956c

to add info to jamies' swap I am doing a 954 swap....I found when I measured the center nut on the top of the triple clamp is 1.1/4" from cent to middle of the tubes meet .....if you find a triple clamp that is same you will have the same rake as your old VTR. as for length of the forks VTR are 29.3/8" and the 954 are 28" from center of axle to top of the fork cap. now you should put the forks in same place if you want the same steering which I do...the length will be 19.3/8" from th center of the axle to the top of the first clamp from the axle when you do this it will leave you with plenty of room to put your handle bars on top which are 50mm the steering bearings are the same as the old VTR so you can use them on the new triple clamp also you can use the caliper as well but you will have to change rotors VTR's are 320mm and the 954 is 330mm and I am using 929 rim 3 spoke and looks just like my VTR there is 2 kinds ....this is easy to do and a 1 day job...thanks to jamie...I will take pictures and Post them ....
ps I think you guys really make this too hard to do....when it is so simple....

parts 954 triple clamps 02
954 forks
954 axle with space from 954
954 calipers
954 rotors
929 rim from 01

TODDSPEED

Been looking over the thread and I think I have some useful info. I just finished my fork swap with GSXR forks, here is how it went:
01 GSXR 1000 forks
954 triples
03 GSXR wheel
TLR rotors
01 GSXR axle
02 GSXR 750 calipers
I cut the flange off the axle so that I could center the wheel between the forks. (this step would not be needed with a TLR wheel) Then I made 4 spacers out of about 3.5 mm aluminium, and placed them between the calipers and the caliper mounts on the forks.

956c

do you have photo's ?

lazn

So even with the older forks you had to move the calipers inward and remove the flange to get it to work?

With the 03 forks, you can't move the calipers inward at all, but I think it should be possible to move the rotors out.. like this guy did for his triumph: http://www.triumphrat.net/speed-trip...-complete.html And that together with removing the flange off the axle would let any of my GSXR forks work..

This means I now have 3 options to me: A 954 setup, a 2003 GSXR1000 setup or a 2004 GSXR750 setup.

What is best for a ~200lb rider?

TODDSPEED

No, but I will take some and post in a couple days.

TODDSPEED

What is best for a ~200lb rider?


Check the Race Tech site, they have all the stock sping rates, plus they give a reccomended spring rate according to your weight. My 01 GSXR 1000 forks have .87 kg/mm, which is a big jump from the .57 kg/mm stock SH springs. The new front suspension + new brakes made an amazing difference at my first track day 3 weeks ago, and it even rides better over bumps on the street too. I weigh 175lbs (no gear) so I guess anything between .85 kg/mm and 1 kg/mm would work for you.

Also, with the TLR wheel you would not need to cut off the axle flange, it would center perfectly without it.

lazn

Well swordfish, we just might have your answer..

lazn

Ok, so:

The 954 forks have .710 kg/mm springs
And both the 03 GSXR KYB forks and the 04 GSXR Showa forks have .85 kg/mm springs.

So theoretically my best bet is still the 04 Showa forks.

swordfish

looks that way. I'll start looking around again.

yruyur

Well 8 hours later and me and Lazn have completed his upgrade. 8 Hours included our first failed attempt at making a stand, having to construct the lift which worked amazingly(never had to second guess how hard we were wrenching on anything) and having to run to get the tire swapped onto the other rim. Ill post the pics and Lazn will tell the story later. We have been on a 30 mile ride so far and everything seems rock solid. Big thing I noticed is that the rake is now sharper.

inderocker

Looks great! I must of missed the post that says what clip-on's were used.....?

lazn

I kept the ones from the first post, Swatt clipons with the 3.5" rise. They work perfectly. The only thing to be aware of is that they can't be all the way forward as that causes the brake handle to hit the mirror stay at full lock. Not a good thing, I actually dropped the bike on a test ride (with no fairings and sliders still on.) because of this.. I was turning around to the left at very low speed and suddenly the brakes came on! But adjusting the bars back about a quarter inch fixed that.

Overall I am happy with the results, the bike is much quicker to turn in now.. almost twitchy.

I think I still need to reroute the throttle cables, and adjust the ignition a bit to make the steering lock function. Otherwise it's done.

The new steering head bearings were easier to put in than I expected, but I can't say if they really made any difference since I didn't try the normal bearings on this setup.

Oh and the last pic is of yruyur's bike to give a comparison.

JamieDaugherty

It shouldn't be. You need to check your geometery. Take your stock forks/triples and measure the distance from the bottom of the lower steering stem bearing to the axle. Now take the same measurement on the new setup. These need to match. Of course, you can tweak as desired in the future (within limits) but you need a known-good starting point.

I can't stress how important this is!

yruyur

I wonder if what I was feeling was not a rake change but if we did not tighten down the steering neck nut enough allowing the front to move around. How tight is that supposed to get?

lazn

Well I measured the stock forks and triple (apart in the garage) and the bike (with the weight on it) and they are really close.. but this means that I need to raise the tubes in the triples since the weight of the bike is compressing the 954 forks.

Really the bike rides great as it is now, just turns in far quicker than before.. I can let go of the bars at speed and is stays straight etc. So I don't think I am far off.

JamieDaugherty

It's probably because of the change to the tapered roller steering stem bearings. Those make the steering movement much lighter (less friction) almost to the point of being twitchy. This does not affect handling by any appreciable amount.


