Will a K1100 front end (triple trees, forks, brakes, wheel, axle, steering stem) fit straight onto a K100?

Yes but you must use the master cylinder for the brakes as well and that means the complete handlebar unit with the throttle and the cable which you may have to play with for internal length.  The switch unit will fit.

Thanks mate,


Wanna take a guess-timate as to the rough cost of all that? 

Tossing up between a K1100 front end with custom made triple trees to decrease trail for a sidecar rig 
OR
Getting a leading link front end made. 

Balance of cost vs desired outcome.

Are the K1100 standard calipers of the floating variety?

Ive also read (maybe in a post by you Rick) that GSX1400/Hayabusa front ends are a simple conversion. Cant find any examples on line...Is it just a matter of using the K100 head stem pressed into the lower GSX triple clamp? and using the GSX master cylinder as well?

Installing K1100 front Brakes on a non-ABS K100RT

This tutorial will help understand what's involved in doing the swap to a K1100 front end.  Well worth the effort, in terms of improved handling and braking.

As for the triple trees, they are compatible.  I'd change the bearings at the same time as the swap although you can get away with using the outer races from the K100 and the inner races from the K1100 so long as they are not showing wear.  That's what I've done with my K75.

Are the K1100 standard calipers of the floating variety?

Yes.  305mm floating on the K1100 versus 280mm fixed on the K100

I've also read (maybe in a post by you Rick) that GSX1400/Hayabusa front ends are a simple conversion.

The K75 Projeckt
1985 BMW K100FF

Is it just a matter of using the K100 head stem pressed into the lower GSX triple clamp? and using the GSX master cylinder as well?

No.  The triple tree spacing is different so you have to solve that problem. Bearings are different as well.  I don't know how you'd adapt the GSXR throttle assembly to the K100 throttle body design.  That would be a challenge.  As would finding all the proper switches on the right hand cluster (turn signal, emergency off, start button and light switch).

Any Aussies wanna hazard a guess at the rough cost of a complete k1100 front end from a wreckers etc?

$1000? More? Less?

The K1100 handlebars mount back a bit further in the fork trees - maybe an inch or more.  I didn't realize this was an issue on my K75 with a K1100 front end until I went touring with a tank bag and it was, to say the least, clumsy using the dash switches with the switches pushed back very close to the front of the tank bag.  (four hole square dash pad)  This may or may not be an issue on a K100.

Before heading home, I lopped off the column for the 4V ignition switch, modded the mounting braces of the dash pad and then fab'd a bracket out of right angle aluminum bar stock to put the dash back where it should be.

Since you'll need a 4V brake master that means you'll also need to use a 4V throttle cable.  There isn't as much slack in the throttle end of the cable. I cured that by bending the arm that holds the cable above the throttle down a bit.

Not sure what you're planning to do fairing-wise but the lower fork tree of a K11 doesn't have two holes in it for mounting a C or regular K100 fairing.

Since the steering stem for K1100 fork trees is narrower than that of a K75 the fluid block damper becomes obsolete.  Only time I ever noticed that was at uber low speeds (stop-n-go in a long stop light line) where it would be a little twitchy - not a big deal.  And that seemed to go away when I switched the bike over to radial tires. (Not an issue on a K100 since only K75s have the dampener.)