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Evoluzione torque arm - K1200s

11K views 32 replies 13 participants last post by  Lenz 
#1 ·
If anyone has installed a Evoluzione torque arm on a K1200s, could you tell me if the longer attachment bolt goes on the front or on the back? Either way I've tried, the short bolt is slightly short on the rear and the long bolt is slightly long on the front. Thanks.
 
#3 ·
tycho said:
If anyone has installed a Evoluzione torque arm on a K1200s, could you tell me if the longer attachment bolt goes on the front or on the back? Either way I've tried, the short bolt is slightly short on the rear and the long bolt is slightly long on the front. Thanks.
the longer bolt goes on the front (if you have esa there is a bracket that attaches to the bolt) - the shorter on the rear. i'm not sure why the shorter bolt is too short - do any threads stick out past the end of the nut?
 
#4 ·
evoluzione torque arm

I put the longer bolt on the front. The shorter bolt on the rear is just flush with the outer edge of the nut. Put locktite on all bolts as per instructions. Rode bike for 200 miles, checking tightness 2-3 times. Everything is fine and the difference in handling is quite noticeable (with all five shims on arm as per recommendation by Ken at Evoluzione from a previous thread). Buying the arm from Evoluzione was well worth the money and am quite satisfied. Thanks for the responses.
 
#5 ·
Do you know if there is any truth to this statement that Ihave read about changing the length of a torque arm on this bike. Here is what it says:

"The drive shaft does not have constant velocity joints (only normal universal joints) and therefore the output shaft must be as near to parallel with the input shaft, so any further increase in length would be inadvisable. It would cause an increase in vibration, tyre wear and impose extra stresses on all the paralever bearings."

I found that on this site http://www.sandbarcomposites.co.uk/items/BMW/K1200R/rideheightadj-plate.php

I have the Evoluzione torque arm. I plan to install it this weekend. But if the statement above is true, I wonder what the effect will really be long term on the bike.
 
#6 ·
bolev said:
Do you know if there is any truth to this statement that Ihave read about changing the length of a torque arm on this bike. Here is what it says:

"The drive shaft does not have constant velocity joints (only normal universal joints) and therefore the output shaft must be as near to parallel with the input shaft, so any further increase in length would be inadvisable. It would cause an increase in vibration, tyre wear and impose extra stresses on all the paralever bearings."

I found that on this site http://www.sandbarcomposites.co.uk/items/BMW/K1200R/rideheightadj-plate.php

I have the Evoluzione torque arm. I plan to install it this weekend. But if the statement above is true, I wonder what the effect will really be long term on the bike.
i know you emailed us this question but i thought i should answer it here. when i first read it something didn't make sense. then i clicked on the link and understood. in the future, if you plan on asking questions and quoting a source, i would recommend that you include the actual quote, not just try and paraphrase. the actual statement sandbar makes is:


"Changing the rear ride height by changing the length of the paralever torque arm is not the correct way, because it also changes the angles between the various shafts in the drive train. The driveshaft uses normal universal joints (and not C/V joints) and the more that the input and output shafts deviate from being parallel, the greater will be the vibration and tyre wear. There will also be excess strain on the paralever bearings and probably the gearbox as well."


now to answer your questions. during normal riding, the angularity between all of the shafts is constantly changing (every bump you hit changes the suspension angles). i do agree that more angularity is not good but how much is too much? i can only go by the fact that the factory powercup race teams used much longer torque arms and after ten's of thousands of miles on hundreds of bikes we've not had any issues. i realize that sandbar is offering a different solution to the same issue (better turn-in) and i'm not sure i agree with everything they say but basically their statements are true. but i also feel that our design is well within the design parameters of the original suspension design.

bottom line, if you feel uncomfortable using our torque arm, please just send it back for a refund.
 
#7 ·
if you install the torque arm and plan on doing some aggressive riding, you will not be dissapointed. I installed the dogbones similar to the ones offered by sandbarcomposites, which in theory accomplish the same changes, and the difference is immediately noticeable. i have had them installed for at least 5000 miles and haven't noticed any changes in the mechanics of the bike in reference to vibration, tire wear, or mechanical deterioration.
 
#8 ·
Ken,

Thanks for your reassurance. Having not been an individual that's made modifications like this to any f the bikes I've owned in the past, I definitely read their statement and got a bit skittish.

Judging by the rave reviews of your product on this and other sites, and not seeing anyone complain of any problems, I'm sure I've just been a bit over-cautious.

Thanks again.
 
#9 ·
evoluzione said:
now to answer your questions. during normal riding, the angularity between all of the shafts is constantly changing (every bump you hit changes the suspension angles).
This is really the most important statement. The universal shafts are not even MADE to be parallel from the factory. The stock torque arm needs to be a little shorter if this was the case.

