T brake mods

[Chuck in Indiana]

Ok, I've finished the Commie Thumper

and The Kid dropped off this T front end.

He wants to use these calipers

and these rotors

I'm guessing that this is not the first time something like this has been done.  ;D I'll be out at Mark's in SoCal where I can rummage through his pile of munt shortly, if there are stock parts that can be used. If so, can anyone point me in the right direction?
No need reinventing the wheel  ~; if it's already been done, but I can make about anything necessary.
TIA

[Perazzimx14]

What is the offset of the T rotor and would you or your son be willing to sell it if its usable??

[rodekyll]

Chuck -- it would help to identify the rotors and calipers.  Also, I'm not sure what you're asking.  If you're asking if anyone has tinkered odd rotors to Guzzi wheels, yes.

I put Honda rotors on a Lester mag.  When I got the hub spacers fitted the calipers needed a 0.060 shim on each side to center them on the rotors.  No big deal, since Brembo rotors are supposed to be shimmed for centering.

The rotors were the big hassle -- bolt pattern was different and the center hole was different, so the indexing shoulder didn't help to center the rotor on the hub.  I centered them and redrilled for bolts.  I needed two circles of bolts.  One for the through-hub shackle bolts, and since I didn't like the clearance on that circle I drilled another circle for rotor-to-hub attachment.

I'm using a NISSIN radial master cyl from a gsxr to squeeze them.

[Chuck in Indiana]

What is the offset of the T rotor and would you or your son be willing to sell it if its usable??

I just stuck a scale on it, and it says about .9" That's about 23 mm. Assuming I get it apart tomorrow, I can give you an actual measurement.
I'm *assuming* it's stock T. I'll indicate it if you want to see if it's warped, but I'm betting it's ok. I'll ask him, but I don't see why he wouldn't sell it.

[Chuck in Indiana]

Chuck -- it would help to identify the rotors and calipers.  Also, I'm not sure what you're asking.  If you're asking if anyone has tinkered odd rotors to Guzzi wheels, yes.

I put Honda rotors on a Lester mag.  When I got the hub spacers fitted the calipers needed a 0.060 shim on each side to center them on the rotors.  No big deal, since Brembo rotors are supposed to be shimmed for centering.

The rotors were the big hassle -- bolt pattern was different and the center hole was different, so the indexing shoulder didn't help to center the rotor on the hub.  I centered them and redrilled for bolts.  I needed two circles of bolts.  One for the through-hub shackle bolts, and since I didn't like the clearance on that circle I drilled another circle for rotor-to-hub attachment.

I'm using a NISSIN radial master cyl from a gsxr to squeeze them.

I assume the calipers are stock T. Braking rotors, that are 20mm bigger diameter, so I'll have to move the calipers. Just wondered if someone had already been down that road and would give me some ideas..

[Hahnda]

I don't know much about using different rotors but I just went through the hassle of gathering the parts to switch the T front wheel to dual disc. You probably already noticed that the bearing carriers are different on each side on the T hub. The rotors you want to use are flat and have no offset like the original. I guess you would want to find another bearing carrier to match the one that holds the disc now and then fabricate some spacer plates to attach the rotors. Or just fabricate completely new bearing carriers that are wider that space those rotors out to the correct offset.

[rodekyll]

That is the easy part.

Once the rotors are attached to the wheel, install the wheel as normal. 

Then slip the calipers over the rotors and put them where you want them on the arc of the rotor. 

Squeeze and hold the handle with something (a few wraps of bungee cord works) 

Measure the gap between the fork lugs and the caliper lugs.  That's the spacer distance you need to make up.

Measure the offset to the lug hole centers.  That's the arc difference you need to make up.

Find some aluminum plate  that's as close to the lug gap (a few thous' skinny is fine, since you use shims to center the caliper).

Shape and drill as needed.


Getting the lug offset correct is a chore when you've got the same spacing for the fork and caliper lugs.  It's easier to do with vastly different mount points -- like putting a 4-pot 'modern' brembo where the P08 was.  That way you have plenty of room for the bolt holes.



BTW -- this procedure comes to me courtesy of a couple of old gents who I met in the Yukon at a rest stop.  They were coming from some village and headed for Daytona, where they were entering their vintage bikes in the vintage races.  Yes, they were riding their vintage racers down the ALcan and across the continent to participate.  When the conversation turned to modernizing bikes for modern highways, they were a wealth of practical information.  Thanks, guys, whoever you were!   ;-T

[Chuck in Indiana]

Yeah, and the calipers need to be moved to accommodate the larger diameter rotors. I'll look when I'm at Mark's to see if there is a bearing carrier laying around. Thanks..

[Chuck in Indiana]

That is the easy part.

Once the rotors are attached to the wheel, install the wheel as normal. 

Then slip the calipers over the rotors and put them where you want them on the arc of the rotor. 

Squeeze and hold the handle with something (a few wraps of bungee cord works) 

Measure the gap between the fork lugs and the caliper lugs.  That's the spacer distance you need to make up.

Measure the offset to the lug hole centers.  That's the arc difference you need to make up.

Find some aluminum plate  that's as close to the lug gap (a few thous' skinny is fine, since you use shims to center the caliper).

Shape and drill as needed.


Getting the lug offset correct is a chore when you've got the same spacing for the fork and caliper lugs.  It's easier to do with vastly different mount points -- like putting a 4-pot 'modern' brembo where the P08 was.  That way you have plenty of room for the bolt holes.



BTW -- this procedure comes to me courtesy of a couple of old gents who I met in the Yukon at a rest stop.  They were coming from some village and headed for Daytona, where they were entering their vintage bikes in the vintage races.  Yes, they were riding their vintage racers down the ALcan and across the continent to participate.  When the conversation turned to modernizing bikes for modern highways, they were a wealth of practical information.  Thanks, guys, whoever you were!   ;-T

And thanks for that, David..