Twinpot Brake upgrade on 78 Skunk

[bobgroger]

I now have collected all the parts except the rotors. Wondering if anyone has used the Bikemaster 752 rotors? A little more than half the price of EBC, twice the price of Chinese wave rotors. They are made in Europe, and look very well built. Even the buttons are held on with E-clips so they can be rebuilt. A pair from Powersports Superstore is $255 shipped. Amazon has Chinese rotors for $116 the pair. WWYD?

http://www.amazon.com/Wotefusi-Motorcycle-1994-1997-1995-1998-1990-2007/dp/B00FE9C5FK?ie=UTF8&redirect=true&ref_=pe_2313390_187747060_em_des

http://www.powersportsuperstore.com/BikeMaster-752-Brake-Rotor-p/tr962040.htm?gclid=CPS54Yzt38sCFYRrfgodKTwL1w&Click=35177

Here is a picture of the actual Bikemaster part

http://www.ebay.com/itm/BikeMaster-Front-Brake-Rotors-Set-752-/311412869790?hash=item4881a74a9e:g:EvgAAOSwLnlWpBJj&vxp=mtr

I am thinking you get what you pay for, but this will never see a track.

[bobtail84]

Just for info, it is easier to look for ZR750 Zephyr calipers over here in the UK and they seem readily available. I've bought some for fifty of lizzies pounds and will see what they are like and report.

My bracket kit are on there way over the pond, thanks Dan, so all I have to do is track down are some serviceable CBR900RR discs / rotors. I'm looking forward to doing this conversion.

[bobtail84]

I have just read the whole of this thread..... What a truly inspiring read salty_monk has replied to my PM and the wheels are in motion for a kit to be sent to me in the UK.
I have found the calipers here in the UK for a good price and I'm still looking for the CBR900 rotors for the right money.
My GS1000 has passed it's MOT test on Saturday 03 19 (this is our road worthiness test) so I have a whole year of playing with upgrades. I will start a build thread to show how I've got to this Point and to show what is next. I do have quite a special engine to fit hence the brake up grade.
I have been truly inspired by the hard work of you guys in this thread, the information and ingenuity. Also a big hand for Dan as it was his hard work that has made this a viable solution for the somewhat iffy standard GS brakes.
Jeff

[salty_monk]

When the anti-dive is working properly it does a reasonable job in my opinion (based on limited rides on others bikes), not as good as the Honda of the same period (which used a mechanical actuator triggered by fork compression rather than hydraulic). It does affect the lever feel though.

The cartridge emulators are way better.

[bobgroger]

The spacer is tight to the hub & the shoulder bolts centralize the whole thing.

You can send me links if you like & I will tell you if they will fit or not... (if they are OEM that is). Make sure you get a rotor dia of 295mm not the 310mm or 320mm.

A lot of people disconnect it due to a spongy lever feel and/or difficult bleeding but there is no need to. It will work either way. If you disconnect it then either simply leave it disconnected or put a block off plate on.
With a plate you will need to create a channel to link the two holes in the fork otherwise the antidive will be constantly active.

I have 83 1100 forks fitted and use a block off plate with a channel in it. I also use cartridge emulators & a stiffer spring. The rebound adjustment on these forks still works after you fit emulators so I now have a fork with adjustable preload, rebound & compression (via the emulator). Pretty good for a 30 year old fork!

Thank you. I have a better picture now. I was afraid of radial runout. I will check to be sure, but the shoulder bolts should work. The forks are a project for down the road, so I will leave them as-is for now. Who knows, the extra stopping power may allow the anti-dive to actually work?

Bob G.

[kingofvenus]

When i put this set-up on my 850, i installed it like it is intended to be. Then i got a set of '83 1100GK forks for it. They are wider than the stock forks so, i had to move the plate that normally mounts on the outside of the fork mounting lugs, to in-between the lugs and the caliper mount. Everything else, the three bolts, the spacer, in place as before. I've had it this way for a couple of seasons with no problems.

[salty_monk]

The spacer is tight to the hub & the shoulder bolts centralize the whole thing.

You can send me links if you like & I will tell you if they will fit or not... (if they are OEM that is). Make sure you get a rotor dia of 295mm not the 310mm or 320mm.

A lot of people disconnect it due to a spongy lever feel and/or difficult bleeding but there is no need to. It will work either way. If you disconnect it then either simply leave it disconnected or put a block off plate on.
With a plate you will need to create a channel to link the two holes in the fork otherwise the antidive will be constantly active.

I have 83 1100 forks fitted and use a block off plate with a channel in it. I also use cartridge emulators & a stiffer spring. The rebound adjustment on these forks still works after you fit emulators so I now have a fork with adjustable preload, rebound & compression (via the emulator). Pretty good for a 30 year old fork!

[bobgroger]

Is there a preference with the Anti-Dive on the GS1100e to keep it or disconnect it? Also wondering looks like some of the listed rotors have a 58MM center hole and some are 62MM. Are these supposed to be hubcentric? According to my crappy calipers a GS hub is ~56MM

[salty_monk]

Suzuki gs 550, all stock apart cbr 900 discs and zx 600 a calipers. I rested with a plate between the fork and the calipers, it's ok for me!

Over here the GS550 only has one brake, a single disc & it is larger than the duals. I am guessing you are outside of the US or the forks are not stock.

[salty_monk]

A PM back at you!

[bobgroger]

PM sent. I finally have a bike that outruns its brakes

Suzuki gs 550, all stock apart cbr 900 discs and zx 600 a calipers. I rested with a plate between the fork and the calipers, it's ok for me!

[salty_monk]

What bike? What forks? What rotors are you using and what calipers? You say "similar" ones above.

Stock gs axle and stock Wheel.

[Chuck78]

Too much torsional (twisting) force on the fork leg if you bring the caliper in further. Are you running stock GS 15mm axle? Spacing the rotors out for most of the adaptation is definitely the better way to go.