Single Sided rear wheel

Discussion in 'Hacks' started by Sidecarjohn, Dec 14, 2009.

  1. Sidecarjohn

    Sidecarjohn Been here awhile

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    The interesting thread on car tyres prompts this particular query.

    We have a BMW K1 with a sidecar attached, which we purchased already built. There have been a number of owners, most I know, and the rig is reasonably sorted. It should be at twenty years old. Overall its an enjoyable, satisfying ride.

    Car tyres are fitted all round. There are no issues with the bike front, or the sidecar arrangement. Perhaps the only mild criticism would be they're all different sizes, however, no big deal for us. The issue isn't tyres, but the rear wheel set up on this paralever version of the four cylinder K (1989).

    At time of purchase the rear bevel drive bearings were identified as something to keep an eye on. Indeed, a set of bearings were already on board. Uncertain as to how many occasions these bearings had been a problem, but replacement had been done just prior to purchase. Unfortunately, 3000 miles into our ownership, the large bearing in the bevel failed. The cage had disintegrated, but fortunately we had stopped before anything else in the bevel drive was damaged. Repair was undertaken and the K was soon back in action. However, a frequent eye is kept on the rear end, checking for play and oil levels, just in case. The BMW has not done massive miles altogether (40,000 plus).

    The issue here is trusting the set up, so much so that we have embarked on a radical amendment to the rear end to provide additional support by making the swingarm twin sided. A BMW steel swingarm and bevel off an R1200C is the basis. A 165 x 15" tyre is the rubber of choice at this stage on an alloy car wheel.

    Any thoughts out there ? Firstly, about the reliability of the single sided BMW rear end. Plus, experiences and ideas about possible amendments. A key question might be regarding the possible effects on the single sided configuration according to whether the sidecar is mounted on the left as ours is, or on the right.
    #1
  2. miggins11

    miggins11 Been here awhile

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    Now that will be interesting when you get that done. BTW John - this is Chris from Ellesmere Port. The system wouldn't let me have my username on the Fed site!
    #2
  3. claude

    claude Sidecar Jockey

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    SidecarJohn,
    Years back when I first considered doing a car tire conversion to the rear of a k bike I had similar concerns about the rear end. Anyhow after doing a lot of miles and abusing the setup on my own bike with no problems we have since done many many conversions to car wheels using the single sided swingarm setup with no issues being evident.
    We have done these conversions using mostly the 165 R 15 tires but have also done them on some HPS rigs running 195 and even 205 tires. No problems have surfaced.
    In speaking to Lowell Neff early on he said he felt there were no issues in using the stock swingarm. That made me feel confident as Lowell's reputation is well respected by anyone who is familar with him and his work.
    In my opinion the single sided swingarm is more than sufficient to do the job at hand based on what we have seen through the years.
    Most anyone who has utlized any of our products will say that we are prone to overbuild most things we do. In light of this we still feel fine using the stiock setup.
    At one time EML provided a steel double sided swingarm conversion for these types of setups but had gotten away from it and back to using a stock single sided setup. Marketing stuff with the original design??? Dunno.
    I think Perry Bushong out of Texas still pushes the use of a double sided swingarm setup which I think he produces himself.
    With all of that being said the bottom line is that if you feel going to the trouble of manufacturing a double sided swingarm for the k bike is the way to go for you then by all means have at it. Too much is always better than too little even if some, like us and many others, feel the stock setup is not too little.
    #3
  4. Sidecardoug

    Sidecardoug Pleasantly pleasing

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    I use a single sided swing arm. No troubles with it. Easier to swap out my back wheels with the set up. (I have both a set of street tires and dual sports.)
    #4
  5. Sidecarjohn

    Sidecarjohn Been here awhile

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    Thanks for replies so far guys.

    Claude, any contact details for Perry Bushong, it could be useful. Plus, I appreciate your advice and thoughts. I suppose my experience of bearing failure has made me wary. Certainly my better half's view of problems with older BMW transmissions doesn't help, if the prospect is being stuck somewhere waiting for a trailer. I need to be confident, so the twin sided thinking is desirable for us.

