RicK G wrote:I am in the process of doing just that except with a paralever rear end but I am sure there will not be enough meat to take that much off, it will leave very little metal for strength. The paralever sits quite a bit more to the right so will work. Also if you take that much from the wheel boss it will hit the swingarm.
The A & B that Charlie talks of is for the 3 spoke K1100 and K75s wheels so is of no concern.

Mikewills wrote:I have recently bought this k1200 wheel after instruction that it'll fit my 1987 model without modifying it. Hoping this is correct as the bike isn't at my home so not sure when I'll get to try it on.

RicK G wrote:

Mikewills wrote:I have recently bought this k1200 wheel after instruction that it'll fit my 1987 model without modifying it. Hoping this is correct as the bike isn't at my home so not sure when I'll get to try it on.

What width is the rim?

jbt wrote:K1100LT rim (3 width, 17 inch diameter) will fit K100 with no modification, as they were available as a "sport" option on K75.
K100RS1, K1100RS,  K1 rim (4.5 width, 18 inch) will fit with spacer  but there may be a light disalignment with the front and may not cope with the monolever swinging arm. BMW allows this light offset.
Others won't fit because of the huge offset with the fron't wheel.
Note that the  larger is the rear wheel, the worst is the handling...
I had tested all the configurations on my K1100LT, the best is the original one with a thin tyre and a 3 inch rim.

On any bike with a double swinging arm, you can fit an larger wheel if you have room enough. On a K , there's few room, and extra width should make you modify the position of the engine, gearbox and transmission in the frame to keep the wheels in line.

Mikewills wrote:

RicK G wrote:

Mikewills wrote:I have recently bought this k1200 wheel after instruction that it'll fit my 1987 model without modifying it. Hoping this is correct as the bike isn't at my home so not sure when I'll get to try it on.

What width is the rim?

It's a 5".
There's a few places on the internet that supports what I've been told that it'll fit. I'll just have to try it I suppose

Two Wheels Better wrote:That thread has brought back some memories, JR. The red RS still wears that tyre size combo tho' now she's got Michelin Pilot Road III out back and an older PR2 up the front. I like them for their straight-line stability with relatively good turn-in, not as quick steering as the Conti Road Attacks, but not as planted as the Pirelli Angel tyres I first used. One day I'll whack the K100RS-16V Marzocchi forks, 17" front wheel and 305mm discs, K11 gearbox and Paralever I've got saved onto it and call it updated. The offset relationship between a Monolever and the K1100RS 4.5" wheel is minimal, but you best use a K11 centra stand and grind some of the left foot away as mentioned in the link.

Side note, my (K100 with K1200RS motor) Big Block Paralever uses a 5" K1200RS wheel (170/60ZR17 tyre, not a 180/55) and it sits centred with plenty of space between the tyre/rim and swingarm.

Next ride, October when I return home.

lumpus wrote:Hi together!

I'm a little frustrated. I read in some forums that it is no problem to adapt a K1100 wheel to the K100. (ok, perhaps with an adapter..)
Now I got one with number 2 331 357 ....
First Problem is, the casted bolts for the brake disc. Ok, I can cut it off....
But there is also big difference in the offset of ~+17.5mm. Which means that I have to mill off 17.5mm on a lathe to get the original tracking line / alignment.

Has the K1200 the same offset?

Do I have the wrong wheel?

Thanks.

jbt wrote:Very nice rim, I've never seen such one on a K. Who makes it?

jbt wrote:Thanks,
I've been searching for a long time for a rim in 4.00 width for K.
With a friend, we're building a race K100, for endurance races, but the rules forbid a rim wider than 4.00, so the 4.50 genuine one is too large.
Very difficult to find...
PVM made wheels with bolted on parts, so making possible to swap the rim itself on the hub, but they're also very,  very rare.

Scottybullet wrote: I'll post pics as soon as i have a place to hide them.

Scottybullet wrote:Looks like with a 170/60/17 rear it'll clear the swingarm I'll post pics as soon as i have a place to hide them. I have the rim bolted up no problem with just enough room if the tire is not wider than 6.5 inches across

Scottybullet wrote:Here is my setup 1996 K1100LT mounted a K1200 5.5X17 rear rim(no oem spacer) with a dunlop roadmaster 3 170/60/17.  I actually gained 1 MM of spacing between the tire and the swingarm from the test tire I had mounted. 

It sits a smidgin off center but I could care less for the rides I'll be taking it on. 

Scottybullet wrote:Here is my setup 1996 K1100LT mounted a K1200 5.5X17 rear rim(no oem spacer) with a dunlop roadmaster 3 170/60/17.  I actually gained 1 MM of spacing between the tire and the swingarm from the test tire I had mounted. 

