Updated Feb 2012

Photos showing the R11's hill climbing days.
Lots I can't answer, how he altered the inlet etc. One of my earliest memories as a young child is a very load scary noise coming from the bike and being told not to be scared. The rider in the photo's is my uncle.
The photo's were taken at the Val des Terres hill climb in Guernsey, one of the Channel Islands occupied by German forces during WW2, the reason for the bike being there. My father returned to the island at the end of the war and started work as a marine engineer apprentice. Most of the work was stripping and salvage of the military hardware left on the islands. I have a catalogue from 1946 showing about 150 vehicles auctioned off. £7 in pencil at the side of the BMW, although I am not sure if he bought it at the auction or later as he told me he got it with a 350 DKW for £7/10s.
He used the BMW on as regular transport until my sister was born, 1951 and then he used the FN outfit he had, that also towed a small boat!
My uncle is still alive, but lives a reclusive life with little contact and not even a telephone. I see him about once a year, but he is very vague when I ask him about the bike and what he did, where did the other bikes go etc. I think he sold some parts to Markhouse motors in London.
The bike came to Yorkshire in bits over the years during the 60's, each time we visited the family another bit came back until we had a complete assembled bike living in the front room. We used to take the car which before ro/ro ferries had to be craned on and off the ship. I am sure there would have been an easier way to get the bike back. It later lived in the shed.
I was 24 when I restored the bike originally and had little to go on, no internet! I painted it black, now I know the bike should really be grey as it was supplied to the military in Cannstadt, Stuttgart. Hence the single SUM. In the past few months the engine has had work, and several new parts to the rest of the bike. It needs an original R11 headlight as the one fitted I believe is R12/17. But it is now running and over the winter will be finished. I have not repainted it as it looks 90%, maybe when the R62 is running I can repaint it correct colour.

Update 5th Feb 2012.

Repro headlight fitted.
I recently sent my uncle some photo's of the R11 along with a few questions regarding it's history. He replied and can now answer some of the unknown.
The bike was bought from the auction by the son (first name unknown) of Sir Ambrose Sherwill. He was the Island Bailiff at that time. My father purchased it from him shortly after. A DKW twin was purchased at the auction by may father and pushed home by him and my uncle. Between them they had bought an R12 combination in the 1950's and the R17 engine came spare with that. With a couple of other R12 engines my uncle purchased over time, he had plenty of bits to play around with. The unknown cylinder heads were R12 with the fins cut off.
The casting around the top of the flywheel was cut to allow a V belt off the flywheel run an Arnott supercharger. He says it was all very "hodge bodge" and done with minimal money spent. He said the charger ran too fast, and the belt would stretch alarmingly with revving. Knowing where the belt was running, I think I would have fitted a guard! The supercharger was bought in 1957 from a scrapyard. The supercharger was sold to Maurice Ogier, a most interesting man I met once many years ago. He has a collection of rare bikes and has engineered endurance racing Laverda's, and I believe the smallest capacity bike to win at daytona. He also has some early Honda 125 and 250 racing machines, one was rebuilt as a magazine feature.
The camshaft was cut and re-welded to allow reversal of the inlet. The bike did the hill in around 50 seconds, today top machines break 30 seconds. The hill climb is still run twice a year, one being a UK national event with the top British and European machines. The other mainly locals. Go Karts are among the fastest things up the hill. Much of the course has steep sided granite walls with no run off area, but they do put some straw bales around the lamp posts!

Feb 17th 2012
The bike on it's earliest photo had the original headlight. This seems to have been replaced with the R12 one it had until recently.
The silencers had also been swapped from un-original to series 5/R12 type. I am also told it had a Bowden carb fitted by my father, and it did run better with this.

Late 50's, mainly R11 but unsure about the heads

blower feeding inlet.

R11/17 blower feeding exhaust port. I believe this photo was taken by the Guernsey press photographer

tele forks and shows straight out of inlet exhaust

another shot around 1962. Again press photographer.

The bike now

bike nearly completed, battery and rear light to fit

paint now 30 years old! New chrome and rubber bits.

R62 before dismantling.

R62. Mudguards repaired, nearly ready for painting.

Earliest photo I have of R11. Taken outside "Frie-au-Four", La Neuvre Rue, Guernsey.

Taken at the Bathing Pools, St Peter Port.

My sister on R11 with Guernsey registration 1624

Taken at "Clairval" my grandparents house.

1941 FN M12?

My fathers other bike, same sister, taken 1951. Again taken "Frie-au-Four"