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Thread: R1150RT Front suspension adjustment

  1. #1
    Bill Lumberg 175781's Avatar
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    R1150RT Front suspension adjustment

    Is there any front suspension adjust method/mechanism on a stock 2004 RT, or is it pretty much deal with it or replace it?
    R75/6, 2004 R1150RTA.

  2. #2
    Day Dreaming ... happy wanderer's Avatar
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    No adjustment on the stock front shocks.
    MJM - BeeCeeBeemers Motorcycle Club Vancouver B.C.
    '81 R80G/S, '82 R100RS, '00 R1100RT

  3. #3
    Bill Lumberg 175781's Avatar
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    Thanks. Local shop opined that my heavy front tire wear (center is fine, shoulders wear very fast, even though 90 percent of my miles are on the interstate) is due to dive or other suspension factors causing too much of the bikes weight to rest on the front tire, "pushing" it through curves. We shall see. I always run BMW specified pressures.
    R75/6, 2004 R1150RTA.

  4. #4
    Rally Rat
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    Its your bike. Check the sag front and rear.

    I personally think factory front pressure is too low and causes cupping on front tires.

    MY 00 RT manual recommends 32 PSI front solo. I run 36.

    I found this out by testing.
    Inflate tire to cold pressure.
    Run the bike a minimum of 20 minutes.
    Check hot pressure. It should increase 10%.
    If its less you need less air.
    If its more you need more air.

    Do this in 2 lb increments.

    I also added a 1/8" (3mm) preload shim to the stock spring. This took the sag from 55mm to 47mm. I adjusted the non adjustable suspension.

    David

  5. #5
    Bill Lumberg 175781's Avatar
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    Thanks. BMW specs 37 front and 42 rear for my bike. When I completely v'd a battleax front in one long day in the mountains, I blamed the tire. Seeing profiling start on a PR2 after a few thousand miles. Time for a change. No such issues with my 75/6.....
    R75/6, 2004 R1150RTA.

  6. #6
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    how many miles on your '04?
    Ride Safe, Ride Lots

  7. #7
    Bill Lumberg 175781's Avatar
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    More than anyone here says a factory shock will last. 43K.
    R75/6, 2004 R1150RTA.

  8. #8
    Benchwrenching PGlaves's Avatar
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    I am at a loss to explain how a front strut (shock and spring) sagging or not will put more or less weight on the front tire causing it to wear at the edges. Maybe somebody more learned than I am can explain where the weight transfer is coming from.

    It sounds like low air pressure and hard braking to me.
    Paul Glaves - "Big Bend", Texas U.S.A
    "The greatest challenge to any thinker is stating the problem in a way that will allow a solution." - Bertrand Russell
    http://www.bigbend.net/users/glaves

  9. #9
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    could readily be low pressure, as PG sugested, tho if you consistently run at37, that should be pretty spot-on for most models/brands of tire (excepting track or off-road duty, of course).

    but at 43K, it is time to replace that shock.
    Ride Safe, Ride Lots

  10. #10
    Bill Lumberg 175781's Avatar
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    I drive fast, but very conservatively, and am light on the brake, even moreso in a turn. I run spec pressure but may try going up a couple of pounds. Thanks for not cursing my darkness.
    R75/6, 2004 R1150RTA.

  11. #11
    Nickname: Droid
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    I don't agree with this comment, I quote, "Local shop opined that my heavy front tire wear (center is fine, shoulders wear very fast, even though 90 percent of my miles are on the interstate) is due to dive or other suspension factors causing too much of the bikes weight to rest on the front tire, "pushing" it through curves."

    I tend to ride corners on power, been told I am an agressive rider. I more feel I am the rider type that prefers to power through corners, and I use minimal braking as I like to maintain my "pace". I used to get terrible front tire wear, uneven, heavily cupped/scalloped. After I replaced the front shock with a quality aftermarket replacement shock tuned for my wieght, bike loading and riding style, all the tire wear issues were gone. I now get even tire wear with very minimal cupping even after 4,000 miles more tire wear than I'd get on the tires with the crapped out original shock.

  12. #12
    Bill Lumberg 175781's Avatar
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    We shall see. Given the proportion of slab and the fact that I generally hold or accelerate through curves, I'd like to get a bit more U time out of my front tire before it begins to resemble a V .
    R75/6, 2004 R1150RTA.

