[Fixed] Brakes: The 1000$ mistake!

mark1122 wrote:

Fish. would it make sense to just drop the speedo gear, to pick up extra clearance? can he not use his forks in the KZ P triples, by bushing the tree clamps?

Dropping the speedo drive cures the disc clearance issue, but creates another issue as a working speedometer is probably also on the DOT inspection list.

Bushing these clamps to fit on those forks? I don't know.

All the kits I make and sell have to be bolt on and can't have tiny disclaimers like *speedo drive must be removed and an expensive electronic speedometer must be purchased and used in order for this kit to fit and pass your local inspection*.
I wouldn't sell any kits if that were the case.

The K.I.S.S. phrase of "Keep It Simple,Sonny" comes to mind. Using a pair of 2 piston floating calipers would be a "simple" inexpensive cure to this situation.

Changing the forks to wider forks,etc. just adds more problems/issues that would/may need to be overcome and the speedo drive/disc clearance issue is still there to be dealt with.

I have measured the grimeca calipers for you.
- Overall width 80.5mm
- Disc slot width 10mm (approx 9mm between pads)
- Width from inside pad to outside caliper on wheel side 36mm
- Pad depth 36mm

You want to line the top of the pad up with the top of the disc. The bottom of the pad on these calipers is also the bottom of the caliper. So from the top edge of the disc down 36mm, you need at least 36mm+clearance between the spokes and the disc. These calipers are beveled at the bottom to aid clearance on spoked wheels, depth is about 32mm at the narrowest part but 15mm higher you are back at 36mm.

The Fish wrote:

mark1122 wrote:

Fish. would it make sense to just drop the speedo gear, to pick up extra clearance? can he not use his forks in the KZ P triples, by bushing the tree clamps?

Dropping the speedo drive cures the disc clearance issue, but creates another issue as a working speedometer is probably also on the DOT inspection list.

Bushing these clamps to fit on those forks? I don't know.

All the kits I make and sell have to be bolt on and can't have tiny disclaimers like *speedo drive must be removed and an expensive electronic speedometer must be purchased and used in order for this kit to fit and pass your local inspection*.
I wouldn't sell any kits if that were the case.

The K.I.S.S. phrase of "Keep It Simple,Sonny" comes to mind. Using a pair of 2 piston floating calipers would be a "simple" inexpensive cure to this situation.

Changing the forks to wider forks,etc. just adds more problems/issues that would/may need to be overcome and the speedo drive/disc clearance issue is still there to be dealt with.

You guys both bring up very valid points, I would not readily dismiss any options, including a front end swap (rather than just forks/clamps), it all depends on how bad you (ElCouz) want opposed piston calipers, preferably the ones you have bought at great expense. I have some experience with this because I just built a whole front end around my caliper/discs of choice including a front end swap, custom offset carriers, wheel spacers etc.

The most obvious swap to me would be to a complete 80-82 GPZ1100 front end (clamps, forks, wheel, axle, speedo drive) rather than a police front end.
I agree with Mark a well executed front end swap should be fine for a mechanical/DOT inspection (especially when they are same brand/year/model family) but I would suggest using the complete front end of the donor bike. The GPZ1100 forks are thicker (38mm) and I believe fork spacing is a bit wider.
The first three things to check:

1. fork spacing
2. GPZ1100 hub width/disc offset (if wheels are different from GPZ750)
3. do the EBC discs fit on GPZ1100 hub
4. speedo drive type

This information will give you a few different scenarios. You may now have the room to space out discs further or have more room for wider calipers. You'll have to check if your gauges etc. can be mounted to the GPZ1100 clamps - all this can be overcome.

If the 1100 hub width and the speedo drive are the same as the GPZ750 and you can or will not work around it than this is your limiting factor, and as the Fish wrote, you will simply have to purchase calipers that work in the confined space you have available now.

Here's a front end off ebay, looks like the speedo drive may be electronic??

cgi.ebay.com/ebaymotors/ORIGINAL-FRONT-R...fPartsQ5fAccessories

Good luck bud.

Hi everybody,

sorry for late reply.

