(https://i.postimg.cc/x8grTxL5/20190324_123616.jpg) (https://postimg.cc/9w4gLB8w)
FZR rotor and spacer made from an old disc mount installed.
(https://i.postimg.cc/Bnrzs9ds/IMG_20871.jpg) (https://postimg.cc/4Y1PbMfF)
R1 caliper installed. A Yamaha Zuma 11MM master cylinder and a used steel braided line were installed and bled. Then the line sprung a leak at the collar so Frank B will procure a new one. All in all a good days work and now Frank has big brakes : :metal: :metal: :metal:
Picture of the finished spacer??
keep in mind, that was a copied test bracket i made, then later did one out of aluminum. its super strong, thats for sure. (the geometry is on the tech library, the aluminum version) the rotor spacer is just a 12mm thick hat ring cut down. however, there were issues apparently clearing a mag spoke. ? I never tried it on a 400.
Yes it is very close to the mag spoke. But it doesn't touch it. On my 75 RD350 I had to relieve the caliper for spoke clearance. The spacer could be a MM or two thicker. Frank is researching a possible alternative from a Ducati with the same bolt pattern. It is functional as is. We had a local shop cut this one out of 3/8 steel plate using mine as a pattern and drilled the holes with my drill press, and elongated to fit as necessary to match the original for fitment with a burr. Thanks again Mark :patriot: :patriot:
Quote from: Kawtriplefreak on March 25, 2019, 09:04:17 AM
Frank is researching a possible alternative from a Ducati with the same bolt pattern.
Ducati discs with 6xM8x80 mm bolt circle generally have only 10 mm offset, so would require a 12 or 13 mm spacer. On my 1977 XS650, I ordered a custom 320mm disc from ISR of Sweden, with 23 mm offset. That left approx. 2.0 mm clearance between fork slider and disc, and gave sufficient clearance between spokes and a Brembo 4 pot caliper with 65 mm bolt centers (late 90s type Brembo 4 pot)
ISR discs cost a pretty penny, but work great, and you avoid disc spacers and longer bolts.
frank can check ducati monster discs, 750s. im not sure of the offset or dia but they bolt on :twocents:
Quote from: m in sc on March 25, 2019, 09:59:02 AM
frank can check ducati monster discs, 750s. im not sure of the offset or dia but they bolt on :twocents:
All Monster 600 and 900, all 600, 750 and 900SS, ST2 andST4, 916 and 748 I have seen, share the same 320mm diameter and 10 mm offset disc dimensions. Some later Ducatis have 5 bolt mounting, so will not fit any RD. The very common Ducati discs with gold colored carrier and round holes in the carrier are very heavy, because the carrier is steel, between 1800 and 1900 g IIRC. A spacer and longer bolts will add another 100-200g, so this is no lightweight setup.
320 mm disc with 23 mm offset, custom made by ISR of Sweden, on my 1977 XS650D. Around 1400 g, no spacer or long bolts required.
Brembo caliper mocked up. I guess RD400F forks are very similar to XS, using the same solid discs and single piston calipers.
^ very nice. :clap:
Half finished caliper bracket, this time around the photo is not mirror image...... :whistle:
The problem seems to be just the spacer thickness, it does need to be 12mm as Mark mentioned but the rd350 rotor hat that we used is only 9.8mm. Never measured it before hand.. :bang:
I have some 1/2 aluminum plate ordered, and some new braided lines.
I like that ISR rotor! Care to share the cost?
The Ducati part I was looking at was just a spacer. I remembered that Mark mentioned that they share the same pattern and in my search I found some spacers listed to fit the Ducati. They weren't offered thick enough to use just one and I don't want to stack them.
Here is a link to the ISR website. Did you know that Eddie Lawson used ISR 6 pot calipers on his YZR500?
http://isrbrakes.se
Looks like a full floating 320 mm disc will end up around 3000 SEK or 325 USD, plus shipping and any US import duty.
IMHO, ISR discs are comparable with the best from Brembo or BrakeTech, with the added advantage of custom carriers to the customers spec. You can basically design your own disc, and ISR will make it for you.
Or you can modify one of their standard discs. My disc is basically a Ducati model, just with 13 mm more offset (23 mm vs 10)
Thanks, I figured it would be expensive, but definitely looks like it's worth it!
Quote from: Frank B on March 26, 2019, 12:29:58 PM
Thanks, I figured it would be expensive, but definitely looks like it's worth it!
Yes, they really are. On my 1995 Ducati Monster 600, I replaced the stock 320 mm Brembo disc (the common early/heavy type, with steel disc carrier/hub) with an ISR full floating disc. Saved around 1 lb/450 g in the process, and braking improved considerably as well. I used EBC HH type pads,and kept the stock Brembo caliper and master.
For an all-out lightweight setup, ISR make calipers with less "swept height", that will allow even lighter "narrow band" discs to be used. For a street RD, a 290-300 mm disc and a 4 or 6 pot caliper should be more than enough.
for the more finalised version of this bracket:
http://www.2strokeworld.net/forum/index.php?topic=184.0