Rennkuh adapters, or how to get R1200RS wheels to fit a R1200GS LC

Discussion in 'GS Boxers' started by jaystonewee, Feb 15, 2019.

  1. jaystonewee

    jaystonewee Been here awhile

    Joined:
    Feb 26, 2013
    Oddometer:
    326
    Location:
    HO
    Alrighty, here goes.

    [​IMG]

    After many mumblings about German GS owners fitting RS/RT 17" front/rear wheels in place of spoked 19/17" front/rears and after much Google-fu along with plenty more alt-tab between Google translate and some German GS forums...I ordered a set of front wheel adapters from Rennkuh.de. Again with the help of Google translate, I contacted Michael Walsh from Rennkuh Shop and arranged shipping to the U.S. as their website allows orders, but not shipping to, North America. The adapters are about 100 Euro, plus 40 Euro air freight to my house.

    I tracked down a near new set of R1200RS takeoffs for a song. The whole package (wheels/tires/TPMS/rotors/et al) cost me a little over $1K shipped to me with nearly new Pilot Sport 4's.

    Now for the fun parts.

    The offset combined with extra width of the 5.5" RS rear wheel causes the outside edge of the tire to hit the stock GS muffler. The offset is also visibly incorrect. Rennkuh offers pre-machined rear wheels for this swap, but I decided to gamble with the deal I found. After a little measuring, 5mm machined off the bolt surface of the RS wheels seemed to do the trick. My Rallye does not have a centerstand, so I don't know if that measurement works for bikes equipped with one. I also cannot confirm how much Rennkuh machines.

    [​IMG]

    The possum catcher still fits. Factory rear lug bolts work, although a shorter length wouldn't hurt as the length of the OEM bolts comes close to the ribs on the inner final drive housing.

    [​IMG]
    [​IMG]
    [​IMG]

    As for the front, this is where the Rennkuh adapters come into play. The kit includes two sets of spacers for the front calipers to fit either 320mm or 350mm rotors (best I can interpret from the writing on the packaging). For the RS front wheel, I used the larger of the two sets of spacers. There are also some smaller bushings that allow the calipers to align on the fork mount. The first image below is probably confusing, but shows the parts. Next time I remove the calipers, I will get a couple detail photos.

    [​IMG]
    [​IMG]

    The adapter kit also includes two bushings that insert into the front wheel bearings that provide proper spacing to fit GS front forks. The stock GS axle is used. One bushing has a recess that allows the axle to sit inside and align it perfectly. Next time I remove the axle, I'll get some details of those bushings.

    [​IMG]

    Lastly, the stock front GS fender meant for 19's looks horrendous with a 17" wheel. I'd seen a picture of a GS with 17's that used an S1000R front fender. The RS fender looks very similar.
    Unfortunately, they mount differently. So...brackets were fabricated from 1"x1/4" aluminum flat bar. A couple holes...a couple bends...some countersinking on the lower bolt thru holes, and some tapping on the upper holes where the S1000R fender mount, et voila! Front Fender.

    [​IMG]
    [​IMG]
    [​IMG]

    The RS front ABS ring lines up perfectly with the GS sensor. No problems there. I do need to research further how to get the TPMS sensors to talk with my bike though (dealer? GS911? special tool to activate TPMS sensors?)

    [​IMG]

    After a quick spin around the block and the results are interesting. The front end is very responsive and it almost falls into turns. Time will tell if the handling and ride are worth the cost, but I enjoy the prospect of saving my TKC80's for the dirty stuff instead of burning them up on canyon runs, commuting or long highway burns.

