BMW K bikes (Bricks)

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MT350Explorer

MT350Explorer
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Guys,

I have tried various ways to make the bike feel more manageable for someone my size i.e. 31" inside leg. The only one that has worked for me is fitting a shock from a standard 2 valve which is significantly shorter than the standard 4 valve shock. The 2 valve is about 14 inches. Have also dropped front forks by 10 mm (just seen in the red circle). The seat height (yellow line) is now 787 mm or 31".

Bike seems to handle well, a bit sharper and a bit pointier. First impressions are I am really happy with this set up Very Happy ; it makes the bike feel much less tippy when I'm pushing it around and a bit more 'to scale' when riding. Clearance is fine for me but if you regularly got your knee down - well it is lower.

Low seat info - using a standard 2 valve shock on a 4 valve Lowsea10

I believe GITH has said (but am open to correction) that all 2 valves have the same short shock that I've fitted and the lower ride height is a function of the attachment points being further apart on the 4 valve thus a longer standard shock. There are 25mm shorter rear shocks for 2 valve bikes made by Realm Engineering -it would be interesting for someone to share their thoughts having fitted one of these?

Cheers
Dave


__________________________________________________
1991 K100 RS 16 valve
    

kfilipow

kfilipow
Silver member
Silver member
Dave, That is a really nice looking bike.

KFilipow USA

    

K75cster

K75cster
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Dave I had a Koni shock on my 75 years ago, it was 330mm (stock is350) it worked fine but having it rebuilt lead to problams with the valve becoming loose so went to a stock 100 shock that had been rebuilt. the bike now stood alittle higher, but off the centre stand and with me on it the shocks both seemed to end up with the same amount of sag (ie more on the stocker than the koni) so really when siting astride the bike or riding it there appeared to be no discernable difference. mind you I do weigh in at 17stone. I thought you're stock seat height was to be 805mm so you seem to have dropped it 20mm if the sag is the same as before then maybe you could go another 10mm on the front to get back to square with what you had before the new shock. So there's a tip check how much sag you're arse has!


__________________________________________________
Keith - 1987 K75c with r100rt replica fairing and half of a 1984 K100rt 1992 K1100LT a blue one

The Clever are adept at extricating themselves from situations that the wise would have avoided from the outset - QUOTE from david Hillel in Out of the Earth.
    

JR_K100RS

JR_K100RS
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G'day Dave , I'm with kfilipow , great looking machine

JR

Melbourne Australia


__________________________________________________
Diamond Grey ( 617 ) 1987 K100RS ( European Delivery ) Original owner
    

ushes

ushes
active member
active member
I have exactly the same bike, the same problem and I'm also looking for a solution! At the moment there's an (almost) new K100RS shock on ebay. I'd assume that this is the shorter length one that you have. Do you have an pictures of the longer and shorter length one fitted, a part number. Mine is I think the standard OEM part and its a Bilstein. Yours ?

How easy is it to alter the front fork length ?



Many thanks

Regards

Steve

    

ReneZ

ReneZ
Life time member
Life time member
Interesting, I went the other way and fitted an 1100 shock on my 100 (35/36 inseam). Just sold the 100 shock, otherwise you could have had a try. Maybe someone else has one you can try??


__________________________________________________
Greetings from Florida! Having a 'new' K  :cyclops:    Surprised-o: 

Rene


BMW K100 - 1985 (0030029) Low seat info - using a standard 2 valve shock on a 4 valve Rain
BMW K1200GT - 2003 (ZK01223)
    

ushes

ushes
active member
active member
Yes, that would be good. I wouldn't really want to spend money on a new shock until I knew that

a) it would fit without problems.

b) it would lower the seat height sufficiently to make the exercise worthwhile

c) any adjustments of the fork length would produce acceptable handling.



Steve

    

ReneZ

ReneZ
Life time member
Life time member
Otherwise could you go for a lowered seat arrangement? There are original possibilities and you see quite a few people swapping from normal (what you have) to lowered and the other way around.

