Hi
Hope some of you sidecar riders can help me out.I am moving my Hitch Hiker car to a /2. It was on a Honda 750 and was attached to the bike with 1/2 inch grade 8 bolts through heavy eyes on strut ends.It was real strong and ridged.So I am not familiar with these ball clamps.I got 2 weldable clamps from Vech.Before I had them welded on the struts I clamped them on bike.It seems no matter how much I tighten them I still can move them and this is without the leverage of the struts or the force of going down the road a 60 mph.I know BMW has been using these clamps like 70 years so I must be missing something.Can anybody straighten me out because I can't see going down the road with a connection point that's anything less than God Almighty strong.
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sidecar attachment
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schrader7032
- Posts: 9038
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Re: sidecar attachment
Welcome to the forum! Others will have some more specific responses. I found some pages on sidecars on Duane Ausherman's site that might be good reading.
https://w6rec.com/eyebolts-sidecar-attachment/
https://w6rec.com/all-models-sidecar-attachment/
https://w6rec.com/bmw-spezial-sidecar/s ... tions-pg1/
https://w6rec.com/bmw-spezial-sidecar/s ... tions-pg2/
One of the attachments on the R69S right side downtube is not a ball joint but is referred to in the first link.
https://w6rec.com/eyebolts-sidecar-attachment/
https://w6rec.com/all-models-sidecar-attachment/
https://w6rec.com/bmw-spezial-sidecar/s ... tions-pg1/
https://w6rec.com/bmw-spezial-sidecar/s ... tions-pg2/
One of the attachments on the R69S right side downtube is not a ball joint but is referred to in the first link.
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.
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Flx48
- Posts: 262
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- Location: NW CT
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Re: sidecar attachment
I've been using my R69/Spezial rig over forty years now, but during that time have only removed and replaced the sidecar perhaps a dozen times or so, with the last R/R probably being 2 or 3 years ago.
The bell does clamp tightly over the ball.
That said, one must at the same time recognize the small size (maybe 1/4" diameter x 3 1/2" long?) of the handle (that turns the bolt that draws the two clamshells into the bell) does not afford a great deal of leverage, so "tight" is a relative thing.
Also recognize the bell and ball joints are, to a certain extent, a hinge joint.
They hold the sidecar and bike together rigidly in two directions: fore and aft as well as in and out, leaving the triangulating braces being responsible for rigidity in that third (hinging) direction.
That you are able to move the ball within the bell after fully tightening, however, suggests that perhaps the clamshells may not be being fully drawn into the bell. (it is the decreasing internal diameter of the bell that squeezes the clamshells tight around the ball)
Not having eyes or hands on the parts involved I hesitate to speculate, but with the information provided would look at why the ball and clamshell halves are possibly not being drawn deeper into the bell.
Best-
George
The bell does clamp tightly over the ball.
That said, one must at the same time recognize the small size (maybe 1/4" diameter x 3 1/2" long?) of the handle (that turns the bolt that draws the two clamshells into the bell) does not afford a great deal of leverage, so "tight" is a relative thing.
Also recognize the bell and ball joints are, to a certain extent, a hinge joint.
They hold the sidecar and bike together rigidly in two directions: fore and aft as well as in and out, leaving the triangulating braces being responsible for rigidity in that third (hinging) direction.
That you are able to move the ball within the bell after fully tightening, however, suggests that perhaps the clamshells may not be being fully drawn into the bell. (it is the decreasing internal diameter of the bell that squeezes the clamshells tight around the ball)
Not having eyes or hands on the parts involved I hesitate to speculate, but with the information provided would look at why the ball and clamshell halves are possibly not being drawn deeper into the bell.
Best-
George
Re: sidecar attachment
thanks George
I tightened the clamp with a long drift and got it as tight as I felt was safe and its not like there was a lot of movement.I was under the impression that all connections had to ridged until I just watched a video from DMC sidecar of installation on a new bike and they used Heim connections through bolted on the 2 lower bike connection points so I guess some movement is OK since those type of connectors are designed to allow movement.I may get a clamp from a different source to make sure that there is no problem with clamp itself.I really don't think there is.
I came up with 2 other issues while setting up and I bet you can clear them up for me
Does it make a difference if the jaws of the clamp are vertical or horizontal ?
Should the clamp mate with ball straight on and not come at it at slight angle up or down or fore and aft?
thanks again
I tightened the clamp with a long drift and got it as tight as I felt was safe and its not like there was a lot of movement.I was under the impression that all connections had to ridged until I just watched a video from DMC sidecar of installation on a new bike and they used Heim connections through bolted on the 2 lower bike connection points so I guess some movement is OK since those type of connectors are designed to allow movement.I may get a clamp from a different source to make sure that there is no problem with clamp itself.I really don't think there is.
I came up with 2 other issues while setting up and I bet you can clear them up for me
Does it make a difference if the jaws of the clamp are vertical or horizontal ?
Should the clamp mate with ball straight on and not come at it at slight angle up or down or fore and aft?
thanks again
Re: sidecar attachment
Hi Slobell,
I'm afraid, without pictures there is a bit of guesswork going on here. I have 3 old BMW with sidecar and all of them have a rock solid connection. The Ball joints tighten up just right and then the 2 braces to the front and under the saddle stabilize the connection. There should not be ANY rattling or loose connection.
So, please, before you go our on the road place some pictures! We want you to be safe.
Klaus
I'm afraid, without pictures there is a bit of guesswork going on here. I have 3 old BMW with sidecar and all of them have a rock solid connection. The Ball joints tighten up just right and then the 2 braces to the front and under the saddle stabilize the connection. There should not be ANY rattling or loose connection.
