Deore BRM510 V-brake mounting issue
08-30-07, 06:50 AM
#1
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Thread Starter
Deore BRM510 V-brake mounting issue
I picked up a set of these brakes for a steal at Nashbar ($8.50 including cartridge brake pads) to replace the front brake on my dad's 2005 Trek 7300FX. When I went to install the V-brake arms, I found that they did not sit as far down on the brake bosses as the originals. This left a big gap at the top between the bosses and the surface that the mounting screw bottoms out on. There's also a big gap left between the fork and the pivot for the V-brake arm. The issue seems to be that the counterbore in the pivot is not deep enough to fit properly on the brake bosses which have an enlarged base (the length of which is longer than the counterbore is deep). I took some pictures which hopefully help explain my issue a little better.
Is this really an issue? I can mount the arms and they seem to work OK but the fit seems hokey compared to the originals. The pictures are taken using an old suspension fork I have at home and the arms fit the same on that fork as they did on my dad's rigid fork (the fork isn't the problem).
Has anyone else experienced this? If so, what did you do about it?
Thanks for any assistance.
Brake boss not reaching the top of V-brake pivot:
Gap between pivot and fork:
Shallow counterbore:
Longer enlarged base on brake boss:
Is this really an issue? I can mount the arms and they seem to work OK but the fit seems hokey compared to the originals. The pictures are taken using an old suspension fork I have at home and the arms fit the same on that fork as they did on my dad's rigid fork (the fork isn't the problem).
Has anyone else experienced this? If so, what did you do about it?
Thanks for any assistance.
Brake boss not reaching the top of V-brake pivot:
Gap between pivot and fork:
Shallow counterbore:
Longer enlarged base on brake boss:
08-30-07, 10:03 AM
#2
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I haven't personally run into this particular problem but ...
I would have concerns about your spring tension pin not being seated deeply enough. It may pop out and then you won't have any brake tension which means your brakes will drag on the rims. Perhaps you can dremel that ridge down a bit.
But it looks like your brake boss still might not be tall enough; in which case a spacer will be needed. Where you will get that spacer? I'm not sure.
I would have concerns about your spring tension pin not being seated deeply enough. It may pop out and then you won't have any brake tension which means your brakes will drag on the rims. Perhaps you can dremel that ridge down a bit.
But it looks like your brake boss still might not be tall enough; in which case a spacer will be needed. Where you will get that spacer? I'm not sure.
08-30-07, 12:56 PM
#3
Senior Member
Thread Starter
If I tighten the brake arm down as is, it still pivots freely. The brake boss should not come in contact with the screw, otherwise the arm would be clamped tight against the fork. The pin doesn't look like there's any chance of it popping out as it's engaged by a few millimeters. I'm considering mounting them and going into a parking lot for some severe duty brake testing to make sure they work ok before using them out on the road. The more I think about it, the less I'm concerned about the appearance of the fit over the functionality.
I'll think about it a little while longer. If can't remember if the brake bosses are removeable on that fork but if they are, I might just have the base machined down so that the arms fit a little nicer.
Thanks for your input.
I'll think about it a little while longer. If can't remember if the brake bosses are removeable on that fork but if they are, I might just have the base machined down so that the arms fit a little nicer.
Thanks for your input.
09-06-07, 04:47 AM
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Hi joejack951, I have the same fitting problem but the brake is working OK. Pic: https://home.iprimus.com.au/reueladhikari/IMG_0700.JPG
09-06-07, 05:15 AM
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Change the studs to ones with a shorter shoulder. I'm seeing flats, so they should just screw right out.
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09-06-07, 05:51 AM
#6
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Hi joejack951, I have the same fitting problem but the brake is working OK. Pic: https://home.iprimus.com.au/reueladhikari/IMG_0700.JPG
09-06-07, 05:53 AM
#7
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Thread Starter
I haven't even searched yet but is it easy to get studs with a shorter shoulder? I've never seen them but then again, I've never really looked. I could always get them machined down at work too. I need to find out if the studs on my dad's bike are removeable though. The fork I took the pictures on is not the fork that will have the brakes mounted.
