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Has your Sprint experienced Rotor warping?

  • Yes I have had Rotor warp problems

    Votes: 16 32.7%
  • No I have not had Rotor warp problems

    Votes: 33 67.3%

  • Total voters
    49
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Discussion Starter #1
Has your Sprint had rotor warping problems?

I have not on either of my 955's Sprint or Daytona but a few of you have so ths should help gauge how big or small an issue it really is.

63,000kms on my Sprint ST. 11,000kms on Daytona 955

DaveM
 

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I have recently noticed a very slight pulsing during braking on my '04 Sprint. It is only noticeable when applying the brake lightly at low speed, such as when approaching traffic lights etc.

I suspect the cause may be brake pad material on the rotors, rather than a warped rotor. I changed the pads, but the problem persisted. When I get a chance I intend to clean / lightly sand the rotors and see if that rectifies the issue.

Mark
 

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Yes, uneven pad deposition is usually the cause of brake pulsing on cagers. Not sure about motorbikes though.
 

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I warped(out of tolerance) a rotor on my '99, and I warped(just to the edge of tolerance) both OEM rotors on my '02. Waiting to see how the '08 holds up. I ruined the replacement rotors on the '02 when I foolishly let a soaking wet bike sit overnight. The EBC HH pads rust bonded to the rotors(which I believe were also EBC parts). When I broke them loose the next morning they scored the rotors where the pads were bonded too them, creating a pulsing during braking.
 

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Yup, but....

Quite a few of you have seen me post several times about this....

I think most of the warping issues are down to dirty bobbins. Certainly I have directly 'rescued' a number of machines over here that were diagnosed with "warped Discs" by cleaning and spinning the bobbins. If they are left dirty enough for long enough the discs will warp as when they heat up under braking, they cannot expand evenly. Catch it soon enough and they go back to being okay. I had my first set changes at 12,000 miles and the tech told me about this.... haven't had another set, and I know that Steventhechef has done this when he thought he had warped discs, and lo and behold..... they were fine.

Rexx
 

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Yes, uneven pad deposition is usually the cause of brake pulsing on cagers. Not sure about motorbikes though.

Welll...... I have to disagree some what. Your pads go on in only one position on a vehicle and are locked in that position.

A real cause of pulsing on a vehicle is that the rotors have not been indexed to the car. As far back as 2002 hub assemblies have not been machined to perfection and manufacturers took to oncar brake lathes. They would mount the rotors then turn the rotors with an on car brake lathe to index them.

Aftermarket shops dont do this and you get pulsing.

On motorcycles with floating disks dirty bobbins can be a cause of pulsing. Clean up the bobbins and usually it goes away.
 

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I had the pulsing/loss of lever on my bike once she was back on the road. I convinced myself that the rotors were warped. But upon the guidance of members here they steered me towards stuck bobbins. Which was the case, but being as I'm lazy I just swapped my old set which were fine for the stuck set and all was good again.
 

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A real cause of pulsing on a vehicle is that the rotors have not been indexed to the car. As far back as 2002 hub assemblies have not been machined to perfection and manufacturers took to oncar brake lathes. They would mount the rotors then turn the rotors with an on car brake lathe to index them.
Excellent point!

In fact, any rotating part that can be installed in more than one orientation should be marked (indexed) so that it reinstalls in the original position.
 

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Well I have had continuing brake pulsing problems on first my 01 Sprint and now my 06 Sprint. Not felt at the lever at all, but most clearly experienced when stopping at low speeds, such as in traffic, when it I feel alternating levels of stopping power, ie braking performance. It is as if there are differing levels of the coefficient of friction around the surface of the disc. Usually this can be managed by keeping the bobbins free (I wasn't aware of this initially on the 01) and it can nearly always be 'fixed' after some continued hard braking, such as a ride day, or a day in the mountains. When the pulsing is bad and you attempt to brake hard from high speed , say 250km/hr, life gets very interesting very quickly!! Shudders like crazy such that you loose forward vision. Realy good when entering turn one at Phillip Island. Three or four laps later and the shuddering nearly gone.

With the 01 in the end I did warp the disc so that the disc was visibly dished but it had no measurable runout. It was sold like that and the dealer was happy to issue a road worthy to it even though I pointed the 'dishing' out to him. With the 06 I have been nearly meticulous in keeping the bobbins free. However the pulsing comes and goes, after hard use. At the 30,000km service I got the bike back with new discs fitted under warranty even though the bike was 2 years 10 months old. All I asked was to try new pads to see if that might help. New discs was a surprise. It is good to see a dealer try hard for you (Wimmera Motorcycle Co at Horsham Vic - I have to give them a plug).

So yes, disc pulsing problems all the way. I don't know what the cause really is. They are not warped and have zero runout. A thought has been that riding sometimes in rain can cause local hard surfacing to occur if water splashes cool the discs unevenly. This sounded like b...s...t at first but is plauseable. The ex chain gang man in qld thought this was the cause. I don't know but I've got new discs for which I am very thankful, but I predict that they too will end up with the dreaded pulsing. A friend with an Aprillia has had identical issues and problems.

Cheers Simmo
 

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Rotor warp issue

The poll suggests approximately 1/3 of the respondents have experienced the problem. I hope that the Triumph factory boffins take note of this fact and try to do something about it.
 

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.... ten years later. Useful thread, front discs on my 955i are slightly warped, noticeable when braking at slow speed. Will try and spin the bobbins (are they supposed to spin?)
 

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I don't know about spin but try hitting them with some penetrating oil and then MANFULLY flex the disc back and forth with your powerful arms.
If the discs are no longer floating they'll pulse when you hit the brakes.

Be sure to clean up the oil drool before riding (and after the next few rides).
I used a 50/50 mixture of ATF and acetone in a squirt can.
 

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.... ten years later. Useful thread, front discs on my 955i are slightly warped, noticeable when braking at slow speed. Will try and spin the bobbins (are they supposed to spin?)
One advise: first clean up thourthly your rotors.
Had the same thing. After measuring them I discovered that...they were perfect. Simply dirty. So now when clean the bike up I clean the rotors as well.

Fred
 

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Thanks for the replies, this forum is an excellent resource.

If the discs are fully floating then I should be able to fit a bolt through the bobbin, nut and washer on the back, and then rotate the bobbin with a socket to free it off.

Slow speed on gravel is a bit of issue currently, avoid touching the front brake.
 

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M6 bolt was too big to fit through the bobbins for spinning, M5 bolt fitted, penny washer either side, nut. Can rotate with spanner, socket or drill. Discs now move easily, no test ride yet.
 

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Warped my car's disks multiple times, but that was because the vehicle was under braked for the power it developed after an ecu tune. Bugger brakes from its bigger brother (4.2l V8 Audi S5) sorted it right out.

As for the bike, never managed to get them hot enough to cause warping or pad transfer.
However I do have clicking from the front rotors when braking. It's only audible below 20 mph but that's probably because of wind noise above that.

I've been led to believe it's worn bolts between the friction material and the central golden mounting. (Bobbins I think)
 
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