The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: Swarfcut on 05.11. 2018 17:17

Title: Plunger Competition Frame
Post by: Swarfcut on 05.11. 2018 17:17
 Just wasting time on your favorite auction site, came across a listing for a competition plunger frame.

 Looks to be a Super Flash type with the goose neck seat tube and extra lugs on the lower rear tubes.
 
 Sorry I am not cute enough to post a direct link, so its up to you to search. "BSA A7 A10 Plunger Competition Frame Daytona"  It's in Michigan, USA.

 Looks to have hit a freeway barrier and be made of some sort of rare precious metal. Never seen one for real, so quite an interesting diversion from the usual.

  Swarfy
Title: Re: Plunger Competition Frame
Post by: muskrat on 05.11. 2018 18:45
G'day Swarfy.
Yep, it's a SF frame. Does look like she's nudged something, top tube has a bow and downtubes also.
https://tinyurl.com/y76twcod
Cheers
Title: Re: Plunger Competition Frame
Post by: Swarfcut on 05.11. 2018 20:24
 Musky, Thanks for posting the link. Sure looks to have had  a close encounter with something solid. That Longstroke posting today was a weird one. I am in the UK, the link gave the German Ebay, Selected translate and up came the "Please ensure..." which you would not expect from an observation of typical German Humour.

 Swarfy.
Title: Re: Plunger Competition Frame
Post by: BritTwit on 06.11. 2018 02:38
All three of my frames S/F had the same bend on the down tubes.  Finally got them straight.  now I'm wondering if they're supposed to be that way.
Title: Re: Plunger Competition Frame
Post by: Brian on 06.11. 2018 04:48
Should be straight. Obviously people who ride Super Flashes are not very good at looking where they are going !
Title: Re: Plunger Competition Frame
Post by: harvey mushman on 06.11. 2018 07:50
Was this a period modification for flat track racing?

reason i ask is my brother just purchased a gold star that the rake has been modified on and were told it was to improve the turn in for flat track racing.

cheers

derek
Title: Re: Plunger Competition Frame
Post by: muskrat on 06.11. 2018 08:15
G'day fellas.
I'd say the motor performance outweighed the braking power  *whistle*.
Both mine do  *roll* got 5 broken ribs and a punctured lung to prove it  *sick*
Cheers
PS: and "get outa the f"ing way" is louder than the horn  *bash*
Title: Re: Plunger Competition Frame
Post by: RDfella on 17.11. 2018 19:57
Derek - yess, we used to do that in the 60's to get quicker turn-in. Bending the tubes was a crude way of obtaining that. When I modified my M21 frame for a different motor I altered the angle (to improve steering) at the top tube instead.
Title: Re: Plunger Competition Frame
Post by: Sluggo on 17.11. 2018 21:27
Ive been off line a bit, But I did look at that listing on Satans swap meet.  As another lister has noted, the seller is a "Butcher shop" and killer of cool bikes.  Sad!  But that IS a Superflash frame.   I have one that has been modified but was not a factory job.
In case the OP was wondering its for room for bigger carbies,,  I hope someone can salvage it, sadly the soulless heathen who parted it out ALSO has the rear section that goes to it in another auction.  WTH???

As to rake and mods,, there is MUCH debate in the Triumph world on this and the factory did a few different steering head angles for more responsive turn in, However must have been some complaints as maybe TOO responsive as they changed it back.  1965 is the golden year and for a unit Triumph 650 is the one everyone wants for racing. Allegedly Ray Hensley copied the 65 geometry for his Trackmaster frames.

Another interesting mod before cerranis and betors became common was to mix and match fork parts.  BSA Triple trees were modified, there is an article about Rickman frames and desert racing where Bud & Dave Ekins talk about setting up desert racers and how they would modify BSA Trees and then slide the forks up and use pinch bolts.  This drops the nose a bit.    I found it in a old cycle world magazine reprint from the early 1960s.  I can dig it out if someones interested...

* EDIT* I tried a google search, Its June 1964 issue and its posted here in this website,
See: https://selvedgeyard.com/2012/02/25/steve-mcqueen-doin-it-in-the-dirt-triumph-desert-bike-by-bud-ekins/#more-28479

**EDIT NOT the article I was looking for,, but its still cool. 

More in the same vein and talks about a variation, using BSA Trees with Cerranis  but still not the article I am looking for, but super cool review of how to set up desert sleds. (And a nice plug about how good BSA Hornets are!

See: https://selvedgeyard.com/2010/10/22/steve-mcqueen-66-popular-science-what-i-like-in-a-bike-and-why/

Eh, Ill find it, but they would cut the top trees and make pinch bolts on the sides, using different fork tubes they would slide these higher into the trees and then clamp them.  Variety of forks used but all were using BSA trees until much later when Cerranis and others started offering light weight alloy trees and some with rake or trail set up in them.  I had a friend with a Boyd & Stellings setup and the neck was totally adjustable.  Really an unusual looking bit of kit.