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Main Area => General GS500 Discussion => Topic started by: 500rider on August 16, 2005, 08:07:43 PM

Title: Four piston brake caliper - mod
Post by: 500rider on August 16, 2005, 08:07:43 PM
Maybe I am not doing the search properly but I couldn't find any references for anyone doing a conversion to a four piston front brake caliper.

I have a friend who has made up a kit to convert norton commandos to four piston brake calipers and could prolly do the same for the GS.  He uses an F3 caliper and I believe a 1/2" master cylinder same as the GS.  

Edit/Correction:  he uses an F3 master cyl and an F4 caliper.  The F3 caliper is a 2 piston sliding type.

Anyone have any thoughts on this?  I have found recently that the front brakes are really weak compared to other more modern set-ups.  I don't believe there is anything wrong with mine.  I just changed the brake fluid and the brake lever is firm, there is just not the same power as other bikes I have tried recently.
Title: Four piston brake caliper - mod
Post by: Chris_B on August 16, 2005, 08:50:07 PM
last time i checked my 99 had a four piston caliper :dunno:
Title: Four piston brake caliper - mod
Post by: Bob Broussard on August 16, 2005, 09:05:13 PM
All you need to do is make a bracket to mount the caliper to the forks.
I mounted a gsxr 1000 6 piston caliper to my my 89. I used a gsxr master cylinder. Unfortunately the gold 6 piston calipers are crap. The stock caliper worked better. The 750 4 piston calipers are much better.
Title: Four piston brake caliper - mod
Post by: Kerry on August 16, 2005, 09:58:11 PM
Quote from: Chris_Blast time i checked my 99 had a four piston caliper :dunno:
It must not be the stock caliper then.  My '99 has a 2-pot unit, as did my '96 and my '00. :dunno:
Title: Four piston brake caliper - mod
Post by: davipu on August 16, 2005, 10:58:34 PM
what's the point? for under 200 you can put a complete kat/rf front end on there and do stoppies all day long.  you put good brakes on shitty forks and you have really touchy brakes that suck even worse for hard riding. because every time you grab a handful you bottom out the forks.
Title: Four piston brake caliper - mod
Post by: Dave Fowler on August 17, 2005, 02:03:49 AM
Hi, I've just done this with a bandit12/old GSXR750 4-piston Nissin caliper.  I spent ages designing the bracket to achieve the maximum contact area between pad and disc while minimising the size of the bracket.
Here's a pic:

(http://www.nottingham.ac.uk/~ppxdrf/pics/Bikes/GS_0705_brake.jpg)

I haven't ridden it much yet as I'm still doing other things to the bike, but as the old disc and pads are wearing in together, it seems to be far exceeding the power and feel of the origional setup.
I can send anyone a picture of the bracket with measurements, or the autocad file (from which the bracket was made) if anyone wants it.
Here's a pic of the nearly finished bike (note SV650 rear shock, GSXR rear pegs and LASER SS exhaust).

(http://www.nottingham.ac.uk/~ppxdrf/pics/Bikes/GS_0705_siderear.jpg)
(http://www.nottingham.ac.uk/~ppxdrf/pics/Bikes/GS_0705_side.jpg)

The next job is to make a new bracket to mount the clocks to the top yoke and fit clip-ons straight to the forks. I was thinking of trying to find some old Honda Hurricane (CBR600F1)  (37mm) clipons. Has anybody got any other suggestions??

Hope some of this is useful.

Dave
Title: Four piston brake caliper - mod
Post by: V8Pinto on August 17, 2005, 06:23:11 AM
How is the feel of that setup?  I've been wanting more lever travel and better modulation out of my stocker.  It seems like all the serious braking happens within a few mm on the stock lever and I'd like to increase that for better control.
Title: Four piston brake caliper - mod
Post by: Dave Fowler on August 17, 2005, 07:44:43 AM
Its hard to say how the 'feel' has been affected as its been a while since I rode the bike with the stock setup and I think that caliper was wasy past its best anyway. However, I never remember being happy with the stock GS brake compared to my CBR600, but I don't perceive much difference now, although I haven't tried braking hard from high speeds yet. I'm using the stock GS master cylinder and brake line. Both work fine.
Title: Four piston brake caliper - mod
Post by: Kerry on August 17, 2005, 07:52:04 AM
Quote from: Dave FowlerI'm using the stock GS master cylinder and brake line.
Did I miss something?  Has the GS started coming stock with SS brake line?
Title: Four piston brake caliper - mod
Post by: Dave Fowler on August 17, 2005, 08:09:41 AM
Oops, no. I meant the brake line with the same length/fittings as that used for the stock caliper.

By the way, I forgot to mention that the GSXR rear peg conversion was inspired by the how-to on Pablo's page (and some very rusty original pegs!). However, I have made some brackets which allow the seat fairing bracket points to be retained. I can post pics of these as well is anyone is interested.


Dave
Title: Four piston brake caliper - mod
Post by: dgyver on August 17, 2005, 08:34:56 AM
Quote from: Bob Broussard.....Unfortunately the gold 6 piston calipers are crap.....

Interesting. I have not heard that. I thought they were the same as the black six pots.
Title: Four piston brake caliper - mod
Post by: Blueknyt on August 17, 2005, 09:32:02 PM
how thick is your adapter plate? is it made from aluminum?
Title: Four piston brake caliper - mod
Post by: Dave Fowler on August 18, 2005, 12:14:40 AM
Hi,

The plate is 6mm mild steel. That is the thickest it can be if you want to mount on the 'disc-side' of the calipers. I drilled out the threads in the caliper and tapped the bracket. There are some thin washers between the bracket and the fork mounting points to provide the correct lateral alignment, but they're only 1-2 mm thick.

Here is a pic with measurements...

(http://www.nottingham.ac.uk/~ppxdrf/pics/Bikes/GS_brake_bracket_4.jpg)

...and here is the autocad file:

http://www.nottingham.ac.uk/~ppxdrf/pics/Bikes/GS_brake_bracket_4.dwg

You also need to file a notch near the top left hand hole so that it mates up with a small protrusion on the caliper, but its fairly obvious and straighforward when you see it.

Hope this helps.

I can be reached at bobdave87@hotmail.com for any more info.

Thanks

Dave Fowler
Title: Four piston brake caliper - mod
Post by: Blueknyt on August 18, 2005, 01:24:35 AM
welp, im trying to make a plate to mount a Katana 600 caliper much the same as you.
Title: Four piston brake caliper - mod
Post by: werase643 on August 18, 2005, 04:51:26 PM
Quote from: Dave FowlerHi,  The next job is to make a new bracket to mount the clocks to the top yoke and fit clip-ons straight to the forks. I was thinking of trying to find some old Honda Hurricane (CBR600F1)  (37mm) clipons. Has anybody got any other suggestions??

Hope some of this is useful.

Dave


consider....that if you go to clip-ons...you have to re design the headlight brackets
Title: Four piston brake caliper - mod
Post by: Dave Fowler on August 19, 2005, 02:25:39 AM
My idea was to remove the plate above the top yoke, on which the handlebars and  clocks are currently mounted. This plate is pretty thick. If I also raise the forks a little, this should give enough fork to mount the clipons (above the top yoke). Then all that needs to be done is to make a different bracket to mount the clock bracket. Am I missing something??