So I need some help

[cleatusj]

Finding some leading lower legs could help reduce trail.

[D.Bachtel]

Just a guess but with 92% of your wheelbase hanging out there on the end you may have the tub pushing the tug around.
That's a pretty heavy wing (with a fuel cell) to be throwing on a fairly light fuselage.

I dunno, seems to me when your lateral almost equals your longitudal things could get squirrely.


Don in Nipomo

[MGV8]

Again thanks for the ideas
I may have been a bit off on some of my dimensions. Between measuring, changing and riding, then posting here, a few numbers got skewed. My track is actually "about 50 inches", it changes with the toe I set. I have a lead of 9.5 inches give or take an 1/8th My wheel base is 58.75 inches which puts the lead any where between 8 3/4 and 11 3/4 if my math is correct I picked 9.5 to start with ( guessing) but didn't really build in any adjustment. My bad. I didn't even think that the head shake would be an issue just pulling or turning issues. I did notice in my circles I did out front of the house. ( the Neighbours get quite a kick out of me, MGB testing you realize) That it really changed how the unit felt after each change, kind of what I expected to deal with. (Notice how the name has changed to Unit) I was quite careful to make sure the Car frame and wheel were level and vertical after each change I made. I have re-thought my mounts and can invest a bit more time in this project before I give up, ( It took 20 years with the Old MGB before we broke the hill record where we run ) Unless I find the perfect GS in the next week or so Then I will bundle the whole shabang up and take it to some one who knows what they are doing. Baring that I will also plan on a steering dampener. I believe that the car is pushing the tug around and due to the lightness of the bike, there is just no mass to counter act this action, with the trail of the bike also reacting to the push of the car. It just becomes more than I can control. Can you say Shopping cart.
Thanks for the offer Jay I may be in touch. I also took all the ASE levels, no real need for me as I am a Red Seal Mechanic here in Canada but it was offered and I wanted to test my self. And Yes the B GT is quite a beast, 450 hp in a 2200 lb chassis, No head shake but the rear wants to pass the front when you get on the gas
Brian

[XL-erate]

One other thing you might want to consider in the equation, Brian: many people have claimed somewhat amazing differences in handling and shake by juggling tire pressures. A major change higher followed by a similar amount of change to lower pressures may be worth looking into. In any event, the higher pressure on bike front tire may make steering lighter. Also there's 3 tires to play with independently so that broadens the possibilities.

[MGV8]

Originally Posted by XL-erate

One other thing you might want to consider in the equation, Brian: many people have claimed somewhat amazing differences in handling and shake by juggling tire pressures. A major change higher followed by a similar amount of change to lower pressures may be worth looking into. In any event, the higher pressure on bike front tire may make steering lighter. Also there's 3 tires to play with independently so that broadens the possibilities.

Thanks I have read that but didn't think to try it. Caught up in the mechanical aspect. Speaking of which, what year, type of VW does the dampener come from, I am assuming older beetle. Year?? 90 degree plain from the fork?? I was also thinking, even though I have jumped on, tugged, pushed etc. my mounts on the bike, that flex there could be a culprit. I do have them separately built and they are solid to look at but once the force of the car is against them. hmmm so many things to think about, finding it a bit of a fun exercise but it is taking a bit too much of my time.
Brian

[RVDan]

check your rear wheel alignment, it probably wouldn't cause head shake but it would mess with steering.

[hahnda]

I have taken wobble out of rigs by adding a couple inches to the lead but that was on rigs where the lead was already on the short side, 4 or 5 inches. You are already over 9 so you are there.

Is the wobble only at low speeds? I assume that since you are in the testing stage you might not have had it up to speed yet? Many times rigs will have a low speed wobble but goes away above 10-15 mph.

You said you checked your steering bearings but have you tried overtightening them so they drag a bit?

When it comes down to it sometimes you just need to install a steering damper. I prefer to mount them from the front sidecar strut to the triple tree or a part of the fork that doesn't move up and down when the suspension cycles if possible. It is possible to mount them to the fork lower but I would try not to.

How are you measuring your toe-in? Are your mounts nice and solid without any play?

[saintpeter11]

RVDan suggested you check the rear wheel alignment. I concur – mine and many other of the CX650E’s had this problem.

Remember (in years gone by) how we used to string the rear wheel to make sure the chain was properly adjusted? If not, here’s how:-


Set the bike in the vertical position with the front wheel straight. You can’t use the center stand, it will get in the way.

Run a string from a couple of feet ahead of the front wheel all the way around the bike – about 6 inches off the ground - to a couple of feet ahead of the front wheel on the other side.

Pull the string snug and ensure that it just touches the sidewall at the front of rear tire.

At this point the string should be equi – distant from the sidewall of the front tire on both sides. (the front tire is more narrow than the rear tire).

If the rear wheel is cocked (probably to the left) you will see it right away.

I had to put a spacer about 3/32” between the driveshaft housing and the final drive unit.

All the best, Pete in Comox

PS I'll be by your way 2nd or 3rd week in April, on my way to pick up another 650E in Calgary, but don't think I'll have time to stop.

[DavePave]

You DO have to play with these things to get them right.

On mine I used 15% of wheel base for my sidecar wheel lead.

I used a binder strap from the frame through the wheel to simulate me sitting o the bike - made adjustments easier.

Also, after you have adjusted the bike - roll it back and forth before you take another toe-in measurement, often the tires will bind on the floor and readings will be false.

Tire pressures DO effect the adjustments. I ran mine up, which makes the bike steer easier and the adjustments were easier as well.

I'd read all the blogs on set-up - etc..... It took me a few practice adjustments before it all made sense - then I really make some head way..... practice makes perfect.

Mine came out good enough that I do not feel I need leading links nor a dampner.


Good luck.

[FR700]

Originally Posted by DavePave

Mine came out good enough that I do not feel I need leading links nor a dampner.

Heretic

[DavePave]

I'l consider myself excommunicated for an hour or so.....

Off to the basement I go....

[FR700]

Originally Posted by DavePave

I'l consider myself excommunicated for an hour or so.....

Off to the basement I go....

Hell no , come sit over here with me ... I've got beer and bacon sandwiches.

Bought them with the money I saved by not doing steering mod's and damper

[diverdown]

you dont need a steering dampner or a leading link frontend, what you need to do is get your set up right and ride it and learn. I have head shake up to about 20-30 kmh. no big deal does not even spill my coffee I hold in the other hand, its all about getting off the computer and learning to ride the rig.I have had the Hack on for a month now and would not trade it for anything. it is an absalute riot to ride, Thanks Jay from DMC, this Hack Rocks

[davet2]

I have a Volkswagen damper on my Harley rig. Google the part number 113425021J. There are many sources for this part and they are as cheap as $20. I don't know if it would work for you but it might be worth a try.

[Feedback Cycle]

IMHO. You can be stubborn (like me) and suffer through countless adjustment and dangerous test runs and MAYBE find a combination that stops the head shake. Or...

You can be smart (like me)
I bought a fork mounting bracket and a VW beetle dampner for $100 delivered. (eBay) Bolt to the sidcar. Few minutes and or hours.

IT ABSOLUTELY, POSITIVELY, INSTANTLY transformed my hack
I wrote about it here.
http://www.advrider.com/forums/showt...=753576&page=7

Fact is, no one else on this board had the unique bike, sidecar, tire, weight, rider, road combination I had. But My head was shaking violently and that's what dampners are for. It flat works for me.