Issue fitting new 105 brake caliper

[zed]

I've just bought a set of Shimano 105 brake calipers for my 2007 Giant SCR 2.0 and the front fits fine, but the back doesn't. Basically the brake pads touch the tyres instead of the rim. The brake pads can't drop any further in the slot (or whatever it's called), so I'm guessing I need to get a rear caliper with a longer drop? Or is there a hack I can do to get it working?

[Duck!]

You'll need a long-reach caliper such a Shimano R650. I would not be too keen on filing out the slot to lower the pads.

[HappyHumber]

Most calipers have their designated reach range specificed in milimetres on the inside of the arms. How does the range compare with the brakes you pulled off?

But yeah, like Duck! says you'll likely need longer reach. I wouldn't modify the calipers as you're suggesting. Sell on the 105s and recoup a bit of your cost.

[Duck!]

SCR was an overseas name for what we called the OCR; the forerunner to the Defy range. They were factory-fitted with long-reach calipers to allow bigger (up to 28mm) tyres.

[zed]

Cool thanks guys.