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Discussion Starter · #1 ·
I recently bought a new old stock 2008 Yeti 575, size Small w/ full carbon rear and was a bit surprised to notice that there is a noticeable amount of lateral flex in the rear end. I see this happening when I hold the frame with one hand and use my other hand to push my rear wheel to the left or right; I can see the entire rear triangle flex in the direction I'm pushing. I do see the wheel flexing against the stays themselves, as evident by the rotor contacting the brake pads, however I also notice the stays moving left and right as well. I've tried this same test on several other bikes, including an Ibis Mojo, Kestrel Edge, and 2010 Specialized SJ, and none of them came close to the amount of lateral flex that I see on the 575.

On the bike, I believe this flex is translating into a bit of instability/rear wheel deflection when going over rough stuff or landing small jumps, so this becoming a concern for me. Other than this issue, I'm pretty happy with the rest of the bike. Are other 08+ 575 full carbon owners experiencing the same thing, or should I have my LBS check it out?

For the record, I'm relatively small (5' 8", 150lbs w/ gear) and don't do anything crazy (aggressive XC/trail riding only... no hucking or big jumps)
 

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gnuH
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A flex test on my 08 does not result in any movement in the stays. Giving a good push/pull on the wheel does not change the smallish gap between the seat stays and seat tube.

Are all your dogbone and pivot bolts tight? Also check your rear skewer tension.

I'm also 150lbs and do not notice any flex whilst riding.
 

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Discussion Starter · #3 ·
I did do a quick check of the dogbone and pivot bolt (non drive side at least) and all seems to be tight. The rear skewer (DT Swiss RWS) is about as tight as I can make it, though I'm not sure how tight it is relatively to a regular QR skewer.
 

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There is some flex in the design of the rear triangle, but it shouldn't be as much as you describe. Also inherent in your test is the flex of the rear wheel/tyre. Check if it isn't this that is causing a lot of the movement you are seeing.

Many riders have gone the option of thru axle skewers and have found significant improvement for a paltry weight gain. Obviously you need to have suitable hubs for this 'upgrade'
 

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www.yetifan.com
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Depends how much force you are trying to bend it all with.

If you've the arms of a gorilla and are intent on breaking something like you wrists of your fingers, then yes I am sure it does all move around quite a bit.

My old 08 & 09 575's did have a little movement, but then I used to ride it rather than spend hours in the garage trying to bend it all out of shape.

There will alwyas be a bit of deflection in anything depending how much force you used.

I would check all bolts are tight to the Yeti torques, and that your rear skewer is nice and tight (and steel if poss) and also that your wheel is built nice and tight.

If your pushing it over hard enough for the brake pads to hit the rotor, then either something is wrong, or your 'industry strength/flex/brute test' is not actually a good measure of the flex of the rear of a bike frame.

I look at it this way, its a 6lb, 5.75" travel all day XC bike frame, good enough to ride all day, if it was 8lb and flexed I'd be worried, if it was 3" and flexed I'd be worried.

I found the worst item for flexing on mine(and the best upgrade ever) was going from a qr fork to a 15mm FOX QR . That made the whole bike go where I wanted.

Also, having gone from Easton Alu bars to carbon, I was suprised how much they flex.

Andrew
 

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Brit on a trip
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I am just in the process of moving everything over to a new frame.

I can move the rear wheel about a bit, but only by applying quite a lot of force and it is it as severe as you describe. Certainly stiffer than the old one.

I still have a fat 2.4 Advantage mounted on the rear, which looks like it will be a bit too tight for the carbon swingarm - nevertheless I cannot get it near to touching the stays.

That has been buzzing the stays on the old bike a little, which wouldn't be tolerated as well on the carbon rear end :nono:
 
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