front brake disc issue

hi guys,
bike just went though its mot and he gave me an advisory on the disc (front) i think he was being nice too as it looked pretty rough on the rolling road read out. i have checked the calpier float, re greased and all is good, looks like the disc is worped a little as when i spin the wheel it slows down at a particular point and i think i can see it slightly too, thing is im skint for a couple of months so im thinking of putting a new standard set of pads in as the old ones have worn down more so on one side and that will buy me some time. currenty the brakes feel fine and theres no juddering or anything, just wanted to check with you lot if ive missed anything or if its anything else! when i can get the disc i will replace the pads with the new disc too. 

It must be slightly warped (or lipped) at some point if it binds when you spin it, an easy way to check would be to put a metal rule edgeways across the disc and turn the wheel to see where the gap gets bigger.
You'll be ok with it, just be careful with heavy braking!

Thanks will give that a go. Looks like your right though . As long as it can wait till the following pay day ill be ok lol

glen.wilson1@gmx.com wrote:hi guys,
bike just went though its mot......it looked pretty rough on the rolling road read out.

Your bike MOT's include a rolling road test?? How exactly does that work?
I heard talk of them introducing it here in future but anyone I've spoken to seems to think it's impractical...

appologies thats my crap description, i mean the brake test unit that has rollers they put it on to test the brake strength 

jonny10 wrote:

glen.wilson1@gmx.com wrote:hi guys,
bike just went though its mot......it looked pretty rough on the rolling road read out.

Your bike MOT's include a rolling road test?? How exactly does that work?
I heard talk of them introducing it here in future but anyone I've spoken to seems to think it's impractical...

It is actually a brake test - you put the wheel to be tested on the machine (which is essentially a roller with some grip on it), it spins the wheel and the tester applies the brake - the machine measures the braking force. They often have a weighing scales incorperated so they can work out the braking efficiency automatically.

We previously had simpler brake tests: one involved demonstrating the ability to stop on a slope of a prescribed gradient, the other involved dragging the machine across the floor and measureing the force required (hence the braking force) to pull it.

The rolling road gives (slightly) more consistent results but mainly (as demonstrated) allows the tester to easily assess fluctuation.

Our MOT administration people have a bit of a hard-on for 'gadgets': you also need to have a machine to test headlight alignment - shining the light at the opposite wall and using a tape measure is not allowed (allthough equally valid, of course).

Right, think I've got it.
....so you're not left sitting on the bike struggling to hold it on rollers, at the risk of being launched across the floor floor of the test centre when the brakes hit, for the entertainment of all present?  Sound.

jonny10 wrote:Right, think I've got it.
....so you're not left sitting on the bike struggling to hold it on rollers, at the risk of being launched across the floor floor of the test centre when the brakes hit, for the entertainment of all present?  Sound.

It would be funnier if that happened, but no, the most interesting thing that can happen is the wheel locking and the roller grinding at the tyre a bit.

I bet if you googled 'roller brake tester motorcycle' then you could find a video... it probably won't be very interesting.