'80 KZ1000-E2 Fork mods-rebuild

Bike is running good now with the finest used ignition pickups I could get for $10 - from a 650 CSR I believe. Turns in well but man that fork is due for a rebuild. I am a big guy- 6'3" 260 #'s, my brother is 6'4" 350 #'s. It is he that is the intended rider. I remember a post in which someone said they made preload spacers for their forks from 1" lengths of PVC pipe and that they used a heavier fork oil (w20?) This was for a 750 if I recall. I'd like this bike to handle it's best and deal with the weight. Any tips on the rebuild? Mods?

progressive springs and synthetic 30w synthetic oil.

There's really not a lot to rebuild. The ST already has the biggest diameter forks ever put on a KZ and tapered roller bearings in the steering stem. A real heavy duty bike all the way around. You can go with whatever preload you like by trying different lengths of PVC pipe or put heavier fork springs. I doubt 99% of the riding public could tell any difference between the varying weights and type of fork oil used.

Ok then, I'll try the 30 weight and experiment w/ the PVC spacers. Any special tools for replacing fork seals? Tips?

You will probably need to make a tool to keep the inner fork cylinder from rotation when you loosen the bottom bolt.

You can use a wood dowel/broomstick but sometimes they don't do so well.

Post edited by: KZ_Rage, at: 2006/11/26 11:23

Preloading can be a pain in the arse when reassembling the fork as the top plug can be a bear to get back in or easily started cross-threaded. The higher viscosity oil will slow the dampening rate but progressive springs will give you the best start to handle the extra 100#'s or so, IMHO. Try just rebuilding them to just normal specs and see how it goes. You can change springs without having to remove the fork tubes from the tree's, same thing with the oil, you can drain and refill while mounted on the bike.



Post edited by: KZ_Rage, at: 2006/11/26 11:31

That's a good point- I'll start with working stock forks. What size bolt is that? That's to put the top caps back in?

Ok - for the inner tube. Duh.

del

I am about the same size as you and find the stock springs more than stiff enough on my ST. I doubt that 30w oil will give a compliant ride... that is as thick as I have ever heard of as far as fork oil goes. Most fork oil is 10w or 15w... even a 350 lb guy will not want to have a harsh ride. The fork tubes on the ST are 39mm rather than 37mm as on the other older KZ models. I would use some Progressive fork springs to maintain ride but soak up the hard shocks for a heavier rider and some Progressive rear shocks as well... You can get 13.5" Progressive 12s with heavy duty springs and the front springs from z1enterprises.com. Adding a tad of preload on the front might be helpful but I would not use more than 1" spacer with the Progressive fork springs.

Thanks for all the info guys.

Thanks for all the info guys.