Front end shimmys when slowing down

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48Pan
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Location: Shakopee Minnesota

Front end shimmys when slowing down

#1

Post by 48Pan » Tue Jun 19, 2007 1:47 pm

My 1948 EL has a shimmy in the Hydra front end when I slow down. I've been told it could be in the fork bushings or in the neck bearings? Anyone had an issue like this that can shed some light? I'm also told there are special tools required to change the bushings is that correct?



Fixman
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#2

Post by Fixman » Tue Jun 19, 2007 2:48 pm

I have the same problem with my 57. I recently had it apart, and the bushings and bearings seemed OK, but I am far from an expert. I can make the problem a little less worrisome by putting in a little steering damper. If I have both hands on the bars, the problem is not noticeable, but it shows up when I stick my left hand out to signal a turn. Even though I am pretty sure the fall-away is set properly, it could be that the head bearing nut is not adjusted correctly. Hope someone has a definitive answer for us.

Kent

48Pan
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#3

Post by 48Pan » Tue Jun 19, 2007 3:18 pm

I've got a damper and it doesn't seem to help much. I agree with two hands it's ok but with the foot clutch and the shift level behind my leg two hands is not happening too often.

PeterRytter
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#4

Post by PeterRytter » Tue Jun 19, 2007 4:29 pm

Remember to check both the front and the rear wheel bearings, they could cause the problem.

FlatHeadSix
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#5

Post by FlatHeadSix » Tue Jun 19, 2007 6:53 pm

48pan

a '48 EL with a Hydra front end? Which bushings are you talking about?

fourthgear
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#6

Post by fourthgear » Tue Jun 19, 2007 8:34 pm

You may also want to check your front tire also , could be out of balance , loose spokes , low on air ( try a digital air gage to check ),rim bent etc. You will of course have to pull the fork tube/leg assem. to check for play in the leg bushings .

108
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Front end shimmys

#7

Post by 108 » Wed Jun 20, 2007 5:39 am

48Pan, I assume your not using the front brake when the shimmy develops? An out-of-round drum could cause it.

King
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#8

Post by King » Wed Jun 20, 2007 12:28 pm

A few years a go a buddy gave me the stock tyre off his new evo when he upgraded to somthing more sporty. I put it on the front of my 51FL and immmediately began to have problems with a low speed shimmy especially coming out of turns. The tyre had a modern cris-cross pattern and probably a lower profile than the 5.00x16s I had been running. I changed back to a stright groved tyre and the problem disapeared.

King

Fixman
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#9

Post by Fixman » Wed Jun 20, 2007 12:30 pm

Actually, on my 57 Pan, a slight application of the front brake reduces the shimmy a little. I am beginning to think that it might be the front wheel bearings. I am looking for a nice original rim and will lace it using an original star hub. The rear is done. It seems that whenever I replace an aftermarket part with an original things get better. Go Figure!

Kent

old1955
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#10

Post by old1955 » Thu Jun 21, 2007 11:01 pm

Fixman
There is no figuring, 95% aftermarket parts are crap!

duoglide58
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#11

Post by duoglide58 » Thu Jul 12, 2007 4:21 am

My '58 had a shimmy with the old Hydraglide forks. I replaced the neck bearings and had new wheels but the shimmy was still there. I finally tore into the fork tubes one year and found that the damper assembly on one tube was in poor shape. Faced with trying to rebuild the forks and pull the old bushings and hone the new bushings. It was cheaper to buy a new set of tubes with the Showa internals. That fixed the shimmy.
Doug

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#12

Post by partshunt » Mon Jul 16, 2007 10:59 am

Shimmys freak me out. When you consider, acording to Palmer, Harley had a shimmy in the earlier panhead frames. To fix it temporarily, they just tweaked the frame a bit to change the fork angle a coupla degerees to fix it before casting another neck. How many of these restored panheads were choppers once with neck angle changes and now the restores had to put them back to stock? Are they dead on? . If a coupla dgrees was a problem at the factory, how are the home brewed restos doing when bringing these critical angles back into the frame to original specs to avoid shimmyas like the Motor Co had to do....? Neck angle of 59.5 degrees is stock I think but correct me if wrong, point to note is, check fork angle also if in doubt..too many hippies werew turned loose in the sixties with a torch, the govenment should have had them pave the Alaska Highway instead. Be a lot better riding country in those days.......Joe

VT

#13

Post by VT » Mon Jul 16, 2007 3:24 pm

I am beginning to think that it might be the front wheel bearings.
Have you had the front wheel off the ground and tried to rack it back and forth with your hands at 12 and 6 o'clock? That might give you some feel for how much slop is coming from your wheel bearings. V-Twin sells a good hub. I have four of them they laced with s/s spokes on black hubs. Their rims were within 1/32 runout.

1950Bobber

front end shimmies'

#14

Post by 1950Bobber » Mon Jul 16, 2007 3:37 pm

Holy shit partshunt!

That's a whole lot of deep thinking there! Hippies, better off, pave the Alaskan highway, NECK ANGLE 59 degrees????? What 'ya smoking Man, can I get some?

1950Bobber

Front end shimmies'

#15

Post by 1950Bobber » Mon Jul 16, 2007 3:51 pm

Just thought I'd 'learn yall' an upgrade I used on my son's shovelhead...I got into a semi-high speed wobble back in the 70's...at about 55 MPH! I survived...thus I'm here to tell you....

I added a frontend-to-frame steering damper on my son's shovel. I had a later MotoGuzzi for a while, which had a damper. I decided to see what effect it really had on the stability at HIGH SPEED! dangerous but...I removed the Guzzi's damper and brought her up to 110 MPH...what a significant difference in that Guzzi WITH and WITHOUT the damper...enough so, that I installed one on my son's HD...I sure didn't want him to ever see a high speed wobble!

Now I know some you guys would revolt against a Panhead with such a device attached from the front end to the frame...but, just thought I'd throw that out to 'ya.

There (may be) no substitute for a mechanically sound STOCK configuration PANHEAD, however!!!!


Jim in Seattle "1950 Bobber" :D

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