LoriRose

I was tuning up my bike and cleaning/adjusting the front brakes (cantis) and noticed that the boss is crooked. I compared to the other side, and while it too is not perfectly perpendicular to the fork, the one on the right is much more crooked. Is this normal? If not, can it be fixed?

ChinookTx

Yeah, that looks bent! Probably not the end of the world as your pads can be adjusted to compensate, but maybe not optimal for braking force.

Trevtassie

Unfortunately it doesn't look like you have replaceable brake bosses as there are no spanner flats. So you've got 3 options as I see it.
1: Leave it and live with it, try and take out the bend with pad adjustment.
2: Very carefully try and straighten it, but know it might break off or crack around the post base. How far in does the thread go? You may be able to use a longer bolt that threads all the way into the base to reinforce it once it's straight enough, even using a 6mm metruc tap to cut a thread in the base.
3: Replace the fork.

If you do 2 and it goes pear shaped you'll end up doing 3 anyway, so make sure you know where you are going to source your replacement fork from... Incidentally the other side looks a bit bent too, they're pretty cheap forks so I'd probably go with 3 anyway, as the chances of getting the bosses straight without weakening them is pretty low and the penalty for failure is high if not fatal.

LoriRose

Adjusting the brake pad has been quite difficult. I could not get the brake to spring back normally like the other side (until I removed a washer from the front bolt), nor get the pad to line up properly - granted, it is an awkwardly worn pad. Upon removing the brake, cleaning out the dirt and old grease etc. from the spring, and then replacing it, I noticed the parts do not sit flush together like the other side. It's weird because I have had this bike for a few years (though have not ridden in the last 2) and it has seen many km! I guess this is the first time I took the brake apart. I imagine it wasn't perfect before and I just lived with it as you say. I tried so many times today to realign the pad, I ended up stripping the inner thread and can no longer get it back on!

LoriRose

Thanks for this! I never considered getting a new fork! You say it's a cheap fork - it's a 1991 look mi70 - not the cheapest but not the best either I suppose. I think I'd feel safer riding with less than optimal braking than I would with a weakened boss. Unfortunately, adjusting the pad has proven to be quite a challenge.

Andrew R Stewart 

It also looks to me as though that other side canti is also cocked a bit.

Canti bosses can be removed and replaced with new. Although the cost might approach that of a low cost replacement fork. Andy

mixteup

I'd give it a try, bending it - Not a lot to lose, if you're contemplating a new fork, anyway.
I've done "minor" adjustments to those, by clamping a good fitting big adjustable wrench to them, and gently bending.
Of course, the usual YMMV disclaimer applies here ............

fietsbob

they should be parallel. did somebody really squeeze the brake lever real hard with bike stopped?
And bend them?

Moving, it would stop hard, and throw you to the ground..


[put a bolt in it before bending so you don't oval the post, itself .. ..]








....

leob1

Some bosses can be removed, these don't look like the removable kind.

fietsbob

willing to burn paint and hire a frame builder and even those, brazed on, steel , can be replaced...

Andrew R Stewart 

Sure if you limit yourself to simple threaded assemblies. But as a hobby frame builder I see this rather differently and tried to say so before. Fietsbob gets it. Andy

LoriRose

Thanks guys. I don't think I want to replace the fork. It's not really in the budget and I want to get riding on the bike asap. My father worked in a steel factory for 35 years and has worked with cro-moly before. He says the best would be to heat it up and try and bend it, but I don't want to ruin the paint. I think I will try bending it back a little with a large wrench but not force it too much. If I have a little success, I think I can manage to set the brake pad good enough. The left side is a little off, but the brake works fine. The wear on the pad is uneven is all. My only problem is I stripped the thread on the right pad, so it might take me a while to get the bolt to catch - I tried for about a half hour yesterday without success and gave up. That being said, any tips for when I try to give it a little bend? Thanks!

mixteup

Putting a screw in the post (as said above), before bending, is a good idea.
As is bolting a dummy axle or piece of all thread in the drop outs.
Brace the fork, at or above the post, with a piece of 2x4, opposing the bend direction.
Clamp the wrench TIGHT to the post - Think positive thoughts - Call in your good karma.
Be brave :~)

LoriRose

Well I did it!! And it was actually pretty easy. Just found the right size bolt, screwed it all the way in and used an adjustable wrench! Didn't take much force and I went slow. I just used the bars as leverage working with the fork upside down. It's not perfect, but it's slightly more straight than the other side now. I am going to leave both as is as I am perfectionist and I think exercising restraint in this case is the best choice - I don't want to do any damage fussing with them. Thanks for your help guys! Much appreciated. Here are the results:

ChinookTx

Nice job!

mixteup

The Force is strong with this one .......

fietsbob

Brake Booster Arches resist the force creating outward splay , under heavy braking forces ..

LoriRose

Well it took quite a few adjustments to get the brake pad in an okay position due to the stripped thread (I had to remove a washer/spacer in order to get enough grab, and move the coiled pin up to the top hole), and it required putting quite a bit tension on the main cable. Is this fine, or will it pose a problem? I've got the cable clamped in fairly tight...is it possible the cable will slowly work its way out from all the tension though?