I’ve heard it said quite often that toe-in should be ¾ to 1”. Some have said ½ to ¾”. It’s a fact that too much toe-in will cause excessive wear on the rear tire of the MC. Why isn’t toe-in set between 1/8 to 3/8” thus causing even less rear tire wear? Then adjust the lean-out until neutral steering. IMO, there are 3 things that are most important to setting up a rig – toe-in, lean-out, & leveling the sidecar frame (left to right & front to rear.
The numbers quoted are just toe-in measurements that have worked for one (or more) bike/sidecar combinations. There is no standard here as some use a 10' measuring point and another may use a wheelbase measuring point. Obviously the same actual toe-in numbers would vary greatly using these different parameters. In your own post you neglected to mention how and where you were measuring to get your toe-in numbers.
Since wheelbases and track widths vary considerably from rig to rig the best option is to use the 1/4" 10 1" (or something in between) toe-in measurement for an index point when mounting the sidecar. Using the same measurement positions, after a trial run you can reduce or increase the toe-in in conjunction with adjusting lean-out by small increments, as needed to achieve neutral steering and even tire wear.
The toe-in and lean-out are rarely spot on with the first alignment figures and will need tweaking to achieve neutral steering on the roads most travelled, with the least tire wear.
BTDT a lot,
Lonnie
Northwest Sidecars
Like lonnie alluded to we discuss numbers regarding toe in but rarely are we really comparing apples to apples. Same goes with other adjustmens also.
I like to think of lean out as the thing that allows straigth tracking and toe in as something that keeps th ebearing loaded and possibly keeps wondering to a minimum. Some may disagree.
Fact is that too much toe in will make for terrible tire wear.
Fact is that a rig with too much toe in can handle very well and possibly give no immedaite indication of a problem.
Fact is that lean out adjustments will make a rig track better or worse.
Toe in? Play with it and see what the results are. We typically run less than 3/4" on most rigs.
Note that wide tired HPS rigs may run a lot of toe in due to running no leanout to speak of. This is the exception rather and the rule with conventional rigs.
We have seen rigs that had a narrow sidecar tire and a larger tire on th eback wear out the sidecar tire early on. This is ntoi th enorm but it can happen. I suppose th etraction the wider bike tire has just overpowers the small tire on the sidecar?
Tell you the truth I really do not understand toe in that well. If a rig handles well. is stable and does not eat tires it is in pretty good shape.
Play with toe in. Learn to read tire wear patternes and have fun.
Along with the usually absent information about how toe-in is measured, sidecar traction is also overlooked in most discussions of toe-in.
A lightly loaded sidecar with a thin hard tire on a heavy bike with a high traction bike tire will have a minimal impact on rear tire wear due to toe-in settings. The sidecar will not generate enough traction to cause significant crabbing of the rig as it travels down the road.
A heavy sidecar with a high traction tire and a passenger on a lighter bike will have substantially more input from toe-in settings to rear bike tire wear as it will push the rear tire of the bike sideways and cause considerable crabbing as you travel down the road.
This "crabbing" happens as the rear tire of the bike and the sidecar tire split the difference of the toe-in setting as the sidecar toe-in pushes the bike tire sidways from it's desired track behind the front tire. How this difference is split depends on the traction ratio between the sidecar and the bike. This phenomina helps explain why some rigs with excessive toe-in don't exhibit the excessive tire wear you would expect, while other rigs with similar numbers that seem the same do exhibit the expected excessive rear tire wear.
Originally written by Hack'n on 5/9/2008 2:11 PM
In your own post you neglected to mention how and where you were measuring to get your toe-in numbers.BTDT a lot,
Lonnie
Northwest Sidecars
I've used the wheelbase on the two rigs I own now.