So, please, before you go our on the road place some pictures! We want you to be safe.
Klaus
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Flx48
- Posts: 262
- Joined: Sun Oct 25, 2020 3:11 pm
- Location: NW CT
- Has thanked: 2 times
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Re: sidecar attachment
"Does it make a difference if the jaws of the clamp are vertical or horizontal?"
The two clamshell halves grasp the ball, encompassing perhaps 80% of the ball's surface area, so my opinion is that the orientation of the two halves is irrelevant, as the halves are in turn encompassed by the bell.
In the case of my rig, I think one set of halves is held at a one to seven o'clock orientation, the other pair at ten to four; so neither are vertical or horizontal, strictly speaking; and this being the setup designed by Steib and endorsed by BMW.
The clamshell halves are held in these positions by the large split pin running through each bell, between the clamshell halves, which in turn prevents the clamshells from rotating within the bell.
And the orientation of the sidecar mounting bells can be changed, for mounting to different makes/models of bikes with the ball mounts having different locations compared to a /2; the bell on mine could be rotated 360 degrees to accommodate different ball mount spacings/heights, meaning the split pin orientation could also end up anywhere on the clock dial.
So my conclusion is no, the orientation does not make a difference, it did not to the manufacturers.
"Should the clamp mate with ball straight on and not come at it at slight angle up or down or fore or aft?"
I guess this is a relativity issue again; one man's straight on is another man's slight angle.
To me, the paramount issues at these connections are: do the clamshell halves seat fully on the ball and, in turn, do the clamshell halves fully seat within the bell.
Once everything is fully seated by the clamshells being drawn fully into the bell, joint integrity is achieved, probably why the design only used the little 3 1/2" handle to draw the connection together.
Once full metal on metal on metal contact has been achieved, one is not going to crush the metal any tighter together with that little handle; it is not like torquing a bolt: there is no stretch to be achieved.
The original design also had a miniature leather belt attached to the hasp end of the little handle, to secure the handle in position, thus preventing rotation of the draw bolt once tightening of the joint is achieved. (I use a very hefty zip tie, the little piece of leather having long rotted away)
The bell and ball joints allow for relatively easy adjustment of camber, toe-in, and body attitude, these adjustments requiring very slight variations of angle of attachment (bike re: chair) at the bell and ball, for each particular combination as the diagonal stays are adjusted/locked in.
So- aiming for a straight on (horizontal/vertical) attachment seems prudent, in an effort to have as full a range of adjustment available as possible.
And again, not having eyes/hands on your project, any thoughts on my part are only speculations, we can only guess at your particular issues given the brief descriptions; so please consider these as pandemic driven musings.
Best-
George
The two clamshell halves grasp the ball, encompassing perhaps 80% of the ball's surface area, so my opinion is that the orientation of the two halves is irrelevant, as the halves are in turn encompassed by the bell.
In the case of my rig, I think one set of halves is held at a one to seven o'clock orientation, the other pair at ten to four; so neither are vertical or horizontal, strictly speaking; and this being the setup designed by Steib and endorsed by BMW.
The clamshell halves are held in these positions by the large split pin running through each bell, between the clamshell halves, which in turn prevents the clamshells from rotating within the bell.
And the orientation of the sidecar mounting bells can be changed, for mounting to different makes/models of bikes with the ball mounts having different locations compared to a /2; the bell on mine could be rotated 360 degrees to accommodate different ball mount spacings/heights, meaning the split pin orientation could also end up anywhere on the clock dial.
So my conclusion is no, the orientation does not make a difference, it did not to the manufacturers.
"Should the clamp mate with ball straight on and not come at it at slight angle up or down or fore or aft?"
I guess this is a relativity issue again; one man's straight on is another man's slight angle.
To me, the paramount issues at these connections are: do the clamshell halves seat fully on the ball and, in turn, do the clamshell halves fully seat within the bell.
Once everything is fully seated by the clamshells being drawn fully into the bell, joint integrity is achieved, probably why the design only used the little 3 1/2" handle to draw the connection together.
Once full metal on metal on metal contact has been achieved, one is not going to crush the metal any tighter together with that little handle; it is not like torquing a bolt: there is no stretch to be achieved.
The original design also had a miniature leather belt attached to the hasp end of the little handle, to secure the handle in position, thus preventing rotation of the draw bolt once tightening of the joint is achieved. (I use a very hefty zip tie, the little piece of leather having long rotted away)
The bell and ball joints allow for relatively easy adjustment of camber, toe-in, and body attitude, these adjustments requiring very slight variations of angle of attachment (bike re: chair) at the bell and ball, for each particular combination as the diagonal stays are adjusted/locked in.
So- aiming for a straight on (horizontal/vertical) attachment seems prudent, in an effort to have as full a range of adjustment available as possible.
And again, not having eyes/hands on your project, any thoughts on my part are only speculations, we can only guess at your particular issues given the brief descriptions; so please consider these as pandemic driven musings.
Best-
George
Re: sidecar attachment
Thanks for taking the time for such a through answer.I got the car aligned and will be bringing the clamps to a welder to have them attached to the struts so there is not anything to show you right now except a side car frame sitting next to a /2. I had been wondering about the reason for the big cotter pin through the bell so you might have saved me some grief when you explained their function. It is pretty cold here in Maine right now and it takes awhile to heat the shop up so progress is on the slow side but I am shooting for spring to have the bike all set up for a side car and the hack clamped on. I guess every side car will have a different toe in,lead and lean out so I am starting with ranges that the manufacturer suggested and after that it just going to be trial and error and probably more trial and more error.
steve
steve