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Upgraded brakes - bolt too short?

SquawkSquawk Posts: 132
edited May 2017 in The workshop
Hey all,

I decided to replace the no-name calipers on the road bike with some 105s, to go with the rest of the group set, and I've run into a problem.

The bolt attached to the caliper goes into the fork from the front. All good so far. However, at the rear of the fork you put in the appropriate length err, bolt: dunno the name of it, the cylinder that goes into the back of the fork and which you screw the caliper bolt into. And that's the problem. It's too short.

The one that was on the bike was too short too, the old calipers had a longer bolt. The calipers go on, but I'd like them to screw on much further to be happy they won't fail. Anyone know what that part is called, and where I can get a longer one from?

If I've made as much sense as a chocolate fireguard pls let me know. Bike is a Trek Madone 2.1 2015.

Cheers

Posts

  • andcpandcp Posts: 644
    It's called a 'Caliper Brake Recessed Nut' and they are certainly available up to 35 mm long (SJS Cycles). try your lbs first, they may have some knocking around.
    "It must be true, it's on the internet" - Winston Churchill
  • SquawkSquawk Posts: 132
    Awesome on the part name, and damn on the size, as I think the one that I've put in is 35mm long already. I managed to get 3.5 turns of the nut, which should give it 75-80% of max load bearing capacity. Not perfect, but only the equiv of me being 3 stone heavier so clearly still safe (unless 16 stone people routinely break bikes).

    Edit
    Took the brakes back off and measured. It is a 35mm recessed nut already. Looks like I need 40mm, and I can't find any sign of a 40mm one online. I'll get on to Trek I think, the bike came with full 105 groupset minus the brakes so it seems impossible that they would have designed it to not be compatible with 105 brakes. Can't really send them back I don't think, already greased up and screwed on a couple of times, but I might ask the question
  • andcpandcp Posts: 644
    They do exist longer than 35 mm, about halfway down the page:
    http://www.torontocycles.com/Selling/V- ... Shoes.html
    ...also....
    http://www.ebay.co.uk/itm/Rockbros-Bicy ... Swqu9Uzxu6

    might have to wait a bit for delivery though!

    eta - it might be worth asking in the 'wanted' section on this very forum to see if anyone has one in their spares box.
    "It must be true, it's on the internet" - Winston Churchill
  • SquawkSquawk Posts: 132
    oooh fantastic, thanks for the links, and great suggestion on the "wanted" section: hadn't thought of that, I've never purchased anything on here
  • thistle_thistle_ Posts: 6,937
    Squawk wrote:
    oooh fantastic, thanks for the links, and great suggestion on the "wanted" section: hadn't thought of that, I've never purchased anything on here
    Can you not reuse the one off your old calipers?
  • The RookieThe Rookie Posts: 27,810
    And that's the problem. It's too short.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • andy9964andy9964 Posts: 930
    What about a longer bolt from the front, to go into the recessed bolt?

    Edit: Doh!! Just thought, it might be integrated into the caliper :oops:
  • SportivemanSportiveman Posts: 157
    I have done the same upgrade on my madone 2.1 . I had a spare couple from old calipers that fitted. Defently go to you're local bike shop they will have some spares prob for free.
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