R1100S - 10mm Shortened Telelever - Page 3

rckendall · rckendall's Garage

Yeah, I'd be interested to know how much you would charge to do another. I picked up a used A-Arm so as to not tie up my riding during this work, so sending it off would not be a problem. The problem would more likely would be your location. Shipping may be a problem.

Anyway, thanks for the photos and let us know more about the logistics/practicality of doing more.

Thanks
Richard

sirslarti · sirslarti's Garage

The guy I did it for is installing it today so should have a ride report soon. Thanks for the extra info motoyoyo. I'll make sure he reads it and we'll let you know the outcome. I would probably charge AU$300 plus return freight if anyone is interested but first we will see if we need to modify anything. Good spotting in the 1/8th sheet. If I do anymore I would get in some thinner sheet. JeffGill is the username of the guy I did the mod for so keep an eye out for his posts.

motoyoyo · 08-18-2010, 05:39 PM

That's a pretty fair price. When I made mine, I figured a guy should have to charge around $350-$400USD to make it worthwhile. Maybe that's just because I'm slower and less efficient than you are at this task. I'm still hoping someone here in the US will give it a go and maybe make some for others. I'm still too busy trying to come up with something I can actually make a living at to be available to make these right now. We'll be watching for a ride report from JeffGill when he gets it sorted and run a few miles.

BTW, my rear shock length from eye to eye is set at around 12.5" or 31.75cm long. If Jeff has an adjustable ride height aftermarket shock he should try this height in the rear as a good starting point. Actually, with the thicker .125 material up front, adding 1/32" to this dimension would actually put the front and rear at the same relative height as mine which seems to work well. I think the stock rear shock height is slightly shoter so it should work fine too with a slightly lower height up front.

Thanks again for helping out a fellow BMW enthusiast with a big project like this

Lars · 08-19-2010, 08:31 AM

Following this thread with interest...

The hole cutter looks like a Rotabroach. They'll spoil you for anything else when cutting holes in thin metal. Or at least they did for me.

My source here. Probably lots of other suppliers as well.

motoyoyo · 08-19-2010, 09:04 AM

The hole cutter may be a nice approach, only if you can fixture the part accurately. The hole position and diameter is the most important part of this mod. It must be aligned as close to the centerline as possible. Making the diameter a close fit with the large steel spacer ID will also keep the parts aigned during welding. If the new hole position is correct and the flattened portion for clearance is good then all else will fall into place without much more precautions.

Even though it may take a bit more time, I still prefer a good scribe mark using the large steel spacer and progressively drilling and filing out the ID of the hole by hand. Of course, if one has access to a milling machine and can make an accurate fixture to hold the a-arm, then it would certainly be a lot more efficient. Lacking access to a machine shop, a little extra time and careful hand work is just as good.

Lars · 08-19-2010, 09:46 AM

As it turns out I do have access to a couple of vertical mills, and a pretty decent drill press with a good vise. For one reason or another I have found myself carefully filing many holes to size over the years to get the accuracy I needed for the job. But I'm a tool junkie, and the Rotabroach set was irresistible

motoyoyo · 08-19-2010, 10:55 AM

Lars, it sounds like you have just the right setup to tackle this mod for your own bike too. With your fast riding skills and the triple clamps you already have, you might really like this change to the old steed. It really gives the front a more planted feel when entering and executing turns. Much more relaxed going quickly now and the clamps still keep everything nice and stable.

Since the Rotabroach dies only come in standard dimensions you will either have to make the hole oversized at .750" diameter or go undersized and file out to the finished diameter. Oversize is ok structurally but it makes it more critical to be able to align the parts for welding. Ideally, if you could get the .750" bit ground down to .722" diameter you could jam right through to the finished size. With a good repeatable fixture you could whip these out in no time...

pmc847 · 08-19-2010, 01:28 PM

My question remains, why not this?

Philip

2wheelmike · 08-19-2010, 02:13 PM

Re-read Scott's post and remember that the line connecting the two ball joints is what determines the equivalent head-tube angle that affects trail. Moving the fork bottoms back (your mod) but keeping the "head-tube" angle the same will increase trail as Scott said. Hope this helps-

sirslarti · sirslarti's Garage

No difference (when riding straight - the pivot point changes though so when you turn it will be different). If someone has access to an NC Mill they could carve you a nice lower clamp out of billet aluminium. Working with the A arm is pretty straight forward as long as you don't rush and make sure everything is accurate. Depending on the weather but we should have a ride report today or tomorrow. About 1 degree celsius outside and a bit of drizzle. I'll post more info on that cutter I used as well. They are amazing and only rely on a good centre punch mark to keep it true.

Stephen.

sirslarti · sirslarti's Garage

Scott and Lars picked up on the Robobroach. These things are awesome...They are a set of Metric Robabroach by Hougen USA. The 18mm is the perfect size for this job and worked a treat. For those who haven't used these before they have a spring loaded centre which retracts as you start to drill and keeps everything centred. Great for clean, accurate holes in sheet metal.

I've added some images of these to my original gallery
MobileMe Gallery

Jeffrey Gill · 08-23-2010, 04:28 AM

First of all, a big thank you to Motoyoyo, with out that brilliant post of yours on the shortened telelever I most probably would have put up with it for another 100,000 Ks, I didn't need 4 months like you to rave about it, one 60K ride was enough for me, what amazes me is why the factory did'nt do it, I know BMW is (was) a fairly conservative bunch, but with no apparent loss of stability at 140ks on bumpy corners it begs the question. Of all the mods on my bike, nothing has been sweeter, and for only $300 and 2hours work(removing and installing)
Turn in was the only issue I've ever had with the R1100s, now it is so effortless it has made a good bike brilliant, will check ride height, laden and unladen shortly, Thanks again, PS Sirslati's work was top shelf, it looks even better in the flesh than in his pics. Regards Jeff.

motoyoyo · 08-23-2010, 08:34 AM

That's awesome Jeff! Glad to hear your positive report on the telelever mod. I too felt the mod was a huge improvement on the first ride. It took me 4 months to decide whether or not it was worth my time to write up the procedure and post it here. Sometimes a mod that takes this much commitment to make is not taken as a serious option for a lot of people.

