Vague Handling II - Pivot Pins

Rapid Dog · 07-23-2004, 09:45 AM

O.K, I'm gear up to do this, got my 12mm socket/allen, my breaker bar, my heat source, Locktite and my wheel off.

Now, do I actually have to remove the torque arm and rear-end or can I just go simple and back off the pins and check & lube/re-torque?

I suppose that the watchamadoodle will fall in side the swingarm when I pull the pins out so, I'll have to do it all....or?...

Your input is welcome and highly cherished.

CarlosT · 07-23-2004, 09:57 AM

Are your pivot pins vacillating?

repoe3 · 10:23 AM

wswartzwel says:

"If you wanna cut corners.... remove bolt 1 reach through the hole and grease the needle bearing that is pressed into the housing.... reinstall bolt.... then remove bolt with jam nut #2 grease that side the same way....reinstall that bolt... then torque the right side, then tighten the left side till there is no play, but the housing will move up and down freely ( this is all done with the rear wheel and torque arm removed)"

we were just talking about this...trying to give credit where credit is deserved...i am always looking for a short cut.

repoe3

Rapid Dog · 07-23-2004, 10:35 AM

Thanks repoe, that answered my question.
I didn't want to go thru removing the rear-end, boot, etc., if it wasn't really necessary...
Sman, do you concur?

JonyRR · 07-23-2004, 11:30 AM

rapid, I recommend you read my previous post on this subject and the discussion between roger and I on the amount of preload needed by these bearings. I think you can m-mouse this by not pulling the final drive, but, buddy, I'd pull it and inspect the bearings, and then you can really grease the snot out of the whole shebang. Another thing you will HAVE to do for this to work correctly is clean the threads on both pins, the locknut, and the threads on the swingarm so the torque values you use are 'honest' and not influenced by dried loctite on the threads. I preloaded my bearings about 50% more than the manual recommends, and tested for correct preload by pivoting the final drive without the brake anchor arm ...I went for just a slight 'drag' and I think that's the preload feel I want for this type of roller bearing. Do it once, do it right, or do it over...

repoe3 · 07-23-2004, 11:36 AM

this topic has certainly taken on a life of its own and kinda makes me wonder if it is being made out to be a bit more difficult or requiring something more than it needs. something about this service just isnt sitting right with me.

repoe3

shannonnunley · 07-23-2004, 12:01 PM

Quote:

Originally posted by repoe3
or requiring something more than it needs.

This statement really really confuses me...

Rapid Dog · 07-23-2004, 01:03 PM

duelling dildos...
O.K., so what I need to do ito get a the bearings and clean and grease them is go ahead and ease the rear-end outm so as to access them fully for some reason...right?.
Oh, and yes I did read your discussion JRR...that was my thread...but as so many threads, they get convoluted and over-described sometimes.
I have the destructions from the BMW manual on how to R&R the differential, just thought maybe that the removal might not be necessary.

Migs · 07-23-2004, 01:06 PM

JonyRR, how many miles do you have on the "over" torqued bearings? Just wondering about long term effects. thanks

JonyRR · 07-23-2004, 01:29 PM

Migs, et al; about 4500mi, and I am monitoring them closely. I do a '9 and 3' test for looseness about once a week and so far, all is good. Tapered roller bearings need a decent amount of preload to function as designed. We'll see how well these hold up long-term, but so far, I'm satisfied. I also used the 'stick red' high-pressure grease that was referred to in an earlier thread (I had to hunt for it and found it at grainger)

Rapid Dog · 07-23-2004, 02:07 PM

When the manual says something about tightening the torque arm "under rider compression" or some such, does it mean you sit on the bike and have someone else torque the arm , or, just put weight on the bike once and then torque?

JonyRR · 07-23-2004, 02:17 PM

I took it to mean a weight appx the same as the rider in gear, then torque the arm. When I did mine, I had the seat off; I put a piece of 5/8" plywood across where the seat was and put 10 cinderblocks on the plywood, then tightened the anchor arm. it was prob'ly lighter than my fat a$$, but better than nothing. I'm betting the friction of the rubber bushing is take into consideration when compression/rebound damping and spring rates are calculated for these things.....

