R1100S - 10mm Shortened Telelever

[motoyoyo]

Markus, there is no problem using the shorter GS torque arm with this mod. This is the setup I am using along with a slightly longer than stock rear shock. The turning response may only be too quick for those guys that have done everything possible to raise the rear height to get better turn in.

In those cases, an aftermarket rear shock with an adjustable height clevis has usually been cranked up way beyond stock height. There is no way a shorter GS arm along with a stock rear shock will result in too quick a turning response. It should be almost ideal in fact.

I have not tried a completely stock rear torque arm and shock with the shortened telelever. I haven't used that rear setup in a long time but I'm sure there would be a big improvement in handling in that case too. I'm 100% certain it would not turn too quickly, but it should also be much better with the short arm up front.

Again, to be clear about the setup. I was one of the riders that had mt rear height as tall as I could stand in order to optimize the turning response. When I installed the shorter telelever arm the bike was still stable but I found that I could reduce the rear height and still have all the turning response I could have ever wanted. The added benefit of this change was a lower overall seat height than I had previously and lower center of gravity, both adding to much better controlled handling.

[Kjell-Anders]

I am considering some surgery in the front of my bike and I have read your turorial with great interest.
However, a guy I know with deep insight in the R1100S, has made a similar modification but only 4 mm offset. He says that the limit for the ball link is 5-6 mm. I have not tried his bike, but he reports that he had to lower the back a little to increase stability.

4 mm is a lot less than 10, I don´t want to overdo the tweak, but am also afraid of adjusting to little.

I have (of course) the shorter paralever arm and an adjustable rear shock. The back of the bike is jacked up to the sky, as much as possible before the shock´s lower end hits the silencer.
I have no stability problems at all, but the bike still cold be easier to turn into corners. My old R850R was quicker.

What is your advice? 4 or 10 mm or something in between?

[motoyoyo]

Originally Posted by Kjell-Anders

However, a guy I know with deep insight in the R1100S, has made a similar modification but only 4 mm offset. He says that the limit for the ball link is 5-6 mm. I have not tried his bike, but he reports that he had to lower the back a little to increase stability.

Kjell, well it took me a couple days to get to my bike to verify whether this statment has any validity. I have to admit I did not check the total travel when I installed the shortened telelever, so I am curious enough to check it out first hand now. I put the bike on a lift, removed the front wheel and front shock.

The fork vents at the top of each leg needed to be removed to allow full travel of the telelever without pressure resistance. I was able to easily lift the telelever until the front fender hit the oil cooler. This is about 3/4" (20mm) past the maximum travel I have ever experienced with my front end and is also the maximum travel allowed by the front shock.

There does not seem to be any excess angle in the ball joint at the maximum travel. Perhaps I could take the bodywork, fender and the handlebars off and see how much further it will go before I feel something binding, but at this point there is no problem with the ball joint angle at a distance of 20mm past the maximum travel the front end will ever see. I don't know what information your friend has come up with to validate his claim of a 5mm-6mm maximum allowable offset, but it seems that a 10mm offset does not cause any problem with the telelever travel as far as I can see.

From my experience with the 10mm offset, I would consider this position as the optimum setting. Anything in the 4mm offset range would be barely noticable and a waste of time IMO. Everyone will have their own impression of the bike's handling no matter where the heights and positions are. Many people are perfectly satisfied with a completely stock set up bike. Others are not. This mod will allow a rider to experiment with different ride heights until they find their own optimum settings.

For some of us with aftermarket shocks, a GS torque arm and a raised rear ride height, the bike still does not handle the way we expect a good, or even average sport bike to handle. This mod allows another element in the suspension geometry that results in more flexibility when setting up the bike to handle the way we want. This mod is not a necessity for everyone. The only riders that will benefit from this mod are people that have done everything they can to improve the handling and are still not satisfied.

[Guest24]

Scott, I see that you've now answered my balljoint question. If this were a conventional fork you'd be modifying the rake via the reduction in the neck angle. What is the overall effect on caster with the reduction in fork angle? Will it require an adjustable steering damper?

[GotRoad?]

Originally Posted by motoyoyo

...This mod allows another element in the suspension geometry that results in more flexibility when setting up the bike to handle the way we want. This mod is not a necessity for everyone...

My new, used telelever, should arrive next week. I'll do the initial cutout & nut removal myself. I don't weld, but I know a local guy with the right skills to get the project finished. Looking forward to the adventure. Thanks again for such an interesting DIY.