It sits a smidgin off center but I could care less for the rides I'll be taking it on. 

beachcomber550 wrote:Not sure what a "smidgen" is in Canada .... about 10mm offset. That said makes absolutely NO difference to the handling ! . . . Even the BMW OEM manual gives values for STOCK offsets !!

Rick G wrote:Please supply the relevant document because I hear this often yet have been unable to find anything in any factory published document supporting the claim.

RicK G wrote:Even the BMW OEM manual gives values for STOCK offsets !!

Please supply the relevant document because I hear this often yet have been unable to find anything in any factory published document supporting the claim.
Please note at the moment I am not calling bullshit but just wish to see the published document.

Dai wrote:Also, both Tony Foale and BMW experimented with front/rear offsets in the 1990s. BMW's conclusion at the time was that it didn't affect handling and actually improved something-or-other, but way too much time has passed to remember what that was. The reason for not putting into production was that it was 'too radical'.

Well: while trying to turn up the reference for at least one of the above (failed), I did turn up an extremely interesting picture of a K-RT undergoing wind-tunnel testing. The fairing is covered in the usual white tufts to check wind flow, but the engine appears to be equipped with one silence per cylinder! I did just try to scan it but the book is a paperback and I'm unwilling to flatten the spine.

The book is

Motorcycle Tuning (Chassis) by John Robinson. ISBN 0-434-91724-9

The picture is on page 171 of the paperback edition. It's long out of print (1994) and what originally cost £5 is now going for north of £50, if you can find one.

RicK G wrote:Even the BMW OEM manual gives values for STOCK offsets !!

Please supply the relevant document because I hear this often yet have been unable to find anything in any factory published document supporting the claim.
Please note at the moment I am not calling bullshit but just wish to see the published document.

RicK G wrote:Well Beachcomber550 when you figure out how to put up pictures then I will give you an answer.

beachcomber550 wrote:

RicK G wrote:Well Beachcomber550 when you figure out how to put up pictures then I will give you an answer.

 I'm seeing 3 images on my posting ???

If you CAN'T see them try the BM Riders forum ... on there too.

beachcomber550 wrote:FACTORY BMW OEM workshop manual - part# 01 51 9 799 101 ....a very useful volume for us l

You'll see that BMW allow for 12mm max. offset .... mine was 10mm [ see my previous post ] with a 5" rim and 15mm with a 5.5" rim. IN 9 YEARS OF HARD RIDING THERE HAVE BEEN NO HANDLING / STEERING ISSUES.

Laitch wrote:

beachcomber550 wrote:FACTORY BMW OEM workshop manual - part# 01 51 9 799 101 ....a very useful volume for us l

You'll see that BMW allow for 12mm max. offset .... mine was 10mm [ see my previous post ] with a 5" rim and 15mm with a 5.5" rim. IN 9 YEARS OF HARD RIDING THERE HAVE BEEN NO HANDLING / STEERING ISSUES.

In reply 37, the page extract I posted was from the BMW manual for 2V K models. The manual beachcomber is citing is for the K1100 so has a differing spec. One page from that manual is attached.

It's likely fair to say that these maximum offset specs were established for BMW's liability protection, that racers can do whatever works for them within the constraints of competition rules, and that performance of a setup for competition might be unsatisfactory performance on ordinary roads at ordinary speed.



As previously stated - I have used my modified Kay ON THE ROAD for 9 years in all sorts of riding conditions with NO PROBLEMS. Finis.

chris846 wrote:Seeing as this thread is (still) about the possibilities of fitting wider rear wheels to a K, I'll add this because some future reader might find it useful.

The 5-spoke (best looking wheels ever) rims fitted to the K1200 are a common choice. They can be hard to get hold of, compared to the very similar looking wheels fitted to boxers from the same era. Most times though, people find they can't use boxer wheels for two reasons: boxer wheels have disc mounting posts cast onto the spokes (Ks don't - the disc is sandwiched between the wheel and the hub), and boxer wheels have too much left offset (sometimes described as 'A' and 'B' wheels - is this to make up the space for the 'missing' disc?)

Well, the problematic extra offset on a boxer wheel can itself be 'offset' by leaving out the k series disc, and using a boxer disc mounted on the wheel. I did this with a 5" boxer rim (there are 5.5" options out there too) and, with a bit of adjustment to the swingarm pivots, it was possible to get the left offset down to just 3mm.

This itself isn't without a bit of grief; the boxer disc has a smaller OD, but a boxer rear caliper is correct for this, and (in typical BMW style) fits straight on the caliper mounts on the bevel drive (K & boxer bevels are very similar). I had to shift the caliper and disc over to the left (spacers on the caliper, machined a bit off the disc mounting posts) but this was to clear a wider, non-standard shock, dunno if this would be necessary with a standard shock.