Workin' on the Chain Gang

MMMM..... three piece sandwich

Today I mounted one of the rear sprockets to the BH hub. These sprockets come blank, with a 7/8" center hole. I had to lay out and drill the 4 holes to bolt it to the hub and also bore out the center hole to 2 1/8". I had to use my big ol' honkin' 14" faceplate for this bit of backyard machining. I had to, first, machine a plug to fit the center hole. this was used to find the actual center of the sprocket to lay out the mounting holes and later to attach it, concentrically, on the faceplate Once I centered it up, it went off without a hitch. I ended up with a center hole that was a bit over the 2 1/8 that I was aiming for but no biggee. It'll be fine. There will be a second sprocket next to it since I will be running two chains. I'll wait until I get the front sprockets mounted up before I machine the other one. I have the QD taper bushings coming in from Grainger on Monday. These are different from the ones that BH uses. Additionally, these industrial sprockets are made for #60 chain which is 3/4" pitch. 630 motorcycle chain is also 3/4" pitch, but narrower. I will be running M/C chain, so all 4 sprockets will need to be machined thinner. My old lathe is getting a workout. If you're any kind of gearhead, shop around for an old lathe. They are indispensable. Plus, when people come into your shop, they will know that you kick ass.
I received the QD bushings and after mounting them and the sprockets on the Curtis output shaft, it looks as if the outer, rear sprocket will bolt up to the hub and line up pretty well. The inner cog will need to be bored out to 6" to fit over the hub. Both of them will be separated with a 1" spacer, drilled and bolted together in a three piece sandwich. This should be done by next week as I am over committed and won't be able to work on it much this weekend

Mounties to the Rescue

I went to replace the fan switch today, since it never worked. I just switched it on and off manually. In order to get a socket on it, the upper motor mount needs to come of. Mine did..... in three pieces. It's a nice piece of machining, but it seems a bit wimpy. I checked with BH and decided that they were a little too proud of their work for the Po' Boy. I made a new one out of some mild steel. Took about an hour. I will, probably, make another one for the left side. I'm gonna make this thing bullet proof if it kills me.

No More Fuelin' Around.....the puns will only get worse

I never was real fond of the electric fuel switchover valve. More to go wrong at exactly the wrong time, so here's my fix. I bought a marine quality manual valve and screwed it into the "in" side of the fuel pump. Later, I will plumb the lines from the main and reserve tank into the two "in" ports on the valve and the 'OUT' will go to the carb. There is also an "off" position. I also moved the whole assembly to the left side so the valve handle will be easily reached and to make as much room for a battery/tool box later in the build

It's Not Easy, Bein' Cheezy

I've been obsessing over the pot metal flanges on my new swing arm bearings, so I went to Grainger today and coughed up the cash and got the genuine Browning, cast iron flange, bearings. You can see from the pictures that they are much more substantial than the Taiwan cheepos. I had to enlarge the hole in the swingarm mount to accommodate them and needed to take a few thousandths off of the bearing housing so they would fit snugly. These are killer and will be maintenance free.

I see no reason why this modification couldn't be done on the stock BH setup as well. You would need to get a 2 1/2" holesaw, a big ol' 1/2" drill (I call mine the Widowmaker) and make a centering jig for the holesaw. This is nothing more than a piece of 1/4" plate with a 2 1/2" hole in it. Center the jig over your existing swingarm bushing, clamp it securely and cut the hole. The jig will pilot the saw on it's outer circumference. They are usually piloted by the 1/4" hole that is made by the drill, but we already have a 3/4" hole, so without some method of holding the saw on target, it will lurch around like a sailor on payday

I picked up two spherical rod ends for the shift linkage also. Oh yeah, I ordered a shiny, new Kuryakyn shift peg to replace the hex bolt. No more cheezy shortcuts.......for now.