    Part of our problem may be attributed to the paralever, and perhaps may not be significant with earlier designs, particularly steel ones. Our current plans involve the steel R1200C arm. Also, it is likely that we will base our secondary arm on the EML idea. The thinking is also considering ease of removal. At the moment I'm dependent upon an engineering friend, who is scheduled for surgery, so some delay inevitable.

    Oh and hello Chris. Spotted the Cheshire address and suspected it was you on ADV. Pity about the name, but lets face it "bitontheside" is a shade common.
    #5
  6. boodalu

    boodalu Full Metal Jacket

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    When you "google" Perry's name you get:

    http://www.perrysmotorcycles.com


    Not sure if this is what you are looking for

    PS: I have an "overbuilt" sidecar from Claude and I love it.
    #6
  7. vortexau

    vortexau Outside the Pod-bay

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    Single-sided swingarms do offer one way to mount a drive to the sidecar. You just have to pick the particular brand/model to suit the side of the road that you ride on in your country.

    [​IMG]
    THIS model can suit sidecar drive conversions with a left-mounted chair. Of course the lefthand muffler has to be shifted away, but a universal joint could be mounted to the center of the rear hub . . . . which would drive a cross-shaft to the chair. Naturally, it would be off-road only without a diff; and there needs to be a declutching system for on-road one-wheel drive.

    For countries driving on the right, the brand/model tug needs to have a lefthand single-sided swingarm. Honda and Triumph are two manufacturers with models running single-sided swingarms.
    #7
  8. MikeS

    MikeS For sure let's do it

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    John

    I've been around BMW for a long time, and also around the Iron Butt crowd for time too. BMW final drives have a reputation in long distance riding conditions under verying highway riding conditions and weather temperatures; a reputation for failed final drives. To confirm, read some of the Iron Butt reports, and you'll see a noticeable and unusually high failure rate of the BMW final drive in these riding conditions. The failure is the crown bearing.

    Only a word of caution on the single swing arm final drive. The crown bearing may be prone to premature failure. My bias is I believe a double swing arm for sidecar application is prudent, IF you do a lot of travel and miles. The wider rear tire results in less tire slide during high speed turns, putting additional pressure on the swing arm and crown bearings.

    That said, I ride a BMW two wheeler, high mileage, with no problems. Also, I have had to replace the wheel bearings on my GL1100 rig around the 40,000 mile area. They are simple and inexpensive to replace. I believe I now have all three wheel bearings renewed in the 50,000 miles I've owned my GL1100.
    #8
  9. Richard-NL

    Richard-NL Sidecar Fan

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    A lot of discussion, but I have never seen any problems, with a single sided rear wheel. ("only internet discussions"). The bearing discussion doesnÂ’t make sense to me. Show me what actually went wrong. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:eek:ffice:eek:ffice" /><o:p></o:p>
    <o:p></o:p>
    @ Vortexau: Explain this to me, please (just kidding):

    [​IMG]<o:p></o:p>
    <o:p></o:p>
    <o:p></o:p>
    Richard-NL :bmwrider <o:p></o:p>
    #9
  10. PaulRS

    PaulRS Dutch fool

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    The bearings to keep an eye on are the 2 small ones the FD pivots in, so carry a spare set.

    It's my experience that, when carrying spares, something else fails. :evil

    Or fit the solid, brass bushings from Rubberchicken, was it?

    Paul.
    #10
  11. johno

    johno Long timer

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    I have used the "chook" bushings, and was very happy with them on my R100GSPD.

