Rear Disc brake long throw and little braking?

jpower
jpower Posts: 554
edited August 2018 in Workshop
Hi,

Just got my bike back after a full rebuild and I noticed the rear brake does not do very much, not like it used too and I have to pull the lever fully back for it to even do anything. The front brake works perfectly.

Is there any bedding in type thing from a rebuild? I plan to take it back but as its a bit of a drive to my LBS I wanted to check it wasn't something simple.

Thanks.

Comments

  • imposter2.0
    imposter2.0 Posts: 12,028
    Some details of the brake type might be useful...
  • jpower
    jpower Posts: 554
    Shimano R8000 groupset di2 if that makes any difference.
  • imposter2.0
    imposter2.0 Posts: 12,028
    Presumably you've tried adjusting-out some of the lever travel..?
  • jpower
    jpower Posts: 554
    Imposter wrote:
    Presumably you've tried adjusting-out some of the lever travel..?

    How do you do that?
  • imposter2.0
    imposter2.0 Posts: 12,028
    This is why it is useful to put as much info as possible in your first post - do you have cable or hydro?
  • jpower
    jpower Posts: 554
    Apologies, its hydraulic
  • imposter2.0
    imposter2.0 Posts: 12,028
    Sounds like you may have air in the system. Unless you are confident in bleeding the brake, it might be best to take it back to the shop..
  • mamil314
    mamil314 Posts: 1,103
    I second taking it to the shop since R8000 groupset does not involve disc brakes -.-
  • Vino'sGhost
    Vino'sGhost Posts: 4,129
    hmmm it sounds like theres air in your system.

    Take the bike back, if its been serviced it should be working and you've paid for it. though depending on time and cost to take it back why not buy a bleed kit and do it yourself. If you've never done it, its surprisingly easy and other than the bleed kit the other tools youve probably already got. (a couple of small ring-nut spanners. I think its 7mm on that system but you can try and see).

    Then you can stand back bathed in manly mechanical fixer glory :)

    Id also look for cracks or damage on the body of the STI / reservoir.
  • jpower
    jpower Posts: 554
    Sorry I was generic mentioning the series it’s specifically ST-R8070 levers and brakes.

    I do love the idea of basking in mechanical glory, but I’d really like to see it done and know the gear to use/buy. I fear it’s a trip back to the shop which is a right pain in the arse and time. Arrgghh.
  • svetty
    svetty Posts: 1,904
    Agree sounds like they've bodged the rear brake service and allowed air in.
    FFS! Harden up and grow a pair :D