Basic sidecar set up?????

[JohnB53]

Hello All, Has been a busy winter so far but I am back on the new to me Sidecar outfit. For those who don't know I have been working on a 1981 650 and a 2003 Velorex 562 this winter. I am working on the subframe now and have a couple questions. 1. The book states the sidecar frame should be 12" from the bike frame. But with a subframe do you still keep the 12" width?. Mine is 12 from the bike frame but only about 8 from the sub frame but has a width of about 48". 2. The book says 8-10 " wheel lead. I am not sure how the lead affect the outfit, what changes from a base of 8 to max of 10? I still have some work to do on the subframe once I get all the basic set up figured out so it may look a little crude now as it is a work in progress and open to change. Thanks JohnB

 

[Jim]

I've been studying sidecars for a few yrs now. Found this info here.
He does some pretty good explaining. http://www.steves-workshop.co.uk/vehicles/bmw/sidecar/sidecaradjustment/sidecaradjustment.html

 

[kshansen]

You will find that everything in sidecars has a double sided effect. Something that helps in one area will probably cause a negative in another area. As someone who has had at least one sidecar on the road since the early 1990's I'm not trying to say they are bad things just facts of the animal.

Assuming you are mounting the sidecar to the right of the bike more lead on the sidecar will make it less likely to nose down when turning to the left, away from sidecar. But as it says in Jim"s post that would be at the expense of increased tire wear. Also more lead will increase the steering effort.

As far as width goes that to is a trade off. More width makes turning toward the sidecar less likely to lift the sidecar but also can have the effect of the drag from sidecar making the outfit to pull more towards the sidecar on a straight road.

One suggestion I would make is to have the lower mounting points at the subframe at the same height or as close as possible to level. Reason for that is when you are adjusting things it will make it easier as leaning the bike in or out will not have any or very little effect on toe in or toe out of the outfit.

With some luck Fred will check in and offer some more ideas. Like changing the forks to reduce the trail on front wheel to make steering lighter.

I have toyed with the idea of putting another sidecar outfit together. As I have a Velorex just sitting out in the barn, not as nice looking as yours and a 1978 XS650 just short of being ready for the road I really don't have any good excuses not to do it. Heck I could even use the mounts I used for over 20 years on the outfit I used for my ride-to-work outfit. But do like the idea of a real sub-frame like you are building better that the separated mounts!

 

[5twins]

With your front clevis mount turned sideways like that, I'm not sure how you will be able to lean the bike away from or towards the car?

 

[kshansen]

With your front clevis mount turned sideways like that, I'm not sure how you will be able to lean the bike away from or towards the car?

Not sure that is even connected to anything at this point.
To me it looks like it is just resting and the top of the front to rear tube of the sub-frame. Hard to be sure from the camera angle!

One point I did not think to add in my last post would be if at all possible I would try to allow clearance for the kick starter to be used. I know it came in very handy on my XS650 outfit. Actually was the primary starter for that one, easier than keeping the electric foot functioning with all the corrosion from road salt!

 

[JohnB53]

Thanks for the comments. The sidecar is just sitting beside the bike. I had just finished tacking the subframe together this weekend and need to get a plan together as to how this sucker is going to get hooked together. It is early and any change needed … now is the time to fix things. Like I said I know nothing about the wild world of sidecars, but I knew nothing of Trikes before I built my VW trike, but I joined BTW and asked a lot of questions of a lot of great people and 12 years and 30,000 miles later it is still putting smiles on my face. I am sure that a sidecar outfit can do the same thing. It looks like I have some reading to do and formulate a plan and go from there.

 

[kshansen]

One more suggestion. On the page you are reading this up near the top in the orange stripe click on "Search Forums" then in the first part type in "sidecar" then in the next section where it says"Posted by Member" type in "fredintoon"

That should give you some reading and you could always send a message to him direct.

 

[JohnB53]

Ok I have what I think is going to be a sturdy subframe . As of now it is just tac welded so changes could be made. As it sits now it has about 10" wheel lead width of 50 1/2". As with all first attempts you find out there is a lot more to it that one thinks. Feel free to offer any insight you may have just be nice as I am old and you might make me cry. Thanks John

 

[5twins]

I'm pretty sure most of the subframes I've seen were just for the lower mounts. I might re-think your upper rear mount, attaching it directly to the bike frame instead. And the car looks pretty far away from the bike. I think you're over-complicating the whole thing. That's quite the massive subframe and could probably be reduced in size quite a bit, also tucked under the bike more to pull the sidecar in closer.

