Saturday, 1 December 2012

15. BSA A10 Chain Gang

Now that the gearbox is in place, it's time to fit the final drive chain and the chain guard. I felt that it was not a good idea to re-fit the old chain as I have no knowledge of how old it is or what kind of life it has had, so I bought two new chains. The final drive chain and the primary drive chain, which  I will fit later.

The final drive chain came with a split link so it was simply a case of running the chain around the two sprockets and fitting the split link. Easy.

Fitting the chain guard was not so easy. Having been tempted by a lovely custom made stainless steel chain guard, on EBay, I offered it up to the frame to find that none of the mounting holes lined up. In fact two of them were missing. Not to be put off I decided after much thought that it was best to use one of the existing holes in the new guard and re-drill the frame. This involved marking the rear chain guard lug lower down than it's original top hole and re-drilling the lug in the new marked position. This gave me a pivot point in the correct position. The guard could then be set at the right angle and the two front mounting lug holes could be measured from that point. These measurements were then transferred to the guard and marked on the guard for drilling.

You would think that to drill a flat piece of metal would be straight forward, but this stainless steel turned out to be exceptionally hard. Despite the fact that I was using a pedestal drill, nothing seemed to touch it and I managed to ruin two drills before I realised that I needed another approach. I phoned my friend who has been an engineer all his life and he informed me that to drill hard stainless steel you need a very slow drill and once you start drilling, don't stop or the surface you are drilling will harden. The drills I had in my workshop were all too fast, but I remembered that I did have a variable speed drill at home that I had never used. With the variable speed drill in the pedestal and a small sharp drill in the chuck I tried. Hey Presto! through it went! I just then increased the drill size 1mm at a time until the holes were done. Isn't knowledge wonderful?



With the holes all done the chain guard fitted beautifully, but it left the bottom rear support lug dangling down from the swinging arm and not being used. It had to go. But I did not want to remove the swinging arm again and I could not get a hacksaw in. The answer was a Dremel with a cutting disc on it and after about 10 minutes the lug had gone and the raw metal repainted. It was now just a case of bolting the guard in place. I decided to put the bolts through from the right side of the bike to allow me to fit polished stainless steel dome nuts on the left side. This done it was on and looked beautiful.

If you have ever built a show bike, or car, you will know that the process is on-going and as you do one thing a new idea emerges that makes you change your earlier decisions. This happened with the chain guard dome nuts. I decided that they looked so nice, I would change all of the nuts on the bike, wherever possible for dome nuts. So I have re-ordered all of the crankcase and engine and gearbox mounting nuts and will change all of the already carefully polished stainless ordinary nuts for domes. More expense!

 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  01.12.12 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

No comments:

Post a Comment