Most of the longer travel dualsport rigs (GSA) seem to benefit from having a sway bar. I perceive this as balancing the effect of longer travel bike suspension vs the shorter sidecar suspension.
I haven't measured exactly how much wheel travel my side car has, but the shock has 5" of stroke. The bike has the stock travel front and rear, just sprung (and valved) different for the added weight. To me a side car is something the passenger sits inside of like my rig: The side hack is basically a platform that the passenger (aka "Monkey") mostly stands on and has plenty of room to move around and transfer their weight to help stabilize the the rig (like the trials bikes in the vid) or here:
One thing that limits where you go in the backcountry on a sidecar is considering what's gonna happen if you get to a point where you can't go any farther and have to turn round and come back. In this pic here, I'd gladly ride WUMPA from the background to the foreground, but I don't have the chops to ride from the foreground to the background no matter what line I picked. Maybe I could walk it through there, but it would be a trick. Part of that is because of the terrain, part because of the rig's limitations, and part because I'm old and fat and can't do half the stuff I was able to do 15 years ago. There were several times in my travels over the past three years where I've gotten to a place and turned around even though I knew I could get through. I turned around because I didn't know if I could get back if I had to. Now, if I had a active monkee with me (not a "passenger" who just sits there), the whole formula changes. With a monkee I can go places I'd never try solo.
The thing about long travel is, sure, it's great to help you crawl through the rough stuff, but that high center of gravity is a limitation for general use on smooth roads. And, of course, the high ride makes off camber situations more dicey. What I'd really like to see is something like this for a sidecar rig-- <iframe src="//www.youtube.com/embed/xpKGemlqAN4?rel=0" allowfullscreen="" frameborder="0" height="315" width="560"></iframe>
But seriously, I was thinking more about hanging out, or standing on the passenger step if you got one.
I was wondering this before, would a Goldwing type air shock and compressor be good for the sidecar to raise and lower it? They are on ebay pretty cheap. Maybe even one on the rear of the bike? Would that do what the Jeep is doing in a limited way.
Never really had to worry about HCG on a solo and on the crawler I just made the track wider and put on adjustable sway bars. I have seen sidecars for adv anywhere from 7"-14" if just graded gravel low and fast is the way to go. It may just be a pipe dream to have a decent exploration off-road rig and expect it to drive 1,500 on the road heading home.
Let air out of the drive tire and avoid the scree to the left of pic'. Then, slow and steady wins the race. Might even be a semi- business opportunity for Barry or Vernon, taking those who have had a rig for a while and showing them the next stage. Ride around the mountain trails and play, follow the leader. .
He is standing there to get an idea of the size of the rocks. The ledge behind him comes to his knees. I would agree stay out of the loose stuff it's on the edge of a cliff. Probably 150'
Once again, people new to this should use their rig to their advantage. For us blokes down under ( chair on the left ), we could put the bike against the abutment, thereby straddling the 3' rock ledge without the chair getting, tippy, due to being on the high side.. I've already sussed out that having a LL with fixed brake calipers allows you to drag the front brakes and get the rig to raise itself to 'hop' over larger rocks/curb at Starbucks. It runs 2" of static sag at the front that I can use to my advantage. Cheaper than air suspension .
Have the car on the otherside would make it feel better. Hadn't thought about the anti dive aspect of brake mount on the swingarm. The Tiger will leap over somethings with just a blip of the throttle. Love that HP
Another thing to consider in your build. Just as the front will rise, the chair's swingarm will compress due to being in a trailing orientation with an independent brake, plus you can use it to skid steer in tight situations. Makes for wickedly small U-turns. Handy in fast turns towards the chair, as it will 'suck' the tub closer to the ground which negates some of the negatives of long travel on the bike. .
So if one was to build a rig for increased car travel then I would ass/u/me that it should have a sway bar. I know the crawlers use some nice set ups that are made from torsion bars. the same could be adapted to a sidecar to the rig coner flat. here is a good example of a kit: http://www.welderseries.com/blog/online-store/sway-bar-kit/ some are even easy to adapt from a suspension build stand point it seems logical to build the swing arm to follow the angle of the tugs swingarm. Most are in the 7 degree range. For the sportster one could copy the mount location for the shocks and length of the arm, that would give a balanced travel and keep the same stroke ratio. If you calculated wheel rate on both the car and the bike then a suspension shop could dial in the spring rates and damping curves that would allow the suspension to operate in unison. I'm more than open for correction as I am comping for a car and bike word and things may not be as they appear
This is Claude's forte. Some bar rates and calculations for you. http://www.1speedway.com/sb_rates.htm Once again, what is it that you want from the finished rig. Yes, you have addressed that question, but , the tub will be lighter than the bike, so mimicking the bike's suspension isn't altogether necessary, nor is it at times desirable. A shorter swing arm, mine are usually in the 5" ~ 9" range ... hey, no personal jokes ... coupled with an arm that is angled upwards at rest still allow for a healthy amount of travel depending on how you design the shock points. Remember, on an outfit it's primary purpose is to add comfort and as long as it doesn't bottom out at speed, it's all good ... it doesn't aid axle articulation so it's not going to assist you in an RTI competition nor on the trail. Chris ( bmweuro ) is the only other builder I've seen on the forum that , if not favors them , has used them with good results. See his build thread on the green R100gspd and modified ural tub. ... oh, there is no advantage in using expensive bike shocks when a multi adjustable car coil over ( some with 36 position rebound and damping control ) achieve better results for a fraction of the cost. .
i was looking at trailing arm for the car. if I do that with the arm angled down when it compresses the wheel moves back and gives a smoother ride. Obviously if I did a leading arm then the opposite is true which way do you have the arm running?
FR 700 has about the best grasp of what you want, you may want to go spend some time with Claude and ride one of his around a bit.Are you building this rig or do you have a fabricator you like ? DB
I have been talking with Claude. I have looked at tons of pics on his FB page and some here. I like his building style. Looks very well thought out. I see a lot of smart engineering on the details of the build. Just the way he does the gussets and mounts. They appear to come from someone who has been fabbing along time with a eye out for a better way. The biggest issue is distance as he is 1,200 miles from me. We have picked out some details but haven't worked it all out. He is swamped right now.
