Board index Flathead Power-Technical Questions, Answers, and Suggestions Knuckles sidecar hook up

sidecar hook up

Post Thu Sep 11, 2008 1:03 pm

Posts: 184
Location: Naples, Florida
Trying to hook up sidecar to 47fl. Question, do you have to remove gas tanks to install upper frame clamp assembly? It's pretty fricking tight in there!

Post Thu Sep 11, 2008 1:14 pm

Posts: 2688
Location: Los Angeles, CA
It all fits in easily without removing the tanks.

Post Thu Sep 11, 2008 3:47 pm

Posts: 184
Location: Naples, Florida
Thanks Chris, I just started looking at it this morning and I wasn't sure.

Post Thu Sep 18, 2008 8:34 pm

Posts: 184
Location: Naples, Florida
So I got the frame attached to the bike, had to remove the left tank to get the upper clamp on, with the tank off it was a piece of cake. I decided to take it for a test ride before i mounted the body which is a 50's carnival ride rocket ship. WOW, i've been riding my knuckles for almost forty years and thought i was a fairly good rider, but this rig almost had me shitting my pants. All over the road, I felt like i was going to tip over to the left and i never got out of first gear! Whats the deal? Does it need the weight of a body on the frame? Is there a site i can go to to help me out here? It looks like the only adjustment i have is lean of the bike toward or away from sidecar with the clamps on the brace bar. Any help or comments would be appreciated before i kill myself or innoncent bystanders.

Post Thu Sep 18, 2008 9:59 pm

Posts: 89
Location: Wisconsin USA
Sidecars suck! They take the fun out of a motorcycle. I saved one from years ago that I used to use in the winter. It will only go on someday if I get to feeble to hold my bike up. Make sure you set it up by the manual. It is important that the bike tips from the sidecar as stated in the manual but it will still suck and not want to turn. It will stay down better with the body on as it needs the weight. I use to run just a frame for riding on the lakes in the winter but strapped an anvil out by tthe wheel to hold it down.


Post Fri Sep 19, 2008 8:14 am

Posts: 3159
Location: Central Illinois, USA

Tighten your steering damper as tight as possible, and then a little more.

Make certain that the hack wheel toes in toward the front of the machine.
(The bike and hack should lean away from each other slightly, until riders and passengers are added.)

Drop the airpressure in all tires.

Sidehacks are enormous fun. But you have to love the absurd.


Post Fri Sep 19, 2008 12:58 pm

Posts: 62
Location: Texas' Big Bend country
Howdy Brad,

First, let me state that I have never set up a H-D sidecar with 3-point mounting; I sure there are probably folks reading this forum who have. However, the basic principles should apply.

That said, I have been running sidecar rigs on /2 Beemers for 30 years and presently have a Russian Ural military-style sidecar on my 2002 Victory V92C. My wife and I rode it from West Texas to San Diego and up the coast to Seattle and back a couple of summers ago. I have also set 4-point mounted side cars up on a variety of bikes for people when I owned a bike shop. Sidecar outfits handle weirdly but predictably when set up right. They have to be properly aligned, just like the front end on your car, if they are to handle well.

Park the outfit on a level cement slab and get a long straight-edge, say a straight piece of angle iron, long enough to make full contact along the sides of both motorcycle wheels. Draw a chalk line on the floor along this straight edge with the straight edge flush against both front and rear wheels on the sidcar side. Draw another line perpendicular to the straight edge in line with the bike's front and rear axles. The sidecar axle should be positioned 6 to 10 inches ahead of the motorcycle rear axle.

Next, place the straight edge along the side of the sidecar tire and draw a chalk line forward until it is even with the motorcycle's front axle. Measure the distance between the two chalk lines at the motorcycle rear axle to the new line. Then measure between the lines at the motorcycle's front axle. There should be 1/2 to 1 inch of toe-in, that is the front axle line should be 1/2 to 1 inch shorter than the rear.

Finally set the lean-out between the motorcycle and sidecar by adjusting the top mount or mounts. This is kind of trial and error. A solid-mounted sidecar that does not have provisions for adjusting lean-out on the fly is set up at something of a compromise; you want it to track straight at the speed you ride most of the time. Just keep fiddling with the lean-out until it tracks straight at 60 mph on a level road, if that is your usual cruising speed. Above or below that ideal speed it will pull slightly to one side or the other. A high crown on the road or a crosswind will also cause it to pull.