[motoyoyo]

Bubba, the change in castor is about 1.2 degrees at ladden ride height with the 10mm shortened a-arm. Yes, it is basically the same as a change in neck angle on a conventional fork. With a telelever the castor decreases (rake increases) as the suspension moves upward through its travel. The castor angle at the ladden ride height is usually what determines the handling characteristics of the bike.

GR, that's great that you are going to do the chop and grind work yourself. That is the most important part where you need to take your time and make your cutouts accurate. A good welder will apprecite everything fixtured in place and he can lay a nice bead in there. In fact, the welds were the only thing I was a bit sloppy with. If I were to do it again I would consider either practicing welding a bunch more or taking it to a pro welder and getting a clean finish to the job.

[Markus from Oz]

There was a A-arm off a low mileage 2004 R11S for sale on Ebay that went for $149 yesterday. Only 1 bid. I almost bid on this myself so that I could have a spare A-arm for MotoYoyo's mod, but work got in the way...

Anyone on this forum buy that thing yesterday? Come on, own up!

[Kjell-Anders]

Many thanks Scott, for all your efforts. I now feel safe with the 10 mm offset and look forward to to the mod this winter.

The only thing that still concerns me a little is the risk of getting a side offset.
Making a properly alighed hole at the top of the lever is no problem, but transferring that to the lower one may be a problem. Everything must be plane and right in place, otherwise it can end up with a mismatch.
Anyway, I will give it a try.

A last question: I have the standard fork clamps. What´s the difference with the clamps you are using?

[motoyoyo]

Kjell, when aligning the offset hole in the telelever arm, only the top hole needs to be accurately aligned. The bottom hole will follow the alignment of the top hole when you use the fixturing bolt to hold all the pieces together. Therefore, if you are careful aligning the offset hole on the top surface of the a-arm, everything will fall into place perfectly. You only need to be accurate one time.

Keep in mind also that the distance between the clamps is a fairly large 18 inches or so (46cm). A small misalignment over this distance would be negligible. As I stated in my procedure for cutting out this offset hole, I prefer the scribe method for accuracy. By using the large metal spacer as a template you can scribe the intended location of the cutout hole and accurately measure it's alignment. Using progressively larger drill bits and finishing with a round file, you can creep up on the scribe mark and get the hole exactly on your scribe marks. Once this is done, there is not much else to worry about.

The clamps you see in the picture are from a previous project I did for the R1100S. They were intended to improve the side to side flex of the stock front end, which added to the steering precision and feel. There were 50 or so sets made and sold to various riders through this site at the cost of producing them. They are no longer being made or offered for sale. Once in a while a set will become available through another rider that is selling them used.

The clamps were, and still are a great mod for the R1100S. The telelever mod does a lot more than the clamps could do by changing the actual steering geometry. The clamps along with the telelever mod is fantastic, but it should be almost as good with the stock clamps as well since the steering effort is so much easier.

[Kjell-Anders]

I plan to do the modification after the season and I am really looking forward to start the work. It surely is advisible to consider a steering damper, at least ensuring that the mount position is adjusted according to the shortened telelever.

Do the modification with the 10 mm offset demand a steering damper? I guess that the front in some situations can become a little more nervous, for exampel in high speed cornering at the track.

If a damper is recommended, what brand and model is best choice? And how is the best way to mount it?

[GotRoad?]

My used A-arm arrived earlier this week! I've been studying the text, drawings and pics in this thread and plan to start this weekend on removing the steel spacer.

[motoyoyo]

Take your time and make sure your top hole cutout is sized and aligned nicely and everything else is fairly straight forward. Be sure to use vise grips to hold your parts and eye protection when you use the grinder. Don't want to mess up your whole weekend at the emergency room.

Also, I wanted to mention something to all the people that are looking for used telelever arms for this mod. If you decide you like the way your bike handles after installing the shortened telelever arm you might want to consider offering your stock one for sale to another person that may want to do this mod.

After having my shortened a-arm installed for the past several months, there is no way I will ever put the stock one back on this bike. Perhaps after there is some more feedback on this mod, some folks may not even see the need for an extra a-arm and just go striaght ahead on modifying their original arm.

Have a good weekend Craig. PM me if you have any questions about the mod as you get into it.

