Front brake rotor conversion single to double 78GS550 help please

[Athena]

First.. yes I've searched the forum and haven't found exactly what I'm looking for or the answer.... come close.. but no cigar.

1978 Suzuki GS550 came with single front break.
We would like to put on dual front breaks.

Is this something that comes from a Kit??

or would this be a 100% pure modification- meaning get dual's off a different bike and find ones that match up or are a near match up and then modify them.??

If they would come off a different bike.. any clue what might work?


Totally lost on this one
~Athena~

[doctorgonzo]

Several thrreads in the Performance mods forum. Pretty sure in most cases it requires new from forks or making a modified caliper mount or both.

[tkent02]

Think you need dual brake forks from a 750 or maybe a 650 with 35mm diameter tubes. 850 and larger bikes have 37mm fork tubes.

I think the 550 has 35mm tubes.

Just a guess, never done it on a 550 myself, just used better pads on the single brake and called it good.

[DimitriT]

I recently completed this conversion on my 82 GS750T (can you believe a big heavy bike like that came with a single rotor????)

Converting your 550 may be a little overkill. My 82 GS550L has a single rotor and once I rebuilt the master/caliper with new pistons and seals and stainless braided hoses, it performs very nicely.

If you are sure you want to convert start by looking at the parts microfiche on www.bikebandit.com and compare front end parts. You want to find fork lowers from a dual rotor front end which can fit on the fork uppers your bike currently has. You will also need new rotors, calipers and a new master cylinder.

Once you've identified the models of the donor bikes which you can use, look for bikes being parted out. In my case the lower front end from an 82 GS650G was a perfect match. I was even able to use the existing wheel and only had to replace a spacer and some hardware.

In your case I would look at 550E models which had the same spacing but came with twin rotors:

http://www.suzukicycles.org/GS-series/GS550E.shtml

[JTsGS650]

Forks and calipers from a GS 650G would be a bolt on application (I think). You'd also need the correct master cylinder for a two caliper application and of course brake lines. I'm not sure about wheel interchangability though...

edit: Damn, I type slow...

[tkent02]

You'd also need the correct master cylinder for a two caliper application and of course brake lines.

Try it first with the existing master cylinder, it pumps less fluid but at higher pressure for a given lever pressure than the dual disc cylinder. This is due to the piston diameter being smaller. So if your lines are tight, and all the air is bled completely, and if the calipers are working as they should be you will get better braking with the smaller diameter single disc MC, as in more stopping force for a given amount of finger pressure.

All three of the conversions I have done have worked very well with the single disc MC.

[Athena]

WOW!!!!... thanks for the information. You guys are the best!!!

~Athena~

[Nessism]

Salty Dan has done the engineering work to put a dual piston Kawasaki caliper on our GS bikes. Should be a significant upgrade over the old style round puck caliper on the early 550's. Unless you are going after a certain look, there should be plenty of braking power available without going to the trouble, and adding the unsprung weight, with dual discs.

[Athena]

o really? Have you got a link to salty dans info sir?

[Nessism]

o really? Have you got a link to salty dans info sir?

Check the Performance Mod forum; there are a couple of different threads on this topic.

[jknappsax]

If you lok in the For Sale Parts forum, I have a "kit" I put together to convert my 1978 GS 750C to dual-front discs. If the 550s have 35 mm diameter tubes, they should slip right into your triple-trees. I decided after I assembled all the parts to go with a GSXR 1100 front end and wheels so I could run 17" radials, then figured if I was going to go to all that work, to sell the 750 and do the conversion on a "new" 1979 GS 1000. Upshot is, I have all the pieces gathered together, including a Daytona fork brace, to turn your bike into a dual setup. PM me if you're interested.