    [​IMG]

    As for questions or comments, let'er rip and I'll do my best to answer or provide insight!
    #1
  2. Lead Wrist

    Lead Wrist More Gelände less Straße

    Joined:
    May 26, 2007
    Oddometer:
    2,481
    Location:
    Zer0-Zer0-Zer0-Zer0
    Congrats - job done, thread posted, that’s hard work in my books... :lol3:clap

    Good to hear that your initial impressions after first test ride were what I originally had in mind when I started my mod, although I’m just half way through, still looking for good used front RS wheel to complete the mod...
    As I’m not big fan of irreversible modifications with machining the rear lug seating surfaces, my approach to resolving the offset and clearance issues at the back is a bit different than yours but the end result will be the same... :D

    Couple of notes in regards to front wheel conversion, which I’m not sure about:
    - it looks like you got full front wheel package, ie. RS front wheel with rotors (which are 320mm) but used larger spacers from Rennkuh to shim calipers out, which are meant for 350mm rotors (or so you said), no??
    I planned to reuse 305mm GS rotors so I may skip that step hoping it’ll work, although if I find RS wheel with 320mm rotors, I won’t say no to it... :D If 305mm rotors work well with 19” wheel, they ought to work even better with 17”!

    - you mentioned 2 spacers for axle included from Rennkuh: that’s one per side? Both GS and RS use only one spacer, on ABS ring side (I think, can’t remember)? I was thinking of starting with RS axle instead of GS’s, so I keep wheel and axle as per original application on RS, and then mod that one if needed...

    For new-to-you TPM Sensors to work, you have couple of options:
    - dealer programming: the easiest way and that works. I didn’t know better at the time so I went that route, it was together with some warranty work so it wasn’t much of nuisance... TY Jesse at CW for not charging me for it!! :lol3

    - GS911 coding: you’ll need hexadecimal TPM Sensor codes which are found on the sensors (when you buy new ones) to be entered into TPM System when you hook up GS911 to your bike. Since you bought used set of wheels with sensors, chances are you may not have the codes and, beside that, you’d have to uninstall the tires to get the info so this may not be that good of an option to pursue...

    - reintroduce new wheels ie. sensors one-at-the-time: it looks like your ‘17 GS follows same suit as ‘13-‘16s GS/As where TPM System’s “brain” can’t processs 2 unknown TPM Sensors at once. Few inmates have reported a work around this and I confirmed it as working on my own bike.
    Starting from both sensors working properly (your old set of wheels), you mount one “new” wheel at the time, go for a ride around the block and within few hundred yards (ok, maybe a mile or so the most :D), TPM System should recognize new sensor being introduced. Then, repeat the process with the other wheel... I did this few times between my 2 sets of wheels and worked like a charm each time... :clap
    If you don’t go to visit a dealer in near future and can find some time to experiment with this option, you could try to put your old rear wheel back on, go for a ride and see it comes back first then continue to ride hoping that the new front sensor will get picked up too... Or, go back put both of your old wheels and start from scratch - I’m confident it should work, “should” being key operating word... :lol3

    All in all, nice exercise with your conversion, done on a amazing budget - I’m jealous on one side and even more motivated on the other to try harder to complete my mod!! Well done and happy super-motarding!! :jack

    :thumb
    #2
    rg sw wa. likes this.
  3. jaystonewee

    jaystonewee Been here awhile

    Joined:
    Feb 26, 2013
    Oddometer:
    326
    Location:
    HO
    I probably read the handwriting on the bags of caliper spacers backwards 320/350 instead of 320/305. There are two thickness'. In the photo above showing my calipers, you see the thicker of the two sets. In the image in the original post showing the bolt/olive/small inner bushing the thinner set of 4 spacers is shown. Thanks for the correction!

    One small gripe about the kit is no instructions or drawings, but the parts and pieces are fairly self explanatory.

    Regarding the front axle spacers, there is just one spacer on the ABS ring side with the spoked 19" wheel. That spacer stays with the 19. The Rennkuh spacers are asymmetrical. I did a quick sketch of them to show the basic external shape (solid line) and internal shape (dashed). I also included the stock GS axle shape for reference.

    [​IMG]

    The RS has inverted traditional forks IIRC. The front axle is different from my research. They're about $130 too. If you do go that route, I'd be curious how they compare.

    I'll give the one wheel at a time TPMS trick a try.