I have measured the grimeca calipers for you.
- Overall width 80.5mm
- Disc slot width 10mm (approx 9mm between pads)
- Width from inside pad to outside caliper on wheel side 36mm
- Pad depth 36mm

Thanks Dutchz, almost no difference between the Nissin 4 pots i have and your grimeca

The most obvious swap to me would be to a complete 80-82 GPZ1100 front end (clamps, forks, wheel, axle, speedo drive) rather than a police front end.
I agree with Mark a well executed front end swap should be fine for a mechanical/DOT inspection (especially when they are same brand/year/model family) but I would suggest using the complete front end of the donor bike. The GPZ1100 forks are thicker (38mm) and I believe fork spacing is a bit wider.

I agree with you that a swap is another solution but i wouldn't do this. I've already put money on my current fork (rebuild at dealer + wheel bearings 150$). Since I've spent all my budget for this motorcycle
I'm very tight on money right now.

The quickest way is to fit calipers that have enough clearance.

Got answer from 2 other company that build caliper that will fit is also VERY expensive (around 800-900$ USD / pair). A friend told me today it's not worth it because the motorcycle will brake faster than accelerate (or required)


I will go with floating calipers. I'm still looking on ebay.

Dropping the speedo drive cures the disc clearance issue, but creates another issue as a working speedometer is probably also on the DOT inspection list.

You are right on that it must have a working speedometer.

BRB later i will try to translate the pdf document from my government inspection.

best regards,
laurent

Well u have a path to follow anyways. this stuff is often troublesome. part of the satisfactions of doing this stuff, is the feeling of gratification u get when u finally overcome the problems u have faced.
Good luck with it, and let us know how it turns out.
Mark.

I feel your pain! I have a 77 kz1000 with fouling plugs. I'm about $600 in and a lot of new parts and still have the same issue. Only different is my wallet is alot lighter.

if its only a $1000.00 mistake ,youre still better off than some of my past experiments! :laugh:

ok guys here's an update.

With the ebay listing of calipers that will not fit... i can't find a solution but to buy original calipers for the moment.

I visited one guy today who was parting a gpz750 1981. Tried his brake before parting it out. ZOMG the lever feel the same as me.. Goes to the bar + very spongy. He told me he as been riding like that for years and its a common problem with these Kawasaki calipers.

Anyway i bought the Master Cylinder + 2 front calipers. Guys is it true that these calipers are always like that (no firm feeling ever achieved?)? I will be crossing my finger when i will be installing them. I hope it will not be spongy ... i want to pass the inspection and finally ride it !


regards,
laurent

Hope it all works out for you.
Good luck.

I jumped in a couple of times, including back when you had been trying to bleed the stock stuff.
For this year to get back on the road I would stay stock if it means failing an Inspection if modified.
Go back to make sure that all of the hydrolics are fresh, make sure where you calipers bolt on that the slides are free, if they hang it can cause weak braking, then back to bleeding, this is going to be time consuming with any brake on a Kaw. You must keep the part of the master near the handlebar end higher than the hose end, pump/ hold bleed. with a clear tube in a clean container so you can see the air. Let it sit with the master on this incline, you want it to let the air escape back to the fluid chamber. You may find the air is in the crossover at the tripple clamps, you may need to have the bike level on the center stand. You can have the caliper loose from the forks and slowly push the piston part way out, then squeeze it back in fully with a C-clamp, with the hose fitting vertical, this will help force the air back to the fluid chamber. I think it gets trapped in the crossover.
And yes, 3 KZ's with disc front, all firm and good feel, don't give up.

I think it gets trapped in the crossover.

Yeah , the T splitter is a real nightmare!

I will bypass it... one long pipe going from MC to first caliper then connecting the second caliper from the first with a double banjo bolt setup.

I want to have chance on my side this time !

When the brake will be finished i will return the 16 bottles of (used) DOT4 fluid I've used on the GPZ to the store. Can wait to see the face of the guy who responsible of taking used oils. :lol:


alright, i will keep you informed guys!


regards,
laurent


EDIT:

you may need to have the bike level on the center stand.

Unfortunately the last owner broke the center stand holding brackets (so no center stand anymore ). I think that bleed with the brake inclined is one of my problems. I will try to jack the bike next time!

When bleeding and bleeding and bleeding I recycle my fluid back to the master, since it is all new and clean anyway. 1 quart bottle for $5.