Understatement of the day

[Ixion]

If it has a rear shock it's a softail, the swingarm is part of the frame (as in one piece or welded in place) it's a hardtail or rigid. Not only cruiser people I have seen a few sportbikes with welded swingarms. Why someone would do that to a sporty I don't know but what ever lifts yer knob I guess.

What about plungers and sprung hubs? No swingarm (rigid frame), but do have shocks (wheel mounted direct on shock, in effect, or actually inside wheel )

[Waylander]

What about plungers and sprung hubs? No swingarm (rigid frame), but do have shocks (wheel mounted direct on shock, in effect, or actually inside wheel )

In truth I don't know. Those are a bit outside my experiance. Probably something in between. Shocked-rigid? Never heard of them before.

[Ixion]

In truth I don't know. Those are a bit outside my experiance. Probably something in between. Shocked-rigid? Never heard of them before.

Just a couple of the weird and aberrant ideas that came out of the British motorcycle industry . Though actually I think BMW were responsible for plungers. which were not as silly as they sound and are probably due for a resurrection.

I blame the British winters myself. Cooped up for half the year, subsisting on things like scrumble, haggis, toad in the hole and brose, deprived of natural light. Inevitably, after shagging everything that moved, and no doubt quite a few that didn't, and drinking everything capable of producing even a mild buzz (including the acid out the battery), some by now half demented designer would sit down, drooling, and start doodling . The results were bound to be outlandlish and bizarre . We motorcyclists endured the results of the doodling for decades.

[Waylander]

Just a couple of the weird and aberrant ideas that came out of the British motorcycle industry . Though actually I think BMW were responsible for plungers. which were not as silly as they sound and are probably due for a resurrection.

I blame the British winters myself. Cooped up for half the year, subsisting on things like scrumble, haggis, toad in the hole and brose, deprived of natural light. Inevitably, after shagging everything that moved, and no doubt quite a few that didn't, and drinking everything capable of producing even a mild buzz (including the acid out the battery), some by now half demented designer would sit down, drooling, and start doodling . The results were bound to be outlandlish and bizarre . We motorcyclists endured the results of the doodling for decades.

Ok now you've sparked my curiosity. Got any pictorial evidence of the suspension systems you mentioned previously? (no idea why I'm typing it out that way...)

[Ixion]

Ok now you've sparked my curiosity. Got any pictorial evidence of the suspension systems you mentioned previously? (no idea why I'm typing it out that way...)

Try these.

EDIT The numbers came out different

#3 and #4 are sprung hubs - a bike with the hub fitted (note the rigid frame) and one of the rear dismantled showing the wheel and hub. The shocks are actually INSIDE the wheel hub!

#1 A chopper using a plunger frame. Note, no swing arm
#2 A schematic of a Zundapp plunger frame.

[Waylander]

Try these.

EDIT The numbers came out different

#3 and #4 are sprung hubs - a bike with the hub fitted (note the rigid frame) and one of the rear dismantled showing the wheel and hub. The shocks are actually INSIDE the wheel hub!

#1 A chopper using a plunger frame. Note, no swing arm
#2 A schematic of a Zundapp plunger frame.

Can't get the last two to biger size but I see what you mean. Ok then I'll change my definition of rigid, the rear axelbeing fixed solid to the frame rather than on some system that allowes it to travel up and down. That better?

[Ixion]

Can't get the last two to biger size but I see what you mean. Ok then I'll change my definition of rigid, the rear axelbeing fixed solid to the frame rather than on some system that allowes it to travel up and down. That better?

Actually, that still classifies a sprung hub as rigid, because the axle was indeed bolted solid to the frame . The wheel rim itself was sprung on the axle (ie the axle never moved)

We could also divert into the even more bizarre realm of hub centre STEERING. Yes they did that too.

[Waylander]

Actually, that still classifies a sprung hub as rigid, because the axle was indeed bolted solid to the frame . The wheel rim itself was sprung on the axle (ie the axle never moved)

We could also divert into the even more bizarre realm of hub centre STEERING. Yes they did that too.

