XTR WM-975 Wheels

[rockyrider]

Having had handmade lightweight wheels before (XTR 960 hubs and Mavic 517 rims with 32x 2.0/1.8/2.0mm spokes - 1590gms with Velox rim strips and no skewers) and found them to be a moderately high maintenance item with a need for regular truing and a tendency to be a bit flexy under my 200 pound body, I was a bit leary about buying a boutique set of weight weenie wheels for my new hardtail build but the XTR 975 wheels were just so dang sexy, and I was going to be running discs, so I went crazy sideways and dropped the big coin on the XTR wheels to get a feathery 1525gm set of wheels.

So far I have been very impressed by how stiff the wheels are, there's no trace of lateral flex when cornering hard, a big improvement over my Crossmax XL wheels, I've already got about 800-1000km on them in 2 months and they are dead true and no sign of tension issues. They compare favourably to the Easton Havocs I have on my all mountain bike in the lateral stiffness department and those have 28mm wide deep profile rims and weigh 1940 gms.

The XTR Scandium rims seem to be playing their part in making a 24 spoke wheel feel stiffer than my previous 32 spoke V-brake rim XTR wheelset. Don't know how much of that stiffness might be attributed to the straight pull hub/spoke interface, but it doesn't feel like the same compromise in stiffness for lightweight that my Crossmax XL seemed to have, either the V-brake or disc versions.

The hubs spin smooth, although the rear hub sounds a bit dry when it's skewer is clamped down in the frame. The freehub is typical XTR, no complaints so far.

The 970 series XTR skewers with the X in the tips really seems to be a bit of stretch from an industrial design point of view. Not a slick bit of design, not even as nice as the 960 series skewers.

UST tires mount up just as easy/hard as my Crossmax wheels, and the valve stems seem to seal nicely without a lot of fuss.

Did I mention the sexy red nipples.

[Spalls]

A fan of bing cherries, eh Rocky?

[rockyrider]

The freehub is typical XTR, no complaints so far. OK, slightly atypical, the freehub developed a tendency to make popping/crunchy noises on occasion, sounding much like a bad crosschain high load mishift, when no shifting was happening. Usually right after a bumpy bit of trail. Return to LBS, they phone Shimano, new freehub is sent to LBS, wheel is fixed under warranty and everything is good again. :D

[rockyrider]

Disturbingly, the brand new XTR freehub has exactly the same tendency to make popping/crunching noises and skip about 1/8 of a pedal crank rotation,which actually makes it worse than the original freehub, where it would make the popping crunching noise but only move about 1/16 of a pedal rotation.

It only happens after a brief bit of coasting or a small backpedal (the sort you do to avoid whacking the pedals on something) or when you coast over really rough terrain and then begin pedaling again. It doesn't happen under high loads like climbing (so far anyway). You can feel it if you manually move the cassette/freehub, you can feel it not quite engage if you just backpedal past a tooth on the ratchet and then move it forward again.

I'm not sure if this is indicative of a problem with the ratchet teeth being too short or the pawl springs being too weak, but it must be an unintended byproduct of trying to make things light and low drag. It feels like there's only one pawl involved, which in comparison to all the bazillion pawl instant engagement hubs seems a bit overconfident.

I had a pair of XTR 960 hubs on mavic rims that I ran on my hardtail for almost 3 years and never once had a hiccup with the freehub, it's too bad that the WH-M975 hub doesn't use the same XTR freehub as the 960 series.

We'll see how it develops, this isn't the kind of performance you want from a $1000+ wheelset.

[ironspoke]

We'll see how it develops, this isn't the kind of performance you want from a $1000+ wheelset.


Are these the most expensive hoops you have ever purchased? You make mention of a previous set you purchased that were also a bit on the high maintenance side.

These items hardly seem worth it if you weight more than 150lbs.


So this Rocky Mountain hardtail you just built up, what is the final weight of the bike and close to how much cash do you have invested in it? Just curious.

[rockyrider]

The XTR's are in the same price range as the Mavic SLR's, they are the most expensive factory wheels I've ever bought. In looking up reviews on the standard XTR 970 series hubs (without the rest of the wheel), they have the same freehub problem, so it appears that Shimano has jumped the shark with the new XTR freehub.

These wheels are stiffer than the Mavics by a large margin and they accelerate like mad, the advantage of those scandium rims.

The Vertex Team is 10kg/22 pounds and the actual cost is a state secret (or should I say estate secret) :D A bunch.

[ironspoke]

Fair enough....thanks for the info.

[rockyrider]

OK, I finally got my second warranty replacement freehub from Shimano (after a 2 month wait) and was able to get out and ride the bike today. No skipping, no crunching so far. That's a good sign.

These wheels sure do accelerate. I would love to find out how light the XTR scandium rims because the wheels just feel so much snappier and more responsive than Mavic 717 wheels or Crossmax SLR's.

[bomberbarnes]

I would love to find out how light the XTR scandium rims


go on, you know you want to... :eek:

btw; is it commonly possible to swap out the freehub for an "upgraded" one. That is; is the freehub / hub interface a standard one or are hubs generally different? I take most things apart with gusto, but have never stripped a freehub...

[rockyrider]

The freehubs used in the assembled wheel are identical to the freehub in their XTR 975 standard hubs, and apparently to the new XT hubs as well. They aren't compatible with earlier hubs as the new ones have a huge axle.

But they seem to have things sorted out, I bought a second set of the XTR wheels from this year's production run from Chain Reacyion Cycles and they have been crunch/pop free on a second bike.