Project Flat tracker

While I have been sitting around on my bum with my right arm in plaster to my shoulder (its a long story) for the last four weeks, and at least another four to go, I have been reading all the bike mags and have been following two blokes building American style flat trackers. I like the looks and simiplicity of those bikes, and started thinking of the bits I have lying around here.
A couple of months ago I bought and resurrected a late 1980s Suzuki TS185 for my son in law to ride with his son and it came with some spare bits that I can use with this project. So far I have collected a Suzuki TF frame (ag bike), Yamaha XT tank, Suzuki TSX250 rear wheel, Suzuki DR front hub I can modify and spoke to 18" rim, TF forks and engine and sundry bits, Honda seat, unknown chamber, etc.

The engine is missing the magneto and flywheel and CDI box.

But I wonder what I will find when I open the cases to fix this?

Going to be a while before I can do anything other than look and plan.

 

Getting frustrated at not being able to get on with this, so decided to start on something small, the front hub.

I cut away the brake drum with angle grinder (my plasma has chucked in the towel) and turned down in the lathe to fit inside of a piece of thick walled 60mm alloy tube. then took a slice from a 100mm alloy bar and turned it to make a spoke flange.

Using a boring bar I made the internal hole a neat press fit to the hub and drilled for spoke mounting holes.

I will have to wait now for another two weeks ( I hope) before I get the plaster off so I can weld together and do final finishing.
When finished should look like this.

Not bad for an old bloke with only one working hand and a 60yr old worn out lathe.

 

Arm out of plaster now (but still weak and in a velcro brace) so able to get the TIG humming on the hub.


Back in the lathe to trim off the weld and true spoke flange, then spoked into a 2.15x18 rim using 3.5mm (9 gauge) spokes and trued up.

 

Got the engine split and all gears inside are good, so it must have been a thrown chain that bent the gear change shaft and cracked the case ( and why there was no sidecover with engine). Put shaft in vice and straightened.
Before.
I ground down a jigsaw blade and cut out the crack to remove all the epoxy that had been pushed into it.


This also gave a bit more room to get better penetration of the weld. I jammed a piece of 22mm mild steel bar into the shaft seal recess to keep the shape and stop any melted alloy from encroaching into the recess while welding.

Clamped in place and TIGed the crack.

Welded inside as much as I could too.

Cleaned up the shaft bearing with a reamer, a good clean up, new seals/gaskets and back together.

 

I brought the good TS home last trip to do some repairs. The front rim had developed a split.

I took all the spokes out and ran the saw through it to clean out the crack and give some room for penatration of the weld.

After welding and grinding back to original size, I gave it a new coat of two pack silver and fitted new spokes.

Now need some new fork seals before putting back together.

 

Today I had some time to work on this bike. I fitted up the forks and front wheel and put on bench. Engine sitting in with a couple of bolts and the remains of the swing arm. Sat the back wheel in the position I wanted to fit it and measured for swingarm length.

Using 50x25x2mm tube I had to modify the ends to fit the pieces of the quick change axel mounts in. This involved cutting a second piece and welding together to make it wide enough to fit the inner pieces. I then took some scrap pieces of 6mm alloy sheet, mounted in the drill press vice and by slowly moving against a cutter in the chuck was able to mill a step on each side to fit the end of the modified tube to use as a chain tensioner.
The pieces needed a rounding of the corners with a file to fit.

And fitted into the modified tube ready to be trimmed and welded to the swingarm.

Raining again and 'arthur' is giving me hell today so that is it for a while.

 

Have done a bit more this week.
Trimmed and welded the swingarm together with a support plate at the joint.

I cut and added a 30mm piece to the top frame rail above the carb to give me a 24deg rake, and with the 50mm offset of the fork yokes (tripple trees to the yanks, but I fail to see how you get tripple from two bits) this gives a 75mm castor (trail to the yanks) and a 56" wheelbase which is very close to the specs I looked up.
I cut and shut the exansion chamber to fit. It is a bit ugly but I think it will do the job. I made a bracket to hold the oil tank from a PW-50 (which holds about 100ml) on the right side and now need to move the right footpeg and brake lever down and back for a better riding position.

 

I had these old 1970s Boge shocks which were the right length.

I found a six point socket that fit snuggly onto the tube top nut.

But when I gave it a turn it fell to bits.

I ground down a cotton picker finger to a small chisel and with drilling and chiseling was able to get the nut remains out. Not pretty inside.

After cleaning the worst off the rest remained usable. (The picker finger is tapered silver thing near tube.)

The shaft seals had been well shot years ago and would just slip down the shaft, no chance of them holding oil. My son runs his own hydraulic business so I got him to order two 11mm seals for me and bought some 50mm alloy bar. This I threaded to screw into the bodies, machined to fit the seals and drilled to fit a peg spanner.

Repainted the bodies and springs with some orange paint close to the original, machined some new bushes from black nylon bar, a good clean up, new oil and assembled.

Ready to fit.

 

Fitted.

 

The alloy bar that I used to make the seal nuts for the Boge shocks had enough left to make one more seal holder, and the remains a spring spacer. Not bad value out of $11.00 of alloy bar.