DavidSoine · 07-23-2004, 02:36 PM

Quote:

...I'm betting the friction of the rubber bushing is take into consideration when compression/rebound damping and spring rates are calculated for these things.....

LOL!

Actually the bushes can fail prematurely if not neutralized as described...plus the bushing is literally a spring with a torsional rate - it will be "preloaded" incorrectly if not neutralized, as was mentioned above.

best,

Dave

JonyRR · 07-23-2004, 02:56 PM

were you laughing AT me, or WITH me? I would imagine that, with the machine preloaded, the bushing is at 'zero' and any up or down movement loads the bushing one way or the other, but there is a torsional load occurring in either direction, which IS part of the overall compression/rebound/spring rate of the swingarm. Hmmm...wonder what a needle bearing in place of the rubber bushing would do for the suspension rate calculation? (rubber bushings are so 1890's)

DavidSoine · 07-23-2004, 03:21 PM

Err....with!

You are exactly right. However, the torsional rate of the bush is negligible compared to the rate of the spring in the grand scheme of things. OTOH they include all those rates in the computer model they are running (DADS, I think).

Isolation is the durability engineer's friend. I expect with needle bearings things would start breaking pretty quick. Plus harshness over sharp bumps/pavement breaks should degrade - those joints must take a lot of fore/aft load.

best,

Dave

JonyRR · 07-23-2004, 03:38 PM

After I replaced the paralever pivot bearings and buttoned everything up, I did the 'bounce test' both without the anchor arm and with, and there IS a definite difference with the arm installed and preloaded correctly.....very distincitvely noticable.....The last aftermarket frame I had (A C&J with a rotax motor) was set up with a full floating rear brake and the anchor arm had needle bearings in both ends. BTW, a C&J is a real work of art. beautiful welds and overall jewel-like quality. Wonder what C&J could do with a 259 oilhead motor....

Rapid Dog · 07-23-2004, 03:47 PM

David, what do you mean by "neutralized"? By preloading the bike and torqing the arm as decribed by Jonny?

roger albert · 07-23-2004, 08:06 PM

Yup,

Everything DS said. Solid bearings are great for responsiveness and minimizing friction, but crap for durability and vibration. The only good applications on a bike are in shift linkages, clutch pivots, or more commonly, steering dampers, where you want very positive control (any motion not fed into the damping tube element is by definition more poorly damped, since the fluid damping is quadratic whereas rubber is approximately linear)

And again, as DS said, the suspension spring effects of that rod are nil compared to the main spring, both due to rate, as well as range of motion and mechanical advantage. It really plays not roll. Very important to get them neutralized though. Just like sag, you want a neutral baseline, less the rubber become unload at one end of suspension travel, and extremely heavily loaded at the other. That's no good, either in terms of peak load, or fatiguing (which I bet ds understands in polymers way better than me) I barely have a handle on metal.

wswartzwel · 07-24-2004, 07:18 AM

Repoe,
Your bike has less than 10k on it, and in our email I felt somewhat confident that your bearings are probably still in good shape. If Rapids bike has higher mileage then they should be carefully inspected and cleaned which would require dissasembly.

Quote:

Originally posted by repoe3
wswartzwel says:

"If you wanna cut corners.... remove bolt 1 reach through the hole and grease the needle bearing that is pressed into the housing.... reinstall bolt.... then remove bolt with jam nut #2 grease that side the same way....reinstall that bolt... then torque the right side, then tighten the left side till there is no play, but the housing will move up and down freely ( this is all done with the rear wheel and torque arm removed)"

we were just talking about this...trying to give credit where credit is deserved...i am always looking for a short cut.

repoe3

Rapid Dog · 07-24-2004, 10:22 AM

I've disaassembled, checked and they are not in the best condition,
I'm going to replace them today.