MOT - warped brake discs

Originally Posted by Wideboy

bloke i use has a very high-tec testing station aswell as garage so he nit picks on any little thing

tis my first bike and first mot but apparently my tester is the same. nice to know that the bike can still pass despite having been crashed and fixed by my own fair bodging hands!

you said youre not sure if the discs went back on the same sides they came off?
discs are rotational arent they?

[Wideboy]

Originally Posted by svtomo

you said youre not sure if the discs went back on the same sides they came off?
discs are rotational arent they?

no markings on them so guess not

[fastdruid]

Originally Posted by svtomo

you said youre not sure if the discs went back on the same sides they came off?
discs are rotational arent they?

Some are, some aren't, Looking at the fiche, it appears SV discs aren't, both sides identical.

Druid

[embee]

Be aware that anything resembling variation in braking as the wheels rotate is almost always put down to "warped discs", which it isn't half the time.

Pad material gets transferred to the disc surface, and any uneven patches will give a variable feel. Often this can be retrieved with abrasive cleaning of the disc and re-bedding them. Just for info.

A few years ago a problem cropped up with a lot of aftermarket car discs, which turned out to be the foundry where they were sourced had changed the casting process slightly (and IIRC trace element content of the iron) and the metallurgical structure was variable round the disc, which gave variable friction coefficient and the feeling of "warped discs". Because it was in the material itself, skimming had virtually no effect and replacement was the only solution.

[Wideboy]

brother just came round and he reckons they where quarter of a mill out, he said it in thou tho but i cant remember what he said

[flymo]

Originally Posted by Wideboy

brother just came round and he reckons they where quarter of a mill out, he said it in thou tho but i cant remember what he said

10

[fastdruid]

Originally Posted by Wideboy

brother just came round and he reckons they where quarter of a mill out, he said it in thou tho but i cant remember what he said

I'm pretty sure the limit is 0.3mm in which case they're fine.

Druid