This winter I am going to install a Steerite-modified triple-tree on my K75C/Dauntless rig. By reducing the 'trail' on the front wheel I hope to make the steering easier.
Right now the rig has about 5/8" of toe-in and about 2 degrees of lean-out, which seems to be a popular and recommended setup. Steering requires effort, but isn't brutal. I can ride all day and not have muscle-aches in the morning.
But handling, and especially emergency handling, is worrisome. I've had some Ex-Lax moments under heavy braking. I'm going for reduced 'trail' more to improve handling than to reduce steering effort.
As I understand it the whole business about creating toe-in and lean-out is also to reduce the steering effort. But toe-in definitely increases tire wear, and probably affects handling, by making the sidecar wheel 'push' sideways against the bike. And I suspect that lean-out also has an impact on tire wear and handling by making the bike constantly want to turn left.
I'm wondering if, with the Steerite mod, I can set the toe-in and lean-out back to zero, or at least reduce them. Having the tires fighting each other seems to me, at root, to be a bad idea. If I can go to a neutral setup and just use the improved steering to counter the natural tendency of the rig to turn right due to aero drag on the sidecar, it seems like a better solution.
Anybody have some experience with this? Has anyone tried reduced or zero toe-in and lean-out after reducing the trail on their front wheel?
Best,
Ed Bianchi
'87 K75C/Dauntless "Lady Carol"
It is my understanding that the Dauntless triple tree modification increases trail.
Phelonius
The DMC sold steering mods decrease trail. How much depends upon the mfg'r. and type of changes.
Lonnie
You may be disappointed in your expectations of your steering mod. Reduced trail means quicker steering which often feels like the rig is darting about until you get used to it, loosen up and don't over correct.
You may be able to reduce your toe-in and lean-out, but if the set up is what is bothering you, you may find you can do that even with out the steering mod.
You should also consider that changing the steering geometry by reducing the trail slightly will not change the fact that you are scrubbing your tires when you corner. It is the nature of the beast for the sidecar and bike tires to push against each other in turns as they describe different arcs through the corner. This is a function of your wheelbase, width and sidecar wheel lead and is not going to change appreciably when you reduce your trail, although it may feel like it has changed.
Toe-in and lean-out do reduce effort and toe-out can make turning away from the sidecar(left) very difficult, but toe-in primarily is used like cambering a car wheel, and lean-out is primarily useful to improve straight line tracking, countering both road crown and the drag towards the sidecar. You should set the toe in as near zero as is practical - most rigs these days are set up between 1/2" and 3/4" . Lean-out can vary considerably and will vary by rig, driver, speeds and road crown. It is rare to get a rig back from a shop and not find room for improvement in the set up. This is normal and no reflection on the shop as set up is a very subjective thing. You should play with it and see what works best for you.
Steering modifications make steering easier and sometimes affect steering wobble. They can be a wonderful upgrade in terms of making the rig more pleasant to ride and increasing the distance you can comfortably travel. Because they reduce steering effort you may be able to modify your alignment, although probably not to zero. But your "ex-lax moments" are better addressed by taking a class, practice and getting some seat time. You may find reduced steering makes things happen quicker and requires more attention and better technique.
Have fun, be careful and practice, practice, practice!
I went to zero lean and less toe-in on my rig ..... having a van tire on rear wheel and sidecar came with a wide car tire ..... I have better tire wear and rig tracks good .... will put car tire on front wheel next year ..... why waste money on M/C tires?? ..... MHO ......
increased RAKE results in decreased TRAIL - folks get those reversed. for a trike you want less trail and thus more rake in the TREES not the neck.
reducing trail on a heavy rig wont make it dart around - wives tale - well unless you go to zero trail... but anything over a inch and a half just drives better.
reducing trail on a heavy rig will make steering lighter
reducing trail on a heavy rig will make emergency response safer and gets rid of bump steer altogether
the ONLY disadvantage to less trail is that it makes it unwise to ride the bike as a solo bike - some can and do do it - not me.
timo482 - 12/27/2010 11:10 AM
reducing trail on a heavy rig wont make it dart around - wives tale - well unless you go to zero trail... but anything over a inch and a half just drives better.
It is no wives tail. That is what reduced trail does and why it reduces steering effort: reduced trail=quicker steering. Quicker steering can feel like the rig is darting around, particularly if you are tense at the handlebars. A death grip and locked elbows magnify steering input both intentional and unintentional, which also feels like imprecise control. A change in riding style will correct this.
