Having discovered that my A10 super rocket was seriously leaking oil, I started to think about what could be causing it. One thing was certain, this was no leaking gasket, this was serious. It occurred to me that it could be only one of two possibilities.
1. The oil pump was not returning the oil to the tank, allowing it to build up in the sump and then be forced out of the breather by crankcase compression.
2. The whole problem could be caused by crankcase compression, after all I had not replaced the pistons or valves as they all looked fairly good to me.
I decided to look at the oil pump first. I removed the right side exhaust and timing cover, along with the tacho drive and took a look at the oil pump. But with no way of measuring it's output a visual check was all that was possible and it looked OK. I then noticed that I had only put a gasket under the main body and had not put one under the tacho drive end of the pump. A quick phone call to Lightning spares confirmed that this could be the source of the problem as without a gasket on both ends, the pump cannot seat properly and sits at an angle to the crankcase. Great, I thought. I fitted the small round gasket to the tacho end of the pump and put the bike back together. Unfortunately the result was the same with large amounts of oil being blown out of the breather.
After a great deal of thought, I came to the conclusion that without the correct test equipment, I might never find the source of the problem and so I took the expensive decision to take the bike back to SRM another 340 mile round trip.
Having taken the bike to SRM in the trailer (which I left there) they got on with the investigation and removed the oil pump and put it on a test rig. The tests proved that the pump emptied the test tank in 14 seconds but took 42 seconds to refill the tank. So my sump was slowly filling up with oil. I said OK to a new oil pump, which they fitted and the oil now returned to the tank correctly. However this was not the end of the problem. Oil was still blowing out of the breather, although nothing like as bad as before.
I gave them the go-ahead to strip the engine and investigate and the end result was that my visual inspection had not been enough to ensure that the engine was fit for the rebuild. In fact it revealed that the engine needed new pistons and rings, re-sleeving of the barrels, new valves and guides, new valve seats and valve springs. Expensive! but there was absolutely no point in reassembling the engine with the old parts in it, so I said "go ahead". A week later I collected the bike and trailer and it ran beautifully with no oil leaks.
Time for its MOT which was just around the corner at a bike shop called "Street Machine" and it passed, although I did have some difficulty with the gears getting it there. Once MOT'd I got the new free tax disc and at last I was on the road.
The first ride was a mixture of total exhilaration mixed with disappointment. The bike handled and accelerated brilliantly. The disappointment was the gear change. No matter how I tried I could not get it to change down once I had changed up the gears. This did not stop me taking the bike to its first show at Thorsby Park where I showed it alongside the scooter (Mods & Rockers) and where it got lots of attention although no win. In fact the scooter won!
After the show I took the bike back to the workshop and tried it again up the road. But the gears were still impossible to select when changing down. I suppose that at this point I became lazy and instead of stripping the gearbox again, I decided to make the trip again to SRM. If only I had asked them last time to road test the bike before collecting it. But I didn't.
So for the third time I took it back to Wales again and this time I said "check everything" "make sure it is 100% before I fetch it back" and they did. The gearbox problem turned out to be an "indexing problem" which they fixed without removing the box and the bike road tested perfectly.
I collected it and brought it home, just in time to attend the Rockingham show, at which it came second out of 120 bikes.
I then took it to the Belper steam rally, where there are no prizes, but it got lots of attention and was photographed for use by a company who make metal wall signs. See:
http://www.ebay.com.au/itm/BSA-A10-SUPER-ROCKET-MOTORCYCLE-METAL-SIGN-/400515757847?pt=UK_CarParts_Vehicles_Manuals_Litterature_ET&hash=item5d40997717
Two more shows followed: The Grantham Show, where the bike won a trophy for "Best Motor Cycle" (and the scooter won "Best Scooter") and Yesterday, back at Thorsby Park, where the scooter won best 60's bike and the BSA Super Rocket won "BIKE OF THE SHOW"
And that is the end of the blog, unless you want more? If you do click "Newer Post" and keep reading.
I would like to express my sincere thanks to Lightning Spares, of Birmingham and SRM Engineering of Aberystwyth, without who's help this project would not have been completed.
My next project: 1954 BSA Bantam.
TWIN LEADING SHOE FRONT BRAKE.
1. The oil pump was not returning the oil to the tank, allowing it to build up in the sump and then be forced out of the breather by crankcase compression.
2. The whole problem could be caused by crankcase compression, after all I had not replaced the pistons or valves as they all looked fairly good to me.
