need to modify hatz flywheel casing?

[Sphere]

Is there a need to modify the Hatz flywheel casing? It seems to be portruding quite a bit in the direction of the gearbox. I have taken a look at pics from Sommer, but I can't really make out what he has done about it. I suppose his casing is flatter so the gear peddle will fit? In the picture at least the fuel filter has to move, but behind it is still a large piece of the black metal casing portruding.

[Sphere]

Today a serious attempt was made at mating the Hatz to the frame. It appears that it is not possible without surgery. Sommer chooses to shorten the downtube, for my frame a different approach was taken; cut two-thirds into the tube, bent it, cut again, bend it and tack it.

Also, the flywheel casing requires slimming; the portrusion at the gearbox side needs to be cut off. I don't know if this is also applicable to the china diesel/yanmar conversions. No pictures yet, I will try to make some before the next phase starts. Lots of debating and small stuff was done, but I will explain in detail later.

[Dan J]

Also, the flywheel casing requires slimming; the portrusion at the gearbox side needs to be cut off. I don't know if this is also applicable to the china diesel/yanmar conversions.

No - but it is a tight fit. There is certainly no room to fit the 5 speed gearbox (which has a larger case) with the standard Yanmar conversion.

Good luck with your conversion Sphere. Look forward to more pictures/news as they happen.

[Sphere]

EDIT: never mind, this Hatz is from an actual Sommer which clearly explains this remarkable "coincedence"
I found a blog which shows a Hatz casing similar to the one Sommer uses in their bikes. Apparently they make several? I would assume this one does fit in the frame.

http://reto-forrer.blogspot.com/2007/02 ... wecks.html

[Sphere]

Here's some pics of open Hatz surgery. There was a bit of play on the crank, so the block was disassembled by someone that actually knows what he's doing. It seems there is nothing wrong though. Another bit of good news is that Hatz NL lied to me (again), this time about the possibility of retrofitting a counterbalance. Even the workshop manual agrees with me. However, we'll see how it goes without one first.