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Sidecar on an R90?

B

bunkyone

Guest
Hey all: Seeing as I can't seem to find a buyer for this lump, I have decided to convert it to a sidecar rig. (That's the original reason for selling the bike, we were going to buy an Ural). I have been told that I will need to replace the rear sub frame, with a unit designed for sidecar use, as well as add a fork brace and steering dampener. This is all before I buy the car. Anyone out there have an R90/sidecar rig who can give me some ideas? Thanks in advance. Vaya con Dios, Dutch
 
Lots of good info and examples on the advrider.com forum in the Hacks section.
You will be adding an additional subframe to the bike to stiffen the chassis and add support to the sidecar mounting, not replacing the rear subframe.
 
I have 2 Airhead sidecar rigs. You do need a subframe, but not to replace the bike's rear subframe. What you need is a sub frame that mounts to your bike main frame and the sidecar mounts to it. It distributes the sidecar loads better than just clamping a sidecar to the main frame. If you rig it up right, it'll be a better sidecar rig than a Ural (IMHO), you just won't have reverse gear, or the option of 2wd.
Here is a link to some pics of my R75/5 rig:

http://pfestus1.smugmug.com/Motorcycles/1973-BMW-R755Dnepr/952327_3YMTF#43760170_hvTrU
 
Hank and Bob; Thanks for the reply. Is the reinforcement kit available? I really wouldn't miss the reverse gear or the two wheel drive, they would just tempt me to get into situations that I couldn't get out of. ( I already have an R1100 for that!!) This is mainly going to get used to haul the wife around, as she suffers from an inner ear problem that makes it difficult to ride on a two wheeler.
 
A variety of sidecar dealers sell subframe kits for various bikes. One of them who has been doing this for a very long time is dauntless motors. Got to dmcsidecars dot com and give them the info on your R90, and what sort of sidecar you're looking at. They may even sell you a sidecar, too!
 
I have a 1983 R100 w/dauntless subframe/sputnic car.Steering was hard and wobbles Perry bushlong (texas)made new tripple trees to change trail,fixed steering.lacked power because of car,got different final drive 37:11 fixed that,need flat profile tires,mag wheels are best because of side load.Cost about 5K. Oh,well,what's money for anyway. Fun Ride!
 
I have a 2002 Velorex 562 on a '77 R100S.

The rigging is Dauntless (now DMC). The "sub-frame" is somewhat visible in the attached photo (it parallels the bike frame--it runs from above the cylinder and follows the frame down below the cylinder to the driver's footpeg area of the frame). Note also (second attached photo) the "loop" just forward of the passenger footpeg, it connects the back of the sidecar to both sides of the bike. The subframe is critical on post /2 BMW's as the "newer" frames can't carry the stresses of the sidecar.

I can take photos of all the rigging and sub-frame if you wish (as the attached photos don't show the parts very well).

Here's a list of how the 100S was additionally altered to tug the sidecar:
San Jose loop fork brace
braced swingarm
Luftmeister anti-dive spring kit
Reg Pridmore upper yoke
new fork seals (BMW)
SAC barbacks (about 2" back and 2" up)
wide/low sidecar bars
Volkswagen steering damper
lightened flywheel
dual plugged with new wires & caps
Dyna coils and Dyna elecronic ignition
Progressive rear shocks with stiff springs
final drive replaced with 37/11

886828076_BtKEB-M.jpg


886831405_tQ4jQ-M.jpg
 
Is it just me of does that hack seem set out pretty far?


:dunno

I'm curious as well, now that you've asked.

This is my first sidecar so it "seems normal" to me. The photo may be a little deceiving as the space between bike and 'car looks larger than reality. That said, a large ammo box was bolted to the sidecar frame when I bought the rig (I've since remove the box).

You are the first to ask the question, now I'm curious. I would like the 'car tucked a little closer to the bike.

Anyone?
 
What is the track width (center of bike rear tire to center of hack tire) with your setup? I'm in the process of getting my piggybanks together so that I can join up my recently acquired sputnik car with my 1978 R100/7...
 
Yeah that looks a bit far out. .

FWIW I have a similar rig, an '81 R100 with the same Velorex car but a year or two older; looks like the mounting setup and hardware are the same also except possibly for a different lower subframe rail. The toplinks and mouting look the same and the steering damper is the same but mounted a bit lower on the fork on yours.

My clearances are 3-1/2" from the bag to the rear body of the car, and 2-3/4" from the valve cover to the body of the car. It's a little too packed in (for the winter) among other bikes to easily measure the wheelbase at the moment but I might do that tomorrow. Based on the amount of thread left on the adjusting links, mine looks to be about as close as you could bring the two together and still have some play to adjust the toe-in/out. I didnt do the original setup but have pretty much overhauled it since I got it and it seems to be set up about right (but I'm not an expert!). I guess the real question is--how does yours ride with the car all the way out there?

Handsome rig, by the way.
 
SFaulkner, your track width does seem a bit wide. Thats not neccessarily bad and will help with stability in right hand curves. For comparison, My R75/5/Dnepr rig has a 46.5" track, and the valve cover is 3 1/2" off the sidecar body.

279659393_hXrxR-Th.jpg


The chair will fly fairly easy in right handers, but I don't think its excessivly easy. My other rig, a R100RS with a larger Motorvation sidecar has a 60" track. The sidecar itself is heavier, and I find it hard to get the sidecar to lift.
 
Thanks for the info on your track width - I'm preparing to setup my 78 R100/7 with a DMC subframe and a Sputnik car - I figured that the minimum track width would be around 48", and this will be my first sidecar, so for me, going a bit wider makes sense. At least with a wider track (within reason), one isn't so hemmed in when trying to do valve adjustments, etc.

Beautiful looking rig - I hope that mine comes out at least to something approaching that, in time.
 
Thanks Dave and Hank for posting dimensions, thoughts, photos...

I've always thought the space on my rig between bike and car looked wide, visually. I'd love to skinny it up. This discussion is interesting in alerting me to what visually looks right and how the width may impact ride-ability. I hope too it is helpful to the OP.

Also, I like the idea of finding a 560 and mating it to the R100S, it's lines seem to fit the 100 better. If anyone knows of a good one out there, let me know. I may not mess w/ my 562 set up at all if I find a 560.

Thanks again for the info. Very helpful.
 
Well, I shuffled the traffic jam a bit in the garage and was able to measure a track width on my '81 R100/Velorex 562 rig. It's only 44" (center to center). The Velorex is a light car so whoever set yours up might have left it that far out to try to keep the chair down. I can tell you, my chair is prone to flight .. .really needs ballast to ride well on right-handers. It sounds like we might have the two extremes on R100's with the Velorex 562, in terms of track width. . .this makes me want to try moving it out 2-3" or so. . .
 
Wow, we have a 6-3/8" difference from Dave's set-up to mine.

My 562, although light, is not prone to flight. I can get it in the air but I have to put some effort into it. On right-handers, it usually stays on the ground unless it is empty and I make the right-hander as tight of a radius as possible. I don't carry ballast in the 'car (but the bike is set-up to run on a car battery which I have in the trunk of the car in a plastic, marine battery box--so, the battery is the only ballast in the 'car, I haven't felt the need to carry any more than that).

So, at least so far we have:

44" if you want the 'car to be "light"
50" if you want the 'car to stay on the ground for most right-handers

On a final note, my rig does pull to the right a bit. I worked on adjusting the rigging for lean. This spring I'll check the toe. I doubt the "wide" set-up would affect pull. Any thoughts on that?
 
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