Sea Otter 2012: Mavic’s new 29er wheels.

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Last year, Mavic held a press conference about its latest 26in wheels. Despite being full of new technology and the latest racer feedback, nevertheless the meeting was prefaced with ‘Yes, we’re working on 29er wheels, but no, we don’t have any to show you yet’.

In truth, Mavic did have some 29er wheels nearly ready to go, but wasn’t ready to release it last summer. With another winter of testing, it’s now ready to release the details to the public. But only after letting us know that 29in wheels aren’t as easy to design as just making a 26in wheel bigger…

Ta daaa! 29ers all round.
Chipps claims it was all work...

According to Mavic’s engineers, there’s a cubic relationship between an increase in diameter and a loss in stiffness, so a 29in wheel is 39% less stiff for the same materials. The same wheel will also weigh 10% more. A 29in will also have around 40% more inertia with the same materials due to the extra mass of the rim and spokes. Basically, what they want to get over is ‘Hey, it’s not as easy as it looks OK?’

 

And then we machine it a bit more...

This particularly seems to affect lightweight wheels, where even on the 26in version, everything is as pared down as possible. Mavic’s SLR wheel is already a good example of making things as light as you can (without going all carbon), with the spoke bed and sidewalls machined out, aluminium spokes and a light hub.

White goes with everything, right?
The un-machined bit is to balance the weight of the valve at the other side of the rim.

 

In order to get the lightest wheel they could, the engineer first tried just scaling everything up. This led to spokes breaking and a weaker wheel. They added more spokes, which stiffened the wheels and they tried fewer, stronger spokes. In both cases, the rim started cracking.

Mavic then tried making the rim a tiny bit (0.5mm) thicker for the same spoke bed width, this seemed to cure the rim issue, but then spokes started breaking on the rear wheel drive side. The answer to that was to shot-peen the drive side spokes for increased surface strength. Finally, it seemed that the issue was solved. So here is the new Mavic SLR 29er. Phew!

 

SLR rear wheel - which will do rear QR, plus 142mm and 12x135 too.

 

 

And the front...

The front wheel will take 9mm QR or 15mm axles. There will be a Lefty version too. Using Mavic’s FORE technology, the spoke bed is undrilled and will take UST (and other) tubeless tyres. Weight for a pair of Mavic Crossmax SLR 29ers will be 1620g

 

Interestingly Mavic’s rufty tufty 26in wheel, the Crossmax ST wasn’t as hard to enlarge. In fact, Mavic did just increase the diameter, test the wheel and proclaim it to be completely suitable for all your 29in all-mountain needs. Does this suggest that the regular ST is a little overbuilt perhaps?

Weight for the29er Crossmax ST is 1710g. It’s still FORE drilled and UST tubeless, and still uses Mavic’s ITS-4 (super clicky, quick pickup) hub. The hubs really will take all the standards, with 9/15 and 20mm covered on the front and 9QR/12×135/142 at the back. Weight is 1710g.

 

Crossmax ST - beefy enough already.

And finally the CrossRide, Mavic’s entry level wheel also gets a big wheel cousin. The Crossride isn’t tubeless and doesn’t have the super quick pickup hub, but it does still offer 9/15mm at the front and 9/12×135 and 142 (options) at the back. There’s also a stronger rear axle and the new 29er specific rim. Weight will be 2020g

 

'I said crank it!'

 

Crossride rear

 

And front 15mm. Neato low profile hubs with straight pull spokes.
'Watch out for poison oak. You can spot it easily. It's green and has leaves...'

Mavic’s new 29ers will start appearing from July. Probably with the SLR wheels first – just in time for the Olympics eh?

 

Chipps

Singletrack Editor

Chipps wasn’t around for the dawn of mountain biking in the UK, but he likes to claim that he arrived in time for second breakfast (about the time he shows up for work, then…) starting in the bike trade in 1990 and becoming a full time mountain bike journalist at the start of 1994. Over the subsequent quarter century, he has seen mountain bike culture flourish and diversify and bike technology go from rigid steel frames to fully suspended carbon fibre (and sometimes back to rigid steel as well.)

His riding style is best described as ‘medium, wheels on the ground, trail riding’ though he’s been spotted doing everything from endurance downhill racing to 24 hour cross country racing. He favours mid-travel trail bikes and claims to be wheel-size, gear, brake and tyre agnostic. In fact, his garage spans most bicycle flavours, taking in steel hardtails, carbon trail bikes, even a mountain bike tandem, along with road, touring and gravel/cyclocross bikes.

While he’s happy to chat about bikes all day, his real interest is in the people and places that bikes can introduce you to and he talks as fondly about the trails he’s ridden and riders he’s met as the bikes that took him there.

Comments (5)

    That seems a lot of extra effort to save the 90g from SX to SLR. SX might have to go on my wishlist

    It’s the law of diminishing returns Stoner. Every gram gets harder and harder to save the more you save.

    Chipps- is it definitely SX and not ST?

    ST is correct camerone, thanks for spotting.

    They have gone on my wish list- do they feel plenty stiff?

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