[rodmcm]

Scott

I'm interested in your comments about ride height and the length of the Ohlins. I think both my front and rear Ohlins are longer that the standard ones. I can adjust the rear using the threaded adjustment but I would need the local importer to shorten the front if I wanted that done.

Is/was your front Ohlins longer than the standard BMW one? If so, have you left it at the longer length or have you had it shortened.

I have contacted Sirslarti with a view to him doing the work to shorten the telelever arm for me as he did for his friend and would like to lower the machine back to its original height.

And thanks for sharing with us, once again, the benefits of your engineering explorations.

[motoyoyo]

Rod, my front Ohlins is a standard length. I believe that the majority of them were sold in this length unless ordered specifically with the extra 10mm spacer added. These were mainly used on the overall taller 2005 BCR which had longer shocks from the factory. I don't have the actual dimensions of the shock lengths right now but could probably find out with a little searching.

I can put together some detailed numbers of my setup but it doesn't necessarily mean it is what everyone will be comfortable with. I pretty much can tweak my heights and tell right away if it is right for me and make adjustments until it feels good. I will start with a good solid rider sag number on the front shock of around 34mm and then play around with the rear adjustable height until I get the turn in feel that I like.

Fairly simple to do by getting your front and rear sag set by the numbers and then play around with the preload adjuster in back until you notice the difference in handling. Once you find the sweet spot, the ideal setup in back is to adjust the clevis to this approximate height with the preload adjuster backed all the way off. This way you are not interferring with the rear sag by having the preload adjuster jacked up to far. Much more compliant. Once you get the clevis adjusted to where you like it, use the preload adjuster only to compensate for added weight or when traveling or two up.

I'll see if I can put some numbers together for you to give you a better starting point. BTW, how are the triple clamps working out for you? The telelever mod is just the thing to compliment the triple clamp benefit. I found that the whole ride height setup is less critical now and a wider range of settings works well with the shorter arm.

[Guest24]

Scott, the Ohlins were the same length as the BMW OEM sport shocks if I remember correctly.

[motoyoyo]

Here's a couple threads on shock lengths for your reading pleasure...

Centerstand on a BCR?

Shock Length

[GotRoad?]

After reading this thread about 1x10E6 times I decided I wanted to give it a go myself. Got myself a used arm off of eBay and got to work this weekend. Instead of making a circular template to mark the cut-out area I used a compass, with the pivot sitting on the midpoint and a steel pin to scratch cutout area. A handheld drill & 0.125" bit was used to drill lots and lots of holes. I used a combination of a jigsaw bit (held with a vicegrip) and a high speed rotary cutting tool to remove the spacer. I used a bench grinder and a small metal cutoff wheel to cut the welds off the spacer. It took some time. Next stop: smooth out the cutout area, but that will be some other weekend. If I don't screw this project up somewhere along the line, I'll have this baby on the road in 2011.





...And, IF, I don't screw it up I'll follow Scott's suggestion & put my unmodified A-arm up for sale here so that someone else can have a go at it.

[twodear]

Originally Posted by Markus from Oz

Scott, I'm seriously considering Stephen doing this Mod for my R11S.

Markus, you have a PM.

[motoyoyo]

Omg...sorry but I'm a bit worried. I'm sure everything can work out well with what you have done already, but it was not exactly what I had intended. First of all I said to cut out a 2.50" circle template and measure back .550" from the edge of the ball joint pockect and scribe the edge.



From what I see from your picture you may have used the original ball joint location as the origin and used a pencil lead compass to mark the intended cutout edge. This does not present a big problem in the end result but it was certainly not what I had intended.

You will be fine in the end, but by all means please be more accurate with the rest of the procedure. Otherwise, you might want to consider having some help with the next cutouts. Don't be afraid to ask for help if you are overwhelmed. This is a pretty difficult modification to make for even an experienced person.

[rodmcm]

Scott,
Thanks for the reply on the shock length. It gives me a bit to think about rather than just trial and error.
I bought my Ohlins from a bloke who was racing a BCR. He bought a second machine for parts and the sale of the Ohlins from it helped him cover part of the costs. I'd say mine is a longer front and I would like to lower the bike so as to be a bit closer to my inside leg measurement for stationary stability reasons.
I am still rapt with the performance of the triple clamps. The bike tracks absolutely rock steadily when heeled over on any sort of road, annoying the heck out of the sports bike riders.
Now, we've just got to speed up the direction changes, although I could just get a new bike but where's the fun in that?