CBR front end swap help

[ducati_nolan]

I just picked up the front end from an old CBR. It's off of an old 1987 huricane and seems to be in pretty good shape. I'm going to replace all the seals and everything on it but I'm wondering if somone can provide me with some dimensions.

What is the diameter of the steering stem on the GS? I think that the easiest way to do this swap wopuld be to turn down the CBR stem to the GS size and then use the GS bearings. OD of the stem and ID of the stem tube in the frame would be helpfull.

A cool feature of the forks is that they have adjustable air suspension, so it's easy to ajust, and of course the dual brakes and clip ons are cool too.

Any help would be great

[dgyver]

You will need more than just an OD.

Upper bearing seat: 24.95mm dia x 11.5mm long and starts 145mm from the bottom of the lower bearing
Lower bearing seat: 30.04mm dia x 24mm long
Threads above upper bearing (for preload nut): 25x1

The rest of the info on the drawing I made is based on the GSXR stems I modified. I have a sketch of the GS stem somewhere. I can dig around for it but you are going to need to do some measuring of the CBR stem and triple clamps.


If those forks do not have a crossover for the air, good luck getting the pressure the same.

[ducati_nolan]

I just did a little searching on this site and found this

87-90 CBR600...HURRICANE 600....maybe cbr400 same vintage
slide the fork tubes out of the honda...complete with wheel/rotors/axle/calipers including master cylinder....and slide into the GS
it has a kewl fender but the spoke design is different
also a F-2 wheel can be made to fit the hurricane front end

I just did some quick measurements and it looks like this will work! They both have 37mm tubes and it looks like the distance between the tubes is the same as well, so I probally don't even need to mess with the stem.

I originally was kind of reluctant to get such an old fork design, but the ease of instalation should definatly make up for it.  awesome.
Cheap too. As for getting the air pressure in the forks equal, I think that if I use a tire gauge, I should get plenty acurate.

Thanks for the measurements though, I may still look into machining the stem, but probally not.
sweet 

[dgyver]

Yeah that quote is from Ken (werase643), so you can do the swap that way. Much easier.

If you need any other measurements, let me know.

The indivual air pressure was a pain since it was low, maybe 15-20 psi. It has been over 20 years since I had a bike with air adjustable forks.

[werase643]

yup that waz me.....

slide them puppies into the GS tripples
the Honda forks might be 1 inch shorter.... I can't remember..that was 11-12 yrs ago when I did that
the GS aftermarket springs will work in the Honda forks
The Honda wheel is a 2.75x17.....MAX 110 tire!!!!!!  a 120 will pinch dangerously on the front!!!!!!!

the air caps are actually a pain in the butt 
you have to add ait with a hand pump
if you go much over 15#....the fork seals will start leaking

the fender is kewl looking at least...helps cover up the ugly rim

[ducati_nolan]

I've been looking for some diagrams of these forks before I pull them apart for a cleaning, new seals and oil but haven't had any luck, and I'd hate to buy a manual for just the forks. Are they simmilar to the gs? should I just start unscrewing stuff and try to put it back the way it came apart?

I was also hoping that the springs/air would be better than the GS, but I guess that this isn't so? I need to get new springs anyways  man, I don't think dual brakes are worth the hassle if the forks aren't any better.....this sucks

anyone want to make an offer  ..... uh actually I may be serious.

[werase643]

the twin brakes are better
the forks are easy to take apart...same-o same-o

the clip-ons are great....
making head lights fit will be worse than installing forks.....and that ain't very difficult either
that bike was floating around Atlanta in the mid 90's...it did handle pretty good..for a gs turd bike....I think I got it for $50....too long ago to remember.....

nothing is bolt on super easy any fool can do it....well that ain't exactly true....most bling parts are....