2002 ST1100 ABS/TCS - front disc are not true

[Dan T]

I have the bike back together and I'm getting a noise from the front wheel. I suspected the disc was bent ever so slightly during the last tire change so I put a dial indicator on them and one disk is .0015 from being true and the other is .005 out from being true. I'm thinking they should be replaced. Where do you find Honda OEM disc for the front wheel.

A friend mentioned that with patience these can be straightened out to being close to be true. Has anyone done this.

I'm thinking the one that is .005 out of true should differently be replaced.
Dan

 

[Bush]

What is the noise you are getting? Five thousandths is pretty minor IMO and unless you can feel a pulsing in the front brake when applied during riding, I wouldn't worry about it. OEM discs available from Partzilla, but hang onto your wallet!

Slight scuffing noise will always be apparent with disc brakes.

 

[Upt' North]

+1 Bush, the run out is minor I think, can you feel judder.
Did you take the discs off.
Did you clean the mating surfaces off.
It would be good to know what the symptoms are.
Never heard of anyone straightening warped discuss not that I think yours are.
Dave Silvers can provide OEM discs, price seems to be creeping up and you should change both.
Hope it helps.
Upt'North.

 

[TerryS]

I thought my discs had warped recently as the brake action was getting a bit uneven. Turned out I had a badly worn wheel bearing. Fixed that, brakes are now back to their best. The calipers are a sliding design that should accommodate a little bit of run-out in the discs.

 

[dwalby]

the factory manual specifies the front brake runout at max 0.012", so unless you slipped a decimal point you're well within factory spec.

FWIW, a new set of OEM front rotors list for about $700, sell for about $500 on the interweb.

 

[Dan T]

Thanks, I didn't think the readings were bad enough or reasons to replace the disc but I wanted to hear what others thought. When I spine the wheel (when off the ground) I don't hear and thing that tells me I might had a problem.

The wheel was off so I could replace the tires and I thought the bearings where good.

The noise sounds like small stones in the tire getting thrown at the inside of the fender. and when the speed get's up to about 25 or 30 I don't hear the noise any more until I slow to about 25 or so and it comes back.

Could it be the bearings?

 

[Bush]

Thanks, I didn't think the readings were bad enough or reasons to replace the disc but I wanted to hear what others thought. When I spine the wheel (when off the ground) I don't hear and thing that tells me I might had a problem.

The wheel was off so I could replace the tires and I thought the bearings where good.

The noise sounds like small stones in the tire getting thrown at the inside of the fender. and when the speed get's up to about 25 or 30 I don't hear the noise any more until I slow to about 25 or so and it comes back.



Could it be the bearings?

Certainly a possibility. Did you check them with your finger? You shouldn't feel any roughness or catchiness when turning the inner races and should need a firm touch to rotate them (not loose feeling).

How many miles on them? OEM wheel bearings went 100,000 miles on my '95 and only replaced them 'cause I figured I'd had my money's worth.

 

[TerryS]

For about $20 per side, I'd suggest swapping the bearings out would be a quick and easy thing to try. DIY bearing replacement is pretty easy, I knock the old bearings out with a long screwdriver, then drive the new ones in using a socket that will bear on the outer race only. On my 92 the bearings are 6004VV size, bought them from my local industrial bearing supplier. The service manual instructs to drive the new right bearing in first, then fit the spacer, then drive the left bearing in.

Feeling for loose bearings is harder than you might think. The best way I've found is to pull the fender off, then with the front end off the ground wiggle the wheel side to side between the fork legs feeling for any clunk.

 

[Slydynbye]

I suspect something Specific to the ABS 2. Look at the ABS sensor, it is probably rubbing the sensor ring.
There are 2 points that determine the position of the sensor, find the 2 bolts and adjust, the noise usually disappears.

 

[kiltman]

Last time I had my front tire changed, the mechanic thought that the sound coming from the front wheel was a result of corrosion inside the spokes of the wheel. ( like sand inside the spokes) I can’t verify that until I replace the front bearing when it goes.

