New wheels = brakes grabbing

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New wheels = brakes grabbing

Postby Wakatuki » Thu Jan 23, 2014 12:30 pm

Just put the new wheels on the Foil. 3000k's and Shimano 105.

I find the braking nowhere near as smooth or predictable as they were before, it seems there is a grab/release/grab sensation when applying the brakes.
The rear is controllable but the front is so violent that you would think the front stem was loose the way it bucks me about, in fact it's got to the point where I can no longer point at things or indicate when in a bunch while covering the front brake. I would even go so far as to say dangerous.

Should I replace the pads and bed a new set in?
Remove the pads and sand in the direction of travel?
Have a cup of cement while I tame them?
Or?.........................

Thanks
Oh and the wheels, while perfectly true have relatively loose spokes, should they not go ping when you pretend to play the harp on them?
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by BNA » Thu Jan 23, 2014 3:35 pm

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Re: New wheels = brakes grabbing

Postby biker jk » Thu Jan 23, 2014 3:35 pm

What wheels are they? Some rims are pinned so there can be a slightly raised section at the join. This can produce vibration until you do enough kilometres to smooth out the join. If there's no raised section at the join, then you would need to look at brake pad alignment, loose skewer, rim cracking/gouged.
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Re: New wheels = brakes grabbing

Postby Wakatuki » Thu Jan 23, 2014 3:42 pm

Hi Biker JK.

They are American Classic Hurricanes http://goo.gl/rQUEUH when I get home I will have a good feel of the surface.
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Re: New wheels = brakes grabbing

Postby biker jk » Thu Jan 23, 2014 3:53 pm

Looks like the Hurricane rim is based on the Argent and is indeed pinned. Note comment about brake pulsing.

"Part of that fantastically low weight is due to the Argent's unusually thin aluminum extrusion. As a result, Shook prefers an older-style pinned rim joint over a welded one, saying the latter introduces heat-related shape changes that then have to be corrected afterwards.

The Argents' sidewalls thus aren't machined, either, but braking performance was still excellent in both wet and dry conditions. We did, however, notice some brake pulsing on the front rim due to a slightly imperfect seam. However, just like in the old days, it eventually went away as things wore down a bit. While we'd prefer this issue didn't exist at all, it's at least a temporary one (the rear one was fine)."


http://www.bikeradar.com/road/gear/category/components/wheel-sets/product/review-american-classic-argent-road-tubeless-wheelset-13-47254/
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Re: New wheels = brakes grabbing

Postby Wakatuki » Thu Jan 23, 2014 4:36 pm

Image
Ok, spoke to the shop he has asked me to toe the brakes. Will inspect before toeing in....
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Re: New wheels = brakes grabbing

Postby biker jk » Thu Jan 23, 2014 5:26 pm

Wakatuki wrote:Image
Ok, spoke to the shop he has asked me to toe the brakes. Will inspect before toeing in....


Interesting. Usually when the brakes aren't toed in you will get a high pitched squealing on hard braking.
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Re: New wheels = brakes grabbing

Postby Wakatuki » Thu Jan 23, 2014 5:47 pm

That has been my experience of non-toed brakes too, like the Big W specials.
I have no noise, just a bucking bronco type sensation, I have moved to rear wheel braking at the moment, not the desired effect in a bunch.
I will give it another 200k's and then return them as not suitable for purpose if it continues,167k's so far.
Bloody great wheels when i'm not trying to stop.
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Re: New wheels = brakes grabbing

Postby Duck! » Thu Jan 23, 2014 8:54 pm

biker jk wrote:
Wakatuki wrote:Image
Ok, spoke to the shop he has asked me to toe the brakes. Will inspect before toeing in....


Interesting. Usually when the brakes aren't toed in you will get a high pitched squealing on hard braking.

Depends on rim finish and/or pad compound. Shudder is also a common symptom of poorly toed brakes. Aslo check headset tension. While it isn't neceassarily the sole cause of the problem, a loose headset will certainly exacerbate it.
I had a thought, but it got run over as it crossed my mind.
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Re: New wheels = brakes grabbing

Postby Wakatuki » Wed Jan 29, 2014 4:02 pm

Ok full circle..............
I basically did nothing and all is fixed.

To the touch there was a small bump on one side probably the pin as mentioned earlier. This has now gone or worn a groove in the brake block!
Either way braking is now smooth and predictable. :)
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