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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: VikingEric on July 14, 2014, 06:03:38 PM

Title: K100 Swapping Wheels, Forks and Brakes
Post by: VikingEric on July 14, 2014, 06:03:38 PM
Hi guys!  Hoping for some helpful information!
I have my faithful 85 K100RS (non-ABS) up for project time.  I'm going the café / nake direction.
I've been doing a good many hours of searching and am having difficulty finding exactly the information I need.

Here is what I want.  I would like to upgrade my front suspension and brakes and use the 3-spoke style wheel from the K1100, R1100 etc.
I have bought and hold currently a very nice 94 K1100 set of forks and yokes.  I know this will be a basic direct swap.  I have a access to a couple wrecked R1100s, a newer K100, and a couple other new bikes like the R1200C.  I do not have access to a K1100.

I do not have brakes or a front wheel from a K1100.  I DO have brakes and wheels from the R1100s.  Since the rear wheel bolted right up and I could find no information suggesting otherwise, I incorrectly assumed the front R1100 wheel would fit my K1100 forks.  I believe the brakes are the same however.
Now, sourcing a K1100 front wheel is iffy as the only ones on Ebay are out of my acceptable expense budget right now.
I believe I can put different bearings in the newer R1100 wheel for the thicker axle and perhaps machine the thicker offset slightly.
Does anyone know a reason why I could not do this?  What would be the simplest way to use an R1100 wheel on my K1100 forks on my K100 bike?  Also, would the brakes work alright?  I believe they would.

Also, can I use the rear master cylinder from an ABS K100 on my non-ABS K100RS?
Title: Re: K100 Swapping Wheels, Forks and Brakes
Post by: jacksdad1963 on July 14, 2014, 06:16:31 PM
K bikes are 4 cylinder bricks, R bikes are 2 cylinder boxer engines, yes?
I have got a K1100LT and the wheels and tyres are different sizes than the K1100RS...whar size wheels have you got?
Title: Re: K100 Swapping Wheels, Forks and Brakes
Post by: VikingEric on July 14, 2014, 06:25:16 PM
The R1100 3-spoke I have now is a 3.5x17
Title: Re: K100 Swapping Wheels, Forks and Brakes
Post by: Scott_ on July 14, 2014, 07:02:03 PM
Eric, if you want to do some research,

http://www.maxbmwmotorcycles.com/fiche/PartsFiche.aspx (http://www.maxbmwmotorcycles.com/fiche/PartsFiche.aspx)

and

http://www.realoem.com/bmw/select.do (http://www.realoem.com/bmw/select.do)

you can do some part # searching to see what is the same between year/models, etc.... for interchange.

Title: Re: K100 Swapping Wheels, Forks and Brakes
Post by: johnny on July 14, 2014, 07:19:31 PM
front wheels are not the same part number and look not interchangeable without mods by looking at the fish...

j o
Title: Re: K100 Swapping Wheels, Forks and Brakes
Post by: VikingEric on July 14, 2014, 07:31:24 PM
Those sites are great and I don't know why I didn't have them already!  However, I do know that the wheels are not the same.  My question is really if anyone knew the easiest way to modify the R1100 to fit the K1100 forks.  Could I simply get new bearings and a spacer for the larger axle?  Or would there likely be more complications?
Title: Re: K100 Swapping Wheels, Forks and Brakes
Post by: Inge K. on July 14, 2014, 08:06:48 PM
http://www.largiader.com/parts/wheels.html (http://www.largiader.com/parts/wheels.html)
Title: Re: K100 Swapping Wheels, Forks and Brakes
Post by: VikingEric on July 15, 2014, 01:30:46 PM
Yep, I also found this site on my searches.  It has GREAT information but I just can't seem to decipher it and it doesn't seem applicable anyway.

My problem is that the R1100 wheel is not the same as the K1100 wheel.  I have a R1100 wheel and I want to know if I can convert it to K1100 forks.  On that site it does provide the bearing sizes so perhaps I could extrapolate from that but I'm wondering if it's practical.
Title: Re: K100 Swapping Wheels, Forks and Brakes
Post by: VikingEric on July 15, 2014, 05:30:19 PM
So, I'm also a bit confused about that site.  It says the R1100 wheel has different size inners on the bearings.  This not the case and doesn't make much sense, I suppose it's a typo.

I've decided to seriously consider bearing swaps.  What is the easiest way to remove BMW bearings?  I have a press but I have looked around and it seems that my options are special tool or heating and dropping it (I don't have a large enough oven and should not use a heat gun or torch).

I have a 20-ton press but the research I have done implies that both bearings cannot come out the same direction.  Am I not able to use the press?

Clymer leads me to believe I cannot use a bearing puller.  Is this also correct?

Also, does anyone know the outer distance from discs on the K1100?  I'm hoping  it's 126mm like the R1100 and not 132 like the K100.
Title: Re: K100 Swapping Wheels, Forks and Brakes
Post by: beachcomber on July 16, 2014, 05:41:28 AM
So, I'm also a bit confused about that site.  It says the R1100 wheel has different size inners on the bearings.  This not the case and doesn't make much sense, I suppose it's a typo.

I've decided to seriously consider bearing swaps.  What is the easiest way to remove BMW bearings?  I have a press but I have looked around and it seems that my options are special tool or heating and dropping it (I don't have a large enough oven and should not use a heat gun or torch).