    The paralever diffs do have some bearing issues. Do a search in Gspot, and on BMWMOA site if you can get onto it.
    #11
  12. claude

    claude Sidecar Jockey

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    PaulRS wrote:
    >>Or fit the solid, brass bushings from Rubberchicken, was it?<<
    Click here: http://rubberchickenracinggarage.com/
    . We have made some up here in house also. They replace the roller bearings.
    WARNING: Rubberchicken is run by well known BMW guru Tom Cutter. He is extemely knowledgeble....but... Tom is NOT a fan of sidecars on BMWs. So, even the gurus can be wong.LOL
    #12
  13. Sidecarjohn

    Sidecarjohn Been here awhile

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    Appreciate your comments Mike S, which further confirms my desire to be prudent and hopefully go with a double sided swingarm. To clarify, it is the large bearing in the bevel drive that has failed, not only for myself, but also for previous owners. Inspection of the design would probably confirm to others my misgivings. Issues about the other bearings in the paralever set up have not been an issue, although I am aware there are apparent problems that have justified after market alternatives.
    #13
  14. BMWzenrider

    BMWzenrider The Road Scholar

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    I have been watching this thread, and feel that I might have something of value to add.

    John,
    When you had the large ring bearing replaced in your final drive, do you know if the shop who did the work checked the shimming properly, or did they just throw a new bearing in with the original shims and bolt it back up??? :confused

    From my reading/talking/research on this subject what it seems like is that most of the paralever final drives will last for 100,000 miles without a problem, but that a few will eat themselves alive in relatively short order, and if the bearing is simply replaced without changing the factory shimming, that it will repeat the process.
    Those units which are re-shimmed seem to perform better over time.

    All of this leads to the conclusion that the shimming/clearances in that large ring bearing are very critical.

    The latest generation of final drive uses a needle bearing on the small end rather than a tapered bearing, I would guess in an attempt to make the ring bearing shimming less critical.
    The ring bearing itself is also actually outside of the final drive fluid bath, and is running in its own grease.
    If there were some way to clean/regrease the large bearing it may help for the high-mileage folks who may be getting compromised seals from grit/grime.
    I don't know for sure, but that is where my thoughts are leading me at this point.... Because simply changing the fluid in the final drive is doing nothing for the lubrication of the large crown bearing which is failing.
    (on the R1200 series units)

    ----------

    As far as why we tend to see a few more failures amongst the "Iron Butt" crowd and in the USA in general, just look at the average usage of the riders...

    In Europe everything is more densly packed. There are fewer opportunities for riders to run for hours on end in searing heat at warp speed.
    Taking a run across the Great Plains will cook the lube in the rear drive unlike anything you will encounter in Germany.

    I would also guess that due to the shorter distances and more densly packed conditions that European riders tend to put fewer annual miles on their bikes than the LD riders here who are seeing the bulk of the failures.
    I know that I follow factory guidelines and change all of my fluids on each bike annually regardless of miles ridden. That would translate to the bikes being ridden less getting their final drives serviced more frequently.

    For the Iron Butt Rally folks, they ride long and hard for days & days; add in the possibility of extended oil change intervals, and seal failure from grit/grime from riding in all sorts of weather, and you have a receipe for added strain/wear.
    Yet look at how many top finishers were on BMW's with those "failure prone" final drives in this year's rally... So they can't be all that bad... :augie

    I don't believe that it is overloading/sideloading that is the main culprit.

    Based upon the information gathered to date, I believe that the issue is a combination of incorrect shimming, heat, and possibly seals/contamination/service factors.

    ----------

    As far as the paralever pivot bearings;
    The factory setup uses a pair of tapered roller bearings at that location, and frankly, it is an incorrect application for that style of bearing.

    A roller bearing is designed to... well.... ROLL..... :rofl

    The rolling action constantly moves the line of contact between the rollers and races, preventing one spot from seeing repeated contact.
    The paralever pivot just rocks back and forth through a very narrow arc of motion. That means the rollers are constantly bearing on the same section of the races over and over again and pounding upon them as the tire hits bumps in the road. Eventually the races and rollers get hammered down from this repeated pounding in the same spot over and over and they get loose or can no longer move smoothly.