I thought the powercup bikes got around the ride height change with a longer shock rather than a longer torque arm. This really is the IDEAL solution as even new suspension plates change the leverage of the swingarm to a not stock value.
 
#10 ·
Er yes - or even no! Sort of!

I reckon that this one of those things where everybody is right - a little bit.

There can be no doubt that the reason for putting a second universal joint on a shaft is to cancel out the angular velocity variations caused by the output and input shafts not being in line on the first universal joint.

Here is a link to a Wikipedia page that can explain it much better than I can.

http://en.wikipedia.org/wiki/Universal_joint

The ideal scenario is that the output shaft from the gearbox should be parallel to the input shaft to the bevel drive, and the paralever system should form a perfect parallelogram. It is clear from the Wikipedia page that the further from this ideal the more fluctuations there are in the angular velocity. That would mean more vibration and increased tyre wear.

Now to the real world.

JCW said:
The universal shafts are not even MADE to be parallel from the factory.
Yes you are right - and the paralever does not even make a parallelogram. I guess design and production requirements meant a few compromises. But, neverthless, in standard form they are not far away and I guess that BMW find that the effects of the variation from ideal to be acceptable within their parameters for service life and smoothness.

But that does not alter the fact that the best solution is parallel shafts operated by a parallelogram.

JCW said:
I thought the powercup bikes got around the ride height change with a longer shock rather than a longer torque arm.
I am afraid that I am always sceptical about comparisons with the PowerCup racers. They only had to last about 150 miles on very smooth surfaces every few weekends and they had attention from mechanics that would be far greater than the majority of road bikes. Tyre wear was not an issue and increased vibrations would probably not be felt or noticed

JCW said:
This really is the IDEAL solution as even new suspension plates change the leverage of the swingarm to a not stock value.
That is not necessarily true. In any event surely the BEST solution would be to achieve the required ride height by changes in the length of the shock and THEN change the length of the torque arm to alter the shaft angles so that they are parallel at the midpoint in the normal suspension travel.

If you only use the torque arm then you are achieving the change in ride height by changing the angle between the shafts. If you use suspension plates then you are achieving the ride height adjustment without changing the shaft angles except in that there will be a slight change because paralever does not have an exact parallelogram

IMHO :thumb:

Do I know what I am talking about? Probably not!!:stir:

sandbar
www.sandbarcomposites.co.uk
 
#11 ·
sandbar said:
The ideal scenario is that the output shaft from the gearbox should be parallel to the input shaft to the bevel drive, and the paralever system should form a perfect parallelogram. It is clear from the Wikipedia page that the further from this ideal the more fluctuations there are in the angular velocity. That would mean more vibration and increased tyre wear.

Now to the real world.


Yes you are right - and the paralever does not even make a parallelogram. I guess design and production requirements meant a few compromises. But, neverthless, in standard form they are not far away and I guess that BMW find that the effects of the variation from ideal to be acceptable within their parameters for service life and smoothness.

But that does not alter the fact that the best solution is parallel shafts operated by a parallelogram.

Do you think it was a matter of design and production compromises that prevented BMW from making the perfect parallelogram?

It is slightly more difficult than that.

If you go beyond the simple definitions found in WIKIPEDIA and read a real book on suspension design such as Tony Foale's book, you would realized that many more factors contribute to the design of the rear suspension.

The main one in this case is to slightly offset the shift in weight and subsequent suspension changes with acceleration and deceleration. A perfect parallelogram would negating this beneficial action. By bringing the front pivot points on the paralever suspension slightly closer than the rear pivot points, you effectively create a swingarm with an imaginary pivot point near the steering head. This reintroduces a slight shaft jacking effect to counteract the acceleration changes to the suspension.

sandbar said:
I am afraid that I am always sceptical about comparisons with the PowerCup racers. They only had to last about 150 miles on very smooth surfaces every few weekends and they had attention from mechanics that would be far greater than the majority of road bikes. Tyre wear was not an issue and increased vibrations would probably not be felt or noticed.
No, but failed transmissions would be rather embarrasing. Let me put it this way. Would I rather trust BMW who has the original design goals, specifications and understanding on modifications for their OWN SERIES and OWN MOTORCYCLE?

Or, do I trust someone who makes overpriced cabon fairings (granted your's are somewhat less overpriced than the rest) who comes up with his own design?

HHHHMMMMMMM?

sandbar said:
That is not necessarily true. In any event surely the BEST solution would be to achieve the required ride height by changes in the length of the shock and THEN change the length of the torque arm to alter the shaft angles so that they are parallel at the midpoint in the normal suspension travel.
Again, too much is being made of PERFECT U-joint alignment. Let me explain...

