The Knuckledragger Takes It's First Breath

Not without some monkeying around, though. (Monkeying around/ Knuckledragger; get it?)

Last fall I finished up the build on my re-creation of a 1950's drag bike, "The Knuckledragger." I did take one stab at starting the bike at that time, but my tendency towards, shall we say, frugality, foiled that attempt. I pulled the battery out of one of my cars to power the roller starter. Unfortunately a weaker than expected battery and a lot of compression conspired to "shoot" the rollers out from under the rear wheel on each attempt.

Then, being the skinflint that I am, I chose to wait till spring to purchase a new battery. Two actually. After conferring with the builder of the rollers, I opted to run them on 24 volts rather than 12.

So, with a pair of 795 cold cranking amp batteries, and the help of our son Joe, it was time to see if the bike would actually run. The first glitch came soon enough. In the excitement of the moment, I forgot to rewire the solenoid on the rollers. I knew better of course, as evidenced by the fact that I realized immediately what I had done wrong when the contacts welded themselves, leaving me helplessly holding the bike up as the the rollers (and the rear wheel of the bike) spun uncontrollably. Luckily, Joe is a veteran of dragbike stuff not always behaving as planned. Without hesitation he started to unhook a battery cable. Hmm. Maybe I should have actually installed that 1/4 turn quick disconnect that I had left over from an earlier drag bike starter rather than just bringing it along.

No problem, at least no problem a quick trip to the local auto parts store for a new $36 solenoid wouldn't solve. With the new solenoid AND the quick disconnect installed, we were ready for round two.



Bike on the rollers, a squirt of raw gas into each carb (in case the alcohol doesn't want to light), high gear, rear wheel spinning, dump the clutch, engine spinning, and.... nothing!

Now what? Not even a pop or backfire. Must not have spark. We pull the plugs and ground them so we can check for spark. Fire up the rollers again, and sure enough, no spark. And its a new magneto! Wait, could I have wired the kill switch backward? With the engine still turning over, I flip the switch back and forth, and low and behold we get spark.

Better check that switch with an ohm meter; I can't believe I wired it backward! Well.... no. Its wired correctly, but it is intermittent. One time you flip it, and it makes contact, the next time it doesn't. Not a very good situation for a supposed safety feature! For now we'll just disconnect the switch from the mag and substitute a blade from a feeler gauge to work as a shut off switch. Besides, we have the front wheel against the building to prevent any really serious surprises.

So, we go through the whole drill again. Bike on the rollers, high gear, rear wheel spinning, dump the clutch, engine spinning, and.... it lives! And not half bad at that. I fully expected to have to do some adjusting on the low speed in order to even get the bike to idle, but I was wrong. It idled and took throttle just fine. But The Knuckledragger had one more monkey wrench to throw at us. No oil pressure.

This was not a total surprise. I had my doubts about the ability of the tiny little pre 1940 pump to pull oil uphill from the trans case, especially at the odd angle it was situated in the VL frame. In fact that is the reason I had a pressure gauge temporarily mounted. Despite a couple attempts at priming the pump, it looks like a separate oil tank is going to be in order. I left a tab on the back side of the seat post for just such a situation.

All in all, I have to admit I am quite pleased. It was fun to monkey around on a drag bike with Joe again (he started drag racing at the age of 15, if memory serves). And best of all, The Knuckledragger runs!

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