 

[jmcarruth]

Before you spend mega bucks on new disks:

Check your bearings

Clean the pistons and lube the slide pins in your calipers.

 

[Dan T]

For about $20 per side, I'd suggest swapping the bearings out would be a quick and easy thing to try. DIY bearing replacement is pretty easy, I knock the old bearings out with a long screwdriver, then drive the new ones in using a socket that will bear on the outer race only. On my 92 the bearings are 6004VV size, bought them from my local industrial bearing supplier. The service manual instructs to drive the new right bearing in first, then fit the spacer, then drive the left bearing in.

Feeling for loose bearings is harder than you might think. The best way I've found is to pull the fender off, then with the front end off the ground wiggle the wheel side to side between the fork legs feeling for any clunk.

I've ordered the bearings and seals for the front wheel. If the noise goes away that's good, if not, not bad.

 

[Dan T]

I suspect something Specific to the ABS 2. Look at the ABS sensor, it is probably rubbing the sensor ring.
There are 2 points that determine the position of the sensor, find the 2 bolts and adjust, the noise usually disappears.

Good point.
when I put everything back together I made sure to measure the spacing for the ABS sensor, 5mm. That did not rub when I spun the wheel. I'm leaning towards the bearings. Maybe something happened when the wheel was on the HF tire changer. The sound is odd and has me stumped. The wheel will come off for the new bearings and I'll double check how it all goes back together.

 

[Dan T]

Before you spend mega bucks on new disks:

Check your bearings

Clean the pistons and lube the slide pins in your calipers.

Thanks for the help. The bearings seem fine but I'm spinning them with my thumb.
The pistons are clean and I made sure the slide pins are cleaned and lubed when I re-assembled the wheel. Because of the tire changer I'm thinking the bears got screwed up. I don't know what else could make that noise.

 

[Upt' North]

Speedo drive?
Upt'North.

 

[John OoSTerhuis]

An additional comment - an often forgotten front wheel installation spec from the Owner’s Manual (page 77 in mine, with schematic):

2. Measure the clearance between the outside surface of the left brake disc and the left caliper holder with a 0.7 mm (0.028 in) feeler gage. If the gage inserts easily, tighten the right and left axle pinch bolts to the specified torque.

John

 

[Bush]

An additional comment - an often forgotten front wheel installation spec from the Owner’s Manual (page 77 in mine, with schematic): John

"often forgotten"? How about never known! I've always relied on the OEM Service Manual for all my DIY needs and it makes no mention of this. So, for over 20 years and I don't know how many wheel removals, I've never done it, nor had a problem. I'll have to check mine now, for curiosity's sake.

Have you had times when things didn't line up within spec?

 

[TerryS]

I've never needed to check the clearance but I always follow the same procedure, tighten the axle bolt, bounce the forks, tighten the clamp by the axle bolt, bounce the forks, tighten the other clamp. I also keep things like axles clean and greased, but I can imagine that one could pull a fork leg inwards if the axle was rough.

 

[SMSW]

You might try backing the pads off the rotors (i.e. push the pistons back into the caliper a bit) so they are not touching the rotors at all. Then, with the bike on the center stand, spin the front wheel. Any sound? HIt the brake pedal and try again.

 

[John OoSTerhuis]

"often forgotten"? How about never known! I've always relied on the OEM Service Manual for all my DIY needs and it makes no mention of this. So, for over 20 years and I don't know how many wheel removals, I've never done it, nor had a problem. I'll have to check mine now, for curiosity's sake.

Have you had times when things didn't line up within spec?

No ForeST, I haven’t, although it’s possible. Here’s the rest of the instructions:

3. If the feeler gage cannot be inserted easily, pull the left fork outward or push inward until the gage can be inserted and tighten the axle pinch bolts with the gauge inserted.
4. After tightening, remove the gauge. After installing the wheel, apply the brakes several times, then recheck both discs for caliper-holder-to-disc clearance. Do not operate the motorcycle without adequate clearance.

Edit: pages 81 and 82 here:
http://campaigns.hondampe.com.au/Motorcycles/manuals/ST1100.pdf

John