 

[fredintoon]

Hi John,
eff me, that's a complicated attachment, eh?
but WTF, sidecar attachment ain't a science, it's an artform. What you have WILL work , and none of the measurements are set in stone.
Harley rigs, for instance, have their SCW lead set at 3" for rigid frame & 6" for rear suspended bikes and Harley sidecar wheels don't have suspension.
Some reckon that Harley sidecar setup measurements have theoretical advantages. Others say they're stuck in the 1930s.
So I'd say weld her up solid and give her a test drive.
And if it's your first ever sidecar ride REMEMBER it ain't a bike no more, it only looks like one.
Solos MUST lean over to corner and the first thing you do to turn left is to countersteer by twitching the bars right to tilt the bike left.
Sidecars CAN'T countersteer. Twitch a sidecar rig's bars right and it'll turn right. Into the far ditch if you are lucky. Into an oncoming truck if you ain't.
I'd advise driving your sidecar rig slowly and carefully to a deserted parking lot and do low speed circles and figure 8s until you get used to how it steers.

 

[JohnB53]

I'm pretty sure most of the subframes I've seen were just for the lower mounts. I might re-think your upper rear mount, attaching it directly to the bike frame instead. And the car looks pretty far away from the bike. I think you're over-complicating the whole thing. That's quite the massive subframe and could probably be reduced in size quite a bit, also tucked under the bike more to pull the sidecar in closer.

I'm pretty sure most of the subframes I've seen were just for the lower mounts. I might re-think your upper rear mount, attaching it directly to the bike frame instead. And the car looks pretty far away from the bike. I think you're over-complicating the whole thing. That's quite the massive subframe and could probably be reduced in size quite a bit, also tucked under the bike more to pull the sidecar in closer.

I'm pretty sure most of the subframes I've seen were just for the lower mounts. I might re-think your upper rear mount, attaching it directly to the bike frame instead. And the car looks pretty far away from the bike. I think you're over-complicating the whole thing. That's quite the massive subframe and could probably be reduced in size quite a bit, also tucked under the bike more to pull the sidecar in closer.

Thanks for the input 5twins Most of what I have done is not to destroy the bike or frame. The bike is a one owner with 8200 miles on it and I want to be able to unbolt and return to stock if I choose to. And yes it is stout. I think most homebuilders tend to overbuild .

 

[JohnB53]

Hi John,
eff me, that's a complicated attachment, eh?
but WTF, sidecar attachment ain't a science, it's an artform. What you have WILL work , and none of the measurements are set in stone.
Harley rigs, for instance, have their SCW lead set at 3" for rigid frame & 6" for rear suspended bikes and Harley sidecar wheels don't have suspension.
Some reckon that Harley sidecar setup measurements have theoretical advantages. Others say they're stuck in the 1930s.
So I'd say weld her up solid and give her a test drive.
And if it's your first ever sidecar ride REMEMBER it ain't a bike no more, it only looks like one.
Solos MUST lean over to corner and the first thing you do to turn left is to countersteer by twitching the bars right to tilt the bike left.
Sidecars CAN'T countersteer. Twitch a sidecar rig's bars right and it'll turn right. Into the far ditch if you are lucky. Into an oncoming truck if you ain't.
I'd advise driving your sidecar rig slowly and carefully to a deserted parking lot and do low speed circles and figure 8s until you get used to how it steers.

Thanks Fredintoon and yes there is way more to this subframe building than I ever thought. Not sure I want to do it again . But I didn't want to stick the subframe lower to lessen ground clearance I have a high school not too far from me with a large parking lot to learn the strange driving habits of a sidecar. I had to relearn my VW trike when I built it. So I think I am going to weld it up and get- R - done. John

 

[5twins]

The subframe may be stout bu some of the sidecar attachment points to it don't look as strong. Those blocks that the eyes thread into originally mounted to a frame tube with a piece of plate steel that wrapped around the frame and was bolted to both sides of the block. And then the eye was threaded in until it pressed hard onto the frame tube. This all "clamped" the eye to the frame tube pretty well. You have just one side of your blocks attached to the subframe with the two small bolts. Support for the upper rear mount with a length of strap steel running to the bike doesn't look too stout either.

