PartZ

First batch with Zündapp goodies except for the already arrived spokes.
This time just quite boring replacement parts.
So to spice up things I took the expensive choice and went for the stainless steel alternative.
Axles and chain tensioners are in this premium choice.
The rest are hollow axle, swing bushings and rubber for the elastic sprocket mount.
I also went for the red NGK spark plug cap/wire.
Also planning to upgrade the ignition/charging system from 6 to 12V and besides that a red "Racing Cable" maybe makes things a little more spicy?

Fan...

Not used at all of this. 

But actually really nice to meet a fan.

Me and the fan 

Smooth Rollin'

Both hubs was in desperate need of new bearings.
Rear because they were just old and rusty.
The OEM Zündapp/Marzocchi front axle have larger diameter than the donor bike so the old bearings had to go there as well.

For the rear I bought SKF local of the shelf.
But in the front I had to go abroad because of the odd bearing size needed.
I found a OEM Suzuki bearing from Koyo in the UK with the new specs needed for the conversion.

To remove the old bearings I just welded a nut to the old bearing and used a slide hammer and out they came.

In the rear it was just a replacement job.
But in the front I also had to machine the center spacer between the bearings from 15mm to 17mm.
And after that it was a straight forward job even in the front.

Next up was the spacer.

I machined the old OEM Zündapp brass spacer to the new measurements and suddenly I had a Yamaha brake hub in a Zündapp/Marzocchi fork.

Next up, fork deconstruction to give the triple tree and legs some massage and shine....

Beefing up the Zündapp frame

Another frame mod that I actually did four years ago was to beef up the swingarm pivot point.
The change is to the new type from the newer Zündapp model.
The swingarm axle diameter is increased from 10 to 14mm.
I have a friend who did this way back so I was keen to try it myself on my ride.
Have no idea how he did but this is how I did it.

This was now possible because I just bought the TIG welder at the time.
So a newer Zündapp "529" frame was bought and butchered up and my older Zündapp "517" frame was cut to accept that piece.
But before any cutting on the old frame could be done a fixture was fabricated to maintain everything straight and on the same position.
When the fixture was made I just had to cut it and increase the swingarm mounting hole from 10 to 14mm and slide the beefy part into place and secure it to the fixture before the TIG was fired up.

Fixture done and the "517" frame ready for cut.

Old "517" frame cut and trimmed to accept the new "529" frame part.

The new "529" swingarm mount testfitted.

The new "529" piece part of the old "517 frame.

Here is the lower M10 fixation point enlarged with the beefier M14 rod.

Just some nice welds and the job is done

Straightening the Zündapp frame

When i´m now rebuilding my old friend the frame needed some love and affection.
First up, straighten it.
The frame had been involved in some serious wall hitting or something similar in the past and this had to be reversed.
The weapon of choice was brute force and fire, an ancient combo that have been successful since day one.

The before shot

The torch was lit and with some heat on strategic spots in combination with me pulling it in the right directions the work was done.
Straight as a ruler? Nah. But definitely good enough.

Mayhem to be made

New wheels for the Zündapp

This will probably be a series of posts about the creating these wheels.
One of my most neglected vehicles for sure is the Zündapp.
My beloved lightweight bike.
A regular 30 km/h moped converted and registered as a motorcycle back in 2003.
Upgraded from original 1hp, 3 speed & 50cc  to 70cc, 5 speed engine, KS125 fork to name a few, but since then just minor focus in the shop.
But in my head and heart the Zündapp have always been number one.
I have even tattooed the Zündapp logo on my shoulder.
#dedication

The goal have always been a bit away from the original look but still with Zündapp parts.
But for the past time it have been more focus to make a caféracer of it.
Over the years I have gathered parts for this build so many things are already on the shelf in the shop ready for next step.

The first thing to take the next step are the wheels.
Hubs was already arranged, the small OEM Zündapp hub in the rear and a big Yamaha drum with unknown origin in the front.

Hub size comparison, OEM hub vs the new Yamaha drum

Rims and spokes was something that I didn't had so a set of 18"x1,85" Borrani Record replicas was bought from Italy and the hunt for spokes begun.

Something like this will it turn out.

To find spokes is no big deal, but in what length? That's the real head scratcher.
First a mock-up with a set of old Zündapp spokes.
In the front the length was enough to make a measurement but in the rear I had to come up with something else to measure.
So I had to raid my kids old party equipment to get some straw's to extend the spokes and voilà I had the rear lengths as well.

Mock up with the straws

Next up:
# Order spokes and nipples
# Mock up the front drum on the bike
# Lace the wheels
# Buy and mount tires and put on the bike

To be continued...

Multiple focus

Not just the Speedster will have attention this winter.
The ugly duckling of Bombus Speedshop, the Zündapp will also have some love.
I have a old dream to made it more of a café racer.
I have gathered parts for this reason over the years and finally this journey have started.
First up, new wire wheels instead of the mag wheels I have now.
This will also give me a nice big drum brake in the front instead the great, but not so nice looking disc brake I have now.

Old pic of my partner in crime for almost 20 years.