Long/Short reach calipers

zzzzzzzz

Replacing the callipers on an '08 trek 1.2. Just had whatever un-branded calipers came with the bike on it, and replacing with 105.

Now, the reach on the 105 calipers is a bit shorter than on the previous ones. I can see that.

So, I can't get the brake pads to line up to the rim.

I'm assuming I just need longer reach callipers...but the reason I'm posting is that it's such a small distance away from hitting the rim, that I may be overlooking something...

Would putting some spacers in to extend the callipers away from the frame a bit make any difference? I'm talking about 2mm short! (The shoes are dropped as low as they will go)

Has anyone replaced the callipers on an trek 1.2/1.5 etc.? What did you replace with?

I've attached a few of pics to show how far off the pads are - you'll see the right rear pad hits the rim fine, the left rear is slightly off- the rear calipers mustn't be bang on straight... and the are the two front pads are both off)

Front Left:



Front Right



Rear Left



Rear Right

rottenhat

Hmmm...that's a bit of an odd one. I thought all short-reach callipers were much of a muchness - if it was just at one end of the bike or the other I would have guessed the hole was drilled a couple of millimetres too high but if it's front and rear, you'd have to imagine it's by design. If you're talking about adding spacers between the calliper and the bridge, I think that would just move the calliper further out along the tangent from the wheel, making the problem worse. If there's a washer you could leave out, that might help.

AstraMonti

Just an (possibly stupid) idea.. but would it be something like that the wheel hasn't sit properly on the frame? Something with the qr skewer maybe?

zzzzzzzz

AstraMonti wrote: »

Just an (possibly stupid) idea.. but would it be something like that the wheel hasn't sit properly on the frame? Something with the qr skewer maybe?

I thought it might be something like that but no, the wheel is sitting in correctly.

I've managed to get the 2 front brake pads to sit on the rim ok. I'd like them to be maybe 1mm lower but they'll do how they are. They have full contact just about.

I'm still having trouble with the rear pads though - one of them sits ok but the other one is slightly off still. No matter what I do to the callipers, the same pad is always off.

zzzzzzzz

rottenhat wrote: »

Hmmm...that's a bit of an odd one. I thought all short-reach callipers were much of a muchness - if it was just at one end of the bike or the other I would have guessed the hole was drilled a couple of millimetres too high but if it's front and rear, you'd have to imagine it's by design. If you're talking about adding spacers between the calliper and the bridge, I think that would just move the calliper further out along the tangent from the wheel, making the problem worse. If there's a washer you could leave out, that might help.

Tried it with/without washer and with a couple of spacers that were on my old brakes but it made no difference.

As I said in my last post, there's full contact on 3 out of the 4 pads. I may just file 1mm out of the arm that isn't long enough...

rughdh

I'd either put the old callipers back on or go for better quality ones with sufficient reach. Something like Shimano BR600, for instance.

blorg

At least one other person on the internet has complained that a Trek brake bridge is positioned too high for standard calipers, OK at the front but not the back, seems a bit crazy on Trek's behalf to be honest, maybe they were prioritising allowing larger tyres.

The higher on one side rather than the other is probably just a centreing issue, you do the inital centre roughly ideally using a cone wrench while tighening the allen key although you can do it by hand either. Fine centreing is then done with the screw on top of the brake, in the middle section. With Ultegra and DA this is a hex screw but looking at your last photo it may be a Phillips head on 105.

You may just need to get long reach calipers though.

zzzzzzzz

blorg wrote: »

At least one other person on the internet has complained that a Trek brake bridge is positioned too high for standard calipers, OK at the front but not the back, seems a bit crazy on Trek's behalf to be honest, maybe they were prioritising allowing larger tyres.

The higher on one side rather than the other is probably just a centreing issue, you do the inital centre roughly ideally using a cone wrench while tighening the allen key although you can do it by hand either. Fine centreing is then done with the screw on top of the brake, in the middle section. With Ultegra and DA this is a hex screw but looking at your last photo it may be a Phillips head on 105.

You may just need to get long reach calipers though.

Oh really? i didn't realise that screw in the meddle section was for centering. Nice one.

I probably do just need longer calipers though. It's just such a small distance off it's annoying.

DirkVoodoo

It's also only a small distance now, but it will get worse as the pads wear down and looks like they might start rubbing off the sidewall.

That is an odd design by Trek.

rottenhat

DirkVoodoo wrote: »

That is an odd design blunder by Trek.

Fixed that for you.

The Shimano R600s are nice brakes certainly - I use and endorse them myself (cheers break out in Shimano sales division...the Rottenhat endorsement is secured) - but they're Ultegra grade and price. It's bloody ridiculous that a road bike intended for short reach callipers should have the hole drilled so high that something as commonplace as 105 brakes will not work with them. If it was intentional, I wouldn't be in a rush to buy Trek again.

peterk19

I have the same problem with my trek 1200 i replaced the standard calipers with shimano 105 calipers and they wont sit right on the back i just filed a bit of the pad away as a temporary fix but still havent gotten around to looking further into it i must do that soon