Rims

Being able to hold a new unlaced rim in your hand is a rare thing. It’s surprising how incredibly stiff they are! Even the usual punishment meted out in the Royal Mail Parcels van doesn’t cause them to go out of shape. I’m after two matching pairs, both black and rim brake compatible, one tough but not excessively heavy, the other cheap but not low quality.

With the odd exception, most notably the fantastic but very spendy DT Swiss EX 5.1d rims on my hardcore XC bike, almost every wheel I’ve ever owned has had a Mavic rim and I’ve only once had a bad experience. This was with a 32h X517 rim that began to crack around the eyelets. In his book, Gerd Schraner speculates that this is due to using high pressure 26” road tyres on a rim designed for use with the lower pressure of MTB tyres. I think this is rubbish, and for two reasons. Firstly, I never used high pressure tyres on that wheel (a rear). Secondly, if you consider the forces at work when a tyre is inflated on the rim, it appears (and I could be wrong here) that the eyeleted surface of the rim is under compression, not tension. My hypothesis is that the cracking was almost certainly due to fatigue resulting from insufficient spoke tension, although the old X517 has a bit of a reputation for this sort of thing so perhaps there’s also an element of fault with the product.

So Mavic’s range is my benchmark. Alternatives on offer are Sun, DT Swiss, Fir, Alex, Bontrager, Rigida, Ritchey and a few others I know nothing about either, so if I’m to go for any of these then it’ll need to be a pretty stonking deal. As I’ve said, for the utility wheels I want something equivalent to Mavic’s XM719 rim, which is not too heavy at 460g when compared with the lightweight XC717 at 420g, yet has a moderately wide profile and is good and strong. The obvious alternative is the rim brake equivalent of the DTs mentioned above, the EX 5.1, but they’re a new model and still very scarce… and very costly. For the budget wheelset I’m looking at the equivalent of Mavic’s XM317 (same as the old X221 and not to be confused with the old X317).