What you need to do is check the lower steering stem bearing to axle center line dimension on both sets of forks without any weight on them. I'll bet that you need to raise the forks so that 10-15mm are showing above the upper triple clamp. Again, the actual number will depend on what your measurements tell you. If my assumption is correct, your bike is actually "raked out" a little. It feels like it turns quicker only because the initial effort is less, but your actual cornering is being hurt. You'll be amazed at the difference. At first you might not like it, but it's really a much better setup than what you have now.

lazn

I am not trying to be argumentative here, and I know you are the suspension guru here.. I am just trying to learn.

From looking at the triples I don't see how it can't not be changed.. Or at least have the wheelbase changed.

If you look at the triples the stock ones put the forks about a half an inch further forward of the steering stem than the 954 triples do.

Also the bikes have different rake measurements.. And rake can determined by either/both the frame and the triples.

Honda VTR1000 Super Hawk
Type: Liquid-cooled, 90-degree, V-twin
Displacement: 996cc
Bore x stroke: 98.0 x 66.0mm
Carburetion: 2, 48 mm flat-slide CV
Transmission: 6-speed
Rake/Trail: 24.8 deg. / 3.8 in. (97mm)
Wheelbase: 56.3 in. (1430mm)
Dry weight: 423 lb. (192kg)

CBR 954 RR Fireblade
Type: liquid cooled, inline 4
Displacement: 954 cc,
Bore x stroke (mm)75 mm x 54 mm
Fuel system: Electronic fuel injection
Transmission: 6 Speed
Rake/Trail: 23.45 deg. / 3.8 in. (97 mm)
Wheelbase: 55.1 inches (1400 mm)
Dry weight: 370.4 pounds (168 kg)

So are you saying: that both triples have the same rake built into them (even with different umm, offsets from the steering stem, I guess you'd call it) and that the bikes rake in this case is entirely determined by the frame?

Tweety

Well... Since those numbers become meaningless once you combine the superhawk frame and 954 triple... I'm fairly certain the steering head isn't the same angle in the frame... It's just guesswork as to what your actual numbers are...

Also remember that the important measurement is the center of the forkleg, not the edge, it can very well be more space between the leg and head, and have the same or similar numbers as the fork leg is substantially thicker...

Measure it and then compare it... I'm fairly certain nobody have done those, or at least not posted them... I have my numbers somewhere, but that's with another fork from yours...

lazn

I understand that, what I don't understand is why the rake is supposed to stay the same after the swap when the new forks are significantly closer to the steering head bearings, and the bikes have different rakes to start with.

Hawkrider

I think you are confusing terms. Rake is the angle of the forks with relationship to a vertical parallel. Now, to complicate things, if you lower the front end of the bike you change the bike's geometry, thus lowering steering angle (rake). More rake than stock will make the bike turn quicker. Too much and it can become unstable. Less rake will make the bike steer slower, and (from personal experience) will also cause the slow speed handling to suffer, making the bars flop out in the direction you are turning.

Offset also has some effect. Offset will affect trail which also affects stability. Offset is the distance (when looking at the upper triple clamp) between the horizontal center of the steering stem and the horizontal center of the fork legs.

All three of the geometries above changed when we did our fork swaps. What you have to do is find a balance between the three for a stable and fine handling ride, with trail being the most important factor. There is a thread around here somewhere where we got into deep discussions and calculations of rake, offset, and trail. A Google search and some reading time wouldn't hurt either.

Hawkrider

Check post #14: https://www.superhawkforum.com/forum...t=trail+offset

JamieDaugherty

The triples do not control rake at all, only the trail (in part). The offset is identical for the upper and lower clamp, they will always put your forks parallel to the steering stem. That's why the frame controls the rake. I didn't measure the offset between the stock triples and the 954 (I should do that tonight) but I don't think it's as much you might be suggesting. The forks are spaced further apart, which might be deceiving you a little.

lazn

Thanks guys! This stuff is fascinating

So my next thing to do is probably to get the bike back up in the air and to match that all important bearing to axle measurement before I sell the VTR parts. Can I do this with the bike at an angle? (I can easily with a jack get the front wheel up enough to do this but the bike will not be square, otherwise I will need to use that 2x6 again)

Edit: oh and I sold all my GSXR stuff on CL for break even cost on it.. I could have held out for more and covered some of the cost of the 954 parts, but kinda just wanted it out of the garage. I still have my VTR parts and another 954 triple so in the end this won't end up costing me all THAT much.

Hawkrider

Offset 33mm for 929/954. 37mm for VTR.

lazn

Ok, so I raised the forks up ~12mm to match the original forks.. OMG! The bike handles telepathically I mean it always went where you thought it was going to go, now it goes where you are about to think it will go. No twitchyness nothing untowards, it still turns quicker - easier than before, but not in a bad way.

Amazing. Thanks guys for all your help!

JamieDaugherty

No problem, I'm glad that helped. I'm also glad that our advice took you in the right direction!

If your experiences are similar to mine, a couple of months from now you will have forgotten what the stock front end felt like. At that point.... you guessed it.... you'll be looking for more.

Tweety

Either that, or you start looking at other parts of the chassis that's not quite up to spec... Like the swingarm and possibly re-enforcing the steering head and frame... Oh there is lots to keep me occupied at winter...

supermatt996

off subject but you ran gixer forks and a 929 triple assembly.im building a fighter out of a 1992 ZX6 and was told you can only run the same triple clamp and fork combo. didnt make sense 46mm is 46mm why would a clamp matter. you guys got any quick insight dont what to tread jack. or maybe point me to someone who knows.

lazn

I ended up with 954 forks too after all.. But the GSXR forks would have worked if I had ground the flange off the axle and spaced the rotors out to the width of the 954 triples.

You can run and 50mm forks in any 50mm triple, the difference comes in the width between the forks and the expected width at the axle. So you may have to make adjustments to make it work.

supermatt996

thanks thats what i needed to hear