Dual disc options on z1 900

I swapped for a 1980 kz 750 front end to accomplish my dual front brake setup, as Jeff said its and easy swap

wouldent the 1976 ltd 900 work same legs as the z1 i think??????? steve

kawman14733 wrote:

wouldent the 1976 ltd 900 work same legs as the z1 i think??????? steve

Although the bike is a KZ, the fork legs are Z1. They weren't fitted to those bikes out of the factory.

stock ltd. cant remember how i did it but thought it was the ltd 900 caliper i did on my 73??????????

Jeff.Saunders wrote:

kawman14733 wrote:

wouldent the 1976 ltd 900 work same legs as the z1 i think??????? steve

Although the bike is a KZ, the fork legs are Z1. They weren't fitted to those bikes out of the factory.

kawman wrote .im pretty shur the bolt spacing is the same though.not positive ltd 900 have a different triple tree bearing too,,, mabee somebody with a ltd 900 could check spacing i did it without maching i think just been 20 years

I'm going to stick to the single disc set up for now. I have an '80 KZ750G front wheel and a '76 KZ900 (I think...it's a 6mm disc with 4 bolts)rotor. Will a stock Z1 axle assembly/speedo drive work with this set up?

Jeff.Saunders wrote:

Your braking would be a little stronger - but you are not going to stop quicker in an emergency - the front tire is the limiting factor there.

I think this is a very valid point/consideration and is the biggest reason I decided not to pursue this "upgrade".

On a Z1, the double disk setup is crazy heavy. Each disk rotor 7mm thick and weighs 10lb. On the later models, they reduced the thickness to around 5mm and drilled the disk to drop the weight.

I've ridden a Z1 with double disk, and actually prefer the single disk setup. Cosmetically the double disk gives a nice balanced look, but I didn't like the increased shock coming up through the bars.

The double disk setup will give a little more stability to the front wheel - the centrifical weight will help keep it pointed forwards - and reduce the likelyhood of wheelies...

not trying to hijack but I think my question is relavent to the topic, will the stock Z1 resevoir/mastercylinder, suffice for a dual brake setup ???? or will a change be neccessary ???

It depends...

1/2" master cylinder came on the single disk Z1, KZ900 and first year KZ1000 - 42mm pistons in those calipers

14mm came on some of the dual disk KZ650's. Those calipers have 38mm pistons.

5/8" masters came on the double disk 1000's - each caliper came with 42mm pistons.

a 14mm master will push roughly 20% more fluid than a 1/2" version.

a 5/8" version roughly 50% more than the 1/2".

If you run a 1/2" master on a double disk setup with 42mm caliper pistons, you run the risk of the lever coming all the way back to the grip under hard braking. If you use calipers with 38mm pistons, you will probably be OK, but will notice more lever travel.

what about 1980 kz 750s ???

I'm not positive, but I believe a larger MC is required for dual disk.