I have it in my mind that the K1100 forks have a different internal set up, maybe spring one side, air the other - or something   and if so presumably they are an improvement?

Question is, are they a straight fit?

Bonzo wrote:I have it in my mind that the K1100 forks have a different internal set up, maybe spring one side, air the other - or something   and if so presumably they are an improvement?

Question is, are they a straight fit?

31 42 2 312 911 & 912, the individual fork leg assemblies, when searched for in a Euro K1100LT catalogue, are the same part number with K1 & K100-16V. So, yes, straight fit as in I'll trade you my school lunch sandwich for yours, each made by the same mum's loving hand.

The Marzocchi forks from a K1100RS will also fit - these too are traditional internally & what I'm using on Big Block.

Yes, they are a straight fit.  The trick comes with the brakes and handlebar controls if you're swapping the whole front end; that part's a slippery slope.

https://k75retro.blogspot.com/2013/09/paralever-conversion.html

K100-16V use a 20mm master cylinder, same as all K1100. Same axle. Same combi switches. Same brake discs. Same callipers. There will be a few ancillary pieces which differ. The 2.5x18 K1100LT wheel obviously differs from the 3.5x17 K1100RS front wheel, but essentially the guts of the forks are the same stuff with no real benefit to be gained.

Two Wheels Better wrote:

Bonzo wrote:I have it in my mind that the K1100 forks have a different internal set up, maybe spring one side, air the other - or something   and if so presumably they are an improvement?

Question is, are they a straight fit?

31 42 2 312 911 & 912, the individual fork leg assemblies, when searched for in a Euro K1100LT catalogue, are the same part number with K1 & K100-16V. So, yes, straight fit as in I'll trade you my school lunch sandwich for yours, each made by the same mum's loving hand.

The Marzocchi forks from a K1100RS will also fit - these too are traditional internally & what I'm using on Big Block.

Cheers TWB,

Just so I'm on the same page, are the K1100LT and K1100RS forks different? Surely they are both Marzocchi.

K1100RS and K1100LT have the exact same fork.

My point is just that, the K1, K100-16V and K1100LT forks are all the same so there is no benefit to be realised. 

At about 4AM I was on my mobile in the dark, as you do, answering this question and didn't bother to also open the RS catalogue in realoem to confirm that they're 31 42 2 312 911 & 912 as well. I do sincerely promise to be more thorough in the future. It's a bad habit of mine, disseminating information.
freely and without an expectation of recompense.

Well, as long as you don't let it happen again 

Seriously though, thanks 

Two Wheels Better wrote:My point is just that, the K1, K100-16V and K1100LT forks are all the same so there is no benefit to be realised. 

Actually, there's a difference. Early K4V have different internals: it's not a cartridge fork but a classic damper device, with spring and washers. It fits specific fork tubes.
Thus, the benefit would be to install a early fork on a K1100: it would allow to set up damping on request.
The best option would be to find the original version of that fork, the M1R which was on Ducatis 851 and Paso, and some Guzzis, fully adjustable...

jbt wrote:

Two Wheels Better wrote:My point is just that, the K1, K100-16V and K1100LT forks are all the same so there is no benefit to be realised. 

Actually, there's a difference. Early K4V have different internals: it's not a cartridge fork but a classic damper device, with spring and washers. It fits specific fork tubes.
Thus, the benefit would be to install a early fork on a K1100: it would allow to set up damping on request.
The best option would be to find the original version of that fork, the M1R which was on Ducatis 851 and Paso, and some Guzzis, fully adjustable...

You're giving all the secrets away! I have the early Marzocchi version on Big Block. This fits up through the 1991 model year then came the change to cartridge type. The easiest way to determine what you have without having to rip into them is to determine whether it's a 10x1 plug and 10mm seal ring at the fork cap, or a 12x1.5 threaded plug with a 12mm seal ring. The latter is the cartridge type and uses the 12mm fork cap plug. Given Bonzo's K100-16V is a 2nd month of 1990 model... he's likely got the early version if they're the originals.

As a Guzzi owner I've got three sets of those Marzocchis up in the garage roof and you're NOT HAVING THEM!