    Thanks for the info!
    #3
    rg sw wa. likes this.
  4. Lead Wrist

    Lead Wrist More Gelände less Straße

    Joined:
    May 26, 2007
    Oddometer:
    2,481
    Location:
    Zer0-Zer0-Zer0-Zer0
    ^^ No worries... Although I plan on taking slightly different approach than you have, your experience has been very "edumacational" for me and has opened my eyes to consider other facts which I may have originally overlooked... :beer

    Reusing GSA's old rotors and RS axle should simplify spacers' trilemma and their need in my case but that remains to be seen and confirmed... Once I acquire my missing components, I do plan on taking all bunch of pics and measurements of the current set-up so I can assess what spacers if any etc I'll need to make my new set-up work for me!

    GL w making TPMSs work for you - at least I got that topic bagged :lol3!!

    :thumb
    #4
    jaystonewee likes this.
  5. Jbrjbr21

    Jbrjbr21 Been here awhile

    Joined:
    May 17, 2017
    Oddometer:
    539
    Location:
    Marion Il
    my rear tpm will eventually find the new wheel senser sometimes its a few miles and sometimes a few weeks,
    #5
  6. Lead Wrist

    Lead Wrist More Gelände less Straße

    Joined:
    May 26, 2007
    Oddometer:
    2,481
    Location:
    Zer0-Zer0-Zer0-Zer0
    Not sure what MY bike you have but if you have 2 sets of wheels and then follow one-wheel-at-the-time swap routine, TPMS "brain" should be able to pick up new sensor within few hundred yards or in about a mile or so - I tested this quite few times on my bike and it was always spot-on... YMMV...:deal

    If it takes few weeks for your TPMS to become alive, you may have some other issues to address - if you have GS911, that can become handy tool to use or a visit to friendly dealer should help too...

    :thumb
    #6
  7. jaystonewee

    jaystonewee Been here awhile

    Joined:
    Feb 26, 2013
    Oddometer:
    326
    Location:
    HO
    Since I am borderline OCD...and have trust issues...I've purchased and Autel TS408 TPMS tool. I also purchased a GS911 (finally). So, I hope to reprogram my ECU to recognize the new RS wheel TPMS sensors. I feel weird riding around a TKC80 on one wheel with the PS4's on the other. You know, safety and all that ;)

    wish me luck.
    #7
  8. Lead Wrist

    Lead Wrist More Gelände less Straße

    Joined:
    May 26, 2007
    Oddometer:
    2,481
    Location:
    Zer0-Zer0-Zer0-Zer0
    Good Luck...:clap

    :lol3
    #8
    jaystonewee likes this.
  9. Boxerbreath

    Boxerbreath 2017.5 GS Black Storm

    Joined:
    Feb 7, 2018
    Oddometer:
    3,041
    Location:
    Lost Angels County
    RS has 17” front and rear yes?
    I put RT wheels on my 05 GS and yes it was pretty quick handling but not something I would do without a steering stabilizer which I had.
    Interesting thread.
    Personally I’d want a 19” front.
    #9
  10. jaystonewee

    jaystonewee Been here awhile

    Joined:
    Feb 26, 2013
    Oddometer:
    326
    Location:
    HO
    Yes. 17s F/R. stock steering stabilizer for now, but I have been itching for a better one.
    #10
  11. Lead Wrist

    Lead Wrist More Gelände less Straße

    Joined:
    May 26, 2007
    Oddometer:
    2,481
    Location:
    Zer0-Zer0-Zer0-Zer0
    Ohlins, who else, would be happy to take your money for steering stabilizer (~400$) if you think you'd need one... I have adjustable SD037 on my non-LC stable mates and have been extremely happy with it. It's direct replacement for hex/cam R12X OE steering dampers (used on telelever bikes so the same may fit LC)... Haven't explored the topic for LC yet but there's a food-for-thought for you to take look-see! :D

    :thumb
    #11
    handensco and jaystonewee like this.
  12. thanassis

    thanassis R 1250GS HP

    Joined:
    Oct 17, 2009
    Oddometer:
    112
    Location:
    Athens, Greece
    #12
  13. Lead Wrist

    Lead Wrist More Gelände less Straße

    Joined:
    May 26, 2007
    Oddometer:
    2,481
    Location:
    Zer0-Zer0-Zer0-Zer0
    That's different type of stabilizer relative to how it mounts ie. it's handlebar mounted... I don't have experience with it myself but do remember seeing it on Hex/Camhead GSs in the past - you may want to search the GSpot and find those posts to get the feedback from inmates who have gone that way... At 500-1000$ it better be good, and since is color coordinated with your bike so I guess you have to have it - no questions about it!! :lol3

    I was referring to steering stabilizer that goes off of the bridge btw the forks on one side and telelever on the other - BMW used virtually same part for Hex/Camhead R12R/S/RT/HP2S and Ohlins SD037 is what I used on my non-LC-GS bikes so I suggested to @jaystonewee to take a look at it if he really needs it...