Like below:

Low seat info - using a standard 2 valve shock on a 4 valve 01_K75


__________________________________________________
Greetings from Florida! Having a 'new' K  :cyclops:    Surprised-o: 

Rene


BMW K100 - 1985 (0030029) Low seat info - using a standard 2 valve shock on a 4 valve Rain
BMW K1200GT - 2003 (ZK01223)
    

ushes

ushes
active member
active member
Mmmm

How much extra leg length would the lowered seat give, any idea ?

Maybe another inch or so would do I think

    

Inge K.

Inge K.
VIP
VIP
@ushes wrote:Mmmm

How much extra leg length would the lowered seat give, any idea ?

Maybe another inch or so would do I think

40mm (760/800mm)


__________________________________________________
Inge K.
K100RS -86. (first owner), K1100LTSE -94.
    

MT350Explorer

MT350Explorer
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Life time member
Hi Ushes

The low seat kit is available from Motorworks second hand. disadvantage I see is that I have tried removing seat foam which mimics the low seat and the ergonomics were rubbish (for me); the bars seemed high up and miles away and I felt like a granny peering over the dashboard of an Austin Allegro. It also looks pants without the side panels (my opinion Very Happy )

16 valve shock is about 15.5 inches from centre of one eye to the other. The 2 valve shock is about 14 inches. So you could ask the vendor to measure before you bid. With the above the reduction in ride height is significant.

Handling. Well I would defer to others for an expert view. My own view is that this modification is commonplace on many bikes and I do not think it will make the bike a death trap if that's your concern but it's your life and risk. It will change the characteristics of the handling - perhaps subtly and you will need to get used to those characteristics. For everyday riding I don't think it would be substantially different. Also worth remembering that you may change the handling a bit buty you may also boost confidence and reduce your accident risk as a result?

Fitting the shock was straightforward and adjusting the forks simple too.

Edit: be aware mainstand will not work so you will be reliant on sidestand only. Mainstand can be deployed for maintenance etc by backing the back wheel on to a piece of wood - I use an old square of kitchen worktop.

Hope this helps
Dave



Last edited by MT350Explorer on Wed Jun 20, 2012 3:12 pm; edited 3 times in total


__________________________________________________
1991 K100 RS 16 valve
    

MT350Explorer

MT350Explorer
Life time member
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JR and Kfilipow - thanks for the compliments. I love the RS's style and the colour. (although have a secret hankering for chrome orange Twisted Evil )


__________________________________________________
1991 K100 RS 16 valve
    

MT350Explorer

MT350Explorer
Life time member
Life time member
@K75cster wrote:Dave I had a Koni shock on my 75 years ago, it was 330mm (stock is350) it worked fine but having it rebuilt lead to problams with the valve becoming loose so went to a stock 100 shock that had been rebuilt. the bike now stood alittle higher, but off the centre stand and with me on it the shocks both seemed to end up with the same amount of sag (ie more on the stocker than the koni) so really when siting astride the bike or riding it there appeared to be no discernable difference. mind you I do weigh in at 17stone. I thought you're stock seat height was to be 805mm so you seem to have dropped it 20mm if the sag is the same as before then maybe you could go another 10mm on the front to get back to square with what you had before the new shock. So there's a tip check how much sag you're arse has!

Cheers K75cster, I'm getting Mrs. MT to check my arse sag! Very Happy

Good thought though - I think you're right re 20 mm at the front; it's a bit lighter but before more adjustment will sit down and work it all out. EDIT: I tried 20 mm tonight. Bike feels planted but front end is a bit bouncy/hard at low speed (20/30 mph), OK over speed bumps though and fine above 30. Might try 15mm.