The monolever suspension of the 1980's had only ONE u-joint. That means that the angular ouput shaft of all these motorcycles suffered this catastrophic vibration you speak of. All those motorcycles, all those rear ends, teetering on the brink of annihalation.

Guess they survived OK for years, huh?
 
#12 ·
Question from someone that really has no idea what a torque arm does. What is the difference between the evolutionize Arm and Pirate's? Do they both provide a quicker turn in? I want to eliminate the factory arm because it's ugly. If i receive a better ride in the process, that's all the better. I think Pirate's arm looks best, but does it function as efficiently as the evolutionize arm?
 
#13 ·
Pirate's arm is stock in length so doesn't change the ride at all. Purely cosmetic.

Evoluzione's comes stock length but can be shimmed to a longer length to improve turn in.

Sandbar and CC71 has plates that basically accomplish this as well.

As far as which is better, I'd have to say I'd go with getting a longer shock. :teeth

But I have evol torque arm, a longer shock AND homemade suspension plates.
 
#16 ·
Resn8 said:
Hi all

Can i ask another Question how would both work on the same bike, say the modified plates and Evo's torque arm.
I found that the more the rear went up, the better the bike transitions. This is more than the plates or the torque arm offered separately. This is offset by a very tall seat AND a sidestand that no longer is functional as the bike tips over too much.

You COULD use both to raise the rear more than each individually and see how it suits your tastes. Or you could use the torque arm at stock length for looks and increased strength and use the plates to make all your ride height adjustment.
 
#17 ·
This looks like it could degenerate into one of those internet/forum discussions where it looks like there is an argument, when what is actually happening is we are talking about different things!!

JCW said:
Do you think it was a matter of design and production compromises that prevented BMW from making the perfect parallelogram?
Yes I do - absolutely.

However I think that I could have worded that phrase a bit better. You obviously read it differently than I meant it. The word 'compromises' was only meant to apply to 'production'. Maybe the phrase should have read "design criteria and production compromises". My mistake - I am sorry.

You are right about the design's attempt to diminish the rise and fall of the rear of the bike due to the shaft drive - the so called 'jacking' effect.

However it does not alter the fact that if you want to eliminate any vibration (or the effects of it) from a shaft that has two universal joints, then the input and output shafts should be parallel. The further the shafts are away from parallel the greater the variations in angular velocity and therefore the increase in vibration and tyre wear.

I think we agree!!

JCW said:
The monolever suspension of the 1980's had only ONE u-joint. That means that the angular ouput shaft of all these motorcycles suffered this catastrophic vibration you speak of. All those motorcycles, all those rear ends, teetering on the brink of annihalation.
Guess they survived OK for years, huh?
I do disagree with you about this. From the moment that BMW started to produce bikes with bigger engines and noticeably more power (compared to modern bikes that is a relative term) in the mid 70s with the R90S and then the 1000cc R100RS, the misalignment of the shaft became more and more of a problem. There was a continuous program of development on the drive train to reduce the vibrations and associated problems. There were vibration/shock dampers in the shaft ( late 70s) and a similar change to the gearbox in the early 80s. Alignments were changed, mountings were moved - all trying to address this issue.

There were no bevel drive pivots to wear and the shaft had its own seperate oil bath. The problems were not 'catastrophic' because the shafts and joints etc were over engineered. I don't think that they differ much in size from the parts used today, but even the most powerful BMW road bike of the 70s (R100RS)only developed about 70 hp IIRC.

In those days BMWs were also renowned for high tyre wear - again compared to modern times, that is a relative term.

Even before those days, this kind of realignment was necessary.

Crankshaft, gearbox output shaft and drive shaft as near as possible a straight line.

If anybody wants to find out if the vibration can be a problem, then just remove the bevel drive and re-connect the shaft so that the universal joints are out of phase.

Just think - the whole problem could be solved with the use of constant velocity joints

sandbar
www.sandbarcomposites.co.uk
 
#18 ·
Agreed with what you said.

However, BMW who has access to both types of joints chose the U joint based on the fact that by design, the paralever suspension can control the angle of misalignment to acceptable levels. It's not a problem in my and BMW's view.

Problems with CV joints are recognized...

By their design, the ball bearings in the cv joint slide and shear. They do not roll as other "bearings." They develop significant heat and waste a bit of energy at anything other than 0 deg. All this is "minimized" by the use of high tech lubes (our friend MOLY) but in high torque applications they are insufficient. They also very sensitive to dirt and other contamination.

Nice discussion...

Sorry, I thought you were picking on me by quoting only me in your first response.

(But I stand by my statement that producers of carbon fiber products WAY OVERCHARGE for essentially the same setup and production that is required for a quality fiberglass peice. That I'm learning quickly making my own solo seat.)
 
#19 ·
Sandbar "Dog bones"

Being a fan and invested in Evoluzione components (thank you for being in business Ken) I opted to try the Sandbar Composites "dog bones" if I get the chance to ride my bike soon I will follow up on the turn-in performance... On the short ride home it seemed responsive but that could have been my 50+ year old brain just enjoying the ride. Once I am out of the casino that I'm evaluating here in sunny Aruba we will see if I make any bets on the dog bones.

Wonder what adding the torque arm now would achieve along with the "dog bones" Ken any thoughts or is it just over kill?

keeping the rubber side down...
Douglas in Las Vegas

Check my bike out on www.2wtmag.com READER'S RIDES search using make...BMW of course, it was ride of the month for October 2007 and the only BMW amongst the other speed machines.


evoluzione said:
i know you emailed us this question but i thought i should answer it here. when i first read it something didn't make sense. then i clicked on the link and understood. in the future, if you plan on asking questions and quoting a source, i would recommend that you include the actual quote, not just try and paraphrase. the actual statement sandbar makes is:


"Changing the rear ride height by changing the length of the paralever torque arm is not the correct way, because it also changes the angles between the various shafts in the drive train. The driveshaft uses normal universal joints (and not C/V joints) and the more that the input and output shafts deviate from being parallel, the greater will be the vibration and tyre wear. There will also be excess strain on the paralever bearings and probably the gearbox as well."


now to answer your questions. during normal riding, the angularity between all of the shafts is constantly changing (every bump you hit changes the suspension angles). i do agree that more angularity is not good but how much is too much? i can only go by the fact that the factory powercup race teams used much longer torque arms and after ten's of thousands of miles on hundreds of bikes we've not had any issues. i realize that sandbar is offering a different solution to the same issue (better turn-in) and i'm not sure i agree with everything they say but basically their statements are true. but i also feel that our design is well within the design parameters of the original suspension design.

bottom line, if you feel uncomfortable using our torque arm, please just send it back for a refund.
 
#20 ·
That site's retarded.
Sorry.
The chicks have way too much clothes on and are ugly. The bikes more so.

Your bike's cool, though. I assume the Power Commander was a custom job. Your A/F ratio is far too smooth to be stock.

This gives me some hope as no one wants to sell me a rapidbike. :wtf :wtf :wtf
 
#22 · (Edited)
evoluzione said:
you can get a rapidbike unit today if you want, it is just that there isn't much tech support available in this country. contact technoresearch (www.technoresearch.com) and they will set you up.
I did.

Apparently even he has changed his policy.

He was reluctant to sell me one if I didn't have a tuner call him up directly and purchase one. Said he did not have anyone in the Chicago area he could recommend. I called two tuners and asked them if they would call some guy up to talk about a product they've never heard of, to try and tune something they've never seen before, for someone they've never met...

You can guess what the response was... NO.

He was nice enough about it and maybe would have folded if pressed. But I wasn't in the mood to beg...

:dunno: :dunno: :dunno:

I even contacted the "other distributor" and after about 10 minutes on the line with him, I felt like I was talking to a used car salesman and had to give up.

That's alright for now. I've got my tach project to keep me busy.
 
#23 ·
A/F results

yes the USB PCIII was a one off installed by Dusty at the LV DynoJet Research Center...he handles tuning for some of the AMA races and such for them...a skilled hand. There next release should do all of us with Dyno Jet propulsion a little happier... I'm destined to have the head work from Evoluzione and remapping by my 52nd birthday...the gift of more power & speed. As for ugly girls, well once your brain is over 50 you'll probably appreciate them more...I do! Of course as my wife always reminds me, what would I really do with 2 twenty-two year old hotties anyway...let me see.
 
#24 ·
battleborn said:
As for ugly girls, well once your brain is over 50 you'll probably appreciate them more...I do! Of course as my wife always reminds me, what would I really do with 2 twenty-two year old hotties anyway...let me see.
:rotf: :rotf: :rotf:
 
#25 ·
#26 ·
all I can say is that having installed the Sandbar "dogbones" and gone out amongst my fellow riders who in the past were leaps and bounds ahead of me in the corners... I no longer see their tail lights...they see mine. So maybe its the "dogbones" or my cocky confidence combined with a few more rwhp that rewarded me with this achievement... ok, it had to be the "dogbones" so the modification from Sandbar works for me. At speed on the straights no un-nerving mishandling either...so far so good.

tycho said:
If anyone has installed a Evoluzione torque arm on a K1200s, could you tell me if the longer attachment bolt goes on the front or on the back? Either way I've tried, the short bolt is slightly short on the rear and the long bolt is slightly long on the front. Thanks.
 
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