BSA Owners' Club Workshop Discussions

The BSA Workshop => Twins => Topic started by: cornishbob on 22 Sep, 2024, 12:17

Title: another dumb question but im going to ask it
Post by: cornishbob on 22 Sep, 2024, 12:17
would putting a spacer, probably 3/8" maybe 1/2", beneath the bottom yoke on the forks affect anything other than increasing the spring tension.

told you it was a dumb question
Title: Re: another dumb question but im going to ask it
Post by: DAVE BRADY on 22 Sep, 2024, 12:27
Hi,

I would say only the spring tension but depending on how thick the spacer, it could cause the spring to become coil bound or the forks may bottom out on full bump.

Dave.
Title: Re: another dumb question but im going to ask it
Post by: cornishbob on 22 Sep, 2024, 13:40
yeah, that was the only,obvious, thing i could see too.

i was thinking about making some clubman style dustcovers/shroudy type things out of stainless.

a thin bit is whats required but didnt want to get them welded because of cost. thats why i was going for thick spacers.

bit of chemical induced thinking needed... do you know much two lemsips and a can of special brew costs?
Title: Re: another dumb question but im going to ask it
Post by: DAVE BRADY on 22 Sep, 2024, 15:20
Hi,

Do you want them full length or are you going to use rubber gaiters?

Dave.
Title: Re: another dumb question but im going to ask it
Post by: cornishbob on 22 Sep, 2024, 15:52
they'll replace the gaiters but they're £60 a pair. i could make them for about £25 but i'd need a bit of tig welding done and thats prohibitive
Title: Re: another dumb question but im going to ask it
Post by: chaz on 22 Sep, 2024, 16:47
spring tension...
bear in mind the age of the springs, might make them stiffer unless they had been replaced.
if old they may have already lost much of the tension.
Title: Re: another dumb question but im going to ask it
Post by: DAVE BRADY on 22 Sep, 2024, 16:54
Hi,

Shiny stainless bits always end up expensive but they will look good.

Dave.
Title: Re: another dumb question but im going to ask it
Post by: cornishbob on 22 Sep, 2024, 17:03
i'm only a pensioner and have lost my heating allowance...wail wail. dont feel sorry though.
Title: Re: another dumb question but im going to ask it
Post by: Gup holland on 22 Sep, 2024, 20:15
Long, long ago I made some of these spacers , as an experiment, makes the forks stiffer.

Threw them in the bin...... 8)
Title: Re: another dumb question but im going to ask it
Post by: idie on 22 Sep, 2024, 20:45
Try Dow type double damping rods.
Title: Re: another dumb question but im going to ask it
Post by: cornishbob on 22 Sep, 2024, 21:32
if theres a possability that the spacers will affect other things to a noticable extent then its probably not worth doing seeing as there are ones available.

dont i wish i went on that welding course when i was working all those years ago.

theres an accute shortage of tig welders around here. one quoted £150 minimum charge.yeah right course i am ...not.

chemical intervention looks more and more like the only way
Title: Re: another dumb question but im going to ask it
Post by: cornishbob on 22 Sep, 2024, 21:37
or..OR i could powdercoat the springs. theres a coaters nearby that does a chrome finishreally good...the drugs ARE working
Title: Re: another dumb question but im going to ask it
Post by: chaz on 22 Sep, 2024, 21:40
my 1969  A50 springs have been powder coated black.
look clean and nice, BUT, has the process affected the tension ?? wont know until I get it running.
Title: Re: another dumb question but im going to ask it
Post by: cornishbob on 22 Sep, 2024, 22:00
powdercoating temps shouldnt affect the 'spring' of springs. unless they left them on reglo 5 over night
Title: Re: another dumb question but im going to ask it
Post by: chaz on 23 Sep, 2024, 07:38
no, but from my apprenticeship, I recall shotblasting can affect the tension on metal.
Title: Re: another dumb question but im going to ask it
Post by: cornishbob on 23 Sep, 2024, 08:50
my background is in aerospace. i could go into the molecular physics of heat treatment but if i did some men in black will come round for a chat.

the treatments involved in springs are a world away from the effects of shotblasting  and the temps involved in powder coating are like a frosty morning compared to heat treatments
Title: Re: another dumb question but im going to ask it
Post by: cornishbob on 26 Sep, 2024, 19:09
ok so the chemicals have done thier job and i am back in the world of sanity.

i have had an idea . ive not followed it through yet

the info i need to know is - what is the fork travel from normal at rest to fully compressed. i can't do it myself because of the number of hands required