That's what I mean about it handling weirdly. You can never just take your hands off the bars while running down the road, the rig will always pull slightly to one side or the other. With wide bars and a correctly aligned rig the pull will be slight and easily compensated for. As Cotton said, a tight steering damper is a big help. The front forks may tend to waggle some at low speeds but should stop as speed increases. Weight in the sidecar helps with stability. A heavy steel-bodied sidecar like the Ural does not usually need ballast, but some of the fiberglass and plastic-bodied cars are tippy without a passenger and may need a sandbag or some bags of lead shot. It is possible to flip a properly set up rig, but you have to work at it. I think they are a lot more stable than a trike.

Because the drive wheel is off-center and you have all of the weight and mass of the sidecar off to one side, the outfit will pull to the right, with a right-hand mounted sidecar, when accelerating, and to the left when slowing. This is very predictable and can be used, with experience, to set the rig up for turns. When turning right, blip the throttle as you enter the turn and the rig will whip around to the right. Turning left, cut the throttle and tap the brake and the rig will wheel left.

I love sidecars. They are kind of Weird-Alice and not for everyone, but they are great for hauling parts, groceries, kids , and dogs. On a sidecar rig dirt roads, mud, or ice hold no fear. When my stepson was 9 his mother and I took him to Disneyland from Texas with all three of us on the sidecar rig. Really turned heads on Sunset Blvd! When you show up on a sidecar rig, folks act like the circus just came to town; you almost always get a smile. Once we pulled up at a motel in Santa Fe with an old Beemer outfit. The 60ish German lady at the desk was staring out the window as we came in. "Ach!" She said, "It reminds me uff der var!"

Hope this helps --- Randall

Post Fri Sep 19, 2008 2:57 pm

Posts: 184
Location: Naples, Florida
Thanks for all the advice! I will try to absorb it all and try each step carefully. I will not try to ride it again until i get the body mounted and then i think i will throw in a few sand bags for weight. Bob, I'm glad i have plenty of other two wheelers so i'm not ruining my fun. Cotten, how do you adjust toe-in of the sidecar wheel? Shim the mounts? All i see is to loosen clamps on big s-bar to adjust lean out of sidecar relative to bike. I'm doing this all for the kid, so he better like it!

Post Sat Sep 20, 2008 10:02 pm

Posts: 184
Location: Naples, Florida
Randall, with this stock knuckle sidecar frame the sidecar axle is 4.5 inches forward of the bikes rear axle. There really is no easy way to change that. I should be able to add flat washers as shims behind the rear flange where it mounts to the axle stay on the frame to add some toe-in if needed. I will mark chalk lines on my shop floor and see where i stand. Thanks for the detailed set up instructions. Brad.

Post Sat Sep 20, 2008 11:44 pm

Posts: 2688
Location: Los Angeles, CA
And be sure that you have the rear mount correctly installed. It does not bolt directly to the frame. The mounting bolts come in from the backside of the frame. Nuts hold the bolts on place. Then the mount is attached and more nuts hold it im place.

Post Sun Sep 21, 2008 7:03 am

Posts: 184
Location: Naples, Florida
Thanks for the tip Chris. I wondered why those bolts were so long. I don't have the nuts between the sidecar and bike frame. With those missing the bracket is almost against the frame and is probably giving me toe-out of the sidecar wheel. That might explain why i was all over the road! Will set it up correctly and mount the body this week with a couple of sandbags for ballast and give it another run.

Post Tue Sep 23, 2008 1:26 pm

Posts: 66
I'm sorry, but you can't casually mention that your sidecar body is a 50's carny ride rocket, and not give us a picture!

Post Tue Sep 23, 2008 6:38 pm

Posts: 184
Location: Naples, Florida
I'll gladly e-mail photo to someone who will post it here for me. I don't know how to myself. The good news is I had 1/2 inch of toe-out. Probably why it was all over the road. Corrected that by installing the nuts between bike frame and mounting bracket at rear axle stay as Chris's photo shows. Now have 1/2 inch toe-in. Am now in the process of attaching the body to frame. Will put a couple of sandbags in for ballast and take for another test ride in a few days.

Return to Knuckles