Bicycle Mechanics - Is this something to worry about?

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View Full Version : Is this something to worry about?


yummygooey
12-01-11, 04:21 PM
I just got a set of new Mavic Aksiums in the mail and noticed the rim joint is not even on one side of the front wheel (the other side is even) like so:

http://farm8.staticflickr.com/7148/6438734423_3e1306917d_z.jpg

Is this a source of concern or am I just semi-freaking out for nothing?


gyozadude
12-01-11, 04:49 PM
I wouldn't be concerned so much about structural strength. But if it's causing a "tick" whenever you brake, that's unacceptable and can affect braking - equally serious. But it's hard to tell if that will happen without a picture that shows vertical offsets and the simplest way to test might be to install and ride. But from the picture alone, it doesn't look very acceptable.

HillRider
12-01-11, 07:10 PM
Tha is odd since almost all Mavic rims have welded joints and are then machined to give a perfectly smooth braking surface. I really think that one escaped their QC inspectors.


JohnDThompson
12-01-11, 07:20 PM
It's not a structural concern -- it's the spokes that hold the wheel together, not the rim joint (we used to take the pins out of pinned rims when building weight-weenie wheels back in the day). If the seam isn't even, you'll get a little "tick" from the brakes whenever the pads cross the uneven area, but it really takes a substantial misalignment to really affect braking.

That said, for what you pay for a set of rims these days it's worth trying to get it replaced.

well biked
12-01-11, 07:32 PM
Tha is odd since almost all Mavic rims have welded joints and are then machined to give a perfectly smooth braking surface. I really think that one escaped their QC inspectors.

I agree, the QC wasn't good on this one. But it's not a welded rim, the Aksium Race wheels use rims with a sleeve joint.

I've been a fan of Mavic products for a long time, but I'm disappointed in the quality lately in the wheels they're producing at the pricepoints we can sell the most, which includes the Aksium Race. I still like their better rims such as the CXP33, Open Pro, and their better mtb rims (all of which use their SUP welding process at the rim joint, btw), but their current entry to mid level road wheelsets leave a lot to be desired in the QC department IMO.

mrrabbit
12-01-11, 08:09 PM
1. Aksiums are not their top-line product, so there will be quality and finish variation.

2. It should not be a problem so long as none of the directly adjacent spokes are severely under-tensioned.

If within the next 9-12 months, one of the two spokes directly adjacent to the joint breaks - and a replacement is put it and the mechanic reports not being able to get it up to the same tension as the other spokes on that side as well...

...call Mavic because then you have an actual defective product.

In other words, you would have confirmation that the joint was misaligned enough BEFORE finish work was applied that resulted in a permanent soft "spot" for one of the two adjacent holes.

=8-)

yummygooey
12-01-11, 08:12 PM
Should I bother trying to get them returned?

It seems like the general consensus from reading online is that this is a pretty typical "feature" and really shouldn't affect the braking... and if I do get the ticking I can just take some fine sand paper and smooth out the joint. It seems to me that this is pretty doable because the rim on either side of the joint are at the same level, but there is a bit of raised surface right on the joint line.

Homebrew01
12-01-11, 08:19 PM
Can you feel a ridge on the silver machined part ? If so, your brake pads will likely grab that spot and be annoying, and wear the pads down faster. I would probably take it for a test ride. If you can feel it, get a new set (with free shipping). If you can't feel it, then it's up to you if you care enough to return them.

reddog3
12-02-11, 07:31 AM
Install that wheel so the low side of the joint is trailing as it passes the brake pads. That'll keep pad wear to a minimum.

HillRider
12-02-11, 07:48 AM
I agree, the QC wasn't good on this one. But it's not a welded rim, the Aksium Race wheels use rims with a sleeve joint.
Interesting as I thought all Mavic rims were welded. The machined brake surface shown in the photo made me think it was.


Install that wheel so the low side of the joint is trailing as it passes the brake pads. That'll keep pad wear to a minimum.
That will work if it's a front wheel but a rear wheel gives you no options.

well biked
12-02-11, 08:47 AM
Interesting as I thought all Mavic rims were welded. The machined brake surface shown in the photo made me think it was.


That will work if it's a front wheel but a rear wheel gives you no options.

No, machining and welding are two different processes, and two different Mavic "features." Mavic calls the machined feature "UB Control" and the welded joint feature "SUP." They have several rims that feature UB Control (machined brake surface) but not SUP (welded joint). CXP 22, Open Sport to name a couple. Also, the rims that are used in the Aksium Race wheelset to name another. Being able to clearly see the joint on the rim's braking surface, as in the OP's pic, is another clue that it's not a welded rim. And it is a front wheel, so reddog3's suggestion is a good one. :)

Homebrew01
12-02-11, 12:18 PM
Install that wheel so the low side of the joint is trailing as it passes the brake pads. That'll keep pad wear to a minimum.

But then the other side will be high and hit the other pad, so you will still get a bump when braking.