More modern cartridge fork options - retaining GS wheels & proper/revised geometry

[Chuck78]

Maxton.co.uk I believe are the ones that make cartridge retrofit kits for damper rod forks. I doubt you'll find a junkyard fork with guts that can swap into a 35mm 1979 fork.
Cartridge emulators and proper spec aftermarket springs will do wonders however, much easoer. And a Tarozzi fork brace. And the popular twinpot brake mod. All bolt on no real mods needed.

[johnod]

Racetech, has single rate springs and emulators.

[mmattockx]

I just bought a GS 750 E dual disc front end for my standard '77 GS 750 and then started in on this thread...arggg! One has to wonder if it would be possible to insert the guts and tubes of a smaller modern cartridge fork into the stock GS 750 stanchions for a stock look? i've heard of this being done with SV650 damper rod forks. One would guess the donor bike would be some gray market type small bore racer replica. or maybe I'm high. Comments?

I have an acquaintance who retrofits cartridges into damper rod forks as a hobby business. It costs more than a set of springs and emulators, but also performs better. I believe that he uses cartridges from one of the later CBR600 models, but I'm not certain of that. Last I talked to him about it he was charging $400 to do a set of forks and that included the cartridges, new Sonic springs in your rate of choice and fork oil if you lived in the US.


Mark

[Chuck78]

I have an acquaintance who retrofits cartridges into damper rod forks as a hobby business. It costs more than a set of springs and emulators, but also performs better. I believe that he uses cartridges from one of the later CBR600 models, but I'm not certain of that. Last I talked to him about it he was charging $400 to do a set of forks and that included the cartridges, new Sonic springs in your rate of choice and fork oil if you lived in the US.


Mark

So your friend is in the US, not Canada? Does he have a website of any sort? Are you free to drop his contact info for others who would like this service?

I was always wondering about retrofitting 37mm GS1000 Forks or GS1100GK 41mm forks. Or possibly GS500E forks to stay under the 38mm class limit for WERA's Formula 500 road race class.

[mmattockx]

So your friend is in the US, not Canada? Does he have a website of any sort? Are you free to drop his contact info for others who would like this service?

I was always wondering about retrofitting 37mm GS1000 Forks or GS1100GK 41mm forks. Or possibly GS500E forks to stay under the 38mm class limit for WERA's Formula 500 road race class.

Chuck,

PM has been sent with the info.


Mark

[kaufen]

Thanks, you lost me with the bushing.

[limeex2]

I have an acquaintance who retrofits cartridges into damper rod forks as a hobby business. It costs more than a set of springs and emulators, but also performs better. I believe that he uses cartridges from one of the later CBR600 models, but I'm not certain of that. Last I talked to him about it he was charging $400 to do a set of forks and that included the cartridges, new Sonic springs in your rate of choice and fork oil if you lived in the US.


Mark

That's a fairly decent price if you price it out.

[mmattockx]

That's a fairly decent price if you price it out.

His prices have risen a bit since, he now says ~$500USD including the return shipping costs. I would still say that is cheap for what you get. The Sonic springs and fork oil are close to $100 and return shipping will be $35+ I expect, so you are around $350 for the parts and labour. I believe he also builds a shim stack to suit your uses so it isn't just a stock cartridge with no tuning done on it.


Mark

[Chuck78]

I emailed him about retrofiting 37mm & 41mm GS forks, but I have not gotten a reply back for several days still. His list of frequently modified forks were all modern sportbike forks that were still damper rod setups, so I was left wondering if internals from a 41mm cartridge fork would even be able to be fit into a 37 mm or 35 mm fork

[mmattockx]

I emailed him about retrofiting 37mm & 41mm GS forks, but I have not gotten a reply back for several days still. His list of frequently modified forks were all modern sportbike forks that were still damper rod setups, so I was left wondering if internals from a 41mm cartridge fork would even be able to be fit into a 37 mm or 35 mm fork

Hmmm. He responded same day to my last message before I sent you his info. He says he does the conversion on Ninja 250 forks, which are also 37mm fork tubes.


Mark

[80GS850GBob]

You guys got quiet!
No one mentioned the '95 Suzi GSX-r1100W USD front end - mine will arrive tomorrow....765mm long forks.
Uses the same GS speedo drive and steering stops. Allballs makes tapered bearings for the fit onto a GS frame.
My current issue is fitment of rotors and bakes to a GS cast front wheel {eventually to be a 17" s/s spoked rim}.
I was thinking of busa 320mm rotors {pre '08} and am being talked into 4 pot calipers instead of 6 pot {once again- pre '08 when they switched to 310mm and a larger bolt pattern}......I'm thinking that the GS I have is 100lbs heavier than a 1000 gixxer and the added stopping power couldn't hurt. I don't need or want to do "stoppies", but I don't want it to lock up if three fingers or more are used.
Any wisdom to impart on this?

[mmattockx]

I'm thinking that the GS I have is 100lbs heavier than a 1000 gixxer and the added stopping power couldn't hurt. I don't need or want to do "stoppies", but I don't want it to lock up if three fingers or more are used.

Any wisdom to impart on this?

I don't know if it's wisdom or not but I would go with the most brakes I could get and then worry about learning to not lock them up. If you can't lock your wheel you don't have nearly enough braking power. And I never use more than 2 fingers. If it takes more than that something is wrong and needs fixing.


Mark

[limeex2]

I know Ill get roasted on this, but its tough to lock up the front wheel. Tire breaking loose and losing traction and then locking, yes. Instantly slamming the brake lever, yes. If your braking that hard, which is good and fun, learn your traction limits. If your looking for 4 pots, they do work better than 6 pots. Check for interchangability with your fork set. I have 4 pots off of a TL1000R or I have 6 pots off of a ZRX1200 if your looking. PM if interested.

[80GS850GBob]

I know Ill get roasted on this, but its tough to lock up the front wheel. Tire breaking loose and losing traction and then locking, yes. Instantly slamming the brake lever, yes. If your braking that hard, which is good and fun, learn your traction limits. If your looking for 4 pots, they do work better than 6 pots. Check for interchangability with your fork set. I have 4 pots off of a TL1000R or I have 6 pots off of a ZRX1200 if your looking. PM if interested.

Just got back to this one....what rotor diameters do those 4 & 6 pots run with?

[mmattockx]

I know Ill get roasted on this, but its tough to lock up the front wheel. Tire breaking loose and losing traction and then locking, yes. Instantly slamming the brake lever, yes.

I don't think you will get roasted for that. If you are talking modern 17" radial high performance tires then I would agree with you. As long as you brake progressively to get the weight onto the front wheel before you really hammer it hard it is pretty tough to lock the front wheel. I would say it is more likely that you end up going over the bars before a modern performance radial will slide.


Mark