Phoenix Fighter

davido wrote: 4inches is about 10cm. Thats about what I have with the ZX9R forks and thats with the bike standing at rest.No paddock stand and no rider.
That is not a lot and (for me) not enough.
I was talking with my local bike shop owner about this today. Fork extensions or dropped triple tree? Im still undecided.With fork extensions,you have a weak spot,with dropped upper yoke you have a weak area,unless you drop the bottom yoke as well,in which case you have an empty bank account!For the money,he reckoned the extensions would be good enough.
I was also thinking about heavier springs in the forks but he thought that wouldnt work because the springs are rated to the weight of the bike. I pointed out that the ZXR springs (in your case GSXR springs) would be rated to the weight of a ZXR (GSXR) which would be a lot lighter than a 1980s KZ so,it should be possible to fit heavier springs without losing effectiveness in the front suspension (probably improving it). Heavier springs would,in theory, lift the front end,though I dont know by how much.Then again,every little bit helps!
Im just running this around in my mind at the minute as I have a ton of other things to sort out first but I need to sit down and figure this all out. First thing is to set up the sag properly ,as the bike is.Take some proper measurements and go from there.

I have an idea for fork extentions that would work but you would not be able to abuse the forks with them on. I don't think this is a serious issue since once they are adjusted they usually stay where they are. Secondly, the triple tree route goes two ways. If you do a drop but keep the same offset as the zx9 you only have to do an upper. If you want to change the offset then you have to make both upper and lower.

Wouldn't changing the spacing by lowering the upper one weaken the whole steering head assy?
Steve

swest wrote: Wouldn't changing the spacing by lowering the upper one weaken the whole steering head assy?
Steve

It would not be as strong as a flat one. The amount of force that it would take to shear a dropped version, I don;t think the triple tree is going to be the only issue.

Im hoping that Ill get away with the offset that I have. I was able to extend the KZ steering stop to work with the ZXR bottom yoke but I had to grind back the edges to get some of the turning radius back.Its still not quite there but I have a couple more cms before it hits the tank,so I will trim a bit more back.Hopefully itll be just enough.
With the extensions,(the way I understand it) Its not about them moving in the clamps,so long as the diameter is good and the strength should be fine.Most of the force will be going downwards.The problem would be when braking.The force goes more forward as the forks want to bend. You would have a joint held together with a couple of cms of fine thread. I dont see anything snapping right away but over time , things might weaken up.
With the dropped top tree,I think its a lot more secure,theres no joint,so your forks would be able to deal with the stresses the way they were designed to but as Steve says, the distance twixt upper and lower yoke would be smaller and although this shouldnt effect the strength,it might have an effect on handeling (speed wobbles etc)
Im not an engineer,so Im not pretending that I understand all of this.I could be completly wrong (It wouldnt be the first time)!

On the bright side,This is pretty much a bolt on choice.If the extensions dont work,its easy enough to switch to the dropped triple (if youve got the cash. )

I like the idea of extensions with sleeves and pinch bolts. They could double as headlight mounts/ears and stiffen up the steering head between the top and bottom triples.
Steve

Kaw A holic..
Check and yes they are 1 . 5 " longer then the 750. And no I don't have and extra set. Infact I have a extra set of 750 that I was going to change one of the inner tubes.
Now I need to check if the inner chrome tube are the same or not.
On the 1100 the outer tube is what is longer. From dust seal to center of shaft it the same length .

spdygon wrote: Kaw A holic..
Check and yes they are 1 . 5 " longer then the 750. And no I don't have and extra set. Infact I have a extra set of 750 that I was going to change one of the inner tubes.
Now I need to check if the inner chrome tube are the same or not.
On the 1100 the outer tube is what is longer. From dust seal to center of shaft it the same length .

Spygon
Thank you, I am looking at a set on eBay. I want to get these fork legs and see if I still need a drop or maybe just less.

So thanks to Ron Z I have sold my RS36's, that same morning I found a set of RS34's with KN pods and carb holders for the same price I sold mine!

Why cant you just have a new set of inner tubes made to fit the length you want? I dont know much but it seems more cost efective

I found a set of 1100 fork tubes for a good price. Its easier to just swap the forks.

I got a set of RS34's but having some issues. I bought a set of carb holders for the RS36s and they worked fine. Since I have been having issues with getting the RS34s to run right I sprayed some starting fluid where the carbs slide into the holders and the idle drops. Confusing since they are brand new carb holders. I have clamps on them as well. Any suggestions? I was thinking of putting some Vaseline on the inside of the holders to get them to seal right.

That might work. If not silicon.
Steve