Compatible brakes for 1981 GS450

[supertorro]

I'm looking to replace the stock front brake caliper on a 1981 GS450. My trouble is not knowing which models have typically compatible calipers?

Some suggestions appear that the early Katanas had 4 piston calipers that fit.
Can anyone point me in the right direction?

The current caliper is in such poor condition it really isn't worth trying to rescue. Aside from which I might do a twin disc setup, as the forks can deal with it.

What are the measurements I need to take into consideration?
Eye-to-eye on the axial mounting plate?
Disc diameter?
How much leeway in terms of disc diameter do you have before it starts to become an issue?

Thanks for any info

[pete]

The only one I know for sure is the left caliper off my Katana is a direct swap. When I'm talking Katana here, I'm talking early as in 81 to 85 Katanas, and the 750/1000/1100 not the popup model.

I know there are other models that use the same calipers but I'm not sure exactly which ones at present, but you could use the parts fiche at Alpha Sports to find the part number then do some reverse searching for other models that share it. I tried the caliper and caliper bracket, I don't think you could use the 450 bracket with the Katana caliper though.

[Big T]

You can do half of a Salty_Monk Twinpot upgrade with a caliper from a GS 500 and an adapter plate

I don't think any other GS models used 4 piston brakes

[salty_monk]

Yes you can fit a CBR rotor & a single Twinpot Ninja sliding pin type caliper to that model with adapters... 4 Piston calipers won't fit as they are too deep, the forks aren't wide enough to provide clearance.

[supertorro]

Phew: timely advice from salty_monk. Thanks for that: was actually looking at the non-sliding type and thinking a bracket could be made..

[pete]

I had forgotten all about the twinpot option! Yep, definitely a goer, but the GS500 caliper mentioned above could have a minor issue. I'm pretty sure the disc on those is on the right side rather than left side, so the bleeder is likely to be at the bottom rather than top. I don't think it's the end of the world but would definitely make bleeding an interesting challenge.

[hannibal]

My notes say the following bikes have that caliper on the left:
87-93 Ninja EX500
90-93 Suzuki VX800

Of course, you can also find the left caliper only from the several bikes with dual calipers.

[salty_monk]

Yep, plenty of sources of calipers. There are more rights (and newer) rights around than lefts due to the Ninja 250. The newest ones come from the 99-2006 Concourse.