Issue with forks / front pads and Evans response
Issue with forks / front pads and Evans response
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Discussion

anonymous-user

Original Poster:

83 months

Sunday 22nd May 2011
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[redacted]

Mars

10,089 posts

243 months

Sunday 22nd May 2011
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Can you recreate the issue without having to put the front brake on? My disc brake pads move in the caliper very slightly, and even though I've got a solid front fork, when I apply the front brake and rock the bike back and forth, I get that knocking as the pads move a little.

If you can categorically rule out the brakes, perhaps soften the fork preload to the point where you can make it knock without applying the brakes, then at least you can counter any assertion that it's brake-related and apply for a reassessment.

I admit that until my bikes' tolerances are such that they work without the slightest creak, knock or ping, then I'm not satisfied. It most often means my learning how they work and sorting them out myself though because shops only have so much patience, understanding, interest, etc...

shalmaneser

6,423 posts

224 months

Sunday 22nd May 2011
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Brake pads do move in the calipers - shimano ones are notorious for it, but Avids may do the same.

If I were you I would confirm that this is the case - a simple visual inspection should confirm this - and if it is put the issue aside; its not a big deal.

The other obvious areas are the headset and the front wheel. check these areas.

Beyond Rational

3,544 posts

244 months

Sunday 22nd May 2011
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CanadianScot

1,916 posts

195 months

Sunday 22nd May 2011
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The rotor itself is tight isn't it? I mean I imagine it would be being a new bike, but I've had a loose rotor before.

I have a Juicy 3 on the rear of my street/dj bike and the pads move ever so slightly. No knocking though.

Rouleur

7,415 posts

218 months

Sunday 22nd May 2011
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Hold the front wheel 90° to a kerb and rock the bars. If you still get a knocking sound then it will be the headset or forks that are the problem as obviously the brake isn't being used.

Rouleur

7,415 posts

218 months

Sunday 22nd May 2011
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No, facing the kerb and rocking back and forth a little. I see you've said the sound's coming from the bottom of the sliders while I was posting but it's worth doing my little test just to rule out other possibilities.

shalmaneser

6,423 posts

224 months

Sunday 22nd May 2011
quotequote all
Rouleur said:
No, facing the kerb and rocking back and forth a little. I see you've said the sound's coming from the bottom of the sliders while I was posting but it's worth doing my little test just to rule out other possibilities.
This technique always seems overcomplicated to me.

Personally I put my hand around the upper headset bearing and rock the bike on the brake; you'll be able to feel if the headset is loose.

The same can be done around the fork stanchions with the brake on, although I would be incredibly surprised if these are loose.

the wheel can be checked for play by lifting up the front of the bike and checking for play by wobbling the wheel by grabbing the rim/tyre and shaking in every direction to feel for movement.

Also, make sure your QR is done up tight!

snotrag

15,627 posts

240 months

Monday 23rd May 2011
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Sounds like the brakes to me to be honest. The pads can move across the pistons slightly. It also creates a funny effect/feel through the wheel. Bear in mind your running a QR by the sounds of it which will not be the stiffest anyway.

To me, honestly, it sounds like the guys in the shop are correct.

frontbum

6,054 posts

188 months

Monday 23rd May 2011
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Sounds like they're right.

Basically there needs to be a tiny bit of movement to allow the pads to move freely when braking and to be removed when worn out. When this is multiplied up by the size of the wheel it seems much worse.

Unfortunately Juicys seem to have a fair amount of play compared to other brakes so it's more apparent. The good news is that when in use, it doesn't (shouldn't at least) cause any issues, as the pads will be pressed agains the edge of the calliper.

edit, just seen this-
OP said:
If I am travelling at around 20mph and quickly flip the front wheel up and jam the front brake, the wheel stops instantly but can be seen to shake from side to side in a split second from the force. I presume this is normal but I have always found that this is the case with this bike.
That could either be normal flex from the QR (make sure it's done up tightly), worn bearings, or cones which have gone out of adjustment. If you grab the tyre, and wobble it side to side is there any movement? Can you swap wheels with a mate to test?

Edited by frontbum on Monday 23 May 09:17