 

[JohnB53]

The subframe may be stout bu some of the sidecar attachment points to it don't look as strong. Those blocks that the eyes thread into originally mounted to a frame tube with a piece of plate steel that wrapped around the frame and was bolted to both sides of the block. And then the eye was threaded in until it pressed hard onto the frame tube. This all "clamped" the eye to the frame tube pretty well. You have just one side of your blocks attached to the subframe with the two small bolts. Support for the upper rear mount with a length of strap steel running to the bike doesn't look too stout either.

As far as the block it is bolted to a 2 x 3/16 flat stock so I think that is as thick or thicker than the outer clamp . If the bolt size is in question I could drill it up a size for more strength . The rear strap is also reinforced on the back side with 1/8" thick 1/2 " angle iron that with the subframe I would think should b as strong as a frame clamp. But then I am no engineer either

 

[5twins]

The point I was trying to make about the eye blocks is they were originally supported on both sides with plate. You have them mounted against and supported by one side only. I would be concerned about the car trying to bend the block back. I think I might make a channel to fit the block into. Then it would be supported on both sides and you could also screw the eye in tight against the bottom of the channel.

 

[fredintoon]

Thanks Fredintoon and yes there is way more to this subframe building than I ever thought. Not sure I want to do it again . But I didn't want to stick the subframe lower to lessen ground clearance I have a high school not too far from me with a large parking lot to learn the strange driving habits of a sidecar. I had to relearn my VW trike when I built it. So I think I am going to weld it up and get- R - done. John

Hi John,
don't quit now, your next sidecar build will be WAY easier, eh?
My builds did anyway, the latest (#6) transferred my SofA sidecar back onto my XS650 and kinda built itself.
And yes, adequate ground clearance is always a good thing.
Your trike experience will have taught you some things about steering a rig but you still have to master a rig's asymmetric handling.
Hard acceleration will turn you right and hard braking will turn you left unless the rig has a sidecar-wheel brake.
OTOH a separately operated sidecar brake can deke a rig hard right real quick unless the sidecar wheel is already lifted.

 

[JohnB53]

The point I was trying to make about the eye blocks is they were originally supported on both sides with plate. You have them mounted against and supported by one side only. I would be concerned about the car trying to bend the block back. I think I might make a channel to fit the block into. Then it would be supported on both sides and you could also screw the eye in tight against the bottom of the channel.

Ok I understand adding another side to make it stronger, but why the need to tighten the eyebolt. Wouldn't that lessen adjustability to a point, And would I really gain that much more strength?

 

[5twins]

It gives sort of a 3 point mount, both sides and pressing out from the back side. Have you ever seen an original? Google "Velorex Universal frame eye mount" for pics. They also sell eyes that will just bolt through holes in heavy plate.

 

[JohnB53]

It gives sort of a 3 point mount, both sides and pressing out from the back side. Have you ever seen an original? Google "Velorex Universal frame eye mount" for pics. They also sell eyes that will just bolt through holes in heavy plate.

Yes I have the original velorex clamps but I don't have a open spot on the front part of the frame. The side marker reflector is in the way so that was the need for the custom mount. But on the original you need to tighten the I boltto keep the bracket from sliding down the tube and I don't have that need on my bracket. I do see that I may have to shim behind the I bolt as if it isn't tight the threads are a little sloppy. But other than that I do think it should work.There is also a 3/8" u bolt clamp on the other down tube just to keep it tighter no side to side movement

 

[5twins]

Well, it looks like you're gonna do what you're gonna do no matter what I say, so have at it, lol. Just make sure your life insurance is paid up, lol. I'll admit, it's been some time since I had my Velorex, but I put it to good use when I did. I drove the rig cross country and back with no issues (other than running out of gas a couple times, lol). Sidecars exert heavy side loads on the bike frame, both pulling away and pushing against it, when you go through turns. The subframes they started coming out with was a way to help deal with this. Most modern bike frames weren't designed for sidecar use. Your subframe certainly is heavy duty but those two top mounts just look weak to me. The struts may bend them right back on their 2 bolt mounts.