Handling

[Chris Lastinger]

My 45 is a joy to ride at 55mph or less but things get scary with an extra 5 to 15 mph. Iget a (high speed?) shimmy,wobble what ever. Twitch the handle bars just the slightest and it's time to change underware! It will also give me a good wobble coming off the throttle. Iknow I read in one of my service manuals that the damper was supposed to help eliminate wobble but this is scary!

Here is how I'm set up. Servi car springer front with shock absorber and steering damper, no ride control. Timken bearings in neck, new 16" star hub front wheel with Avon tire. Rear wheel is original 16' with rebuilt star hub and Metzler tire. I'm running 18psi front and rear. Any ideas would be really really appreciated since this is one problem that smells like road rash and if memory serves me that stuff hurts! Chris

[cheifrider]

chris, sounds to me like you are runnin an awful low air pressure ,i know with the cokers im runnin they are real stable at 25-28 psi . i also run avons on my 48 wl and my 41 u and they also like this pressure range . the u likes a little more air (heavier?)good luck,tom

[Chris Lastinger]

Handling

I'll give the higher pressure a try. I did some checking yesterday and found that my rockers weren't as tight as I thought.( stupid me for trusting someone else to put things together right). I'm thinking that will probably help some to. Chris

[George Greer]

Hi Chris,

I am breaking in a new top end on my WLA, because the fella that built my engine had the pistons ring gaps on both cylinders almost aligned up in a row!!

Finding that out agravated me to no end!!! ....but I was lucky enough to find NOS front and rear cylinders with fitted pistons in Holland and NOS intake and exaust valves in Berlin.

Nice to know that once I break in the engine, and am able to run it at speed there is a potental "wobble" at over 50mph..I do have the steering damper and fork dampers on it too.

I am running Coker tires at about 38 PSI..

George in Germany

[Rod K]

Chris; If the rockers were'nt as tight as you thought, maybe the

fork neck bearings should be checked also. Prime candidate for

wobble if they are loose. Put the rear stand down, jack the front

fork off the ground. Grab the rear fork legs and see if there is any

front to back play...Rod

[AdminGuy]

I would also check to ensure that the tires are running in-line. ie the correct off-set of the rims and axel spacers.

yes- a tank slapper is usually from neck bearings loose or no steering dampening. I don't think the bike should be dependant upon the dampening to solve alignment problems. It's just a helper to smooth things out- imo. Best of luck.

[George Greer]

So this should be safe enough to ride around 65 MPH with no problems with wobbles IF all checks out fine???

I don't want to run into a dangerous situation with this motorcycle once I am able to run at speed.

Perhaps that's the reason that the military had speed restrictions on them???

George Greer

[AdminGuy]

Personally no. I would correct the problem without the use of a steering dampner at 50mph. It should be smooth.

If she's smooth at 50 then I'd tighten the steering dampner and dial her up a bit. maybe 65.

I think you've got some work to do on her. Keep talking here and we all should be able to help you out with some direction. Alot of variables to sort through.

Did ya check the neck bearings?

[Chris Lastinger]

Handling

Thanks loads guys! Uped the air pressure to25,checked neck bearings and tightened them up 2 notches just for good measure since I couldn't really tell if I had any play but figured maybe just a little tighter wouldn't hurt, tightened the rockers. Went for a ride and found at 50-55 with no damper applied there is no wobble and it handles nicely if I drive properly. I'll explain in the next paragraph. Tightened the damper dropped my hands (stupid idea) and found the bike tracks to the right ever so slightly which says I have an alignement problem I'm thinking rear wheel angled left a little. Right now I've got the rear apart and rechecking the alignement since I did have an axle alignement problem that I thought I'd solved also rechecking my work on the star hub.

Sat down with a beer and started a trouble list. When did I first notice the problem, speed,when did it first scare me what was I doing. Things like that. First time 60+ and snapping the throttle shut (twice on same day). Next time 60+ last minute panic dodge of a chunk of steel I didn't see(really wobbled that time). Not believing what had just happened I took it back up to 60 and twitched the handle bars like a dummy and needed clean drawers afterwards. I'm finding that at 40+ I can make the bike do a really short lived mean shake if I do a really quick turning of the bars right to left. Reckon that's why all the MSF courses teach turning the bars only when duckwaking in the parking lot. I'm sure some of the problem was the nut behind the wheel but I'm double checking everything thats been suggested. Chris

[Userdn2731]

Tire pressures

Wow! I can't beleive you guys are running that high of tire oressures. On my '47 45 with 5x16 tires I run what is in the old manual. I run 12 front and 14 rear riding single and add a pound or two to each with a passenger, Rides smooth and good tire wear. Any comments?

[bmh]

Carefull tightening those neck bearings, If they are too tight you'll get a wobble also. The steering must still move free and easy. With the dampener ( if you have one) set completely off , I usually like to see the front end "fall off" at about a half inch.
Brian

[Rubone]

It all depends on the tires you are running. Old Goodyears on my UL run great at low pressures. Modern compound and construction techniques usually require that they be run much higher in the 25# to 35# range. I have found that most of the issues attributed to Cokers go away with 28-30# in them. Also no bike with 16 inch wheels will be as stable as 18 inchers. That is why so many of the early bikes handled so well, much better geometry. That is also why all the frame changes in the 40's on Knuckles, trying to get those big tires to handle! I regularly run my 45 in the 65 MPH range and it never twitches.
Robbie

[Tom Wilcock]

Handling

I suppose you also checked if all the spokes were tight. I experienced similar problems once and the only thing I could find were some loose spokes in the rear wheel. Seems fine now.

[Tom Lovejoy]

I run 18 front and 15 rear on my SS, runs fine and steers true, steady and tracks very well. Used to run far more pressure, but on the freeway I had a bucking bronko - could not keep my feet on the boards! A 90 year old ex Indian racer and tuner told me to run the less pressure. Some folks say thats nuts, the tire store would freak, but its been working well for me 16 or so years anyway. I have had good wear too, going to check my bearings this weekend I think, been a couple years.