I have a 20-ton press but the research I have done implies that both bearings cannot come out the same direction.  Am I not able to use the press?

Clymer leads me to believe I cannot use a bearing puller.  Is this also correct?

Also, does anyone know the outer distance from discs on the K1100?  I'm hoping  it's 126mm like the R1100 and not 132 like the K100.

The oilhead [ R ] forks are different - as are the wheels. The spindle [axle ] is not the same length either !

I'm assuming these are the 3 spoke wheels ? Simple solution [ and cheapest ] would seem to be sell the R wheel and brakes etc., and buy a K wheel which will fit right up with the relevant 4 pot calipers.

The rear caliper will work just as well with or without ABS.

If you think that's fun, wait until you do the K1200S 5 soke wheel conversion !
Title: Re: K100 Swapping Wheels, Forks and Brakes
Post by: VikingEric on July 16, 2014, 09:18:00 AM
They are the 3-spoke wheels.
I know that buying the correct wheel may be the simplest but for various reasons it may not be my cheapest option.
I'm still researching my options.  I may create a build thread soon.
Title: Re: K100 Swapping Wheels, Forks and Brakes
Post by: pdg on July 17, 2014, 04:43:08 AM
If you can get a bearing that fits in the hole in the wheel, and fit over the spindle, then it will be bearingy and spinny and fine....

Make/modify/source spacers to get the wheel in the right place in the forks, then it will be inliney and fine.

Brakes are brakes. If they squeeze the pads on to the right place on the disc then they will stop the wheel being all spinny and be fine.... Might need to space the caliper or make a mount plate to get it central over the disc though.
Title: Re: K100 Swapping Wheels, Forks and Brakes
Post by: jacksdad1963 on July 17, 2014, 10:39:11 AM
I've had a great idea....

Sell the bike and buy the one you want.... :dunno

My brick is a 1995 K1100LT, the outside distance on the discs is 126.6 mm  :2thumbup:
Title: Re: K100 Swapping Wheels, Forks and Brakes
Post by: VikingEric on July 17, 2014, 10:48:21 AM
If you can get a bearing that fits in the hole in the wheel, and fit over the spindle, then it will be bearingy and spinny and fine....

Make/modify/source spacers to get the wheel in the right place in the forks, then it will be inliney and fine.

Brakes are brakes. If they squeeze the pads on to the right place on the disc then they will stop the wheel being all spinny and be fine.... Might need to space the caliper or make a mount plate to get it central over the disc though.

Yep, that's about the conclusion I came too.  I have the bearings out of the R1100 wheel right now and my K100 wheel is in the oven as we speak.  Things should go fairly smoothly.  My only concern right now is that there is a 4mm offset or rise on the inner race.  I will take a picture of this later.

I've had a great idea....

Sell the bike and buy the one you want.... :dunno

My brick is a 1995 K1100LT, the outside distance on the discs is 126.6 mm  :2thumbup:

I'm afraid I don't have that kind of cash on hand.  Actually this is a Café build and I want the upgraded K1100 forks and some sweet 3-spoke wheels.  This is also a bit of a fun learning process as well.  Time I have plenty of.  Money less so :)  Thank you for the measurement on the discs!  That matches my R1100 wheel discs and give me confidence.

I will update more later.
Title: Re: K100 Swapping Wheels, Forks and Brakes
Post by: jacksdad1963 on July 17, 2014, 02:39:07 PM
I know what you mean about money!
I also like to build and modify my own vehicles, I do things 'just for the sake of it': makes the bike/car/4x4 my own  :2thumbup:
My Isuzu Trooper 4x4 is an example....
Title: Re: K100 Swapping Wheels, Forks and Brakes
Post by: VikingEric on July 17, 2014, 06:04:54 PM
I've ordered a couple bearings for $20 each that will work.  The spacer from my K100 will work with maybe a mm or two trimmed off.  I MIGHT have to have machined off 2mm from the shoulder on the axle.  Will post pictures later on a build thread in a few days.
Title: Re: K100 Swapping Wheels, Forks and Brakes
Post by: VikingEric on July 19, 2014, 07:35:52 PM
Got my bearings in the freezer now.

Do I need the spacer between the bearings?  What benefit does that provide?
Title: Re: K100 Swapping Wheels, Forks and Brakes
Post by: Inge K. on July 19, 2014, 07:42:02 PM
Your bearings won't be very happy when you tighten up the axle nut w/o a spacer between them.
Title: Re: K100 Swapping Wheels, Forks and Brakes
Post by: jacksdad1963 on July 19, 2014, 08:37:03 PM
You MUST fit the exact size spacer, otherwise the bearings will fail within a mile  :2thumbup:
Title: Re: K100 Swapping Wheels, Forks and Brakes
Post by: VikingEric on July 19, 2014, 10:26:07 PM
I blame the beer.  The answer is so simple I can't believe I missed it.
Okay I will be sure to use a correct size spacer.
Title: Re: K100 Swapping Wheels, Forks and Brakes
Post by: jacksdad1963 on July 20, 2014, 02:05:03 PM
Good man Eric!
I work on the old fact: there's no such thing as stupid questions  :2thumbup:  :riding: