Blog: Shimano Dura-Ace Hubs

31 Aug 2014

Dura-Ace training wheels

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These wheels are built for stiffness and strength thanks DT Swiss Competition spokes and a deep rim profile. They’re not light wheels but weight is often misunderstood. More weight means more energy is required to propel the bike forward, most noticeable when accelerating. But when cruising at high speed, heavier wheels have a flywheel character that makes the bike feel like it wants to keep going. Light wheels may climb best but heavier aerodynamic wheels improve descending.

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 would give it a try.

To make this project work I dug up some NOS Shimano Dura-Ace 7900 hubs that were begging to see the road. For my first try I turned to the pioneers of tubeless, 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 is 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. One important thing I noticed is spoke tension dropped with tires mounted. While this is normal the tight tubeless tires caused tension loss in excess of 30 percent! I had to correct this to ensure wheel durability.

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