BMW K bikes (Bricks)


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AJ.Valente

AJ.Valente
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Background: Two models of 2-valve K100s were imported to the USA in 1985; the RS and RT, mechanically the same except for rear end ratios and weight differences of 10 lbs. The RS "road sport" model became the more popular of the two and about twice as many were produced. The RT was the top-of-the-line "road touring" model that featured full faring and mid-height handlebars.


Early US models are distinguished by the clean rear clip, and the bike featured here (prod# 0052864) had its rims painted to match by the original owner. This machine (below) had been well maintained including all required warranty work with dealer servicing stickers extending to 46,000 miles.*



Both RS and RT models feature windscreen air foils requiring full-face helmet for proper operation.** The RT faring extended down lower to cover the rider's legs as well as rising up higher to match the handlebars. Remarkably, this configuration fairly obscures the tank roundels, which are the originals shown here. On this bike the lower farings are replaced with the '89 style with air foils to redirect air past side vents to improve engine cooling.



Back in 1985 it would have been outrageous to fit an RT with race tires, but over the past 25 years tire technology has advanced significantly. This rendition will ride on new bias ply Bridgestones using the RS configuration--a V-rated BT-45 110/90 front and H-rated S-11 130/90 rear.*** The BT-45 "Battlax" is a dual compound rubber with hard center and soft sidewalls. Due to its rounded profile the bike seems lighter, is easier to tilt, and has vastly improved low speed handling characteristics. The sports-touring S-11 "Spitfire" is also a duo-compound tire that combines excellent handling with a tread pattern designed to shed rain water. **** Wind blast on the full faring is the one knock against the RT, but these tires make recovery that much easier.


(above: Original under seat sticker with tire recommendations from 1985)


Here in upstate New Hampshire about 100 mi. from the Canadian border the bike resides in the "barn" during winter while necessary maintenance and upgrades are performed (see links below). In early spring it's rolled-out sans' panniers and engine safety bars saving about 10 lbs. Rubber plugs are fitted to holes in the lower fairings where safety bars normally pass and it's ridden this way for about 2-weeks while everything is checked-out.




to be continued . .


* Purchased by current owner with 56k mi. and currently has 62k mi. on the clock.


** Riding with an open face helmet on the RT at freeway speeds requires the rider to constantly duck down under the windscreen due to excessive wind and noise. But, a full-face helmet relieves this problem and creates a perfect bubble of air all around it. I ride with the G-Max GX68 that has 9 separate air vents and is very quiet at speed, it's a great combination with the '85 RT.


*** Last year the bike had V-rated Metzlers on front and rear (100/90 and 130/80 respectfully). It has been written that 110/90 on the front can be unstable in tight cornering, and this seems true of the Metzler as the heavily ribbed pattern seems to resist rolling. The Bridgestone pattern is much smoother and readily invites rolling into curves. A review of the Bridgestone Battlax on K-bikes said it was not good at high speed cornering, however Bridgestone doesn't make a Battlax rear tire of 130/80 so the report is not clear on this important point. At any rate, we're using the H-rated Bridgestone Spitfire on the rear, and its cornering characteristics are excellent. The speed rating of H-rated tires is still 130 MPH, so it's not like we're loosing any performance.


**** see: http://video.chaparral-racing.com/v/32759/bridgestone-spitfire-s11-sport-touring-motorcycle-tire-review/



Winter upgrades on this bike:


1) LEDs in guages; https://www.k100-forum.com/t223-led-lights-in-the-instrument-pod-plus-sealing-out-the-moisture


2) Compartment lid lanyards; https://www.k100-forum.com/t5472-compartment-lid-lanyards


 



Last edited by AJ.Valente on Thu Mar 13, 2014 10:14 am; edited 3 times in total

    

2Back to top Go down   Early USA Model '85 K100RT Rendition  Empty Nice RT Sun Apr 21, 2013 5:38 am

mawhera

mawhera
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I have the same model in NZ, goes real nicely loves a long run. Ive cruised at high speed when safe and doesn't seem to mind cross winds even with luggage, very torquy power curve that pulls good top end 220kmh 2 up when conditions are right. Love the colour same as mine. Mawhera Very Happy

    

3Back to top Go down   Early USA Model '85 K100RT Rendition  Empty What would happen if Sun Apr 21, 2013 3:17 pm

ibjman

ibjman
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I've been wondering.....what would happen if a guy tried to refit a couple of those extra side airfoils from the RT to some RS lowers. Never seen it. What think?

    

AJ.Valente

AJ.Valente
Life time member
Life time member
ibjman wrote:I've been wondering.....what would happen if a guy tried to refit a couple of those extra side airfoils from the RT to some RS lowers. Never seen it. What think?

Can't say for sure, I'm not that familiar with the RS.



