Twinpot Brake upgrade on 78 Skunk

[Darin Jordan]

OK, not wanting to risk those "inexpensive" aftermarket rotors, I have found myself a set of the 99-2000 CBR600F4 Stock rotors that appear to be in good shape on ebay.

Ordered some ECB Kevlar Pads for same.

Got the black powder-coated brackets this weekend (Thanks, Salty-Monk!).

Also received my 1988 Ninja 750 Calipers in fine condition.

Need to look over the calipers carefully to see if they need rebuilding (most likely will anyhow), but otherwise, I think I have everything now to do this update.

 

[GS-cafe]

Quick Question for those here who might have experience with some of the aftermarket rotors listed on Ebay... The ones sourced from Hong Kong, etc.

They look cool... but are these substandard materials and should they be avoided?

Would like to buy brand new rotors for this conversion, so looking for options.

Thanks!

i had some of those China disks on my previous bike (1997 Suzuki TL1000), they worked perfectly, i also was a bit reluctant on using those, but after lots of searching on bad reviews, i couldnt find any, only hearsay, i did find plenty of pictures of broken/sheared Galfers,Braking EBC and Brembo disks.. all after heavy use on a race track i might add..

but on an old GS?? i would put those on in a heartbeat...

 

[Darin Jordan]

i had some of those China disks on my previous bike (1997 Suzuki TL1000), they worked perfectly, i also was a bit reluctant on using those, but after lots of searching on bad reviews, i couldnt find any, only hearsay, i did find plenty of pictures of broken/sheared Galfers,Braking EBC and Brembo disks.. all after heavy use on a race track i might add..

but on an old GS?? i would put those on in a heartbeat...

I'll keep this in mind of the stock ones I purchased don't work out. It's always a crapshoot going from just pictures, but they supplied some pretty decent pictures from all angles, so I feel fairly comfortable.

 

[Nickolarge]

Fitted my rotors and calipers at the weekend. No problems with the fitting. The brackets worked perfectly. I had some binding but that was ok as I was only putting the bike on the road today. The seals for the calipers arrived this morning and after cleaning out the bodies and fitting the seals everything is ok. What pads should I be using? The calipers came with some EBC HH pads that seem to have plenty of life in them but I will be fitting new ones as I don't cut corners with my brakes.

 

[steve murdoch]

EBC HH pads work great.
If they have plenty of meat i would use them.
Excellent reviews from M-S. http://www.motorcycle-superstore.com/11048/i/ebc-double-h-sintered-brake-pads

 

[salty_monk]

Yes EBC pads are really good. The Stock Tokico ones are pretty good too. The generic "organic" ones around definitely don't have as much bite.

If the pads are in good shape, worn evenly, not scored & not soaked in brake fluid then they should be ok to use... Make your best judgement and remember any pad will need bedding in.

 

[Darkspeed]

Pm sent...need some of these brackets.

Re: pad choice, ebc hh is a good pad for street and I've used them for a bunch of bikes, but they do fade under very hard riding or track use. For my fast bikes I use vesrah rjl now. Make sure the surfaces are clean, flat and worn even if you plan to reuse them like other guy said

 

[Nickolarge]

Went for the first proper ride tonight. The brakes are fine with the old pads. Two finger braking. Excellent.

The bike seems to have developed another slight problem though that I don't remember from riding it over the previous few years. After overtaking some cars as I pulled back in I got a bit of a front end shake like the beginnings of a tank slapper. Any ideas?

 

[salty_monk]

One back at ya... Still got some brackets here.

 

[Chuck78]

Well we sorted that out... We now know how to fit them to the 85 550E! No change in parts but slightly different configuration.

I do have some more brackets here if anyone is in need.

I believe the solution that you came to is probably the same fitment that is needed to use this brake mod on the GS 1100 GK with its 204 mm center to center 41mm diameter fork legs, much wider & thicker than most GS's. the brake mounts on the fork legs set in much further and are much thicker, but still, that bike was a very special beast all on its own.

 

[salty_monk]

Yes could be!

There are still a few sets of brackets here and I have one full kit with some 2006 Concourse calipers (the very last year you could get these calipers on anything)

 

[Nickolarge]

Here is a picture of mine with the brake mod fitted.

 

[salty_monk]

Looking good!

