Disaster!

Saturday was a high-speed race to prep the bike for Sunday's hare-scramble. There were two main things left to do: first was to sort out the shocks, second was to sort out the chain.  Now, these two things should have been a snap, but I'm slowly learning that finding suitable parts in this town is next to impossible.

Only one place sells metric nuts and bolts, and they're closed on Saturdays. Luckily I picked up some bits on Friday, namely some nuts and bolts that fit the shock mounting holes in the swing-arm. But to my surprise, the holes did not match the ones on the shocks themselves, which were 12mm rather than 10. Dad and I searched all over town to find some sort of insert to do the job, some sort of bushing or other small cylinder that had the proper outside diameter (then we could drill out the inside diameter to fit), but to no avail. Finally we hit the motorcycle salvage and managed some 10mm grommets off an old Suzuki in the yard, which the guy let me have for free! Note to self: next time go there first!

After that we searched for some chain. No motorcycle dealer in the city had 520 chain. Unreal. We were sent to John Deere by the Kawasaki dealer, but they didn't have any either, and the Suzuki dealer sold us a brand new, heavy-duty job for $150 that doesn't even fit. Finally we managed to find some links at Peavy Mart and splice together the chains from the '71 and the '74.

After some other bits and parts that needed sorting, I made an exhaust mount out of one of the grommets that we pressed out of the shocks, since the last owner had apparently lost the original and simply wrapped the bolt with what seemed like an entire roll of electrical tape.

 It was now 7:00: fifteen hours until the race. I got everything together, and loaded the bike in the truck and was off to the track for the first (and only) test run:

As you can see, the bike needs to be rev'ed quite high to take-off.

The chain broke soon after that and ate its way into the case. We were done.

I think it's time for a new dirtbike.

Good News and Bad News

The good news is that I was able to get the axel holes machined out (for another whopping bill--I'm beginning to think about switching shops next time), and yes, the axel nuts fit.

The bad news is that

1. The shock holes on the swing-arm are smaller than the holes on the shocks, which means I either have to drill out the holes on the swing arm or try to find new mounts for the shocks
2. Because the swing-arm is so thick, once the axel nuts are through and threaded, there won't be enough room for the adjusters (not that they fit anyway)
3. The brake cable seems like it may be... ahh who am I kidding, they are too short, but I'm hoping that once the wheel is on and the suspension takes up some weight and lowers the frame it will free up some of the cable.
4. Last time I ran the bike it wouldn't run for more than thirty seconds, but that may have been because I couldn't rev it high enough to ride it with any competency since I was in a residential neighborhood
5. I still don't know if the bloody wheel will even fit with the brake in place.
6. The race is on Sunday morning
7. The possibility that I may have to race the most dangerous motorbike ever built is quickly turning into a reality

Nothing's Ever Easy

Right, so the new swing-arm came back from the machinist today with a bill that almost made my eyeballs explode. The tab for the brake mount was nicely done as were the new bushings to accommodate the new swing-arm, but damn it was expensive! I mounted it on the bike after a trip to Princess Auto for some spacers ( read: washers) to fill the gap between the swing-arm and the frame, but I mistakenly sized them to the bushings rather than to the pivot arm, so after another trip to Princess Auto I finally fitted it. At first it was a bit loose, but tightening the pivot-arm nut cured it. I mocked it all up just to get a look at her after I repainted the fenders I bought off ebay, but that may have been wishful thinking...

I began to put wheel adjusters when I noticed that the new swing-arm was thicker than the old one, so the adjusters wouldn't fit onto the new, thicker, aluminum job! I muscled them on as best as I could, hoping that once the axel was tightened, they would come in line, which lead me to my next discovery.

The lengthy oval-like axel holes are smaller on the new swing-arm! This means that the old axel nuts won't fit. Now I'm screwed.

My first idea was a dawn-lit run to the Motorcycle Salvage to see if I could find workable parts, but further thought led me to conclude that the DR 500, the model from which this swing-arm comes, must have a smaller axel. So even if I got new axel nuts that fit, there was no way the old axel would fit through it.

I tested my theory, and sure enough, the axel barely even made it through the holes alone, never mind while shrouded by two axel-nuts. So there goes idea number one.

Idea number two was to use a smaller axel, but then it wouldn't fit my wheel, and there is no way I'm changing that, so that idea was gone as quickly as it came.

My last option is to take the swing-arm back to the machine shop and have the holes enlarged to match the old ones. I just hope he can do it tomorrow. The race is on Sunday and there is still a ton of stuff to do, like ensuring the bike will run for longer than 30 seconds.

I'm beginning to think I might have to run Dad's Bike. Heaven help me.

Swinger

Race day is coming up and I'm having doubts about whether or not Ricky's Bike will be ready in time. After calling around I managed to snag an aluminum, box-type swing-arm from B.C. to replace the original tubular steel one. The TMs are notorious for frame flex, although I've heard that with the frame modifications that came in '73 the major problems were cured. Nevertheless, I read that the swing-arm from a DR 500 is a bolt-on replacement that enhances the handling ten-fold. It's a bit longer, which shouldn't be a problem as I intend to replace the shocks anyway, but the big problem is that the bracket for the brake steady isn't on the swing-arm as it is for the TM. On the DR, the brake steady, which is just a tubular shaft that holds the brake-drum in place, is connected to the frame, whereas on the TM it is connected to the swing-arm. The other problem is that the swing-arm pivots, which are basically axels, are different sizes. The DR's has a larger Outside Diameter, which means it won't fit through the frame holes. I thought I could simply use the TM's pivot arm, but since it has a smaller OD, it creates play within the DR's swing-arm. Nothing's ever as simple as it seems when it comes to modifying motorcycles.

I thought of two solutions: the first option is to enlarge the frame holes so that the new pivot arm can fit, but I always operate under the assumption that one should avoid permanently modifying the frame as much as possible, so that is out. The second option, which is the one I'm going with, is to weld a tab onto the new swing-arm that would accommodate the old brake steady, but since it's aluminum and I don't have a TIG welder, I had to source it out, so hopefully it will be finished by Monday.

The other thing is that the bushings that hold the pivot in place are different sizes, so I'm getting some custom made that will have the OD of the DR and the ID of the TM. Sweet.

I'm not sure if I'll need to buy a new chain or add some links to the old one yet, and probably won't know until the swing-arm is mounted, but either way it shouldn't be a big deal. It's just more money; speaking of which, my new motocross gear came in this week: Thor "Rage" pants and jersey, a Thor clear chest protector, and Fly racing gloves. My ensemble is now complete except I was a bit optimistic when ordering the pants and they are too small, but new ones are on the way. If anyone is interest in a brand new pair of Thor Rage motocross pants, size 34, drop me an email.  $40 + Shipping.

I'm still crossing my fingers that everything will be ready come race-day. My back-up plan is to run Dad's Bike, the 1971 TM 400. It is a wild beast, a widow-maker, a shoulder-dislocator, and a bone-breaker, but it will be my only option.

 Mark Twain said that in twenty years, we will regret the things we didn't do more than the things we did. I'm trying to keep that in mind.