Each time I rode the bike I felt so good about the way it handled that I finally broke down and had to share it with the rest of the R1100S family. I never dreamed that the first person other than myself that would experience it would be half way around the world from me. Kudos to you and sirslarti for taking a chance on the mod and getting it done. Have fun with your new bike!

Lars · 08-23-2010, 09:57 AM

Quote:

Originally Posted by motoyoyo

Lars, it sounds like you have just the right setup to tackle this mod for your own bike too. With your fast riding skills and the triple clamps you already have, you might really like this change to the old steed. It really gives the front a more planted feel when entering and executing turns. Much more relaxed going quickly now and the clamps still keep everything nice and stable.

Since the Rotabroach dies only come in standard dimensions you will either have to make the hole oversized at .750" diameter or go undersized and file out to the finished diameter. Oversize is ok structurally but it makes it more critical to be able to align the parts for welding. Ideally, if you could get the .750" bit ground down to .722" diameter you could jam right through to the finished size. With a good repeatable fixture you could whip these out in no time...

Thanks, Scott- first order of business is to get the bike reassembled after replacing the front frame, finally getting the subframe straight (I think) and getting the front Ohlins back from rebuild so I can ride it for a baseline. I've barely been on the bike in the last year. Carpal tunnel syndrome got so bad I couldn't ride, or even work on it. Got both wrists slit in June, much better.

I expect that I'll do the mod, just a question of when. As for making multiple copies, see comment about CTS above

Don't wanna go through that again...

Markus from Oz · Markus from Oz's Garage

Hey Stephen, nice work on the photos of your work.

Motoyoyo, thanks for taking the time to post your design.

Stephen, I am definitely interested in getting this mod done by you. Could you email me your contact details please. markusmuller@exemail.com.au

I installed the shorter GS torque arm on my R11S about a year ago which also helped with turn initiation but this mod sounds even better. The shorter torque arm raises the rear a little but this is no drama. In fact, getting the bike on and off the centre stand is finger light now but there is still plenty of stability on the stand.

twodear · twodear's Garage

Markus, PM sent

sirslarti · sirslarti's Garage

Hi Markus. I've emailed you my contact details but am happy to supply my mobile and email on this thread if nobody objects.

shreddr · shreddr's Garage

I do believe that the shortened a-arm is a great mod, and has been a huge improvement on my R12S, but the RT arm swap is a much simpler route than relocating the pivot hole. It seems that without well fabricated fixtures, the possibility of not getting the new location perfectly correct is pretty high. If you want to move the hole back 10mm and end up with 9.9mm it is probably no big deal, but if you are off center by that same 0.1mm you could end up with a bike that tracks weird, and handles a bit strange. How are you ensuring proper alignment with this mod?

sirslarti · sirslarti's Garage

"shreddr" an A Arm swap like you did with the 1200S would be awesome if there was such a beast for the 1100. Fabricating the 10mm mod on the 1100S A Arm isn't too bad using 'Scotts' instructions as a guide. I can see how you could get yourself in trouble if you didn't have the right tools and experience in doing this mod. I found it easy enough to ensure accurate offset if you use the bearing centres at the other end of the A Arm as the Datum. If I had to do another one I would fabricate an accurate Jig which would save all the measuring and marking out.
Its great to see active mods happening on all the BM's. I thought my GS was modified heaps but you guys make it look stock!
JeffGill is coming with us on a 2500k ride in a couple of weekends so that should give his A Arm a good test...

Stephen.

Markus from Oz · Markus from Oz's Garage

Quote:

Originally Posted by motoyoyo

Great to hear someone has jumped in and tried out this mod. Thanks for posting the pictures too. Wow, you actually had a cutter to make the hole cutouts? Very cool. Nice job on the construction and the welds. It looks like you used .125" thick material rather than .094"? The thicker sheet material will raise the front by 1/32" but I doubt it will affect anything. When you set up the sag in front be sure it is not less than 34mm with rider on board. 34mm-35mm should work well.

With the front end laden sag set, you can experiment with the rear shock length to get the right handling feel. If the rear height is high, the steering may be too quick. You should be able to lower the rear height a bit to get good steering response as well as a lower seat height. I will see if I can get a measurement of my rear shock length for you to compare with your friend's shock.

Be sure to check the ball joint boot for clearance underneath the a-arm. The ends of your curved plate look like they may limit the clearance a bit. If it clears by .03" or so it should be fine. Have you thought about what you would charge to do another one if someone asks? Be sure to post a ride report after you guys get the suspension dialed in.

Scott, I'm seriously considering Stephen doing this Mod for my R11S. However, considering your comment above (highligted & underlined) regarding rear height, I have a question. I have installed the shorter GS torque arm which raises the rear height and helps with quicker turn in. If I do the A arm mod, will the two combined be overkill? Or can I leave the longer GS torque arm, do the A arm mod but adjust rear shock?!?

My bike has the OEM shocks but I am a light weight and I have read on this forum that for lighter riders the standard shocks are OK...(not wanting to start another suspension thread)

Any advice appreciated...