Results 1 to 7 of 7

Thread: new rear drive

  1. #1
    Registered User
    Join Date
    Jun 2008
    Location
    Oregon
    Posts
    32

    Smile new rear drive

    I'm am thrilled to death with the new lower gear ratio I just had put in my rear drive for the R1100RT that's the tug for my EZS Summit sidecar. Only rode it home from the shop that did the work. It became obvious pulling away for the first time (up a slight slope) that slipping the clutch was a thing of the past. 32 mph @ 4000 rpm is perfect for riding in the city. Only got up to 50 mph for a short distance and while that's too slow for 5th gear it was obvious that using 5th gear at around 60 mph will definitely be possible. With stock gearing, starting up almost any incline needed the clutch slipped. On the highway, 4th gear was necessary to run 60 to 65 mph with had the engine running at 4500 to almost 5000 rpm. To actually used 5th gear I needed to wind it up to approximately 70 to 75 mph to be able to use 5th without feeling like it was almost lugging the engine (maybe not the correct word). Basically it was just working the engine way too hard for my liking.

    Even though temps here are still in the 30's it's supposed to get warmer to the 40's in the next few days. When it does, I'm going riding to find out what the 5th gear really feels like.

    This is one of the earliest Christmas presents I've ever given myself.

    Absolutely love this rig.

  2. #2
    Registered User
    Join Date
    Jan 2006
    Location
    New Hampshire, USA
    Posts
    453
    What is the new FD ratio? Who did the work?
    BMWs in my garage: 1982 R65LS, 1978 R100/7

  3. #3
    Registered User
    Join Date
    Jun 2008
    Location
    Oregon
    Posts
    32

    New final drive

    Quote Originally Posted by boxermaf View Post
    What is the new FD ratio? Who did the work?
    Sorry to have to tell you that I don't know the new ratio. I have great faith in Cheshire Motorsports here in Portland, OR. Simply told Daric what I wanted and left it to him. His only comment is that the RD was now quite close to what the old BMW's designed for sidecar use had.If your anywhere near Portland, OR I highly recommend Cheshire Motorsports.

  4. #4
    Curmudgeon At Large Bobmws's Avatar
    Join Date
    Mar 2003
    Location
    Astatula, FL
    Posts
    1,117
    Quote Originally Posted by jkmolt View Post
    Sorry to have to tell you that I don't know the new ratio. I have great faith in Cheshire Motorsports here in Portland, OR. Simply told Daric what I wanted and left it to him. His only comment is that the RD was now quite close to what the old BMW's designed for sidecar use had.If your anywhere near Portland, OR I highly recommend Cheshire Motorsports.
    I believe to 850 oilheads had a lower rear drive, also some of the GS models had different ratios.
    Bob Weis
    '04 K12RS - Hannigan Hack
    www.earplugco.com

  5. #5
    Registered User
    Join Date
    Aug 2005
    Location
    Somers, NY
    Posts
    540

    Fyi

    My wife has an '04 R1150R with an EZS chair. Granted it has the six-speed tranny, but she runs the motor for hundreds of miles at a time around 5000rpm's. If she drops below 4500, she downshifts. She finds that's where the bike runs best.... although the gas mileage does suffer a little bit.
    Somers, NY

    Just enjoying the ride.......

  6. #6
    Registered User
    Join Date
    Jun 2008
    Location
    Oregon
    Posts
    32

    Smile new rear drive gears

    Quote Originally Posted by sdpc2 View Post
    My wife has an '04 R1150R with an EZS chair. Granted it has the six-speed tranny, but she runs the motor for hundreds of miles at a time around 5000rpm's. If she drops below 4500, she downshifts. She finds that's where the bike runs best.... although the gas mileage does suffer a little bit.
    My '99 absolutely loves 4500 rpm. Anything much less and it starts to act like the old VW Beatles. Hit the slightest grade and it's down a gear. 4500 rpm and almost all grades on an interstate are no problem.

    I find that with the new gears I run at about 65 mph at about 4300 rpm. Still really enjoying the new ratios.

  7. #7
    Registered User
    Join Date
    Jul 2011
    Posts
    3
    I replaced the final drive on my R1100R rig with one from a R850R. This lowered the ratio from 3:0 to 3:36. It made a huge difference. Before the change 1st and 5th were almost unusable. Now 70mph in 5th and I am only running about 4400-4500rpm. I still get about 34mpg with a fuel additive(ethanol equalizer). Fully loaded with boss monkey and her luggage and I can still pull off with no problem.
    Bill D.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •