Front wheel question

cbertozz

cbertozz

Hero member
Location
Australia
Picked up some new wheels for racing but having a few issues.

So my friend fitting the front wheel for me while I?m away said:

?The shoulder for the brake rotor cage is on the black wheel 73mm and on the silver wheel 80mm, the bolt circle is the same, but the rotor is not centered, I wouldn't use it like that?

He said ?Talk to the gurus and ask is it ok to just bolt the rotors on??

So...whaddaya think?
 
The spigot is to centralise the disc, too prevent run-out and provide a positive location.
The bolts create a high level of friction between disc and mount thereby preventing movement.

The clearance in the bolt holes will allow run-out and possible movement and vibration.

I would not use a sub-standard, bolt only location on a critical safety item.
 
The black wheels are the new ones

IMG_2090.JPG
 
Would definitely not consider that for a front wheel. Just have someone make up a plate with an I?d of 73mm and od of 80mm and some way of securing it in place. Maybe Loctite it to the hub. The grade that requires heat to remove it.
 
If I understand correctly you think the shoulder is undersize for the front wheel?

The disc rotor bolts directly to the rear wheel, no spacers required.
The disc rotors for the front wheels each sit in a 10mm wide spacer (needed for the correct offset) and this has radial thickness too, so these spacers need to be present when you bolt the front discs to the wheel, and the 73mm shoulder will support the spacer and the spacer takes up the distance between shoulder and rotor.
 
Thanks Grant, that?s the gist of it. I?ll ask Mike to read this thread in the morning as I only know what he?s told me and it?s late here.
 
I don't have a photo to hand of these spacers but I think they were needed when using 750 alloy wheels on the triples, and the spacers hung around on all the 180s. When the 6 spoke RGS wheels came out they did away with the spacer as the wheel was machined for the discs without spacers.
 
Hi Carlo, here is a pic of the spacers! If you need some - I have some lying around, but shipping to Australia could be hefty.
Ciao, Gert
 

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Thanks Gert! Appreciate the offer.

I will see if Red or Greg has something first as it would be quicker and cheaper, although I very much doubt it will be quick enough.
 
Just knock one of the original spacers off, the are just a light press fit, and take it to an engineering joint and have it copied x 2.

I have two spares, but are in storage, buried under half a sheds worth of stuff.
 
Yes exploring options. I hadn?t even thought to say, I suspect Mike didn?t want to do that but if it?s easy enough to take them off the old wheels then we should do that.

I?m in Sydney for a couple of days, increases my chances of finding some if not.
 
cbertozz said:
Yes exploring options. I hadn?t even thought to say, I suspect Mike didn?t want to do that but if it?s easy enough to take them off the old wheels then we should do that.

I?m in Sydney for a couple of days, increases my chances of finding some if not.
Click to expand...

Just be careful, the wheel alloy is much softer than the spacers, don?t just hit between the two with a hammer and screwdriver. The wheel will dent. I bent and ground away a brick bolster, to a similar shape of the spacer OD, and rotated the position to tap them off square. Worked good, but if I ever need to break a brick, it?ll break in a crescent shape  :D
 
Can't see any spacers fitted to that 80mm OD front wheel? And there was no mention of needing to alter the offset in your query. I take it it isn't a Lav front wheel? Confused ...
 
Piranha Brother 2 said:
Can't see any spacers fitted to that 80mm OD front wheel? And there was no mention of needing to alter the offset in your query. I take it it isn't a Lav front wheel? Confused ...
Click to expand...

I'm confused now that you've pointed that out Q ............ and what are the three dowel pins for, not seen that before. Could what you have as a front wheel off a 500?
I've had nothing to do with them. But know the OD of the rotors are smaller, maybe the flange ID is too  ???
 
chrisk said:
I'm confused now that you've pointed that out Q ............ and what are the three dowel pins for, not seen that before. Could what you have as a front wheel off a 500?
I've had nothing to do with them. But know the OD of the rotors are smaller, maybe the flange ID is too  ???
Click to expand...

Well by the sounds of it Carlos has a 750 swing arm.... so why not some 500 bits also !
Heinze variaty  :P
 
It always did have two odd wheels and given it had the wrong triples on it (which I replaced after the racing crash last year) it woud be fair to assume it had been in a bit of a bingle back in the UK, although I was oblivious to that back then.
 
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