Vibration

[panwars]

Description: What could change internally to make that much vibration, and not make noise?

Hi panfans,

I just bought a 61 in a 49 frame in june 03. remounted engine properley, ran valves (Hydraulic), tuned and timed, mounted super E, new diamond primary, and secondary, comp good and even. Bike runs great, engine runs real strong, and quiet(for a pan!) I had ridden about 1500 miles, mostly short trips 100 miles or less, when I got a new worse vibration. I had changed exhaust from shot guns to drags before with no change, but added shorty mufflers about the time the vib started???? The vibration comes on about a third in to the power band in all gears and neutral. I have 24 theeth on engine and 24 on trans which puts vibration about fifty in fourth. It makes my feet move on the boards, and just seems severe for the rpm I am at. I rode hard last weekend and now I coud swear it is worse yet. I just spent the weekend pressure testing the intake (no leaks) re- tuning and timing. pulled tanks and checked all mounting, still good. Primary is good. Now what? What is coming loose in engine??? What could change internally to make that much vibration, and not make noise? What else could be wrong outside the mill???? HELP PLEASE.

[sleeper]

My '48 was bad with the vibrations, then I added an anti-vibration bar that goes thru the lower downtube loops [for sidecar] except this just goes thru the loops & tightens up & took away most all of my "Bad Vibes".
This was done very long ago, I'm pretty sure that bar is still made. Just my 2 cents...

[panomania]

Post by panomania on Apr 19, 2004, 5:32pm

my 48 has always gotten a vibe at about 60mph. im not sure of the rpms but it also does it in neutral. where do you get one of these anti-vibration bars?

[haggis]

Pano... V-Twin's ( Dammit) got the anti vib; bar also seen them in J&P's Vintage Catalog.
Panwars....check back in the postings for bad vibration.(Cotten nailed that one...)
Got to make sure that top motor mount is not under sideways stress, or you'll vibrate your nuts off. Haggis

[sleeper]

I just read "Big Time Vibration," It sure seems that Cotten & Jack had the right direction on this one..
Can't take anything for granted!! Only after that is all sorted out, will you know if you need or want a vib.-bar... I like them anyway as they strengthen the frame as well.. ;D

[panwars]

Damn, I must be going nuts, I have checked every thing including mounting, and I could swear this thing used to be smoother but,,,,,, today I checked out an 81? sturgis with solid mounted shovel and the damn thing shook worse than my pan. I don't think I am going to sweat it any more, I have improved the rest of the bike so much I must just be more in tune to engine feel now, who knows. I like the tie bar idea, but have a pipe right in the way, or does it mount a different way than I am imagining, Loop to loop?

[sleeper]

No unfortunately, it goes straight thru loop to loop

[PBR]

Panomania, Paughco is the original manufacturer of the vibration bar, this was originally used on the sidecar setups, I have one on my '46 F PBR

[panomania]

i need to mount a couple of these things on my bike. i'm lucky to have any teeth left not to mention the twins. and haggis thanks for the cussing, i need that from time to time to keep things in prospective. my ol lady usually just smacks me. the cool thing is, after about 6 natural lights it dont hurt near as bad.

[Olsen]

Hmmmm..... if vibrations show up without warning, i would check for a broken frame. Look for hairline cracks around motor mounts and/or under the tranny. Maybe even around the welds on the rear end, that goes for a rigid only off course.

[sleeper]

Olsen, I agree with ya. Sudden changes like that require looking into!!
This is not just limited to rigids though. When I owned my '63 Pan it cracked just below the swing arm on the left side. Hairline, but drove me nuts trying to sort it out. Later I think the Factory Gusseted that area to strengthen that weak spot. If I remember right?

[weezeo]

If its a swinging arm Id look into the bearings also But if your not used to a rigid it is a heap of difference on it. Especially on an extended ride. But like Cotten said the main thing and the 1st thing to check is the top motor mount, other than that i can't think of anything else to check, make sure that the wheels are locked in good, front end is tite and if So than get used to it

[dereborn]

Billy! - I'm interested in this vibration-bar... Is it made in any special material? If not, it sounds like it wouldn't be too hard to fabricate one yourself?! Can you tell me a little more what it is like?