Disc Runout

[Firefox]

Anyone in the vicinity of Dublin got a handy way of checking Disc runout?
I may have a warped disc and I want to get it checked before I go looking for replacements.

 

[buellzebub]

Anyone in the vicinity of Dublin got a handy way of checking Disc runout?
I may have a warped disc and I want to get it checked before I go looking for replacements.

Put the bike on it's centre stand and tape/cable tie a marker pen to the fork leg of the disk you suspect with the pen tip towards the disk. Then spin the wheel and slowly move the pen towards the disk, very carefully and very slowly till the pen tip JUST makes contact with the spinning disk. If there is any warpage/run-out, the pen will touch the high spots first. This is a very crude method though and you may get false results if the floating disk mounts are worn.

HTH

Mick

 

[Firefox]

thanks

thanks for that Beelzebub.
Went into work last night and found a non-tosser biker who has the necessary magnetically mounted measuring tool, so with luck, I'll know next week. It could well be the mounts. I've torqued them to the right setting, but they don't seem to float the way I remember the discs on my 1150RT used to.

 

[john_aero]

why do you think its warped? i use a magnetic dial gauge and clamp it to the fork

 

[Firefox]

magnetic

I've sourced someone with a magnetic guage who will check it over the next couple of days I hope. There isn't shuddering at higher speeds, which I would have expected if the disc is warped (or am I wrong). but as I slow down, at about 20 mph or less, I think, there is a sort of brake/run through/brake/run through effect. I'ts not a problem as much as an annoyance, but obviously I want to get it sorted.

 

[john_aero]

ah you just managed to make yourself an abs unit out of the disk.

ya either disk or axel, mate mine had same prob as well. must ring and see what it turned out to be

 

[Firefox]

magnetic

why do you think its warped? i use a magnetic dial gauge and clamp it to the fork

Tried to put the magnetic clamp on fork but it wouldn't stick! Did you have any problems with that?
Clamped it to a manhole cover and stood bike beside it. Not the most accurate, but it seems to be over spec on the left disc. Need to get it checked more accurately to see if it's the disc or the mounting points.

 

[john_aero]

i can do the check if you want, i have the magnetic unit and dial. i think i clamped it to the chrome section where get better hold.

 

[Firefox]

chrome

i can do the check if you want, i have the magnetic unit and dial. i think i clamped it to the chrome section where get better hold.

Chrome! what bloody CHROME? it's a GS

thanks for the offer though, might have to take you up on it.

 

[john_aero]

Chrome! what bloody CHROME? it's a GS

thanks for the offer though, might have to take you up on it.

oops hahah. well the dial is in work getting callibrated so i can do it next week