On Brakes and Bosses

[John Rinker]

Hey All,

I've got an older set of XT V-brakes that I'd like to try on my Hunq. The issue I'm running into is that the bottom of the bosses seem too wide for the diameter of the V-brake. As such, the spring pin won't engage in one of the 3 convenient holes (you, know, the spring-pin engagement holes). 

Anyone have any ideas or experience with this.

Cheers,

John

[JohnS]

Hello John,

I recently had a frame/fork powder coated so it had the same problem, the powder coat paint partially filled in the holes. So I used a drill bit to ream the holes out. I don't recall which size I used, but I can check if needed.

Good luck,

JohnS

[John Rinker]

Thanks John! Actually, it's not the holes that are the problem, but the base of the brake bosses, just before the holes, is where the boss is too wide to allow the brakes to slide down far enough so that the pin goes into a hole. 

Cheers,

John

[Garth]

John, In the absence of the background of the bike and what brakes it had, the obvious question is do other brakes fit ? 

Are the bosses "too wide" for any brake, or the inner diameter of the brake "too narrrow" for any bosses ? 

As I recall, I needed to lightly sand one of canti bosses on my Bombadil as I wasn't able to get any cantilever on all the way. It didn't take a lot, just a light bit of sanding with fine grit emery cloth. 

[JohnS]

OK John, I understand the problem now. I agree with Garth, sanding the brake boss would be needed. Be sure to remove enough so that you can remove the brake in the future. One time I used the screw to push the brake onto the boss. When I went to remove it some years later, I had to use a gear puller. It won't budge otherwise.

JohnS

[John Rinker]

Garth and John,

Thanks very much for your responses. My Hunq originally had the Tektro cantis that fit fine. It now sports Paul's Neo retros, but as the spring system on these is integral to the brakes themselves they don't need to slide down all the way to the 'skirt' of the boss where the holes are. (Is there a name for this part of the boss?)

I'll try sanding with emory cloth and see how this goes. Thanks.

Cheers,

JOhn