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Reducing lever throw on Avid Frankenbrakes

Discussion in 'Downhill & Freeride' started by toodles, Apr 8, 2008.

  1. toodles

    toodles Turbo Monkey

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    I've just done the fanboy thing and built up a set of code calipers on ultimate levers. The front brake works brilliantly, however the rear has much more throw than I'd like, especially given my preference for running my levers fairly close to the bar.

    I've already reduced the lever throw as much as is possibly via the adjuster on the ultimate levers, but it's still more than I'd like. I'd put it down to a actuation ratio issue but the front works great. It might be a bleed (i'm notorious for bleeding brakes half-lagered and then wondering why they don't work right) but I've done this brake a few times now and it's consistent now.

    Any suggestions for reducing throw? I tried pumping the lever with the caliper off the rotor, but it seems to self-adjust back to the point of having too much throw.
     
    #1 -   Apr 8, 2008

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  2. Eurotrash

    Eurotrash Monkey

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    I would have suggested the pumping lever with no rotor but seeing as you have already done this, make sure you have enought fluid in the system, you are using a MC that is designed to push pistons with a small surface area with a twin piston design and big surface area. You may not have enough fluid in the MC reservoir. Maybe try bleeding the brakes with the pistons not fully pushed back in to get some extra fluid in there.
     
    #2 -   Apr 8, 2008
  3. buckoW

    buckoW Turbo Monkey

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    I have always thought Avids have too much throw. When they are well worn in it gets worse, IMO.
     
    #3 -   Apr 8, 2008
  4. wysiwyg

    wysiwyg Monkey

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    Bleed them up with the pistons slightly out of the calipers thus reducing the movement until bite point?
     
    #4 -   Apr 8, 2008
  5. Ian Collins

    Ian Collins Turbo Monkey

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    ding ding ding
     
    #5 -   Apr 8, 2008
  6. buildyourown

    buildyourown Turbo Monkey

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    I have the code 5's, which are essentially the same brake minus the bling. You can change the bite point a lot by playing with the bleed.
    Try opening the engagement point adjustment all the way out, then bleed them. Then readjust.
     
    #6 -   Apr 8, 2008
  7. Tmsracing37

    Tmsracing37 Chimp

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    I kinda of agree with euro trash on the MC size.

    I am having the same issue, with a new set of code-5's (Juicy levers with code caliper). The fronts work great, but I have noticed on my rear caliper that the left side pistons just "twitch" while the right side piston actuates in and out a lot better. The issue is, when you first center the caliper up with the rotor they feel great, but after a couple runs down the trail the pad material wears away and left side can not make up the distance, thus more and more throw before the pads engage the rotor.
     
    #7 -   Apr 8, 2008
  8. Urinal Mint

    Urinal Mint Monkey

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    I just built the same setup and mine works awesome. To get the back brake how I wanted, I bled them vertically by attaching the lever to a dowel about 5 feet off the ground, then I let the line hang straight down and screwed the caliper into a piece of wood near the ground. I couldn't believe how much more air came out of the lines from my standard bleed with the hose on the bike. The brake feels amazing now.
     
    #8 -   Apr 8, 2008
  9. Supa8

    Supa8 Monkey

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    Try just bleeding the lever again and make sure you pull the air out and lightly push fluid back in as it make a big difference. Worked for me.

    Make sure you adjust your ideal lever/distance placement first then do the bleed. You can back the pad adjustment in a bit (4-5 clicks ) from wide open ( as the manual suggests ) and still do the bleed as well. I like my levers close to bar and found that this was the best way to get it right. It will leave you with some further adjustment as the pads wear.
     
    #9 -   Apr 8, 2008