I'm gonna have to have a nice long face to face talk with you before I start building bikes arn't I. You just have to much info and bike history locked up in tht head might aswell put it to good use. Exspecially since I waanted to try and figure out a way to make a softail look like a rigid without just hiding the shocks inder the tranny. Seems it's already been done.

EDIT: found a better diagram of the plunger suspension HERE.

[Motu]

Apart from the sprung hub there were different forms of plunger suspension too - don't call them shocks because there was no dampening in these things,just springs.The Aerial (sp??) had short trailing links on it's plungers,like mini swing arms,this allowd the rear wheel atleat to swing in an arc,normal plungers just went up and down,with a slight forward lean.On a left corner my plunger BSA used to roll the worn chain off as the suspension compressed and loosened the chain.There are tales of severed heads for those foolish enough to dismantle a sprung hub....

[Ixion]

Apart from the sprung hub there were different forms of plunger suspension too - don't call them shocks because there was no dampening in these things,just springs.The Aerial (sp??) had short trailing links on it's plungers,like mini swing arms,this allowd the rear wheel atleat to swing in an arc,normal plungers just went up and down,with a slight forward lean.On a left corner my plunger BSA used to roll the worn chain off as the suspension compressed and loosened the chain.There are tales of severed heads for those foolish enough to dismantle a sprung hub....

Yeah, that was one honking spring !

[eliot-ness]

He says its defiantely a twin. Which means Model 7 . Heh if it was a Manx I'd be bidding SO damn fast !

Yea, I didn't read the twin bit. The "Manx" of that era still had the 'international' engine. I'd be bidding against you. As it's a twin it must be 1948 or later. Still a good buy, hard to find one for sale but the 49 ES2 single in restored condition is still selling for around $10000 in the U.K. The model 7 twin would be worth more. If the engine /gearbox are complete and most of the cycle parts are there it would be a reasonable cheap and easy rebuild. Nothing complicated in those days. Mechano was more challenging.
The 'plunger' suspension, apart from being undamped, worked vertically, not in an arc, and so tightened the chain on compression. Adjustment thad to be made for one or two up riding or risk breaking the chain or jumping off the sprocket. I think it was BMW who brought out a curved version but can't be sure. Triumph's sprung hub was a disaster that should never have happened. On the rare occasions that it worked no more than around an inch of movement was avallable, again with chain tension problems.

[Motu]

I don't see any substantial sidecar lugs either,that would indicate a twin as they were not considered a good sidecar puller back then,that was ES2 territory.

[vifferman]

I like the evolution of terms; starts of as "complete bike" then as he actually checks out what he's selling, it seems there are quite a few bits missing. And "tank is mint" (I thought the definition of 'mint' was 'as it was when newly minted(made)', becomes "there is no rust or any sign of dents there are some superfical scratches only".

[Brian d marge]

Just a couple of the weird and aberrant ideas that came out of the British motorcycle industry . Though actually I think BMW were responsible for plungers. which were not as silly as they sound and are probably due for a resurrection.
.

Nooo the plunger is an abomination ,,,the chain goes through a bizarre arc which ( from memory does strange stuff to the length nnn)

It was a stop gap measure to apease the Major and Miss Amplebottom as they tended to stick with things ridged...

either that or a patent squabble .....

For best handling, you cant go past a ridged ,,( having had a ridged triumph chopper ,,,yess yess )
I Love the things ,,,, you would be surprised how comfortable they are

BTW the modern arrangement is so perfect either ,,,look how close they want to put the swingarm pivot to the gearbox sprocket ,,,,,

Now your Ridged doesnt have that problem as the chain throw is constant ,,,and If you use the MZ enclosed chain One would assume you would be throwing the bike away before the chain wore out ....

Fashion isnt it a wonderfull thing,,,exposed fork legs ...Phaaa...what ever next

Stephen
Proud supported of Luddites since 1966 ( Didnt Mr Moore do well that year!!)

[Motu]

Rigid frames handled great,no flex,no sprung/unsprung weight crap,max weight on the rear wheel...you sure knew what was happening back there.With a sprung seat the bike just floated under you on rough roads - you don't see speedway bikes with woosy floppy rear suspension.