Cheers
Dave

Cheers
Dave


__________________________________________________
1991 K100 RS 16 valve
    

14Back to top Go down   Low seat info - using a standard 2 valve shock on a 4 valve Empty Low seat info Wed Jun 20, 2012 7:37 pm

kfilipow

kfilipow
Silver member
Silver member
Did the factory use the same saddle frame for all models of K100? If so, for what production years?

KF

    

K75cster

K75cster
Life time member
Life time member
Dave I hope mrs MT remembers how careful we are when we answer that question.

Kfili I'm aware of 3 bases 2 for pre 85 1 metal and 1 plastic and 1 post 85 which to my understanding is plastic having never heard of a metal post 85 seat base. If you are referring to the bike frames then i'd need help there, the touch points where the rubber pads sit appear the same but the boys who own them would be better off answering that one. regards Keith


__________________________________________________
Keith - 1987 K75c with r100rt replica fairing and half of a 1984 K100rt 1992 K1100LT a blue one

The Clever are adept at extricating themselves from situations that the wise would have avoided from the outset - QUOTE from david Hillel in Out of the Earth.
    

16Back to top Go down   Low seat info - using a standard 2 valve shock on a 4 valve Empty Realm Engineering shock Thu Jun 21, 2012 3:24 pm

electric_monk

electric_monk
Silver member
Silver member
When I got rid of my old 8v bike I kept the Realm Engineering shock for the 16v.

It fitted without any issue but it made getting the bike onto the mainstand a pain, so much so that the bike fell over against a low wall leaving a rather unsightly score on the upper fairing....I learnt to be careful.

However after the first run on it with a passenger I found that the shock body was scraping against the swing arm, so I removed it. It's a damn shame because it is a great shock and I do intend getting one for the 16v.

    

ReneZ

ReneZ
Life time member
Life time member
Interesting comment. I have a Realm shock as well and with me (20 stone Embarassed ) and my son (14 stone) I have not had it touch anything (I think). Better have a good look at my arrangement then!


__________________________________________________
Greetings from Florida! Having a 'new' K  :cyclops:    Surprised-o: 

Rene


BMW K100 - 1985 (0030029) Low seat info - using a standard 2 valve shock on a 4 valve Rain
BMW K1200GT - 2003 (ZK01223)
    

Rjtrucker

avatar
Silver member
Silver member
I ride a K1100LT and I have a 28" inseam. I used the low seat conversion and it was the worst seat I ever sat on. After just a few hours my butt was KILLING me. I went back to a stock seat and installed a 2V K100 shock from YSS. I also pushed the tubes thru the triple trees by 5/8" or between 15 and 16mm. This did not adversely affect the handling of the bike. I have since that time taken a job with EPM Performance which sells YSS and HyperPro shocks so anything I say at this point just sounds like a plug for them. But I installed the shock 2 years before I started working for them. The only problems I have had is that the bike is hard to get on the center stand but with some practice I can do it and if the wife gets on back( our combined weight is over 400LBS. Me being over 250) I will drag the side stand in a few turns. I might just need to add some preload before she gets on the back. Luckily she rides her own most times. I also do pull a cargo trailer or a time out camper with the bike.


__________________________________________________
Ron S
NJ USA
74 R90/6 cafe project
93 K11LT
85 K100RS
85 K100RS turbo project.
And a load of K100 projects and parts.
    

Rjtrucker

avatar
Silver member
Silver member
the length of the YSS K100 2V shock I use is 350mm compared to the stock K1100 which is 380 or 385mm long. If you feel that that is too much of a drop I do know that we can make you a shock @ 360mm which will not drop the bike as much. We also do offer front fork springs for that K100 and K1100. If you or anyone else wants more info feel free to contact me.OK here is the "PLUG" EPM will give 10% off to all members of this forum. Just mention you got this discount info from Ron Scibetti with the permission of the boss.


__________________________________________________
Ron S
NJ USA
74 R90/6 cafe project
93 K11LT
85 K100RS
85 K100RS turbo project.
And a load of K100 projects and parts.
    

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