    The aftermarket bushings that are sold as a replacement are better because you have a large arc/area of contact between the mating surfaces to spread out the load, rather than just a few narrow lines of force between the rollers/races as in the factory bearings.
    The bronze is also a oil-impregnated material, so it is essentially self-lubricating, extending the life.

    My stock pivots are still holding up, but when it is time, you can bet that I will be replacing them with the aftermarket bronze bushings! :clap
    #14
  15. Sidecarjohn

    Sidecarjohn Been here awhile

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    I can't account for previous bearing installation on my machine, although I know the guy who worked on it last, and trust his ability. On the other hand, I'm happy about the repair job done for me.

    However, I have to say the large bearing doesn't inspire me with confidence for what I'm asking it to do as a sidecar man. The large diameter seems fine, but the narrow width is another matter altogether. That BMW has varied the number of ball bearings in the recommended spec bearing also creates some doubts. I operate on a principle that if it doesn't look right, it maybe isn't, and for me it just doesn't look right.

    Comparison between the rigours of Iron Butt and European use, to me is questionable. Long straight highways there might be, but with no cornering loads (solo use), it could be a machine is less stressed. Equally, the idea that the USA is made up of desert temperature conditions, which therefore influences mechanical integrity, is open to debate.

    I do concede that some folk enjoy trouble free motorcycling, whilst others have different experiences, even with the same model. I find much to make me happy with our BMW, and just need to remove lingering doubts about one facet. Maybe a radical solution will be the judgement of others, but it all became radical the moment the original owner fitted a sidecar, plus made associated alterations. All part of the obsession really.
    #15
  16. claude

    claude Sidecar Jockey

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    This discussion is probably one that could go on forever with little to no results apart from how each person here personally feels.
    With no reservations I can say that we have done many many BMW sidecar hookups and have had no problems with the single sided swingarms. I can also say that Hannigan has done many many more than us and seem to have no huge concerns. We see that some here with much more experience under varied conditions than many of us have stated they see no real issues. It is historically true that EML did have a double sided setup but got way from it.
    I did have concerns with the single sided swingarms years ago and questioned those who I felt had experience with them. Lowell Neff was one of these folks. He has a well earned reputation in the USA and is well respected. He said he didn't feel there was a need for concern from his experience. In speaking to others I get the same type of responses.
    With all of that being said I did know of one person who had a Ural on a K75. He was new to sidecars and was doing well in learning to operate them etc.. Then he kind of quit cominuicationg after he had went to Texas on a trip.
    He said that 'Someone' convinced him that he must have a double sided swingarm to be safe with his outfit......oh well.
    So, all in all, to me anyhow the overall track record of the durability of the single sided swingarm speaks pretty darn good for itself. But like I said everyone must do what THEY feel neds to be done to give them peace of mind....so it goes.
    #16
  17. Stroker

    Stroker motorcycle traveler

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    I might as well throw my two cents in. My '98 R1100GS is only a "part-time" rig but it is always ridden hard and overloaded with weight. When the sidecar is on I switch to car wheels. Prepairing for our last Mexico trip, with the hack attached, (12,000 total mi. approx.) I had our friend Tom Cutter rebuild the final drive. This was at 66k miles and was only done as a precaution. At that time the pivot bearings came out in small pieces. As previously mentioned in this thread the stock needle bearing are not suitable in this application. Bad BMW engineering choice. Of course I installed Tom's brass bushings kit at reassembly. All that squeaking and side-play went away. The bike is all apart right now for a ceramic clutch job and a 100k inspection of everything. The brass bushings look like new and the final drive seems nice and tight. I believe that properly setting up the final drive is crucial (Thanks Tom!), and I change my final drive oil often to look for metal particles. Any type of machinery that is stessed more than normal needs a little extra attention. This is true of hot rods, racing cars and bikes, and certainly sidecar rigs. I'm not saying that one sided final drives will never fail. Anything used beyond its design limits will break or wear out. :wink:
    #17
  18. Sidecarjohn

    Sidecarjohn Been here awhile

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    Take Claude's point totally. Let's terminate this thread, so that we can absorb ourselves elsewhere. Thanks for everyone's interest and contributions.