I decided to look at the oil pump first. I removed the right side exhaust and timing cover, along with the tacho drive and took a look at the oil pump. But with no way of measuring it's output a visual check was all that was possible and it looked OK. I then noticed that I had only put a gasket under the main body and had not put one under the tacho drive end of the pump. A quick phone call to Lightning spares confirmed that this could be the source of the problem as without a gasket on both ends, the pump cannot seat properly and sits at an angle to the crankcase. Great, I thought. I fitted the small round gasket to the tacho end of the pump and put the bike back together. Unfortunately the result was the same with large amounts of oil being blown out of the breather.
After a great deal of thought, I came to the conclusion that without the correct test equipment, I might never find the source of the problem and so I took the expensive decision to take the bike back to SRM another 340 mile round trip.
Having taken the bike to SRM in the trailer (which I left there) they got on with the investigation and removed the oil pump and put it on a test rig. The tests proved that the pump emptied the test tank in 14 seconds but took 42 seconds to refill the tank. So my sump was slowly filling up with oil. I said OK to a new oil pump, which they fitted and the oil now returned to the tank correctly. However this was not the end of the problem. Oil was still blowing out of the breather, although nothing like as bad as before.
I gave them the go-ahead to strip the engine and investigate and the end result was that my visual inspection had not been enough to ensure that the engine was fit for the rebuild. In fact it revealed that the engine needed new pistons and rings, re-sleeving of the barrels, new valves and guides, new valve seats and valve springs. Expensive! but there was absolutely no point in reassembling the engine with the old parts in it, so I said "go ahead". A week later I collected the bike and trailer and it ran beautifully with no oil leaks.
Time for its MOT which was just around the corner at a bike shop called "Street Machine" and it passed, although I did have some difficulty with the gears getting it there. Once MOT'd I got the new free tax disc and at last I was on the road.
After the show I took the bike back to the workshop and tried it again up the road. But the gears were still impossible to select when changing down. I suppose that at this point I became lazy and instead of stripping the gearbox again, I decided to make the trip again to SRM. If only I had asked them last time to road test the bike before collecting it. But I didn't.
So for the third time I took it back to Wales again and this time I said "check everything" "make sure it is 100% before I fetch it back" and they did. The gearbox problem turned out to be an "indexing problem" which they fixed without removing the box and the bike road tested perfectly.
I collected it and brought it home, just in time to attend the Rockingham show, at which it came second out of 120 bikes.
I then took it to the Belper steam rally, where there are no prizes, but it got lots of attention and was photographed for use by a company who make metal wall signs. See:
http://www.ebay.com.au/itm/BSA-A10-SUPER-ROCKET-MOTORCYCLE-METAL-SIGN-/400515757847?pt=UK_CarParts_Vehicles_Manuals_Litterature_ET&hash=item5d40997717
Two more shows followed: The Grantham Show, where the bike won a trophy for "Best Motor Cycle" (and the scooter won "Best Scooter") and Yesterday, back at Thorsby Park, where the scooter won best 60's bike and the BSA Super Rocket won "BIKE OF THE SHOW"
I would like to express my sincere thanks to Lightning Spares, of Birmingham and SRM Engineering of Aberystwyth, without who's help this project would not have been completed.
My next project: 1954 BSA Bantam.
MODIFICATIONS & REPAIRS
This section has been added after the renovation and keeps you up to date with any changes or problems I may have with the BSA A10 Super Rocket.
TWIN LEADING SHOE FRONT BRAKE.
After taking the BSA A10 to several rallies and going on a few road runs, one thing was very apparent. Whilst the performance was great, the brakes were definitely 1961 and in order to come to a stop in a sensible distance, it was necessary to use both the front and rear brake and change down through all the gears and in modern traffic, this just wasn't good enough.
So I started looking at possible front brake modifications and it didn't take me long to realise that what I needed was a "Twin Leading Shoe" front brake.
This first picture shows the original brake. Although it was totally overhauled and was one of the later full width hubs, its braking ability was still extremely limited.
So after searching the Internet, I found this one for sale on EBay. As you can see, it's a reproduction one, but nicely made. Unfortunately, apart from the outer rim, the rest of the back plate is a rough sand casting and all of the lever system was galvanised. So two jobs now faced me. Firstly strip off all the lever system and send all of the parts off for chrome plating. Secondly, start the long job of polishing the back plate up to the standard of the rest of my bike.
The good news was that it came with a nice new set of brake shoes and the new brake fits in my existing brake drum nicely and the axle passes through the centre hole perfectly.
