BSA Owners' Club Workshop Discussions

The BSA Workshop => Twins => Topic started by: aso215kd on 20 Dec, 2023, 16:27

Title: Campbell Silencers
Post by: aso215kd on 20 Dec, 2023, 16:27
I recently purchase a '64 A-65 that has Campbell silencers on it.  They are loud, not the original exhaust note at all.  I found that Campbell is no longer in business.  Does anyone make any baffles so I can restore the original sound?
Title: Re: Campbell Silencers
Post by: JOHNSTONE on 21 Dec, 2023, 12:11
Have a look at classicbikeshop's website.

Regards

Rich
Title: Re: Campbell Silencers
Post by: rhyatt on 21 Dec, 2023, 13:42
I bought some perforated steel tube from ebay.
Squashed the end over and pushed it into the end of the exhaust pipe where it entered the silencer , worked fine.
Armours in Bournemouth do mutes that should do you as well.

Take the edge off
Title: Re: Campbell Silencers
Post by: Allan G on 21 Dec, 2023, 14:39
The Armours silencers are very nice but rob the bike of a lot of power.

fit a sleeve into the tail pipe section, with an ID of between 1 1/4" and 1 3/8", this will give a suitable back pressure and quieten the exhaust note dramatically. The bike will feel like it has more midrange torque too.
Title: Re: Campbell Silencers
Post by: aso215kd on 28 Dec, 2023, 20:51
Thanks for the responses.

Allan G, do you mean a straight length of pipe with no baffling (thus reducing the ID of the silencer)?
Title: Re: Campbell Silencers
Post by: neil1964 on 29 Dec, 2023, 09:11
On tweaked Triumph 500 Daytonas I found the Campbells gave best power at top end (slight dip at 4500rpm) and decent response at lower end.  The Armours were restrictive at top end, did not have the dip but then ran out of go around 6500rpm (geared for 13.5mph per 1000rpm). 
I did not notice a noise issue. I'd tried other exhausts (ditched reverse cone meggas - too loud) long conical type fell apart.
As a speed hungry youth the Campbells were great (although tended to crack around the body next to the mounting bracket (probably should have fitted the sway braces that Boyer recommended.