  13. #13
    Nickname: Droid
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    "Dive" and "other suspension factors" I feel have nothing to do with it at all. Front End Dive is a chassis torque reaction to braking. The Telever front end does not dive-react like a conventional fork. But the front tire load under braking is not a factor of the Telelever fork or of a standard front fork (that does dive). The chassis braking torque dive reaction is a factor of wheelbase, chassis center of gravity, rider/load placement, and applied brake force. I detailed what I feel are the reasons for wierd front tire wear on Telelever equipped BMWs, especially the RS Oilhead, in my post regarding tire cupping wear.

    As to tire pressure, I typically run 40 psi on the front and 42 on the rear. With the Wilbers shocks on my RS and with those tire pressures, I get very even tire wear and practically no cupping/scalloping even with 14,000 miles on the front tire. This has proved itself with three different front tire brands over three seasons and riding on the same roads and with the same loads.

    For me, on my 94 RS, the one thing that impacted tire wear was replacing the worn out front shock with a quality built, properly calibrated and tuned shock. Note I did not specify a particular brand. I feel any aftermarket, rebuildable, quality shock, tuned for your riding style and riding loads will produce this result.

    My theory, is that crapped out shocks (no damping action), allow the front end to "flutter" minimally, but at a high frequency, that we cannot really feel. But, it causes the leading edge of the tread blocks on the tire to compress/squirm at a high rate. This happens both during steady state riding and light braking. In fact, I feel the "vertical flutter" is reduced/eliminated during braking. This, along with underinflation, leads to increased/uneven tire wear due to tread block squirm and heat generation. Road crown, riding/braking style, twisty versus straight/interstate I feel have nothing at all to do with excessive cupping/scalloping/uneven tire wear.

  14. #14
    Rally Rat
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    Quote Originally Posted by ANDYVH View Post
    "Dive" and "other suspension factors" I feel have nothing to do with it at all. Front End Dive is a chassis torque reaction to braking. The Telever front end does not dive-react like a conventional fork. But the front tire load under braking is not a factor of the Telelever fork or of a standard front fork (that does dive). The chassis braking torque dive reaction is a factor of wheelbase, chassis center of gravity, rider/load placement, and applied brake force. I detailed what I feel are the reasons for wierd front tire wear on Telelever equipped BMWs, especially the RS Oilhead, in my post regarding tire cupping wear.

    As to tire pressure, I typically run 40 psi on the front and 42 on the rear. With the Wilbers shocks on my RS and with those tire pressures, I get very even tire wear and practically no cupping/scalloping even with 14,000 miles on the front tire. This has proved itself with three different front tire brands over three seasons and riding on the same roads and with the same loads.

    For me, on my 94 RS, the one thing that impacted tire wear was replacing the worn out front shock with a quality built, properly calibrated and tuned shock. Note I did not specify a particular brand. I feel any aftermarket, rebuildable, quality shock, tuned for your riding style and riding loads will produce this result.

    My theory, is that crapped out shocks (no damping action), allow the front end to "flutter" minimally, but at a high frequency, that we cannot really feel. But, it causes the leading edge of the tread blocks on the tire to compress/squirm at a high rate. This happens both during steady state riding and light braking. In fact, I feel the "vertical flutter" is reduced/eliminated during braking. This, along with underinflation, leads to increased/uneven tire wear due to tread block squirm and heat generation. Road crown, riding/braking style, twisty versus straight/interstate I feel have nothing at all to do with excessive cupping/scalloping/uneven tire wear.
    Does this mean my new R1200R with 6,000 miles on it and worn out Metzler Z8 tires mean I need new shocks? Running 36/42 like the manual says.

    I have put my finger on where the forks slide while riding. I can feel no "flutter" on any of my bikes. At 14,000 miles I will be on my 3rd set of tires.

    What kind of rider/riding are the factory shocks set up for?

    I have only had cupping issues when I put 32 psi in the front of my 00RT. I raised it up to 36 and the problem went away.

    David

  15. #15
    Rally Rat
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    Here are a set of Z6 off my 2,000 RT. They have 6.000 miles on them. Look closely, you can see the left side is worn more than the right. Both tires are as they were mounted on the bike.

    I blame the left side wear on my driving style. All my bikes do it, I like to turn left more than I like to turn right. It goes all the way back to my road test in 1976. Left circles were easier for me than right.

    My RT is the only bike that wears the front out as fast as the rear. I also have worn out a couple front PR2 more on the side than the middle, but in the end they are shot at 6,000 miles and past the wear bars at 7,000.



    The Z6 seemed to wear the most even to me. Now I am running PR3 on most of my bikes. Still 6,000 miles.

    David

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