As requested...17" GS500 wheels...

[Mark M]

Mark, go measure the forks on your RMZ.


If I ever do run with the inverted forks I'll be using RM250 because the steering stems are compatible and the bearings are going to be easy to swap around. What I'm going to do is either get two left forks or install a "left" fork leg in a "right" fork tube. Then I'll make some 1-piece clamp on caliper hangers to bolt to the fork legs so I can retain my dual discs and run an alloy wheel. I'll add that to my S4R-esque sssa to my "for gits and shiggles" list.

I was thinking street bikes, myself. I have looked at the MX forks before and they would work, but not without issues. They have a large offset on the axle which reduces trail by a good 25mm over a center axle fork, you need to add another caliper hanger (as you mention), the spring rates and damping are way off for street use and you need to internally alter them to reduce travel. Even with all that, they are attractive because of the length and sophisticated damping systems. Current MX forks are so far ahead of street forks it is ridiculous.

I have never run the numbers on the trail issue, but I would bet stability would become a significant problem with the smaller front wheel and fork offset.

Mark

[makenzie71]

I was thinking street bikes, myself. I have looked at the MX forks before and they would work, but not without issues. They have a large offset on the axle which reduces trail by a good 25mm over a center axle fork, you need to add another caliper hanger (as you mention), the spring rates and damping are way off for street use and you need to internally alter them to reduce travel. Even with all that, they are attractive because of the length and sophisticated damping systems. Current MX forks are so far ahead of street forks it is ridiculous.

I have never run the numbers on the trail issue, but I would bet stability would become a significant problem with the smaller front wheel and fork offset.

Mark

Have you ridden a motard?


Now, I'm not sure how the offset compares between the inverted forks and the standard forks, but my old EX500 was a hoot to run around with XR forks and I was able to keep it competitive, but it did require a lot of work...they weren't the best candidates for that particular task.


Travel isn't an issue...if you really think about it, where you have to put your hanger for the caliper to keep it as sturdy as possible, you've shaved nearly 5 inches off...maybe not quite that much but you do have to remember that just because they "can" travel 12 inches, doesn't mean they have to. You can look at it as never being able to bottom out lol. But, the biggest benefit...and it's a great one...is that they can be refitting for hard, competitive 100% pavement use for next to nothing simply because of how HUGE the aftermarket is for them. On top of that, you can rebuild them in a couple hours for $20...except the most modern cartridge forks.


In fact, now that I'm thinking about it again, I really want to find me a set of RM250 forks, some .98kg springs, some 20wt oil, so start tinkering...

[jwhelan65]

the 1100 is the longest USD fork option available? did you use any sort of modded/swap lower triple (929/954 IIRC is the ticket)? would you care to let go of the stock upper triple if i needed it?

jed
Not sure if they are the longest by they are definitly longer than the 750's. The lower triple is the stock 93 GSXR. I actually sold my top triple on ebay..sorry. As far as the 954, the upper mounts directly to the gixxer forks giving you the much needed clearance you need when you swap out the front end. The only catch with the 954's is it may be alittle more challenging to mount risers given the shape of it.

hope this helps

[Mark M]

Have you ridden a motard?


Now, I'm not sure how the offset compares between the inverted forks and the standard forks, but my old EX500 was a hoot to run around with XR forks and I was able to keep it competitive, but it did require a lot of work...they weren't the best candidates for that particular task.


Travel isn't an issue...if you really think about it, where you have to put your hanger for the caliper to keep it as sturdy as possible, you've shaved nearly 5 inches off...maybe not quite that much but you do have to remember that just because they "can" travel 12 inches, doesn't mean they have to. You can look at it as never being able to bottom out lol. But, the biggest benefit...and it's a great one...is that they can be refitting for hard, competitive 100% pavement use for next to nothing simply because of how HUGE the aftermarket is for them. On top of that, you can rebuild them in a couple hours for $20...except the most modern cartridge forks.


In fact, now that I'm thinking about it again, I really want to find me a set of RM250 forks, some .98kg springs, some 20wt oil, so start tinkering...

I have not ridden a motard, but I am familiar with them. Don't forget that your GS has steeper steering geometry than an MX bike does (I believe, I don't think the GS is that slack). You just have to look at the combination of triple offset and axle offset to see what you will end up with when installed. If you don't shorten them, they will be way too long in the original MX configuration. My RMZ forks are about 37 1/4" from axle center to top of tube as it sits on the stand. You need to lose about 4-5" of that to be correct with a 17" front wheel.

I'm not saying that they won't work, just that the offset issue needs to be carefully checked and they need to be re-sprung and valved to suit pavement work. If done properly they should work very well. They are much bigger diameter than any street forks (my RMZ forks are 47mm tubes) and the damping systems are much more sophisticated than street units.

Edit - If you do a set of RM forks, keep us posted. I would love to go that route as well if you have good results with it.

Mark

[makenzie71]

I have not ridden a motard, but I am familiar with them. Don't forget that your GS has steeper steering geometry than an MX bike does (I believe, I don't think the GS is that slack). You just have to look at the combination of triple offset and axle offset to see what you will end up with when installed. If you don't shorten them, they will be way too long in the original MX configuration. My RMZ forks are about 37 1/4" from axle center to top of tube as it sits on the stand. You need to lose about 4-5" of that to be correct with a 17" front wheel.

I'm not saying that they won't work, just that the offset issue needs to be carefully checked and they need to be re-sprung and valved to suit pavement work. If done properly they should work very well. They are much bigger diameter than any street forks (my RMZ forks are 47mm tubes) and the damping systems are much more sophisticated than street units.

Mark

total length is something to keep in mind...so you have to hunt down forks with straight tubes to rise them a bit. Between rising them and cutting the springs just a hair it worked with my EX but it wasn't an inverted set and my clip-ons allowed me to bring the legs up quite a bit in the forks.


Gonna have to do some figuring

[gmansyz]

Rotors

Hiya Jed, I got the rotors for the front you have.
$100 plus shipping.
G

[gmansyz]

More Rot

Or if you desparately want to make caliper adaptors you can use these 320mm Road-Race EBC rotors.
G

[jed.only]

Hiya Jed, I got the rotors for the front you have.
$100 plus shipping.
G

Or if you desparately want to make caliper adaptors you can use these 320mm Road-Race EBC rotors.
G

prices? these are for a 5bolt katana wheel?

[gmansyz]

P

Okay. $100 plus shipping for the 310 GSXR rotors.
And for the EBC's? More. I haven't thought about how much. I had them lightened so I am into them for a bunch but don't expect to get it all. And not as much as $600. Less there. I had the unnecessary material removed from any place the pads don't rub. They are a big enough heat sink as it is.
GREG

[gmansyz]

Forgot, yes, they will fit the 5-bolt Katana and the GSXR/Bandit/RF series. Anything that would use the offset rotors. The later models that take the flat rotors have two different sized bolt circles. And the caliper clearence is tight to the wheel.

[jed.only]

so ive been researching old posts about this. ive read that the katana front wheel will bolt up, as well as a 5.5 rear if the gs1100 or bandit swingarm is used. am i wrong? i dont care to swap out forks at this time if at all possible.

[makenzie71]

My front wheel is the same a all the swoopy Katana wheels. Bolts right up, you just need to be careful of spacers and you will lose the speedometer without some fancy trickery...I suggest going aftermarket.

[jed.only]

My front wheel is the same a all the swoopy Katana wheels. Bolts right up, you just need to be careful of spacers and you will lose the speedometer without some fancy trickery...I suggest going aftermarket.

bah. cant lose the speedo. ive got a rad set of clocks from a 72 T500.

[makenzie71]

Then you'll need the kat speedo drive. It won't read accurately so you'll have to do some math on the go...

[jed.only]

Then you'll need the kat speedo drive. It won't read accurately so you'll have to do some math on the go...

that i can fix.