Hello everyone, I'm the 3rd owner of a 1985 K100RS. It has about 88000 miles and I'm looking to add a 4.5" rear wheel and a Buell 1125r fork setup. I really enjoy this bike.
I believe this would be a great addition to an already great ride. I'm in Bakersfield, CA.

Welcome aboard Debonair , as far as the rear wheel goes , take a look at this thread

https://www.k100-forum.com/t2713-wider-wheels-radial-tyres-on-a-k100

JR

Welcome Debonair - I'll be in CA in October wont have the trusty RT but thinking of hiring something suitably equivalent - is there good riding out there?

Welcome to the club.

I've done the more modest bolt-on rim upgrade to my '85RT (see link in my signature). It's just the 3" rim in the rear, but still the improvement to ride and handling is tremendous. I would recommend this simple upgrade to all RT sport touring rides even if you can't find the very rare 3-spoke front rim.

A very few people have modified the front-end on early K-bikes, of which the '85 with Euro cam is the prime model. If yours is the California emissions model it has a little less HP, but the improvement to braking may still be worth it for a purely sport ride. The rear end mod is a little easier, just modify a center-stand from a K1100. 

:bball:

welcome aboard
have fun with the mods ...and enjoy the ride

Thank you everyone for the warm welcome. I have done some homework and have the parts mentioned. I'm only in need of time to do the mods. Warren, we have great riding in my area. HWY 155 is good, Keene is real good too but the lions trail is great! Let me know when you get out here...