    :thumb
    #13
  14. thanassis

    thanassis R 1250GS HP

    Joined:
    Oct 17, 2009
    Oddometer:
    112
    Location:
    Athens, Greece
    Hello Lead Wrist,
    I understand your point, but the issue with the stabilizers mounted on the lower bridge is that you can not adapt them during the ride. You have to stop! On the other side, stabilizers mounted on the upper bridge are adapted “on the fly”.

    PS I know Powercellperformance from my KTM times. Top quality products
    #14
  15. jaystonewee

    jaystonewee Been here awhile

    Joined:
    Feb 26, 2013
    Oddometer:
    326
    Location:
    HO
    The Powercell stabilizer is a bit much for my taste; both cost and design. I'm sure it works well and the adjustability on the fly is nice.

    I will likely stick with the factory location with a Yacugar/Hyperpro/Ohlins unit. I'm looking for some adjustability and an incremental improvement over stock.

    Thanks for the info!
    #15
  16. Lead Wrist

    Lead Wrist More Gelände less Straße

    Joined:
    May 26, 2007
    Oddometer:
    2,481
    Location:
    Zer0-Zer0-Zer0-Zer0
    A-ha - good point, thanks T!! I'm much more "set-it-and-forget-it" kinda user... :D

    I do play with it at the beginning to set it, like you'd do with any suspension related doodad. Once I find what I like, that's it and time go riding (if only this winter would end)…

    :thumb
    #16
    jaystonewee likes this.
  17. jaystonewee

    jaystonewee Been here awhile

    Joined:
    Feb 26, 2013
    Oddometer:
    326
    Location:
    HO
    Autel TS408 TPMS sensor tool 101.

    Only has automobile TPMS sensor settings.

    Thankfully, the Autel tech support forum search showed that using a Saturn Astra will activate BMW TPMS sensors.

    SO, I now have the hexadecimal addresses of both sets of wheel sensors.

    Next step...fire up GS911 and try to change addresses there.
    #17
    thanassis likes this.
  18. Lead Wrist

    Lead Wrist More Gelände less Straße

    Joined:
    May 26, 2007
    Oddometer:
    2,481
    Location:
    Zer0-Zer0-Zer0-Zer0
    Awesome tip for someone who'll follow at later date!! :clap

    You've done the most difficult part as far as new TPMSs are concerned - GS911 programming once you know the hexadecimal codes is much easier... Just don't forget to convert hexadecimal codes to decimal as that's what GS911 will take... :D

    :thumb
    #18
    jaystonewee likes this.
  19. jaystonewee

    jaystonewee Been here awhile

    Joined:
    Feb 26, 2013
    Oddometer:
    326
    Location:
    HO
    Changed settings on the Autel TS408 to read address in decimal. Changed TPMS addresses using GS911 laptop utility. Quick ride around the block before it dumps snow tonight confirms success!

    Can't wait to get some miles on the new setup. Making a Baja run in April, spoked wheels with TKC's will be back on for that trip though ;)
    #19
  20. Lead Wrist

    Lead Wrist More Gelände less Straße

    Joined:
    May 26, 2007
    Oddometer:
    2,481
    Location:
    Zer0-Zer0-Zer0-Zer0
    Congrats on the success story - you got to the end of it in record time!! Fully deserved an Atta Boy :wings:beer !!

    Your thread was great inspiration so I managed to make some progress too - my 17" front wheel is on its way so hope to "join" the 17" super-motard camp-fire by the time the winter is over... :lol3

    :thumb
    #20
    jaystonewee likes this.