I have 78BMW R100RT w/ Velorex 700. I have gotten a nice BMW earl fork to install. Here's what I have found. The earl fork will lower the front of the bike , a result which I do not want. Measuring the earl and comparing to stock fork, there is a difference in overall length from
the top of the 3-tree to the axle of 3 to 5 inches, depending on weight on the bike. I measure the earl fork with BMW shocks(Koni rears)not earl shocks. I will use the same 19" snowflake wheel w/ dual disk.
1. what is the length of the original earl shocks (with weight applied)?
2. what angle (estimated) should the earl fork be to function correctly?
90 degrees? 110 degrees? 120 degrees?
(I do not want to alter the pitch of the bike...tracks straight and true)
3. what are others' solutions to the problem of maintaining the bike's pitch relatonship to the road and car when installing an earl fork?
It appears to me that I will have to make "extended mounts" for the shocks to gain the indicated difference in length. Gee, what a quandry, eh. Jon
Gee whiz, y'all, I really figured that I would get some response. I thought there would be others who put the earls fork onto R100 and
encounteresd the same thing. Is there anytbody out there?
Try to find the forum for BMW conversion motorcycles. Those guys talk about all kinds of BMW swaps, hybrids, bitsas etc. That's the place to get this kind of info. Good luck! H.
There is also the issue of having to bend the leg's and cut the braceing bar out and replace it with a straight piece, otherwise the whole lot will clatter into the timeing chest. Then there's the issue of the bearing's on the triple tree. They're not compatable with the /7 headstock.
I have done this conversion and if I can I'll try to up-load some photo's. In all honesty I would look out for some 2nd hand L.L's on ebay. It'll be much easier and less time consumeing to fit.
Safe riding Karl.
Photo try #1
Sheesh that's not so big. I'll try again.
Safe riding Karl.
Photo try #2.
Well, now, Karl, I see another mod that I have begun, the external alternator...4 brake lights, 2 fog lights like yours and doubled turn blinkers...car battery in sidecar.. Of course mine is on the other side and the belt will go through the side of the cover instead of out the front. I hope to get the alternater behind the RT fairing lower when finished.................and , your sidecar is on the wrong side for US, ya know. It is a very smooth looking rig.
How about your project building photos of the steering head and earls fork?
Jon
Jon - Computer's wer'nt around when I did the front-end mod,as to the alternator. I think you'll find that if the belt is put in the timeing chest 1, there wont be enough clearance between bike frame and belt.
2, the belt can flap around a fair bit so It'll catch.
I thought about what you're intending doing (putting the belt in the timeing chest), but I could'nt do that cause of the bike frame.
I put one on an RT but had to adapt the lower fairing for the alternator to fit. Nothing drastic if memory serve's me right, just a bit of cutting. The alternator swop is the best thing (mod) I've done. Never touched it in 10 yrs and only now have I changed the belt and yes a nice big battery in the boot.
Safe riding Karl.
Karl,
How about a shot or two of the hack side of the outfit?
Inquiring minds want to see.
Ride safe,
Lonnie
Northwest Sidecars
Hey, Lonnie! Glad you joined in. How about some sage advice for my project?
Jon
I won't be much help here, I'm afraid. I'd put the early LL's on eBay or a Beemer site and use the money for mods on the R100 triple trees from Peter Smith at Side Effects or another raked triple clamp supplier.
Lonnie
I sure wish somebody would help me with the dimensions in my first
entry to these threads..length of earls shocks and angle ya know.... Here in LA (lower Alabama) hacks are few and far between and it's 99.9% "hog" country. Closest BMW shop is 250+ miles...B'ham, Atlanta, Tallahassee......I have not found how to access "factory" type spec data on PC yet to look it up myself, either. Maybe somebody could help that way, eh.
Jon
First off, here's the photo's of the hack;
http://www.bmbikes.org.uk/Forum/viewtopic.php?t=7593
Jon, the shock's I put on are the same length as the BMW rear one's. As you will have seen in my photo's, you have to weld a new mount on either side of the swingarm. The height of these mount's is dependant on getting the arm level. Mine are from the top of the swingarm fork to the centre of the hole (for the suspension); 3 1/2 inches. This should work for you too, as I had the bike wheel on at first, before I put the 15 inch rim's on.
You'll also need to weld some mount's on for the brake's. These I originally put on the bottom of the arm, using the Brembo calliper's. I have since mounted the brake's (AP Lockheed) on top and dont get any up-lift when brakeing. They are also floating on Triumph rear brake steadies.
The harder bit is to cut out the bottom bar on the leg's. Then you'll have to heat up each fork with some serious heat so as to be able to bend them forward. About wid-way down the leg. The back of the fork leg to the timeing chest is approx 6 1/2 inches when it's right. This has to be done to avoid the leg's crashing into the timeing chest. If I were to do it again, I would go for about 7 inches as it's a bit quick on the steering at 6 1/2 inches and I think 7 inch would have slowed it down a bit more. You get used to it though.
Alot of this fabrication buisiness is a case of 'suck and see', if you get my drift.
I too am the only one on a small island with an outfit and like you have no access to tool shop's. Hope you've got some good equipment?
Good luck.
Safge riding Karl.
P.S. This is not a job for the 'faint of heart'!
Thanks Karl. This will be helpful. I have gotten Yamaha brake cylinders to try with the Brembo rear brackets...might have to make my own anyway.
I note on your rig that the brake lines are routed out front and down to stay cleanly away from the wheel /pivot action. I like that. I have Koni BMW rear shocks for the earls. All the bending may present a problem in getting it out of true, ya know. Build a jig? Do each side sepaately?..or try to to bend both at same time...hmmm...that's a tuffy for a home garage/shop. How did you account for the temper of the metal after the heat /bend process? To stiff, they'll crack..too soft they'll bend..hmmm..maybe bend it cold in a big shop press? I am getting all my duckies in a row for the winter to try it. It is HOT humid summer here in L.A. (lower Alabama near Mobile). I will do it as a mock up on my other project bike , 79 R100T, then change it over to the sidecar scooter. I do not want to disable that one until I can get'er goin' again quickly. It
drives true right now and is a pleasure to ride. Yhanks for the data on measure for set-up. I'll try to get back to you w/ pics when I have something to show.
Jon - The fork's I got someone to heat them up about mid-way down and then put them in his 'press'. I put the spindle in whilst all this was being done. It took 2 goes as the first go was not enough. I should have gone for the 3rd try and got it to 7 inch, but I'd had enough nervous tension (pun intended). This was all done 20 yrs ago so the fork's have stood up well. On the bottom swingarm I put a grease nipple in the centre for the bearing's.
When I had the Brembo's on I did'nt need any fancy fitting's. I just welded a bracket on the arm and hung them on that (I had the bike wire wheel set-up at first).
Are you intending having you're brake's floating too? I could send you a close-up of my set-up if you wanted. But then again I've got 15 inch wheel's now, but hey it might give you food for thought.
You had anymore thought's on the car alternater job?
Safe riding Karl.
P.S. It was quite hot here today - 19 degC. That's very hot to us North of civilisation (better than that - No Wind) LOL.
