Stans ztr alpha 340 rim bulge

Discuss light weight issues concerning road bikes & parts.
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Tenlegs
Posts: 273
Joined: Wed Jul 16, 2008 10:37 am

by Tenlegs

I've just had a front wheel built with this rim (updated version), on the first ride I felt excessive pulsing of the brake, on inspection there is a noticeable bulge on one side of the brake track, it starts exactly at the welded joint and is 70mm long, measuring the width of the rim at this point with a micrometer shows it's 21.6mm (+1.35mm) wide compared to 20.25 for the rest of the rim.
This bulge appears only when the tire is on and fully inflated (95psi) and it disappears when deflated!
Image

by Weenie


eric
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by eric

Scary! 1.35mm is a lot. I've found that anything over .25-.30mm causes noticable pulsing. Sometimes even less.

sigismond0
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Joined: Tue Feb 05, 2013 8:29 pm

by sigismond0

Warranty those rims ASAP.

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prendrefeu
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by prendrefeu

Image
Exp001 || Other projects in the works.

tinozee
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by tinozee

Is this an older 340? I have thre pairs of these and on the first pair it seems the rims were really thin. I had some malformation around the nipple holes over time after retensioning a few times. They just seem to be pretty thin and fragile rims. I think that's why they came out with the 400 honestly.

Weird to see a bulge at the brake track thopugh...

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bikerjulio
Posts: 1901
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Location: Welland, Ontario

by bikerjulio

That's not rideable.

My experience with the early version of these rims was related to poor joint quality. Looks like you have a different quality problem.

Considering the price they were pretty disappointing.
There's sometimes a buggy.
How many drivers does a buggy have?

One.

So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.

http://www.youtube.com/watch?v=GekiIMh4ZkM

uraqt
Posts: 810
Joined: Mon Apr 03, 2006 8:53 am

by uraqt

bikerjulio, I agree.

I had two that pulsed 1st gen, will not use then again.

C

kulivontot
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by kulivontot

I crashed on monday going down a descent because a rock bent the bead of my rim inwards knocked the entire wheel out of true. It was clear that there was bulging at other spots on the rim where the uneven spoke tension had pulled the rim material out of the way. I would not ride that rim. V1 340 rims btw.

eric
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by eric

Aiee! I'll ride chinese carbon down a 55 mph descent with no concern but I wouldn't use that rim.

Part of me wants to tell you to pump the tire up to 140 psi to see what happens. But only if you have a safety cage to put it in. The rest of me says to let the air out right now, keeping your face as far away from the rim as possible.

Tenlegs
Posts: 273
Joined: Wed Jul 16, 2008 10:37 am

by Tenlegs

This is the updated (heaver) version, pulled the tire off and the rim has a crack in the corner of the bead seat
starting at the welded joint and running along it for a couple of inches or so, I can flex it open with a bit of finger pressure quite easily,
the joint is poorly finished inside and out and theres quite a noticeable step at the joint inside.
If I pumped it up to 140psi I think it would open up like a sardine can.
Image
sorry don't know whats up with the pics

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prendrefeu
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by prendrefeu

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Exp001 || Other projects in the works.

by Weenie


eflayer
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Location: SF Bay Area

by eflayer

I have a set of custom wheels built on older Stans 340 rims. Even though they are older version rims, the wheels have very low miles. On the rear wheel, while I was cleaing the rim yesterday, I noticed hairline cracks around at least 4 nipple holes. I have read many postings on the net about this cracking issue. Has Stans ever taken responsibility for what seems like a faulty product? If not, why not?

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