Paradigm Shift

I decided to switch gears (pun intended) a bit and make the shifter and linkage today. Here's what I came up with. I may put Heim joints on the ends of the rod if it needs them, but I think this will be OK. It shifts just fine sitting still while making the requisite VROOM VROOM sounds. The hex head bolt will be replaced with something a bit more attractive

Powder coating blues

I recall reading on the V8riders site that there were some problems with the powder coating on some of the older bikes. I have noticed a great deal of peeling on my frame, some from before and some as a result of the modifications that I have made. On closer inspection it does not appear that the frame was sandblasted prior to coating. All the metal has the cold rolled finish still on it. No wonder it's falling off. I have had quite a few items coated over the years and the guy always stresses proper prep work for a good job. Thorough cleaning and sandblasting is paramount. I'm surprised that BH would take such a crummy shortcut. I will not. Actually, since I'm a cheapwad, I'll probably paint it. Depends on how much is left in the ever dwinding pot when I'm done

What a groovy and swinging cat Carl is.......

The swingarm is mostly complete. There is a bit more finish welding and grinding to do, but it looks like it'll work. There could be some chain/belt clearance issues later on, so there may be some minor notching on the left side. We'll see. I did a quick and dirty wheelbase measurement and it looks like it'll be about 82 inches. I will bolt everything up, later today, and drop it down on it's wheels to have a look-see and to sit on it and make VROOM VROOM sounds

Metallurgy for Dummies/Carl/John

Some concerns about my use of mild steel for my swingarm have been raised. There are terms that always bring a knowing smile and a nod of the head to most people. Terms like "Board Certified", "Micro Brewed", "Heliarc" and "Chromemoly". While I have no problem with the last two, I believe them to be, at times, buzz words. I'm a lousy TIG welder, so that's out the window on this build. Cars, bikes, high rise office towers and a myriad of other stuff has been built out of mild steel, with success for a hundred years. They have been gas, arc, MIGed TIGed, bolted, rivited, furnace brazed and even glued together. I believe my swingarm will be just fine. I don't know what BH uses, but the induced hydrogen embrittlement from the chrome plating would certainly negate some of the advantages of using chromemoly. I'm gonna run it and like it. If it fails, I doubt that it will be catastrophic. I will be keeping a close eye on all of the modifications for signs of failure. Just ride in front of me so the parts falling off don't hit ya.

Don't mock my mockup

Here are a few more shots of the bike mocked up. The overall proportions look good. I don't want the stretch limo look. I welded up the swing arm mounts last night. Next, I will connect the two swingarms with a crossbrace that loops under the Curtis box to keep the wheelbase as short as possible.

No huge errors or problems.........yet. I did have a slight problem with one of the mounts. I didn't properly brace it and when I finished welding it in, it drew about 1/4 inch from the heat. A bit of heat with the rosebud tip and a judicious application of the BFH eliminated that screwup. Yes, I knew better, I thought the laws of the universe would change just for me. Man plans.... God laughs.

Stay tuned as I continue to create problems and attemt to solve them

Light at the end of the tunnel, dim but perceptible

Today I made up the swingarm mounts. There will be two on each side rather than the one that BH uses. No real, solid, engineering reason why. I just thought it would be better, or at least no worse. Tomorrow is Saturday, so I'll be able to spend all day in the shop. I hope to have all the welding done and maybe take it off the jacks and see how it looks.

I've been thinking about final drive options. The Gates belt that we have on our bikes will be way too short. They only come in a few sizes and, evidently, there isn't one that will fit. Gates makes a belt called the Eliminator. It is supposed to be stronger than the GT, but it won't fit the BH pulleys. The pulley for this belt are only (I think) available in steel. A 70 tooth weighs 50 lbs!! The last option and the one that I am considering is chain. I will be running two 630 chains side by side. It should handle the power and look bad ass. I need to look at a double strand sprocket and see if there is room for the two chains. These sprockets are made for a special double strand chain. The regular bike chains may rub against each other which doesn't seem like the hot setup to me. More research. The devil's in the details, but it's been done before.