Have you ever ridden a "Plunger" frame bike?

Hi everyone,
I guess this post has been precipitated by reading the posts regarding the resurrection of the Amen-framed chopper (posted elsewhere on this site) and also the fact that one of my friends is finally getting his plunger-framed Indian Chief together after a mere 40-something years.
Anyway, I've ridden rigids, twin shocks, monoshock frames of many varieties, but cannot remember ever riding a plunger-framed bike.
I know that there were numerous shortcomings with the design - mainly chain tensioning and also twist in the rear axle as the suspension moved, but for short guys like me (165 cm), the potential for lower frame rails in the seat area would have real benefits.
So... if any of you would like to give me your two cents worth, I'd be glad to listen. I also think there are engineering solutions to the problems I've already mentioned.
Many thanks,
Pat Cowan,
Vintage Motorcycle Fiberglass / Pacomotorstuff

Helen Keller rode a plunger and fired a plumber on the same day. Only thing is her favorite color is corduroy, so I don't think you should trust her opinion.

Pat ............. move on mate

I rode dozens in the late 50's early 60's as they were generally freebies. A lot had seen sidecar service and all the problems of the rear end were amplified by that use [ mis-use ].

However, I never rode a newish one - so my experiences [ VERY bad ] could have been down to worn parts and bad maintainance.

By the early 60's I could afford donors with normal twinshock suspension.

To be objective about your question - lack of any effective dampening is my main recollection - with the back end doing it's best imitation of a pogo stick.

Ever ridden a sprung hub Triumph ?????????

Ya Beach, you might be right - move on LOL! I looked at the shortcomings of all of the plunger systems I've ever seen - Indian, BSA, Matchless, AMEN (and other aftermarket frames) etc etc etc and wondered if they could be engineered out, but probably not totally...
I did the notched frame thing on one of my 350 Yamahas about 40 years ago - keeping the twin rear shocks but lowering the frame tubes in the seat area - and it worked well enough I guess as it still gave me stock ground clearance.
Maybe I should look at a rear suspension like a '60's Bimmer, with the weird (to me) mid shock mounting system?
As for the sprung hub Triumph, you might want to explain to the teen set (ie., anyone under the age of 50), just WTF it was and how it worked...
Pat

Pat - I was going to suggest the early BMW frame - very low and there's been some awesome specials built around that frame. I'll dig out some from my German BMW Magazines.

How did the Triumph sprung hub work ??????? BADLY.

On my 16th Birthday I passed my motorcycle test and immediately swapped my James Captain Trail bike for my Dad's SPRUNG HUB T'Bird. I remember the excitement / fear / exhilaration [ not in any order ] trying to squeeze the magic Ton out of it down a local hill [ 2 miles long ]. I have NO idea what the terminal speed was as I had an almighty tail wagger which almost pitched me off and took all my efforts to bring it to a stop without further mayhem.

It was another of those solutions looking for a problem .......... didn't last long.

I have a workshop manual somewhere in my loft showing the sprung hub in section - I'll try to didg it out.

I remember one brave soul who fitted a sprung hub into a plunger frame - albeit on a chair !

my BSA is a plunger and while it is a ton of fun to ride the suspension is not of anything you would call quality(sprung seat helps yer spine)
sure you could modify and fit a real shock, but why ? a swingarm frame can be just as low in the seat

Here it is in all it's glory [?] Essentially a plunger miniaturised so it would fit inside the hub.

It only had 2" of vertical travel - as much use as a chocolate fireguard comes to mind.

Edward Turner has to hold his hands up for this abortion - but in his defence [?] he DID nick the idea from an aircraft suspension landing gear - should have left it there IMO