The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: bikerboy on 23.01. 2013 14:45
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I have a bitsa A10 that I have thrown together from old parts and I am just completing it. When it comes to the exhaust system there appears to be a change in part numbers at 1957.
I have it in a B31 frame (the one with the kink in) and the engine is a Super Rocket.
Does anybody know what the difference is between the pre 1957 exhaust and the post 1957 exhausts as I dont have a clue which one I should get.
Thanks in advance
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I'm pretty sure that it's all to do with the silencers. The pre-57 silencers were of parallel contruction and much longer that the later more bulbous ones. Therefore the pre-57 exhaust pipes are much shorter in order to maintain the overall length.
Both systems will fit but they won't mix and match.
Beezageezauk.
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Hi Bikerboy.
Armours list both silencer and exhaust as different from 1954 to 1958 and 1958 to 1962.
They still manufacture in the UK, and product is of good quality and competively priced against imported ones.
I have there complete s/steel system, and they fitted very well.
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Up to 1957 the pipes kicked up at the rear and the mufflers were cylinder shaped.
From 1958 the pipes were parallel with the ground and the mufflers became cigar shaped.
The pipes are bent differently along the frame tubes as well.
Trev.
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Hi
May I suggest you give Armours a ring and ask them the question? always found them very helpful.
Regards
Nick
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Well thanks for your replies I will ring armours and hopefully they will be able to supply a set of downpipes and goldie style silencers :)
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Mine's got siamese pipes and a goldie silencer , you'll enjoy the noise don't know about the neighbours though ,regards BobH.
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The down pipes I bought from Armours were too big to plug in to the head. They told me I needed to open out the exhaust ports. Right on.
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sounds like a one time only plan!
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The down pipes I bought from Armours were too big to plug in to the head. They told me I needed to open out the exhaust ports. Right on.
That replicates my experience. I bought siamsed pipes and they did not fit, and more to the point, when I complained the proprieter was extremley rude. He told me that after all his years in the business of making exhaust pipes he was not going to be lectured to by people like me. And what did I know about exhaust pipes anyway!
John
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The down pipes I bought from Armours were too big to plug in to the head. They told me I needed to open out the exhaust ports. Right on.
Can't believe they said that. I know where I won't be going for future exhaust systems - the correct diameter tube is a fairly basic requirement!
Jim
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Also had trouble with Armours siamesed pipes. Diameter was about OK but the lhs (short) pipe really was too short in the port. Fortunately had oxy/acet at that time and added a piece to suit.
Terry
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That must have ruined the chrome?
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The join is inside the port and once the finned ring is in place it's not noticeable. Without the extension there was no space for the ring.
Another set of siamese I inherited (with a sadly neglected '59 SR) was made up in a similar way, before finishing of course. The tubing used for the main bends is smaller dia. than the welded end pieces, which match the port id and the welds are obvious when fitted. I have no idea who made that set but guess the very tight bend on the lhs short piece proved too difficult.
Terry
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Well so much for armours.
I rang and told them what bike I had and that I wanted goldie silencers on it and they supplied both downpipes and silencers. They told me that as I wanted goldie silencers that I would need to fit the older style pipes (pre 1958).
None of them fitted or came anywhere near to fitting. The left hand pipe once it was in the head the fixing bracket was at least and inch and a half away from the frame. The right hand one fitted but once on the silencer supplied by armours would not slide on far enough, the fixing hole for the footrest to go thru was at least 2 inches further back than it needed to be.
When I spoke to them they just said send them back and we will refund. Thats great but it dont put a set of damned exhausts on my bike.
I have to admit I was not impressed with them one little bit.