    For what it's worth, when I've eventually got my expected amendment completed and fitted, I'll report back.
    #18
  19. BMWzenrider

    BMWzenrider The Road Scholar

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    Just wish to clarify a couple of points.

    I specifically stated that I do NOT believe that the failures that are being seen are a result of extra load/stresses being placed on the final drive units.

    I believe that it is primarily a situation of incorrect assembly/shimming of a few units, possibly combined with excessive heat soaking from long high-speed runs and not changing the fluid frequently enough (oil breakdown/contamination).

    -----

    If redesigning this area on your rig is what it will take to make you feel confident in the reliability of your bike, don't let anyone talk you out of it.
    Having lingering/nagging doubts while riding/touring will ruin your enjoyment of the experience. And that just is not worth it.

    What I have done to quiet that little voice for myself is to do the research; talk face-to-face with as many high-mileage owners as I can to get my OWN statistical database; and then found a good price on a used final drive to keep on a shelf, ready to be shipped to me as needed, if the worst should happen while out on a trip...

    You need to do whatever it takes to quiet your own little voice... :deal

    YMMV...
    #19
  20. BMWzenrider

    BMWzenrider The Road Scholar

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    Discussion moved to here from link below, so as not to hijack the tread...
    http://www.advrider.com/forums/showthread.php?p=12880992#post12880992

    I dunno....
    Yes, there are some failures, but not nearly the percentages suggested in the uproar created by the "internet amplification factor".
    (And I hear that Ural is having some problem with holding the final drives together on their rigs lately, with that massive 40hp they are cranking out...) :augie

    The K12LT is about the only one that I know of where the final drive is probably a bit underbuilt for the bike's weight. They took the earlier design and pressed it into service on that bike when it should have been beefed up for the added mass.
    The "open axle" version came about due to the need for a final drive to handle the increasing horsepower & weight of some of the newer bikes, and the tendancy of some owners to overload them with trailers and such.
    Most of the failures of the this new model were earlier units when BMW said lifetime oil fill, and some owners were stupid enough to believe them. Not even doing the initial 600 mile drain to remove the bedding-in debris from the oil.

    My bike came to me as a salvage wreck where the P.O. had slid the back wheel into a post and had hit it so hard that it totally lunched the rear wheel. Broke a huge chunk out of it!
    This is what the wheel looked like when the bike arrived on a pallet
    [​IMG]

    Yet even after taking that kind of devastating hit which had to have transmitted quite a shock to the bearings, my final drive is still going strong after more than 30,000 total miles, and 20,000 hard sidecar miles...
    Never even took it apart to inspect. Just change the oil regularly and ride.

    This bike has a HUGE and HEAVY sidecar attached, and I am not known to baby it when riding... :evil :deal
    (see my Deal's Gap, gravel/mud, snowpacked and other pics at my travel pages...)
    Just out in town yesterday I did a left-hand power-slide with it to feed into traffic quickly during a U-turn. Just gave it a bit more throttle and let it come around quickly for me.
    Didn't want to stop and wait for the approaching traffic... :augie

    My early version 2005 final drive has been seriously abused.
    Hammered into a post at speed by the PO.
    Hammered down miles of dirt & gravel when heavily loaded with the sidecar and touring gear.
    Attach the twisties near my home regularly where I am sliding a bit to the left, and raising the chair to the right, with a wide and sticky winter car tire giving me plenty of grip...
    It has been run fast after being frozen-solid overnight outdoors in winter, mudslung, road-salt soaked, and ridden for hours non-stop in desert heat on the way to the National Rally last summer (with more than a couple of mountain pass attacks before/after).

    [​IMG]

    But I change the F/D oil every 12,000 miles and don't worry too much anymore.
    It is still solid, dry, and no play.

    YMMV
    #20