Mavic rims - thin sidewalls (again?)

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bgnukem
Posts: 119
Joined: 20 Dec 2010, 5:21pm

Mavic rims - thin sidewalls (again?)

Postby bgnukem » 14 Jan 2019, 12:46pm

Was recently given a free 26" wheel built with a new Mavic XM317 rim.

Measuring the rim sidewall with my Iwanson dental caliper (essential item for around a fiver IMO) revealed a braking surface thickness down to 0.9mm in places and always less than 1.2mm thick. Added to this there is no visible wear indicator (groove or holes) in the braking surface to warn of impending failure.

This is the second instance of thin-walled Mavic rims I've seen recently, and indeed I wore out a rear rim in around 2000 miles on my commuting bike last year. Even the cheapo Ryde Chrina rims from Spa Cycles are around 1.5mm thick initially.

Needless to say I won't be using them again. Maybe a heads up for people to check their sidewalls before it's too late!

Cheers,

Ben

Brucey
Posts: 32690
Joined: 4 Jan 2012, 6:25pm

Re: Mavic rims - thin sidewalls (again?)

Postby Brucey » 14 Jan 2019, 1:38pm

Mavic have made lots of rims with lots of names but isn't XM317 a disc-brake rim not a rim brake rim?

BTW for several years Mavic's wear indicator was a notch machined into the inside face of the thinnest part of the rim. You wouldn't know it was there (which of course it is only on rim brake rims....) unless it breaks through or you know to look.

FWIW Mavic do make rims with thin braking surfaces (in which they are hardly alone these days) but they are also quite lightweight. Chrinas are OK in many ways but they are easily the heaviest 'narrow' rim you can buy; about 600g IIRC

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

thirdcrank
Posts: 28000
Joined: 9 Jan 2007, 2:44pm

Re: Mavic rims - thin sidewalls (again?)

Postby thirdcrank » 14 Jan 2019, 1:38pm

The Mavic XM317 Disc Rim is designed for mountain bikes and is an affordable option for commuting and off road adventures. Made from 6106 aluminium alloy, the 26" rim weighs just 445 grams and is designed to be used with disc brakes. (My emphasis.)


https://www.sigmasports.com/item/Mavic/ ... sc-Rim/II4

bgnukem
Posts: 119
Joined: 20 Dec 2010, 5:21pm

Re: Mavic rims - thin sidewalls (again?)

Postby bgnukem » 14 Jan 2019, 5:25pm

Oh well, maybe my 'free' wheels isn't much use then, since I need it for a rim-braked bike!

Funny how the braking surfaces are silver though (but rim hasn't been braked on) and the rest of the rim is black anodised?!

However, I've noted similarly thin sidewalls in another set of Mavic rims for rim brakes which I had built up a year or so ago. Can't remember the exact model of rim but they were similar to the XM317.

I believe the 700c version of the Chrina is supposed to be 515g in weight. They seem to have dropped in quality since the Ryde rebranding and my wheel builder wasn't impressed with the last one I gave him. I see Spay Cycles are selling Exal rims instead but the LX17 is even heavier than the Chrina at 575g.

Is there any sensible, cheaper alternative to the H Plus Son Archetype for a 17mm internal width rim brake rim?

hamster
Posts: 3012
Joined: 2 Feb 2007, 12:42pm

Re: Mavic rims - thin sidewalls (again?)

Postby hamster » 14 Jan 2019, 5:33pm

Brucey wrote:Mavic have made lots of rims with lots of names but isn't XM317 a disc-brake rim not a rim brake rim?


With Gallic logic they made an XM317 (rim brake) and 317 disc. The sections are completely different. If it has a machined wall it's the rim version, the disc one is a v-section.
See below:
https://www.chainreactioncycles.com/mav ... 27034?mx=a

While they are a bit thin they have lasted 10,000 miles on my MTB singlespeed, which gets all-year use. The rear is now getting dished on the braking surface and is probably approaching the end of its life.

Brucey
Posts: 32690
Joined: 4 Jan 2012, 6:25pm

Re: Mavic rims - thin sidewalls (again?)

Postby Brucey » 14 Jan 2019, 5:43pm

this one

Image

appears to have a machined (and then anodised?) sidewall and (unlike many other disc rims) looks like a rim brake rim apart from the word 'disc' on the sticker. There are 317 rims which are more obviously meant for rim brakes;

Image

and 317 rims that aren't.

Anyway it probably isn't quite clear which rim the OP refers to.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

hamster
Posts: 3012
Joined: 2 Feb 2007, 12:42pm

Re: Mavic rims - thin sidewalls (again?)

Postby hamster » 14 Jan 2019, 6:09pm

The V ones are all obviously machined as they have a bright surface with visible tool marks contrasting with the anodised finished of the body.

Brucey
Posts: 32690
Joined: 4 Jan 2012, 6:25pm

Re: Mavic rims - thin sidewalls (again?)

Postby Brucey » 14 Jan 2019, 6:47pm

-not once someone has used a rim brake on them....?.... :wink:

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

bgnukem
Posts: 119
Joined: 20 Dec 2010, 5:21pm

Re: Mavic rims - thin sidewalls (again?)

Postby bgnukem » 15 Jan 2019, 12:40pm

My sticker doesn't have 'disc' on it so I guess is intended for rim brakes.

So it's still cr@p then!

Brucey
Posts: 32690
Joined: 4 Jan 2012, 6:25pm

Re: Mavic rims - thin sidewalls (again?)

Postby Brucey » 15 Jan 2019, 1:17pm

was this rim new then? BTW did you look for an 'internal notch' type wear indicator?

FWIW most new Mavic rims I have measured (accurately, using Vernier calipers) in recent years have been ~1.35mm wall thickness. Not as much as I'd like but pretty average these days.

However a new-style Open Pro (UST) rim I measured at 1.0mm when it was brand new.... :shock: . I predicted that it would wear out very quickly but actually it didn't get the chance; despite the reinforcement at the drillings, it cracked.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

bgnukem
Posts: 119
Joined: 20 Dec 2010, 5:21pm

Re: Mavic rims - thin sidewalls (again?)

Postby bgnukem » 15 Jan 2019, 7:14pm

No, I didn't. Will have a look later this week.

This is the third new rim-brake Mavic rim I've had which has measured 1mm or less from new, the other two being a similar design and maybe teh same model on a pair of wheels built for me by Rose Cycles in Germany.

So far one wore through in 2k miles.

rjb
Posts: 3101
Joined: 11 Jan 2007, 10:25am
Location: Somerset (originally 60/70's Plymouth)

Re: Mavic rims - thin sidewalls (again?)

Postby rjb » 17 Jan 2019, 12:19pm

This happened on our tandem ride today. :(
Fortunately on the way home with 1/2 mile to go.
Mavic 721 26" rim. Approx 15000 miles, rear wheel.

IMG_20190117_120641.jpg
IMG_20190117_120615.jpg
At the last count:- Focus Variado, Peugeot 531 pro, Dawes Discovery Tandem, 2 Dawes Kingpins, Raleigh 20, Falcon K2 MTB dropped bar tourer, On One Pompino, Longstaff trike conversion on a Falcon corsa. :D

bgnukem
Posts: 119
Joined: 20 Dec 2010, 5:21pm

Re: Mavic rims - thin sidewalls (again?)

Postby bgnukem » 18 Jan 2019, 11:29am

Ouch! Pretty graphic demonstration of what happens!

15k is pretty good though, and especially given the greater braking demands of a tandem. No wear indicators on that rim I assume?