Brake Upgrade Options on 550's?

[cp___32]

Hello,

I'm hopefully going to take my bike for a safety check in the coming weeks. Both of my rotors have slight grooves in them with the rear being slightly worse than the front. I've checked the thickness and currently the rear is about 6.5mm and the service limit (as per Clymer) says 6.0mm. I might be able to turn them down to minimize the grooves but can't eliminate them completely without making them thinner than the 6mm limit.

Either way the bike will likely need brakes in the near future so I was curious what my options might be. The EBC OE replacementfor the rear is about $215 which seems a little steep (I know brakes are super important and not the place to pinch pennies but...). Would those be the absolute best route, or is there a common swap that can be done either as a direct bolt on, or with minimal modification/fabrication?

[tkent02]

Rear brakes don't do much anyway, just run what you got. Put the extra effort into decent front brakes.

[cp___32]

Thanks for the advice, but I don't think that will fly with the shop owner if he says I need to replace the rear rotor before he will sign off on the safety check.

I know that $215 will get me a new rotor but I have a feeling there are more cost effective and higher performance options that can either be done for around the same cost (or maybe even less). What I'm hoping for is advice on what to look into or where to head next. If the OEM one is my only viable option then that's fine, if there are other ways I'll research them to see if they are for me. Unfortunately in this circumstance I don't think "do nothing" is one of my options if I plan on riding any time soon.

[hampshirehog]

Loads of secondhand discs out there and cheap as chips. The rear brakes are plenty strong enough (too easy to lock the back up if you ask me) so I'd just pop a used disc on it.

The front end is the critical bit.

[Suzuki_Don]

You could try this mod if you want to stay with a single front disc, but you might want to go with a less ugly bracket. I was only experimenting with this one.





Above is a twin piston caliper set up for the GS models with a single disc. You get better braking without changing the front forks to adapt for the twin discs. The standard heavyweight GS disc has been replaced with a 98/99 Honda CBR900RR Fireblade disk (310mm). The standard GS discs of any size will NOT WORK on this conversion. The caliper used is from a Kawasaki, or Suzuki GS500, GSX1100G (91, 92, 93) or VX800. Make sure if doing this conversion that you get the left hand caliper, they make them for both sides, left and right.

[cp___32]

Thanks for the advice!
"Cheap as chips" eh? Somehow I knew I'd look over and see you were from the UK.

Thanks Don for the info. I checked from work and saw your "Above is..." and wondered what was wrong because I didn't see anything. Turns out my work comp wouldn't load the photos so when I got home it made much more sense. I'll see what some of my local salvage shops charge for used rears, and those varieties of calipers.

Anything to watch out for when creating the bracket? I have a decent milling machine at work and a friend who is willing to help me (CNC Tech) so all should go well once I figure out a design.

[Smokinapankake]

Salty Monk has been known from time to time to supply those brackets. He has them made somewhere here in the states out of steel. Very nicely done and work a treat!

[Suzuki_Don]

Salty Monk has been known from time to time to supply those brackets. He has them made somewhere here in the states out of steel. Very nicely done and work a treat!

Salty does not do a bracket for the single rotor, only for the twin rotors, the bolt spacings are different. It is one of his brackets in the picture, but it is only a mock-up and the holes in the bracket for a single rotor would have to be drilled with slightly different hole spacing to prevent any movement under braking conditions. There are other alternatives.

[Suzuki_Don]

Anything to watch out for when creating the bracket? I have a decent milling machine at work and a friend who is willing to help me (CNC Tech) so all should go well once I figure out a design.

The main thing is to position the caliper over the rotor and check for clearance to see if the bracket can go inside the fork mounting holes or whether it has to go on the outside. I was able to fit mine on the inside as seen in the accompanying picture. Position the caliper to center the brake pads over the rotor to get the most coverage as possible then mark the template and make the plates up. All you really need is a pedestal drill. My plates are made from 5mm steel and work fine. There are four different mounting holes on the caliper bracket (the bracket that comes with the calipers) so choose whichever ones suit. I used different mounting holes than Salty to make the plate less obtrusive. Make allowances for when the brake pads are new as well as worn down (more material vs less material).






.

[dogmotor]

Don,

Thanks for posting the detailed pics.

What kind of braking performance do you get from that conversion? I rode some new (modern!) bikes recently and have been a bit unhappy with the braking performance from my '78 GS750 ever since. Is it 2 finger lock 'em up or something between that and stock?

Thanks again,

Mark