Sidecar shock

Doug,
Talk to Doug Bingham if you haven;t already. You coudl use another shock (longer)if you added a shock mount farther forward on the frame tube. Do not weld too close to any of th ewatsonian fittings as the frames are brazed together.

Doug Bingham will give me the phone # for Watsonian as he doesn't stock parts. I have a gift certificate for Works shocks , trying to keep it economical. Seems like no one knows what I am asking. Doug in Mesa AZ.

Wouldn't hurt to call Works.
Spring rates can be deceiving in that you have a bell crank arrangement working on the shock when installed.
A spring raste of say 150 pounds will gain rate as it compresses. This means that the 150 initial spring rate which may be rated at 1" compression will go up another 150 as it compresses another inch...this is with a straight wound spring. Progressively wound springs are another story as they have some coils close together and some farther apart. The close together coils are soft but when they enter into coil bind or reach a certain spot when compressed then the other coils take over.
If you have a shock that will fit maybe try it and see what happens.
Another thing you coudl do is if there are any race car shops around you they may have a spring checker. This would tell you what you have now and give you a better idea of where yopu may want to go from there.
Sorry for what may seem to be a stupid answer.

Thank you for responding, what you said sort of makes sense to me. My shock is probably 30 years old , as is the sidecar ,and I have put on about 62000 miles on it in the past6 years. Who knows how many miles it had before I got it. How do the sidecar manufacturers determine what size shock to use on there sidecars ? Doug in AZ.

Originally written by Doug Hasert on 10/13/2007 4:32 PM

Thank you for responding, what you said sort of makes sense to me. My shock is probably 30 years old , as is the sidecar ,and I have put on about 62000 miles on it in the past6 years. Who knows how many miles it had before I got it. How do the sidecar manufacturers determine what size shock to use on there sidecars ? Doug in AZ.

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I woudl contact the shock manufacturer of choice. Have as many specs as you can at hand including the design of the swingarm itself. I recentlywent through this with one we are building and the spring rate I thought would be right was nowhere near being in the ballpark.When a swingarm has a bellcrank type assembly on it to mount the shock all of thast shoudl be considered. Mine had a ton of leverage working on it when the suspenion went into bump and very little actual shock travel. This was not the best design but woudl work with a very stiff shock. The stock watsonian isn't that radical though. Progressive seems to be the manufacturer of choice among most sidecar builders today. I would think they could help you out if you want to go to the source or you can just expeiment as mentioned previously. You coudl also contact Dauntless or soemone and probably get a shock from them that could be adapted. Again, that mount on th eframe can be redone for a longer shock if need be. On ours we built a new shock mount and incorporated a n adjustment into it to allow the tilt of the rig to be changed easily if desired. Keep in mind that a shock when laid pretty flat shoudl be a gas shock.I din;t know that years back when we did our conversion and the regular shock that was put on did seem to work pretty good to us. But then again they say bumble bees can;t fly 🙂

I just went through this on my Dneper. I found a Dneper source that had new Russan shocks for about $170 plus shipping. I can't see spending that much on such a low quality item. My old shock disassembled itself inside. I found some Honda shocks that measured out right and put the Dneper coil spring on the Honda shock. Cost about $40 and a couple of hours. Coincidentally, the new shocks measured 11.5 inches eye to eye. You are right about motorcycle springs not being stiff enough. The Honda spring wouldn't even hold the weight of the empty sidecar.

Originally written by Mark in Idaho on 10/14/2007 10:00 PM

I just went through this on my Dneper. I found a Dneper source that had new Russan shocks for about $170 plus shipping. I can't see spending that much on such a low quality item. My old shock disassembled itself inside. I found some Honda shocks that measured out right and put the Dneper coil spring on the Honda shock. Cost about $40 and a couple of hours. Coincidentally, the new shocks measured 11.5 inches eye to eye. You are right about motorcycle springs not being stiff enough. The Honda spring wouldn't even hold the weight of the empty sidecar.

What model Honda?

I have never tryed this on a sidecar shock but just a thought, what about adding coil spring spacers? Maybe it would beef it up a little. I had to do it on a car one time when I changed from a 350 to a 400 engine. I know this is a whole different ballgame. I may try it myself to see.

Mike,
The bike I ride is an 83 GL650 Silverwing. The shocks I bought came off an 84 Magna. I chose this shock because the seller stated the distance between the mounting eye as being 11.5 inches and they were cheap. I had to cut down the top eye to fit the shock hanger on the car and make an adapter connect the lower eye to the swing arm.

Originally written by xs1100sgman on 10/15/2007 8:56 AM

I have never tryed this on a sidecar shock but just a thought, what about adding coil spring spacers? Maybe it would beef it up a little. I had to do it on a car one time when I changed from a 350 to a 400 engine. I know this is a whole different ballgame. I may try it myself to see.

I have done this and it does make a difference. There are different types of course and some work better than others. The twist in inserts work okay if you can get them in.
I have also bound two coils together to increase overall spring rate. No need to cringe it works okay...lol.
The best thing I have found, if the shock is one that can be taken apart, is a rubber bumper that slips over the shaft of th eshock. These can be had through stock car products online and come in different degrees of hardness. The shock will compress to a certain place and then the rig actually rides on the rubber bumper.
Shade tree engineering can work quite well actually. Of course you won't get a facy decal to put on your rig and will not be abel to enter into the discussions about how much you spent on high end shocks but if the rig handles well and is consistant who cares.
Kinda in the realm of saying "when the green flag drops the BS stops"...lol
Hey if the 350 and 400 were both small blocks there shoudl have been little issue with the springs...oh well.:-)

I recetved a reply from Watsonian. They use a shock with a spring rate of 100 lb/inch. I now have a starting point . Thanks Claude and others for the input. Doug

Originally written by claude #3563 on 10/15/2007 9:19 PM

Hey if the 350 and 400 were both small blocks there shoudl have been little issue with the springs...oh well.:-)

Hi Claude,Less than a quarter mile down the road on my 1st run with the engine change I hit a dip in the road and bottomed out. I think the coil springs were already worn out, not sure. I like the idea of the rubber pad at the bottom of the shock shaft, I think I will check into this myself, should like it should work pretty good, thanks.