Simson AWO designer Ewaldd Daehn 100 years anniversary

Notice from last week's Suhl newspaper that Ewald Daehn would have been 100 this week. He actually passed away in 2012 aged 97.

First Vintage Rally entry accepted

Riding along on Siegfried

Saturday at last and first chance for a decent run on Siegfried. Started 1st kick and ticked over tick, tock, lovely. Great run pulling strongly but oil leak at cylinder base upon return.

Sunday. Wiped off oil. Same start procedure, Velo style as always, but reluctant to start. Still not got hang of choke / throttle settings but after a rest away he went. Decided on A Great Big Ride to Northampton to show off Siegfried to VMCC. As always, like kids and dogs, bikes know when to let you down. My triumphant entrance was accompanied by the silencer coming loose and clattering on the road. Mmmm. Anyway nothing zip ties can't fix. After 30 minutes of Oh - it's a copy BMW I had had enough. Started 1st kick then clutch cable suddenly found the free play I had been looking for all by itself and I kangarooed away in front of the crowd.

Also one of the early morning swings on the kick start had suddenly spun all the way thru on the ratchet so now have stiff leg to show for it,

But all in all a success, the oil leak did not come back and Siegfried ran great.

At long long last Siegfried not running rich

And here is the image that has cost a fortune and 2 years to get to. Siegfried running correctly, no more sooty plug. Instant fix thanks to Mikuni carb conversion but head rework by Stu Rogers was well worth it as it had a broken inlet spring, wrong guides and valves. Also 12v contactless ignition was incorrectly set so that too was worth it. How does he go? Just as you would expect a heavy 250cc single to, pulls like mad and thumps up anything. Starts 1st time and ticks over like a clock. Delighted

Mikuni carb conversion

Despite trying hotter spark plug, up to 6 from 8, Siegfried disappointingly ran rich and out of uphill puff last time out. I consulted at length with Zweiradhaus Suhl who told me that the original BVF carb was never much good in the first place and that fitting their Mikuni carb conversion would cure any problems in the carb dept. As the £ is currently so strong against the Euro I decided their would never be a better time to get one so ordered everything necessary to do the job in one hit. It came with a new extra long throttle cable. Fitting this revealed a brilliant piece of clever engineering that I have not seen before. The throttle cable emerges from the twistgrip through a hole in the bars. I just thought that this was just German obsession with tidiness. The reality is that the Simson engineers realised that throttle cables snap due to metal fatigue about 1 cm away from the nipple as the central cable is coiled and unwound over and over as on a conventional twistgrip. Much better to have a straight line pull with no coiling. Thus the inside of the twistgrip tube has a raised worm drive. This mates to the slider which holds the cable nipple and which slider has a diagonal groove to accept the worm drive. The slider sits in a channel. As the twistgrip is turned so the worm drive causes the slider to move outwards thus pulling the cable. The cable exits through the bars because it has to. What a great little piece of engineering.

Mikuni carb conversion

Here is the other view of the Mikuni carb

Siegfried's Fork oil

The ride on Siegfried being very bouncy today I finally took a look to see what the fork oil was like. This involved buying a huge 35mm socket which just a tiny bit too small. At this stage I decided, look, it's my bike after all so I hammered it on. Off with the top yoke spring bolts and off with the drain plug. Result - not a drop came out. Both legs should have 0.075ml fork oil but only the gear lever side has a drain plug. So, on the basis that the drain plug side was empty, I took it as a fair guess that the other side would be too and filled them both. The forks now seem firmer but the rebound is still apparently undamped. Will only know when I go for a ride, if ever the cold, slimy roads dry up for long enough.