Front Brakes..

Discussion in 'Speed Triple' started by mikesouthby, Nov 30, 2017.

  1. mikesouthby

    mikesouthby Member

    May 16, 2017
    11
    8
    Swindon, WILTS
    I have been meaning to research and ask this question for a while but not sure how best to describe it..

    So, when braking so slow speeds, and by that I mean when using the front brake to pull up to a stop at lets say a set of traffic lights, I find that during the final 10 mph the brakes 'pulse' meaning that its hard to come to a graceful, smooth stop. Now I realise the logical response will be that a disc is warped but I don't believe this to be the case as braking over that speed is perfect with no issues at all, with no vibrations or feedback through the lever (in fact even at the low speed there is no feedback through the lever), it's only at very low speeds that I notice it. I have spun the front wheel up whilst on a front stand and the wheel spins freely with again, no apparent problems with the disc. I'd also go as far as saying - if I recall correctly though I would have to test - that braking heavily at slow speeds is fine too, it's only when applying gentle braking to stop gracefully to that problem appears to manifest itself, thats not even to say it it a problem!!

    Does this make sense, appreciate my description is probably not the best. Can anyone offer any explanation?
     
  2. tcbandituk

    Subscriber

    Apr 8, 2016
    2,807
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    Maybe some sort of ABS issue?
     
  3. Madmatt

    Madmatt Member

    Sep 22, 2017
    8
    8
    London
    Hi. I had a similar problem on my last bike a Tuono v4, with brembo brakes. I changed the pads and gave the discs a good clean with a scouring pad. And also cleaned the buttons. That fixed the the slow speed judder.
     
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  4. Oldyam

    Oldyam Grumpy Old Git

    May 14, 2017
    610
    500
    ireland
    Take a very close look at the discs, this can be caused by very small adhesions to the disc from the pads, usually caused by coming to a stop with high brake disc temps and parking for a length of time allowing the brake material to fuse to the disc ( especially if the brake pistons have been a little sticky ). The varying thickness of the disk is only felt at v low speeds & light applications as the difference is so small.

    You could try cleaning off any slight marks with a scotch brite pad or similar
     
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  5. Col_C

    Col_C I can't re...Member

    Aug 5, 2015
    1,431
    800
    Cornwall
    #5 Col_C, Nov 30, 2017
    Last edited: Nov 30, 2017
    Had identical symptoms with mine, mentioned it to dealer at 1st year service, not really expecting anything to be done. The dealer put in a warranty claim for new discs (and pads), was approved and fitted a couple of weeks later. I've not had any further problems a year or so later. It's either very slight warping or I've also heard claims that uneven surface glaze of some description can cause it (which might be cured by a dose of heavy braking to remove surface?).

    So no, it's not an ABS problem IMO.

    Don't forget to post here if you take it further and get it sorted, it's looking to be a relatively common issue.

    Edit:
    Oldyam/Madmatt 's suggestion might be worth a try (mine was one oscillation/slight increase in braking per rev of wheel only at speeds 5mph or less, so wouldn't really describe as a judder). I had tried cleaning/rotating the bobbins without any effect, tried brake cleaner on disc surface but not scouring pad as they looked perfect/no discolouration.
    Like you, as the issue was so slight I nearly didn't bother mentioning to dealer, so hats off to them. (I'm usually slagging dealers off for shoddy work :))
     
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  6. mikesouthby

    mikesouthby Member

    May 16, 2017
    11
    8
    Swindon, WILTS
    Glad I asked now, had been working on the assumption it was just 'character'...

    Bike is due to go back into the dealer in the next week anyhow to have the replacement Arrow system fitted under warranty as mentioned elsewhere so have just dropped the service guys an email asking them to have a look at the front brakes whilst she is in.
     
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  7. Yorkshireman

    Yorkshireman Crème de la Crème

    Dec 12, 2015
    3,399
    1,000
    Barnsley
    I found a fairly large flat blade screwdriver pushed into the bobbin would turn it enough to free it and a shot of brake cleaner expels any crud.
    If the bike is going to the dealer ask them to put it on the brake roller used for MOT testing, that will show up any pulsing as the wheel only turns quite slowly and should be a perfect test for your symptoms.
     
  8. capt

    capt Elite Member

    May 8, 2016
    3,050
    750
    western Australia
    Another possibility, the Head stem bearings have come loose ! I replaced my standard roller head stem bearings with tapered, as I had similar issues, brake's weren't touched ! But the shuddering and such at low speeds when braking disappeared.

    Cheers capt
     
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  9. youngy

    youngy Active Member

    Oct 30, 2017
    38
    28
    Peterborough
    Absolutely this. Before I collected my bike from the dealer it failed the MOT on brake pulsing even though nothing could be felt at the lever. New discs and pads.
     
  10. Purpleronnie

    Purpleronnie New Member

    Dec 3, 2016
    11
    3
    Up North
    Agree with col_c. Had exactly the same issue. Took it in for 12month service on Saturday and explained the problem with braking. Mechanic took it out for a couple of minutes then confirmed warped discs. Being replaced under warranty.
     
  11. Purpleronnie

    Purpleronnie New Member

    Dec 3, 2016
    11
    3
    Up North
    Agree with col_c. Had exactly the same issue. Took it in for 12month service on Saturday and explained the problem with braking. Mechanic took it out for a couple of minutes then confirmed warped discs. Being replaced under warranty.
     
  12. Col_C

    Col_C I can't re...Member

    Aug 5, 2015
    1,431
    800
    Cornwall
    This is looking increasingly like a common problem, don't forget to put a brief post here
     
  13. mikesouthby

    mikesouthby Member

    May 16, 2017
    11
    8
    Swindon, WILTS
    So, had the dealer investigate the brake issue this afternoon whilst the bike was in having some other work completed. They ran it up on their MOT test equipment and then a brief road test and confirmed that not only are the front discs out of balance, they are actually an MOT failure (not great on a bike thats less than a year old..) which came as a bit of a shock. So, a warranty claim is being processed and a new set of discs should be ordered in the coming days for replacement.
     
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  14. Jester Jak

    Jester Jak New Member

    Sep 11, 2016
    15
    3
    Cornwall
    My 2012 (8k miles) was recently MoT'd and to my shock the tester picked up the front brake discs as grabbing. I was present when he tested the brakes and it was very evident from the needle on the brake test gauge jumping up and down whilst using light front brake. He cleaned the discs but the problem was still there. As the bike was out of warranty I had to fork out for some new discs. I opted for some new EBC discs as the Triumph discs seem to have problems, I know of another Speed R rider that has gone through two sets of front discs!
     
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