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Brake Rub only when riding
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I have a new P3 and also a new set of Enve 6.7 tubs with PowerTap G3. I have never ridden carbon wheels before. If I lift the back wheel and spin the wheel seems perfectly true. When riding I am getting a constant sound of what I am pretty sure is brake rub. I took the wheel out and I can't see any marks from the tyre rubbing the frame.

If I grab the top of the wheel I can wiggle it a few mm - lateral flex. That is enough to touch one of the pads. I am assuming this is happening when I ride because my weight is causing the wheel to flex? I am a big rider, 6'5'' tall and 210lbs. It happens all the time, not just climbing or sprinting.

I just popped it on the turbo and tried opening the brake but I couldn't get it to make a sound either way. Assuming the turbo is taking most of the weight and the wheel flexes less. I need to ride it on the road with the brake open, can't do that this minute as its dark where I am.

Is this normal flex and is it a case of fiddling with the pad position as much as possible to get rid of it or just having to put up with it (robbing me of watts though)?
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Re: Brake Rub only when riding [iwaters] [ In reply to ]
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The bearings on the wheel seem loose which will cause lateral flex and brake rub.
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Re: Brake Rub only when riding [Tri Slow Poke] [ In reply to ]
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Ah OK. Needs to go back to Saris for new bearings I believe?

Think it will be OK to race in a couple of weeks and sending back at end of season?
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Re: Brake Rub only when riding [Tri Slow Poke] [ In reply to ]
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Tri Slow Poke wrote:
The bearings on the wheel seem loose which will cause lateral flex and brake rub.

I think this. Bearings loose or finished.
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Re: Brake Rub only when riding [GWcanrun] [ In reply to ]
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Thanks both. I just went anger looked again. Spinning the wheel there is a bit of a grinding sound. Originally I thought it might be the rd not being adjusted but it makes more sense that the bearings are fubar.

The rims are new but the pt is 2nd hand so it could have a fair few miles in it.
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Re: Brake Rub only when riding [iwaters] [ In reply to ]
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I define "flex" as movement due to "stretching" or bending parts. EG, the rim is weak, or the spokes are loose allowing the wheel to bend under load.

On the other hand, if the bearings are loose I would not call that "flex", but rather simply "movement". In this case, I would expect that the movement is "free" (takes no (or very little) force to induce), and that the wheel simply moves between two limits with a noticeable stop when each limit is reached.
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Re: Brake Rub only when riding [iwaters] [ In reply to ]
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How does the spoke tension feel?
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Re: Brake Rub only when riding [jimatbeyond] [ In reply to ]
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Squeezing pairs together they seem pretty tight all round
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Re: Brake Rub only when riding [iwaters] [ In reply to ]
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Have your shop check the dishing on the wheel.
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Re: Brake Rub only when riding [iwaters] [ In reply to ]
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If your PT is 2009 or earlier, try tightening the lock nut on the drive side of the hub. In theory you'd need a 17mm cone wrench but I do mine with a pair of needlenose pliers. It is the first one he shows in this video (with the 12 mm axle).

https://www.youtube.com/watch?v=ECVFaHPeWpY
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Re: Brake Rub only when riding [iwaters] [ In reply to ]
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Do you have a Saris dealer in the area? Bearing adjustments/replacements are pretty straightforward repairs. Sending it off somewhere may take weeks to return.
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Re: Brake Rub only when riding [Tri Slow Poke] [ In reply to ]
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Don't think so. In the UK it seems all repairs go to Paligap. They say 10 days for a repair.

They are only race wheels so after my last race I can send it off. Going to take it to the lbs who built the wheel and get them to check.

Hope it's not the spokes as the enve have internal nipples and the tub will have to come off.
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Re: Brake Rub only when riding [Rocky M] [ In reply to ]
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Rocky M wrote:
Have your shop check the dishing on the wheel.
Two comments:
1. Why? If the wheel was mis-dished that would show up even off the bike.
2. You don't need a shop to check dish. Just spin the wheel in the bike and see if it's true and centered between the brake pads. Then remove the wheel and insert if the other way round. If it's no longer centered, it's mis-dished.


http://www.jt10000.com/
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Re: Brake Rub only when riding [jimatbeyond] [ In reply to ]
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Spoke to LBS who built the wheel. They said its possible the spokes have settled after the build and need re-tightening. Its going in to them tomorrow.

Rather annoyingly the Enve have internal spoke nipples so the tub will have to come off. Hope that survives the removal process as it was brand new when the wheel was built :-(
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Re: Brake Rub only when riding [iwaters] [ In reply to ]
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I'm going to go counter to what everyone told you here, and say this is normal. You're a big dude. It's a spoked wheel. You can expect some kind of lateral movement, especially under heavy load. If it were me, I'd check the powertap pre-load bearings. Then, widen your rear brake until you can make it not rub. If it rubs when the brakes are pretty wide, then I'd have it looked at.
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Re: Brake Rub only when riding [nickwhite] [ In reply to ]
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nickwhite wrote:
I'm going to go counter to what everyone told you here, and say this is normal. You're a big dude. It's a spoked wheel. You can expect some kind of lateral movement, especially under heavy load. If it were me, I'd check the powertap pre-load bearings. Then, widen your rear brake until you can make it not rub. If it rubs when the brakes are pretty wide, then I'd have it looked at.

Can kinda confirm... I'm a big guy and I have yet to find a wheel that doesn't rub under heavy load (like sprint climbing). Especially with the new wider wheels. I resolved it simply by widening my rear brake.

Even my Zipp Disc rubbed if I was sprinting hard.
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Re: Brake Rub only when riding [nickwhite] [ In reply to ]
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If it is normal that would be ok, the rubbing is only slightly annoying. The bike shop will take a look for no charge. If they thinks its fine then I will fiddle with the gaps on the brakes
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Re: Brake Rub only when riding [iwaters] [ In reply to ]
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What rim and how many spokes?
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Re: Brake Rub only when riding [lyrrad] [ In reply to ]
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Enve 6.7 24 spokes
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Re: Brake Rub only when riding [nickwhite] [ In reply to ]
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Bike shop have had the wheel back, stripped the tub and re-tensioned the spokes. The checked the bearings and said they seemed fine. Guess you are right and its normal. The Enves are apparently very wide anyway so will need to fiddle with the caliper and reduce it as much as I can. I also realised at the weekend that I have put on a fair bit of weight when injured. They don't have an upper weight limit but hopefully once i lose that again it might stop them flexing as much.
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