Question for the REAL machinists out there...

[Montreux_Blue]

What about a notch like on a lawnmower flywheel and crankshaft with a tap in key to keep it from spinning?

[crazy steve]

...Typically allow .0005 press fit per inch diameter on steel and twice that on aluminum...

Thanks John, that's what I wanted to know; so my plug should be .001" oversize (for a 1" hole) for a 'press fit'. Should I use some sort of locktite product to install this? Or I suspect that just 'pinning' it will be more than adequate to prevent any possiblity of rotation.

Got a line on a late ('02-07 touring) caliper for a reasonable price, so I'm going to give this a shot.

'78E original owner

[jmnjrpa]

Fred

is right about the loctite for the application they used it for but your needs are far different. If you don't go the weld it up method then I would suggest drill and press a pin (aluminum) 90 degrees (or at some angle) through both parts before drilling out to size. Pin could be 3/16 to 1/4 inch. The pin should enter the thick portion of the plug.

[randy]

What about a notch like on a lawnmower flywheel and crankshaft with a tap in key to keep it from spinning?

Good suggestion, poor example. That woodruff key is as close to shearing as I've ever seen. And I've sheared enough of them to know

[Schming]

Offset?

Hi Steve, I might have missed it somewhere but I was wondering which way You needed to offset the caliper. If the XSisting rotor is too tight couldn't You have it turned down in diameter?

What I want to do is fill an axle hole, then redrill to a smaller size and offset it a bit. This won't turn, it's strictly a locating hole. I'm installing HD 4-piston calipers on the FJ front end I'm currently thrashing to install, and have decided to go whole-hog and use a hd 4-piston rear too. The caliper looks like this:
http://cgi.ebay.com/ebaymotors/ws/eB...m=160425492340
The existing axle hole is .750" and I need to reduce it to 17mm; the offset is to correct the slight difference in rotor diameter (about 1/4").

I like the hot/cold idea; maybe I'll put the caliper (when I get one) in my oven and see how much expansion I get....

'78E original owner

[Ivan]

That might be the best solution yet. If you only need to take .125 off the raduis of the rotor, it would be easy, then you could just make a concentric bushing and not really even worry about a press fit.

[crazy steve]

I thought about that, but I don't have quite enough swing on my lathe so I'd have to pay somebody to do this. And if I ever need to replace it, I'll be right back in the same boat; by altering the caliper mount (a non-moving, non-wearing part), it will simplify things later.

'78E original owner

[fredintoon]

I thought about that, but I don't have quite enough swing on my lathe so I'd have to pay somebody to do this. And if I ever need to replace it, I'll be right back in the same boat; by altering the caliper mount (a non-moving, non-wearing part), it will simplify things later.

'78E original owner

Hi Steve,
lotsa those disks around, if ever you go back to stock you can easily buy another one.
Leave the disk on the bike, remove the caliper, put the bike on it's centerstand, run it in 1st gear on high idle and take an angle grinder to to the disk O.D. as it rotates.
Take it slow and allow lots of cooling time for the disk and for the motor.