Last edited by AJ.Valente on Thu Jun 27, 2013 7:28 pm; edited 1 time in total

    

AJ.Valente

AJ.Valente
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With summer fast approaching it's time to convert "road bike" to "touring bike." After all, isn't that is what the "T" in RT stands for? This is really the best of both worlds as the RT is superb in this role too.

Saddle bag's are only rated at 80MPH, so no more romping on the open freeway in this configuration:



Additional mods to get ready for the road were as follows:
Fork Mounted Road Lights: https://www.k100-forum.com/t5634-retrofit-rt-w-k100-fork-mounted-lights
Mirror Mount GPS: https://www.k100-forum.com/t6154-rt-mirror-mount-gps

With all the high wattage lights on the road now, a single beam headlight doesn't cut it any more. The Bosh road lights look great and do a super job! Am no longer intimidated on 2-lane blacktop at night anymore.

Tested the GPS on a 200mi trip last week. It gets some reflection from noon-day sun, but otherwise works perfectly as I was able to get around in a strange town without any problems. Am alerted at every turn, and no need to take the eyes off the road in this configuration.



Also, the engine safety bars are now in place, so no more knee-scraping corners in this configuration.



OK--thats all for the 2013 Rendition project. Hope to see-ya out on the road!



Last edited by AJ.Valente on Thu Mar 13, 2014 10:15 am; edited 5 times in total

    

LWT_Big_Cheese

LWT_Big_Cheese
Silver member
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Interesting what you say about the full-face helmet.

I have been riding with an open-face one and certainly get a lot of noise. I tried a flip-front jobbie but it seemed so very claustrophobic after the open face.

I like the open face one around London. People can see you are a person and the windscreen keeps stones away (so far).

I was thinking of getting a flip-front that my wife could wear when she accompanies me and it would then give me a choice of what to wear day-to-day.


__________________________________________________
'92 K100LT

No warranty implied or given.

May contain nuts
    

7Back to top Go down   Early USA Model '85 K100RT Rendition  Empty bags Wed Jun 26, 2013 10:36 am

ibjman

ibjman
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I understand the bags speed rating.

In my personal experience, I have had 2 separate events where I was on the freeway at an "indicated" 140 mph, one of which was with a passenger as well.
I experienced no i'll effects from either at high speed. It would lead me to believe that the speed rating warning is more a matter of "legalities" than of fact.
Just my (foolish) opinion.
AJ, can you tell me more of what you know about the "mirror mount" gps mounting?
I didn't find it in the link about the lights.
Regards, Ibj....

    

Rick G

Rick G
admin
admin
The speed rating came about I believe because some police riders came undone and of course being "highly experienced riders" had to blame something and said it was the fault of the panniers without any futher explanation.
BMW then accepted this as they wanted to continue selling them to police and put a warning in the riders manual and I think they also issued a special bulletin.
I seem to recall that it was New South Wales Police that made the claim.
I have on many occasions riden a K100 to over 200kph without any effect from panniers


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1999 K1100 LT with a Big Block 1200
    

MikeP

MikeP
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BMW advised a reduction in speed when panniers were fitted long before the K was launched. It's simply an exercise in liability limitation.

The so-called "wobble and weave" was an issue way back when BMW bikes had twin shocks and wire wheels. It raised it's head again when (here in the UK) the Boxer was replaced by the K-RT. BMW's answer then was to fit the 'S' forks to the 8v RT/LT police bikes.

All bikes can experience instability. It seems to be dependant upon the variables of road surface, tyres, load, speed, condition of the suspension etc, etc.

There's only one bike that I ever felt was inherently unstable in police spec and that was the Honda Pan 1300. It wasn't a lottery like the BMW's (they'd wobble and weave if the conditions were conducive), the Pan 1300 would always try and spit you off once you reached a certain speed and what's worse, unlike the Beemer, there was no way that you could ride through the instability, the Pan just got worse until the point where rider and bike parted company. There were several bad "offs" including one fatal and it happened when the bike was tested in an effort to try and understand the problem (the rider was quite badly injured).

Honda were given the chance to fix the problem, they couldn't and the bikes were taken back. Interestingly, as we were suddenly short of six bikes and BMW couldn't supply enough K1200RS-P (because there was a sudden demand from other UK forces that had bought the Pan), we got six K1100LT-P's destined for Australian police.

    

AJ.Valente

AJ.Valente
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ibjman wrote:AJ, can you tell me more of what you know about the "mirror mount" gps mounting?
I didn't find it in the link about the lights.
Regards, Ibj....

Fixed.

Here's the link:

https://www.k100-forum.com/t6154-rt-mirror-mount-gps

    

11Back to top Go down   Early USA Model '85 K100RT Rendition  Empty Thanks but/..... Thu Jun 27, 2013 10:23 pm

ibjman

ibjman
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Can't open the url link in the redirected page

    

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