so sure

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I’ve been riding my road tubeless wheels lately, playing with tire pressure. I started a little high but dropped down to 75psi on the front and 80psi on the rear. The comfort of the tubeless Ultremo ZX is beyond what I’m used to from clinchers but fast and sticky at the same time. Really nice.

Unfortunately the experiment came to a premature end today when I hit some unknown particle and sliced the rear tire. The cut was far too large to be managed with sealant and, adding insult to injury, sealant sprayed the face of the rider on my wheel. Without any loss of control I rolled to a stop and was pleased to find the tire well-seated in spite of total deflation.

The flat happened on Highway 8 east of Calgary at a spot covered with oil residue — yesterday that spot was host to a head on collision between an SUV and a semi-trailer truck. The SUV was launched 90 meters backwards; the truck caught fire and burned out. The SUV driver was killed and the truck driver was taken to hospital with injuries. There must have been some debris left behind.

It’s hard to say if another tire would have survived. The Ultremo ZX, at least in its clincher version, is known for performance but not for durability. I’ll get another and carry on.

Road tubeless has been around for a little while and it has gotten good reviews from the likes of Leonard Zinn. So far I’ve been reticent to try road tubeless but when Schwalbe released their excellent Ultremo ZX tire in a tubeless variant, I figured I’d give it a try.

To make this project work I dug up some NOS Shimano Dura-Ace 7900 hubs. For my first try I turned to my offroad rim vendor, Stan’s Notubes. I got their Alpha 400 rims in 24/28h to match my hubs and put them together with Sapim CX-Ray spokes. The Stan’s rims built up very smoothly and total weight came to 1500g on the nose — plenty respectable. On top of that I installed two layers of Stan’s 21mm yellow tape and 44mm road valves.

Mounting the tires was a little hairy. The Ultremo ZX tires needed levers and I drafted a pair of toe straps to hold the tires in place as I worked their final sections. There’s some skill involved and my speed was better on the second wheel. In the end I found compatibility between tire and rim was excellent. I had my air compressor ready to go but was able to seat the bead with a floor pump. Each tire got 2oz of Stan’s sealant and neither shows signs of leaking air.

Of course it’s all about the ride. My short test ride was very positive — I find the wheels extremely comfortable even with a skinny 23mm tire. Before blabbing too much I want to put more miles on these wheels and play with tire pressure. Details to follow.