Hello,

I have a 1985 k100rs I just picked up. The previous owner's son laid it down and rashed the fairings and one fork has a leak and possible slight bend to it.

I want to upgrade the front end, brakes and wheels.

I have a k1100rs fork set with 4 pot brembos I am bolting onto the k100rs.

If I go with the 3 spoke wheels from the k1100rs then it would be bolt and go.

Unfortunately I really like the looks of the 5 spoke r1100/k1200 wheels.

It looks like the front will be a direct bolt on (although I can't find any information on the rotors. Will they work with k1100rs front end?)

The problem seems to lie in the rear. I am rather handy with a wrench and welder and am not afraid to cut/weld or bolt on new parts to make the rear wheel fit but I prefer to keep things as close to stock as possible.

I have not been able to find a detailed account of fitting a rear 5 spoke wheel on a k100rs.

It looks like there will be issues with the muffler and possibly the center stand. Swingarm? (rear 5 spoke wheel is 5 X 17)

I am going to continue to use it as a sport touring bike. I love the weight, wheelbase and simplicity of the design, just want better handling and stopping power.

If the mods become too much or will impede the touring aspects of the bikes (saddlebags) then I will just go with the 3 spokes.... but damn I like the looks of the 5 spokes

I am asking for any help, guidance or links that can help with this modification.

Thanks in advance.

heres a few links to what we have done recently

http://k100rt.aforumfree.com/t2713-wider-wheels-radial-tyres-on-a-k100


modified k1100 centre stand bolted up to the k100 rt

yeah thats a great post. I'll be following that if I end up putting the three spokes on but I am trying to see what the mods are for the 5 spoke k12/r11 wheels. Especially the rear.

Thanks for any help on links.

The 3 spoke wheel is very marginal on a K100 unless you use a paralever drive and swingarm. I have seen a 5 spoke on a K1100 with a paralever setup but there is no wayu a front 5 spoke will go onto a K100 or K1100 front end and a front end from a bike with a 5 spoke will not fit on a K100 or K1100.
If you really want to do the job I dare say it could be done but I certainly would not like to be paying the engineering bill you would be better off just buying a K1200 and keep the left over for a bit of riding.

Hey Rick
Thanks for the comment.

You raise some good points.

The main modification on the front wheel is to cut a new stainless axle and spacer. Other than that the 5 spoke will work great on the k1100 front end.

I have done this a few times on some airhead projects and it runs about $50-$75 at a machine shop in my building.

I've run across several pics of people (mostly EU forums) dropping both 3 and 5 spoke wheels on k100s


I've rounded up all the parts to do the swaps for about $600

I like the k100 platform as they're lighter and simpler than the k1100rs for sport touring. They're simple and the 1985 had a hotter cam set up that gives them enough pep and a smooth delivery of power.

I just want to upgrade the front end, braking and traction.

I would be interested to see the conversion as I have understood that the 5 spoke have the bigger floating discs that attach directly to the wheel spokes. Please post some pics I would like to see how it is done.

I think the best part of that thing is the wheels.
Maybe it's just that I don't like most cafe racers as they have an unfinished look about them.
Looks like he is running carbs too.

Rick G wrote:Looks like he is running carbs too.

..........it looks like it`s just KN`s on the end of the intake tubes.

Yeah I can see the bar across the back of the TBs but it don't make it look any better.
Should have a collar and leash on it.
One that I do like is the one that scheffers is building it probably will turn out looking finished.
Blakey might like it, Red with black zip ties.

Ta for the link, Inge. That thing looks rough as guts. I appreciate it for it basic-ness. It shows what can be done with a will and some hand tools in a back shed. Am I wrong or is that a piece of flat, mild steel holding the calipers onto the fork leg? Man.

An MOT or TUV inspector wouldn't like it much. Perhaps that's what I like about it.

Yeah, think it would be a bit fun for you guys down there who like to play with the wheels.........
and especially since it also is a Aussie.

http://www.motorsport-tech.com/wheel_adapters.html

can always get an adapter from a 4 to a 5 lug

Inge K. wrote:

Rick G wrote:Looks like he is running carbs too.

..........it looks like it`s just KN`s on the end of the intake tubes.

I'm wondering how well it runs without the mass air-flow sensor/flapper
inside the missing air cleaner box?

Dale S wrote:I'm wondering how well it runs without the mass air-flow sensor/flapper
inside the missing air cleaner box?

It's a K1100 and with the Motronic, there is no MAF like on the K100.

Actually, the K100 4v and K1100's used MAS - Mass Air Sensors, while the early K's used MAF - Mass Air Flow sensors.

Big difference.  

In the MAF the air goes through the opening and actually opens a vane (air pressure) which causes a potentiometer to vary voltage as a signal.

MAS sensors have a heated wire in place of the vane (less impediment to airflow, less finicky).

Both combine those signals with outside air temperature and other readings to regulate fuel flow.

MAS is much more accurate.

I know the hotwire flow sensor from working with cars, but I never seen such a device in the air intake system on a 4V K-model.

I would like to know where it's hidden and if possible the part number, please.

Here's a 5 spoker in a K100; he told me he just used 2 of the steel spacers.

 

Paul.

I would bet it's 20mm ofset to the left, at least right hand corners would be a breeze.