Fork Cartridge Conversions?

[mmattockx]

I did some searching here and found nothing, so figured I would ask. Has anybody done a cartridge conversion on a GS fork? The vintage race guys have been doing these for years now, gutting the standard damper rod forks and retrofitting in the cartridge system from current forks. It gets you shim stack damping that is rebuildable, tunable and vastly superior to even cartridge emulators but takes effort and costs $$ if you pay someone to do it.

Any experiences/comments?


Thanks,
Mark

[Dogma]

I've never heard of it around here. Folks around here who aren't satisfied with emulators just swap on some cartridge forks.

[tkent02]

When you do it, I want to know all about it. Which forks, which cartridge, how well it works, what it takes to do it.

So far I haven't found any rear shocks that works anywhere near as well as the front forks with emulators, so it might be a waste of time and effort unless you have a trick up your sleeve for the back too.

[mmattockx]

I've never heard of it around here. Folks around here who aren't satisfied with emulators just swap on some cartridge forks.

Yeah, that seems to be the common way to go. It is reasonable and gets you bigger forks, brakes and new wheels that will take radials. For those of us that want to keep the vintage look it isn't so great, though. I think the vintage racers started doing this because there are classes that don't allow swapping the OEM fork but allow internal modifications. They are stuck with the small diameter fork tubes but get the benefits of modern shim stack damping systems.


Mark

[mmattockx]

When you do it, I want to know all about it. Which forks, which cartridge, how well it works, what it takes to do it.

So far I haven't found any rear shocks that works anywhere near as well as the front forks with emulators, so it might be a waste of time and effort unless you have a trick up your sleeve for the back too.

It is more an "if", than a "when". If I do it I will send them to someone who does this all the time for money, I don't have the experience or machine tools necessary to do it at home. Most sport bike forks from the mid 90's - 2009 use a 20mm diameter cartridge, so the details of that are not really critical. After 2009 some started using 25mm cartridges. I understand the Showa pistons have bigger ports than the Kayaba pistons, so Showa is preferred. The guy I would use is making his own pistons with big ports like the Race Tech gold valve replacement pistons, so they are an improvement over either OEM piston design.

Rear shocks are easy, you just spend money. The higher end Works Performance piggyback shocks are decent and Ohlins will set you up very nicely for cubic $$$. I have Ikon's on my '82 1100E and they are OK, but definitely nowhere near as good as the higher end sport bike stuff like Penske or Ohlins.


Mark

[tkent02]

Forgot about the Ohlins. Have them on my 1000, but I haven't ridden it yet.
How much money are we talking about to have this fork mod done?
After decades on crap suspensions I will pay a lot for a decent ride.

[mmattockx]

Forgot about the Ohlins. Have them on my 1000, but I haven't ridden it yet.
How much money are we talking about to have this fork mod done?
After decades on crap suspensions I will pay a lot for a decent ride.

The guy I know that does it charges $450. That includes new straight rate springs and whatever cartridge he is using in the conversion (I think it is a Showa unit) with a reworked shim stack to suit your bike and riding style. The new pistons he is doing cost more and I don't think he has received the first batch yet, so they are an untested entity at this point.


Mark

[Chuck78]

The guy I know that does it charges $450. That includes new straight rate springs and whatever cartridge he is using in the conversion (I think it is a Showa unit) with a reworked shim stack to suit your bike and riding style. The new pistons he is doing cost more and I don't think he has received the first batch yet, so they are an untested entity at this point.




Mark

who is this guy, and does he have a website for his shop or services?

[mmattockx]

who is this guy, and does he have a website for his shop or services?

No website that I know of, I know him from another email list that we have both been on for many years. His name is Matthew Patton if that means anything to anyone. If you are interested I can ask him if he is looking for more work and pass on his contact info to you.


Mark

[mmattockx]

who is this guy, and does he have a website for his shop or services?

I was emailing with Matthew yesterday and he mentioned he has an Ebay listing for his conversions of the SV650 forks:

http://www.ebay.ca/itm/151473386350?ru=http%3A%2F%2Fwww.ebay.ca%2Fsch%2Fi.html%3F_from%3DR40%26_sacat%3D0%26_nkw%3D151473386350%26_rdc%3D1

Mark

[BigD_83]

I was emailing with Matthew yesterday and he mentioned he has an Ebay listing for his conversions of the SV650 forks:

http://www.ebay.ca/itm/151473386350?ru=http%3A%2F%2Fwww.ebay.ca%2Fsch%2Fi.html%3F_from%3DR40%26_sacat%3D0%26_nkw%3D151473386350%26_rdc%3D1

Mark

$400.00 is not a bad price for the amount of work required and time saved.

[mmattockx]

$400.00 is not a bad price for the amount of work required and time saved.

I don't think so either. I think he charges $450 for other bikes due to having to fit the conversion into a new set of forks but it still seems like a bargain. I have seen others charging $800 or more for the same thing.


Mark

[Chuck78]

That sounds like a pretty great price even at $450... Converting to a GSXR fork often requires major mods to run the wheels of choice (if you wish to retain stock or wire spoke wheels), therefore $450 to mod a good GS fork (I'd assume you'd really want to only do with the 37mm forks so you get more stiffness) isn't a bad deal at all. The GSXR 41mm forks are probably lighter (thinner walled) however, so maybe that's still a better bet depending on scenario.

[mmattockx]

That sounds like a pretty great price even at $450... Converting to a GSXR fork often requires major mods to run the wheels of choice (if you wish to retain stock or wire spoke wheels), therefore $450 to mod a good GS fork (I'd assume you'd really want to only do with the 37mm forks so you get more stiffness) isn't a bad deal at all. The GSXR 41mm forks are probably lighter (thinner walled) however, so maybe that's still a better bet depending on scenario.

Yeah, there is no way to do a decent conversion for less than $450 unless you get all the parts for super cheap and can machine the various adapter/spacer bits at home. Considering that the rest of the chassis will still have the flexi-flyer frame and skinny bias play tires, fork stiffness is likely not the limiting factor anyway. For me gaining cartridge damping while keeping the OEM looks is the big deal.


Mark

[landshark]

I spoke to a suspension guy over here. I slightly confused him by saying i wanted cartridges, not cartridge emulators. He was going to talk to raceteck to get a price from them, so maybe it would be worth contacting them as well?