If the original poster is having exlax moments, reducing trail is unlikely to improve that, but it will have a number of other benefits, as you point out.
If his alignment is that far out, adjusting that will help. Tire pressure and wear can also make a difference. Otherwise exlax moments are
most often a result of technique and apprehension. Training and practice are the best cures for that.
RedMenace - 12/28/2010 9:20 AM
timo482 - 12/27/2010 11:10 AM
reducing trail on a heavy rig wont make it dart around - wives tale - well unless you go to zero trail... but anything over a inch and a half just drives better.It is no wives tail. That is what reduced trail does and why it reduces steering effort: reduced trail=quicker steering. Quicker steering can feel like the rig is darting around, particularly if you are tense at the handlebars. A death grip and locked elbows magnify steering input both intentional and unintentional, which also feels like imprecise control. A change in riding style will correct this.
If the original poster is having exlax moments, reducing trail is unlikely to improve that, but it will have a number of other benefits, as you point out.
If his alignment is that far out, adjusting that will help. Tire pressure and wear can also make a difference. Otherwise exlax moments are
most often a result of technique and apprehension. Training and practice are the best cures for that.
The smaller the trail the more the outfit may feel like it is darting. Many tend to oversteer an outfit when trail is reduced from stock. It takes some time to get used to the easy steering that reduced trail allows.
True Darting or wandering can, however, be caused by the tire design and/or width of the front tire amomg other things.
WARNING! From time to time a les than good overall setup can be masked by easy steering thet trail reduction creates. Tire wear among other things will indicate a poor setup.
Bump steer can be caused by various things not directly related to reduced or stock trail figures. Poorly mounted steering dampers are sometimes the culprit.
the toe in and lean out have to be right - or at least within reason - no matter what front end is used.
a steering damper really should be installed, but often is not - some just tighten the swing by in the front end. but it cant be just "loose"
all in all a improper set up is a bad thing, a driver who cant drive is a bad thing.
a sidecar with steering that doesn't hurt your wrists at the end of the day and runs straight and true and makes your wife comfortable is a good thing.
Trail for purposes of discussion can be thought of as caster on a car as it provides a self centering effect when underway. The less trail there is the less of this self centering effect is in play. Less self centering translates into easier steering.
If we were to look at the trail numbers on various bikes in stock form we would find that touring bikes have more trail than sport bikes. Why? Touring bikes should provide a stable and easy ride to eat miles. Sport bikes however are designed for the twsities and need what may be called 'flickability' to get through the esses in good fashion.
On a sidecar outfit we reduce trail to provide ease of steering. This is done in various ways. If you go to the sidecar industry council site or sidestrider.com there are some diagrams on how trail is measured. Studying these diagrams will allow one to see what can be done to reduce trail.
Seldom is the steering head angle changed in relation to the stock frame of the bike. The angle may be changed slightly when the front end is lowered though. The term 'raked trees' has created some confusion as this term is not to mean changing the actual steering head angle (rake) at the frame but just to modify or remanufacture the triple trees to move the front wheel forward reducuing trail. More confusion comes about when we talk of variouse degrees of raked trees. Why? The steering head angles of two bikes may not be the same so raking one 6 degrees is not the same as raking the other 6 degrees etc etc.
The less trail there is the less road feel will be present. Some can tolerate less trail than others. Personally I like to feel the road on my own outfits.
Racing outfits may run zero static trail. Just to get an idea of what negative trail is like run a rig up and incline and then coast backwards down it....not coll, no self centering at all.
Just about everything we do has an element of compromose in it. Where to create to best compromise for the conditions is the question.
I PUT A HARLEY SIDECAR ON MY RIDGED FRAME SHOVELHEAD. IT HAD STOCK RAKE WITH STOCK TREES. I MESSED AROUND WITH THE LEAN AND THE TOE, BUT THAT HAS A LIMITED ADJUSTMENT ON OLD HARLEYS. IT WAS HARD STEERING BUT IT WAS OK. THEN I PUT A HARLEY FIXED RACK TRIPPLE TREES USED ON OLD SERVI-CARS. THIS WAS LIKE NIGHT AND DAY. I DON'T HAVE A STEERING DAMPER AND HAVE NO PROBLEM RIDING WITH IT EMPTY. IT IS ACCUALLY HARD TO LIFT THE SIDECAR UP. BEFORE THE TREES IT WAS UP ALL THE TIME. 50 55 IT RUNS NICE AND TRUE.
