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Underslung Rear Caliper conversion on a Z1R
Posted: Tue Jul 23, 2013 5:30 pm
Author: Fred the Zed
Hi
For reasons I won't go into, I'm thinking of converting the heavy, chunky, ugly caliper and disc arrangement on my Z1R to something a little slinkier looking and underslung. I understand that the torque arm mounting on the swingarm needs swapping to the underside from it's current position but don't worry, I can sort that easily enough.
I was looking at either a disc, caliper and carrier off a ZRX1100, ZXR750 or ZZR1100 for the mod. I want to keep the original wheel. Has anyone else out there done an underslung rear brake caliper conversion on a Z1R / Z1000 who can offer some advice please?
Fred
Posted: Tue Jul 23, 2013 8:17 pm
Author: KeithZ1R
Think Chrisu is your man
Posted: Tue Jul 23, 2013 8:31 pm
Author: Z1parR
Pigford or GB will have ideas on this too , i should think .
There's a few serial modding types about on here

Posted: Tue Jul 23, 2013 9:13 pm
Author: chrisu
KeithZ1R wrote:Think Chrisu is your man
mine is a brembo baked into the single sided hub so very off piste.
Posted: Fri Jul 26, 2013 12:22 pm
Author: Ginger Bear
The Tokico caliper you are talking of was fitted to many bikes, ZX7R GSXR600/750 SRAD Early Busa's etc.
You might be able to use the complete caliper & carrier assembly, just sleeving down the spindle hole on the carrier & modding spacers to get the caliper in line with the disc.
I'm sure the disc mounting holes wont line up, so you may have to re-drill it, or make some sort of adaptor plate. or have a 'one off' disc made.
If you don't or can't use the existing carrier, it wouldn't be too hard to make a new one, from something like 10mm aluminium plate/bar.
Thanks for the advice
Posted: Sat Jul 27, 2013 7:04 am
Author: Fred the Zed
Thanks for the advice guys... I'll apply my mind to what will perform / look the best.
Fred
Posted: Sat Jul 27, 2013 12:15 pm
Author: Ginger Bear
Just found this pic on Ebay...... Thought it might give some inspiration.

Posted: Sat Jul 27, 2013 7:24 pm
Author: Fred the Zed
Sweet
Posted: Mon Jul 29, 2013 8:51 pm
Author: big green bus
Put an ap calliper and brembo master cylinder on mine and it would not hold it on a hill ! You need to make sure you get the ratio correct or you will have no brake or a one that locks with the lightest touch
Posted: Tue Jul 30, 2013 5:20 am
Author: Fred the Zed
Good point, well made!
Can you post a picture of it up for me to see? How did you sort out the hanger arrangement?
Fred
Posted: Thu Aug 01, 2013 3:06 pm
Author: Ginger Bear
Fred,
I took a couple of pics of Jak's version last weekend....... Just for you!
Notice the use of small washers/shims to get the caliper central to the disc.

Posted: Thu Aug 01, 2013 6:00 pm
Author: Fred the Zed
Hey Ginger Bear
That was very decent of you. It's a project that will take a little thought, but should be worthwhile in the long run.
Are Jak & Big Green Bus one and the same person?
Once again, thanks for the photos and pointers.
All the best
Fred
Posted: Thu Aug 01, 2013 7:46 pm
Author: hillbilly
just to let you know,i have a brembo on my yellow beasty,its upside down,thing i found out.was that it wouldn't bleed up properly,so i had to de mount it,put it on the top of disc,then bleed it,then put back on at bottom.
Posted: Thu Aug 01, 2013 8:05 pm
Author: Ginger Bear
Fred the Zed wrote:
Are Jak & Big Green Bus one and the same person?
Definitely NOT.

But both 'TOP' blokes all the same.
Posted: Fri Aug 02, 2013 7:05 am
Author: Big Fluff
If you do go ahead with this conversion, you may want to think about making the caliper floating, and attaching the torque arm to the frame.
If you fasten the 'short' torque arm to the swing arm then it's straight forward enough, but as you know, when the brake is applied the rear end will dip.
In previous bikes (inc. my old Moto Martin) I turned a bush within the caliper carrier, so that when the rear wheel spindle is pinched up, the caliper and carrier bracket are free to swing 'float'. Fabricating a longer torque arm and fastening to the underside of the frame will then allow you to brake with no dipping of the rear end.
It's all down to personal preference but much prefer the feel of a floating rear brake.
Will