 

[Thumper88]

Thanks for the brackets Dan! Just got back from a spirited ride--huge improvement.

 

[salty_monk]

Nice! - Thanks for the pic

 

[80GS850GBob]

I'm a convert!...well, I'm going to be soon.
I welcome the added front stopping power for my old girl, heavy as she is - user name is my bike {how clever, I know} - but what I have to question is this; what is every one doing for the rear brakes? It's opposed singles back there, but couldn't that be improved?
I know, the majority of stopping is done on the front{s}, but wouldn't it be even better for a rear brake upgrade as well?...and to have it "match" too?
My main concern for the upgrade was improved stopping power, but let's be honest here, it looks good {win/win} and runs nearly the same cost as twin oem rotors but better stopping.
I sort of worry about the looks of the back end.....since I'm guessing that even though mine weighs more, my buddy on his CB750 will be getting a good look at it from that view. {unless he gets a jug kit, then I'm in trouble}....seriously though, rear kit?

 

[Guest]

I'm a convert!...well, I'm going to be soon.
I welcome the added front stopping power for my old girl, heavy as she is - user name is my bike {how clever, I know} - but what I have to question is this; what is every one doing for the rear brakes? It's opposed singles back there, but couldn't that be improved?
I know, the majority of stopping is done on the front{s}, but wouldn't it be even better for a rear brake upgrade as well?...and to have it "match" too?
My main concern for the upgrade was improved stopping power, but let's be honest here, it looks good {win/win} and runs nearly the same cost as twin oem rotors but better stopping.
I sort of worry about the looks of the back end.....since I'm guessing that even though mine weighs more, my buddy on his CB750 will be getting a good look at it from that view. {unless he gets a jug kit, then I'm in trouble}....seriously though, rear kit?

I have the fronts done on my '79, stock rear is plenty just the way it is.

 

[Chuck78]

the stock rears usually do pretty darn well, if you look at most modern sport bikes, they might have a 2 piston sliding caliper in the rear, but the rotor diameter is substantially smaller. If you did a lot of heavy loaded touring and needed more rear brake, get a rear rotor and the caliper hanger bracket off of a 1977 GS 750 (in 78 I believe they downsized the rear rotor slightly from 295 down to 275 mm). The stock rear was on my 77 when I got it, and it was way too much rear brake, very easy to lock up the rear. Some people intentionally leave some air in the lines just to give the rear brake a little more feel and cushion on the stock setup. Your bike is heavier, so maybe that might warrant not doing so. The opposed piston caliper and 275mm rotor is adequate for mine with aggressive riding on a lightened 485lb GS750. any more substantial caliper and swept brake pad area and you would definitely need to downsize the rotor diameter again.

I absolutely love the stopping power of my 296 millimeter dual twin pot front set up. riding in the most tightly packed nonstop twisties this past weekend on a 300 mile backwoods Appalachian round trip, I was reminded how I basically only need one finger the majority of the time when properly judging my speed going into turns at least. A few surprises over blind rises led to me reaching a second finger in to panic stop/brake check.

 

[Chuck78]

Salty's recommended & very well researched front brake upgrade makes our bikes (with suspension valving/spring upgrades & excellent tire selection) fully capable of very spirited (aggressive) riding in the most fun terrains possible, such as the nonstop Appalachian foothills in the SE corner of Ohio near West Virginia, like this Labor Day ride we just did through a segment of Wayne National Forest & surrounding State Forests (about 230 miles of BIG smiles plus 70 travelling there):



Never ending big hills everywhere densely packed, and me picking the route with the absolute most & tightest curves. try to find a straight road on that entire map! They don't exist! I have absolutely no problem and no complaints ever with my brakes' capability while riding aggressively in this terrain, as well as Northeast West Virginia mountains.

 

[salty_monk]

Very nice! It should be possible to fit one of the Honda front rotors to the rear which would match up the look as the PCD is the same on both front & rear Suzuki wheels from memory.

I don't know what the offset (or dia) of the rear rotor is. Assuming Chuck78 is correct above you'd need the 77 caliper hanger (hopefully the axles is the same dia) for a 295mm rotor and some hub spacers to make it work. - I'd have to look at it. From a performance standpoint I would be very surprised if you need any more rear end performance.