Forum

[Beezabryan]

My Flash & a Box keeps a straight line on neutral throttle, handles equally well on UK and European roads whether or not fully freighted.
Although there is a basic configuration for attaching a sidecar chassis to a motorbicycle frame there are too many variables involved to have absolutes.
I suspect you are correct Jeffers when you say "It's rather a long time since I've set up a chair."

[jefrs]

The idea /is/ that yours or any other combo keeps a straight line on neutral throttle, which is why there is a fancy bike/chair alignment.

The toe of the chair and the lean on the bike pushes the bike rear out so it needs a little offset, otherwise your bike would go round in circles. Back in the day we completely stripped and rebuilt quite a few old combos, I distinctly remember the Squariel with a chair the size of a Pullman dining car; Red Hunter, Panther, BSA Sloper, etc etc, a long list.

And this is why I suggested contacting Watsonian for correct alignment on their Squire chair.

[papasmurf]

Fitting a sidecar is a black art. However a differential in clearance of the wheel and mudguard does suggest a basic problem unrelated to sidecar setup. Is it possible to detect ANY movement horizontally or vertically in the wheel manually. Has a spacer been left out. Are any/all of the pivot point bushes/rubber mounts knackered.
As far setting a side car, it should be set up with the outfit carrying the weight it is most likely to be used with.
(On our outfits I use bags of coal, to set up the sidecars.)
There are vast differences from outfit to outfit. Lead in of side car wheel from rear wheel of motorcycle is different. Lean out depending on wheel/tyres used can be from zero for car type wheels and tyres to one and half inches for motorcycle tyres.
Toe in varies due to length of wheel base of motorcycle, and lead in of sidecar wheel. For instance the toe-in on our CX500 and Velorex sidecar is 7/8ths of an inch, on the K75S and Squire ST1 sidecar it is 1 and a 1/4 inches.

[Beezabryan]

Different days, different types of sidecar, vastly different roads from back in the days of BSA Slopers etc and rather different tyres.
As PapaS' says nailing together a motorbicycle and a sidecar chassis is a black art with little science involvement.
But all this has nothing to do with the original query, where I am inclined to agree with BW. Practicality beats theory

[jefrs]

I still think the rubbing is probably due to mudguard misalignment (which is where BW and I started) but something Papasmurf said re spacer missing - the EFI does have a spacer on the brake plate which if left out would move the wheel over to the right. I have offered up the brake plate with the spacer missing but it seems obvious that something is wrong and play hunt the washer.