The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: mrbuck on June 20, 2014, 03:41:15 PM
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My '81 R100 centerstand goes way over center after 33 years of wear and my neighbor has agreed to run a bead over the contact surfaces of the centerstand.
I noticed this had been addressed on another post and hopefully someone can direct me as how thick a bead to run and how to reshape the contact points.
Since I too am now 33 years older than when I bought the bike new any help will be much appreciated. :P
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The best I can describe it is you need to fill in the tapered gap between the frame stops and the the stand tips as shown in the picture. What I did was to jack up the bike until I thought the angle of the stand was correct and photographed the gap at the stand stops. Depends on the amount of wear but the weld needs to taper from 1/8" or 3/16" thick at the tip down to nothing at the bottom edge. You can see that the bottom edge doesn't touch the frame stops in any case. To improve the stands contact with the stops you need to build up the thickness of the tips on the inside as well. I thickened up both sides. Putting the weld on is the quick part followed by much angle grinding and trial fitting.
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Mister Buck, I recently completed this rehab on my 1978 R100S whose centerstand went so far over-center as to elicit a very strong 'grunt' every time I had to take it off the stand.
My issue was not the frame-to-stand contact points -as they were fine- but rather a well worn ground contact patch that had worn through the stand's tubing and created a large, flat contact surface.
I yanked the stand and took it to my favorite welding shop where one of the employees is a hard core 60+ class MXer. He understood what was needed, added quite a bit of electric arc weld build-up and then proceeded to grind the stand to a proper radius. He even added a bit of metal to the foot tab that had been worn away. Cost me $30.00 and a sixer of Coors Light -his lunchtime beverage of choice.
So much nicer that I sometimes go out to the shop and just lift the bike off the stand and back on. Easy Squeezy.
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fi196.photobucket.com%2Falbums%2Faa1%2Fmontmil%2FBMW%2520Chassis%2FR100Sstand_zps4765a50a.jpg&hash=9cc93b1c67c27daf790ccef602a80314d525cb85) (http://s196.photobucket.com/user/montmil/media/BMW%20Chassis/R100Sstand_zps4765a50a.jpg.html)
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fi196.photobucket.com%2Falbums%2Faa1%2Fmontmil%2FBMW%2520Chassis%2FRepairCtrStand1_zps2b839ce6.jpg&hash=38a07f573916b27a4c962316fdfa4618511662bb) (http://s196.photobucket.com/user/montmil/media/BMW%20Chassis/RepairCtrStand1_zps2b839ce6.jpg.html)
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Barry and Montmil....EXCELLENT RESPONCES!!!...and with pictures as well. Exactly the info I needed to weld the stand and another area to check.
I have a metal lift to work on the bike and of late have had to use straps from the back of the lift to the crossbar on to stand to enable me to keep the bike from sliding forward as I try to lift it up and back....pretty scary and rough on the back.
By the way, I have also checked to see if the bolts are tight :D and if the holes in the stand and bushings are worn out....all possible culprits.
Thanks again, Guys. I appreciate it.
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*bump*. To make this easier to find. It's time to get some welding done. Center stand has been removed. Here's hoping for some improvement!
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Guys, I have what I believe to be an R100 center stand, in very good condition. If you don't get your own stand fixed up, I could bring it to Willville for you sometime soon. Just holler ;)
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Steve, thanks for the offer. We actually replaced the stand with new but that didn't help because the engine case where the stand rests has worn away. It is easier to build up a 3 or 4 mm of metal on the stand than repair the engine case. It appears the geometry of the stand/engine case allows a lot of over-center movement over time when the case wears away.
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I'm not sure I understand your comments about the stand contacting the engine case and wearing it down. I don't believe there should be any centerstand to engine case -oilpan? of?- contact. None of my three Airheads have this sort of contact.
Gotta photo to show the worn case?
Are the chassis stops for the stand in good condition. That should be the contact points when the bike is on the stand. I'm thinking there may be some wear that is unseen or not noticed within the stand / chassis elements.
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I'm not sure I understand your comments about the stand contacting the engine case and wearing it down. I don't believe there should be any centerstand to engine case -oilpan? of?- contact. None of my three Airheads have this sort of contact.
Gotta photo to show the worn case?
Are the chassis stops for the stand in good condition. That should be the contact points when the bike is on the stand. I'm thinking there may be some wear that is unseen or not noticed within the stand / chassis elements.
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OK, contact point somewhere around the bottom of the bike. [smiley=bmw_smiley.gif] .Upside down with a mirror and flashlight details get vague. :D
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I think you mean the frame stops that Monte was referring to.
One issue might be that the stand tips don't contact the frame stops across the full width and only bear on the outer edges which promotes rapid wear. If that's the case it will help when the stand is welded to thicken up the tips on the inside. In my photo above you can see how mine are also thickened up in a triangular shape on the outside of the tips for added strength. Thankfully I didn't have the weld the frame which would have been more difficult.
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It does appear that there is only approx. 1/2 contact across the face(s) of the tips. My next door neighbor is doing the welding and I will pass your suggestions on to him. Thanks.