However trying the wheel back in place with the new brake fitted revealed two small modifications necessary. Firstly, with the retaining nut on the axle, holding the plate in place. It would not fit between the front forks and I couldn't get the end caps on the bottom of the forks. To cure this I had to put the retaining nut in the lathe and turn it down to half its thickness. Now the wheel and hub fit between the forks.
The next problem was that the lug on the inside of the right fork, that stops the back plate rotating when the brake is applied, would not fit between the slot on the back plate. This was only about 1mm too tight so I removed a little metal from the back plate slot with a Dremel fitted with a rotary sanding disc. The wheel and hub now fit perfectly.
Polishing the back plate took a very long time, as the surface is quite complicated with lots of small nooks and crannies. I found some very useful bits for my Dremel, which consisted of some small green rubber tipped bits that were impregnated with a fine abrasive. These were great for getting into difficult places but wore out very quickly and I think I got through about 15 of them before I was totally happy with the finish.
Now all of the bits arrived back from the chrome platers and they look much better. So after re-assembling the back plate, the wheel with its new hub could be fixed into place between the forks. and this presented another problem. The mudguard stays now did not fit. The front one hit the air intake and the rear one hit the actuating mechanism. I was faced with a decision: make some bent stays or reposition them. I decided to go for the latter.
The front stays were easy. The aluminium plates that I had made to fix the front stay to the fork end cap had an offset lug on it. By swapping the left plate for the right one I offset the front stays sufficient to clear the air intake.
The rear one was not so easy. I decided to take the mudguard to my friend at Unit Two Services, Ilkeston, and ask him to cut off the rear lugs and reposition them as my welding skills are poor and he's brilliant at welding stainless steel. So I marked to mudguard where I wanted the lugs, higher up the mudguard and left him to it. He cut them off and re-welded them back on perfectly, so all I needed to do was re-polish the mudguard and refit it.
Obviously I did both sides of the mudguard so that they would look symmetrical and now the stay clears the mechanism perfectly.
The final thing to do was adjust the brake and then road test it.
Wow!! just a touch on the brake lever stops the bike dead and I'm happy with the way it looks too.
So I started looking at possible front brake modifications and it didn't take me long to realise that what I needed was a "Twin Leading Shoe" front brake.
This first picture shows the original brake. Although it was totally overhauled and was one of the later full width hubs, its braking ability was still extremely limited.
However trying the wheel back in place with the new brake fitted revealed two small modifications necessary. Firstly, with the retaining nut on the axle, holding the plate in place. It would not fit between the front forks and I couldn't get the end caps on the bottom of the forks. To cure this I had to put the retaining nut in the lathe and turn it down to half its thickness. Now the wheel and hub fit between the forks.
The next problem was that the lug on the inside of the right fork, that stops the back plate rotating when the brake is applied, would not fit between the slot on the back plate. This was only about 1mm too tight so I removed a little metal from the back plate slot with a Dremel fitted with a rotary sanding disc. The wheel and hub now fit perfectly.
Polishing the back plate took a very long time, as the surface is quite complicated with lots of small nooks and crannies. I found some very useful bits for my Dremel, which consisted of some small green rubber tipped bits that were impregnated with a fine abrasive. These were great for getting into difficult places but wore out very quickly and I think I got through about 15 of them before I was totally happy with the finish.
Now all of the bits arrived back from the chrome platers and they look much better. So after re-assembling the back plate, the wheel with its new hub could be fixed into place between the forks. and this presented another problem. The mudguard stays now did not fit. The front one hit the air intake and the rear one hit the actuating mechanism. I was faced with a decision: make some bent stays or reposition them. I decided to go for the latter.The front stays were easy. The aluminium plates that I had made to fix the front stay to the fork end cap had an offset lug on it. By swapping the left plate for the right one I offset the front stays sufficient to clear the air intake.
The rear one was not so easy. I decided to take the mudguard to my friend at Unit Two Services, Ilkeston, and ask him to cut off the rear lugs and reposition them as my welding skills are poor and he's brilliant at welding stainless steel. So I marked to mudguard where I wanted the lugs, higher up the mudguard and left him to it. He cut them off and re-welded them back on perfectly, so all I needed to do was re-polish the mudguard and refit it.
Obviously I did both sides of the mudguard so that they would look symmetrical and now the stay clears the mechanism perfectly.The final thing to do was adjust the brake and then road test it.
Wow!! just a touch on the brake lever stops the bike dead and I'm happy with the way it looks too.
