19. BSA A10 Exhausted Time To Sit Down

The next stage on the renovation of my BSA A10 Super Rocket is to fit the exhaust. All of the original exhaust parts were pitted and dented in fact the only parts worth keeping were the two finned heat sinks. So I re-threaded them to take 8mm Allen key stainless steel bolts and polished them as best I could between the fins and that was the total of the old exhaust renovation. The old exhaust pipes and silencers I put on eBay and despite a very honest description and photos of all the dents and damage, they sold for excellent prices. So that went a little way towards the cost of the new exhaust system.

I then decided to buy a pair of stainless steel swept exhaust pipes off eBay and new Rocket Gold Star silencers from Lightning Spares. Until I spoke to them I had not noticed the difference. Super Rocket silencers are the same cigar shape at both ends. Rocket Gold Star silencers taper towards the front of the bike. You live and learn! The picture above shows the original exhaust.

I offered the new pipes in place along with the new silencers and it was immediately apparent that I would need a couple of spacers, where the silencers bolt to the frame to hold the new front pipes away from the engine casing, so I set about making some aluminium spacers and also replaced the rear foot rests, which hold the silencers in place, with new polished stainless bolts. No need for the foot rests as I'm putting a single seat on it.

At the front of the new exhaust pipes were two welded on small tubes set at right angles to the exhaust pipes. I soon figured out that, as these new swept pipes did not follow the line of the frame, they could not be bolted to the frame to secure them. The answer was to fit a bar between the two pipes and through these tubes to secure them to each other. But what to use? I found that the inside diameter of the small tubes was 10mm and that started me thinking about what I already had. My firm uses a lot of 10mm stainless steel threaded rod so I measured the required length and cut a piece off. Next I measured how much thread I needed either side of the fixing tubes and marked that. This left the long bit in between the two threads. My first thought was to cover it with a tube, but then a friend suggested that it would be better to simply put the rod in my lathe and turn the threads off, leaving a smooth bar in the middle. Brilliant!. Having done that 10mm nuts were acquired and a chamfer turned on all of the nuts so that they could bottom on the fixing tubes without hitting the exhaust pipes. All polished and fitted it looked a treat and allowed me to adjust the distance between the two pipes to ensure crankcase clearance.

The standard BSA exhaust clamps just did not look good enough, so I pulled out a card that I had collected at the Newark Classic Bike Show, in January, and phoned the man. He had exactly what I wanted beautiful 42mm stainless Allen Key clamps ready polished.

Now just a case of fitting it all. It originally came as a surprise, when I first stripped the bike, to find that there was no secure fixing for the exhaust pipes into the cylinder head. To ensure that I did not get leaks I put a liberal coating of high temperature silicon sealant around the pipes before fitting them and behind the finned heat sinks. All then bolted in place and it looks just great.

Just as I finished fitting the exhaust, my seat brackets arrived. I had been waiting for them for weeks. Having decided to fit a single seat, I had seen the one I wanted on a photo on the web and after making enquiries, I found out that it was originally off a BSA Lightning. Finding a stockist on the web was not too difficult, but when it arrived it was obvious that none of the A10 fixing points lined up. This meant that I had to design a seat bracket system from scratch. So I set about making one out of aluminium. See picture on the right.

I also had to re-drill the front  seat mounting fork to bring it nearer to the A10 frame mounting. That done I had sent the aluminium bracket off to have a proper and stronger Stainless one  made.

Now at last I could try it in place and offer the seat onto the bike. I fitted the new bracket into the seat and the new support bridge piece onto the mudguard and tried it in place. It fitted but the seat was a little off to one side. Not surprising really as aluminium is so easy to bend . But it only required one hole being re drilled on the bracket under the seat and it fitted perfectly.

It had occurred to me that I deeded to remove the seat easily to get at the battery. So the bracket was designed with the two studs sticking down, which passed through the new mudguard seat support bracket. I then turned two large aluminium knurled knobs to fit the studs and hold the seat in place, putting two rubber washers between the knobs and the bracket to stop them vibrating off.

Now, with the Gold Star petrol tank just sitting in place, the seat could finally be fitted and a first idea of what the bike will finally look like could be seen. What do you think?

 I would love to read your comments on this blog. If you would like to make some please click "Subscribe to: Post Comments (Atom)" at the bottom of this page. If you would like to be automatically informed when a new episode is posted then please tick the "Join this site" box at the bottom of the page. Thanks for reading. Kevin

 Copyright K. Hopcroft  10.03.13 All rights reserved
 You can contact me on: hopcroftscoot@gmail.com

My Other Blogs:

1961 Ariel Arrow Super Sport Motorcycle :
http://60sclassicmotorbikes.blogspot.co.uk/2014/01/1961-aerial-golden-arrow-restoration.html

Miniature Land Rover Defender:
http://miniaturelandrover.blogspot.co.uk/2016/02/1-miniature-land-rover-defender-idea.html?view=timeslide

1971 VW Karman Ghia Convertible Car:
http://karmannghiarestoration.blogspot.co.uk/2017/03/1-karmann-ghia-retoration-project.html

Motorcycle Trailers / Caravans:
http://motorcycletrailersandcaravans.blogspot.co.uk/2018/01/1-motorcycle-trailers-problem.html