Jockey Journal Forum banner

1940 SS Knucklehead: People's Champ 5 Build"

118K views 327 replies 63 participants last post by  Rigidspeedtwin 
#1 · (Edited)
OK, I know a lot of you have seen my girder fork thread, so a bit of this is rehash, but I wanted to get some of this stuff on here chronologically. If you read the fork thread, you can probably read the beginning of post 1 and then jump to post 4. I posted this over on another (the other) forum that prefers angle grinders to machine tools (but I still love them). It's going to seem like a huge blast right off the bat, sorry about that. I'll update it as I go from now on. Maybe print it out in full color on your company's printer and go read it in the shitter, IDK.

So, a bit of backstory, everyone who knows me knows I talk about this thing all the time. I was trying to keep it on the DL online because I was trying to get invited to a "cool" event like born free or Brooklyn. I've since decided that I'm just a nobody and don't really deserve to be invited anywhere. Maybe sometime in the future. Also I am simply just not good at selling myself on social media, so here's where I'm at and I'll update this as I go.

Basically the whole project started like this, a titled basket 1940 EL motor.



By now I've accumulated basically all OEM (not year correct, though) external parts. I'm going to use S&S/Jims/Andrews internals. The motor will be mostly stock. I don't plan on making it anything other than clean, I want to leave all the "wear" marks in the parts that have accumulated over the last 75 years. Sort of like how I shined up this cam cover:



For the sake of the story, not much has happened with the motor, I've been too busy with other things to really dick with that. Also, for the sake of the story this is going to be a little out of order, but no one's probably reading any of this anyway.
I wanted to build a fork for this build, so here's the story of that:
Drew it in cad.







Got castings made from 3d printed wax off cad models. Material is 316L. This is not inexpensive, but I don't spend much money on things besides motorcycles, so it was within budget. All said and done I have into this what a nice condition early springer would cost.



Had to machine the castings. Fixturing these was often difficult and quite a learning experience for me.























 
See less See more
19
#65 ·
Re: 1940 SS Knuckle

Madness.
You don't base jump by any chance do you?
I do. Or did. I'm at least partially "retired". Made about 800 jumps over 5 years, had a very close friend, who was a better jumper than I, die on a jump that we'd all consider "safe". Not that I didn't know it was a real possibility, it just bummed me out. Also, when you're actively jumping, you need to be on your shit and thinking about it 24/7. Obviously I've got other things going on.

Here's a base video I made a few years ago. This is edited, many of the jumps were illegal, so those ones are just a blank screen.



I feel like this sis 2016/2017's version of the "Japanese custom built from scratch" thread, where the whole goddamn board keeps refreshing their Jockey Journal tab just to see if Newman did anything recently.
Thanks. I post a lot more on instagram, because sometimes I don't have the energy to write up a whole post.

Here's a quick video of a kicker arm I finished yesterday...



And some modified kicker gears...



And how I modified them:



And then there is a mystery transmission part... all these things are related..

 
#64 ·
Re: 1940 SS Knuckle

I feel like this is 2016/2017's version of the "Japanese custom built from scratch" thread, where the whole goddamn board keeps refreshing their Jockey Journal tab just to see if Newman did anything recently.
 
#66 ·
Re: 1940 SS Knuckle

Super intrigued. Obviously there is something going on with a cable; I see the stop on the arm and the ditch for it to lay in on the wheel, but I have no idea what the fuck it's for.
 
#70 ·
Re: 1940 SS Knuckle

Sorry again for more instagram videos, but check these out. The culmination of two months of work. Basically, i reimagined the kicker side of the transmission and made it open, sorta like an old indian. Since the bike is a very "skinny" build, the widest thing by far was the tranmission, so I sought to move the kicker inboard. My end design moved the right most edge of the transmission in about 2.5 inches, which is pretty significant. In order to do this I had to get rid of the torsion spring, so I replaced it with a cable and linear spring. The net result force is nearly identical to measured values of a stock kicker spring. The rest of the transmission parts to seal it are already fabricated, and I've mocked them up on a dummy transmission.

Couple hundred hours of work here between design and fab time. Hope you enjoy.





 
#75 ·
Re: 1940 SS Knuckle

Here are some actual pictures of the trans parts:

This little guy locks the CShaft from spinning.



The CShaft passes through the trans and also supports the kicker.



Here are some shots with the throwout bearing installed. It has bearings on both the inside of the "cup" and on the outside where the fork contacts it.



This is the throwout cup. Thrust ball bearing inside, radial bearing outside on the fork. Believe it or not this part was made 100% on the bridgeport with zero CNC.



Here are a few more shots.







You can sort of see some of the sealing parts in there, I had to add 3 orings, two plugs, and 2 lip seals, and will also have to seal some of the bolts.

Unlike a standard 4 speed, the kicker clutch gear always spins and is engaged with the kicker clutch hub. The only time it "ratchets" is when the kicker is moving backwards. The kick gear is a sector gear that is "out of the way" while the bike is running. Having smooth re-meshing with the stock style gear was poor, so I was forced to modify the gears a bit:



The left is a baker gear the right is a vtwin.

Here's how I modified them it took FOREVER.



Lastly, here's a video of me wiggling some stuff around.

 
#79 ·
Re: 1940 SS Knuckle

How many pounds of preload are on those springs for the kicker return? Main reason I'm asking is I'm wondering how far up your ass that pulley cap is going to go if that cable be decides to let go? Lol!!! Really well thought out and nice work btw
 
#81 ·
Re: 1940 SS Knuckle

How many pounds of preload are on those springs for the kicker return? Main reason I'm asking is I'm wondering how far up your ass that pulley cap is going to go if that cable be decides to let go? Lol!!! Really well thought out and nice work btw
Haha! It's only about 100 linear lbs.

Amazing work man, your attention to detail and the obscene baffles me. That's seriously skinny. Like Rezi I've modified kickers to be angled inward and less obtrusive but your level of detail is unreal.

Cannot wait to see this beast together. I hope it's going to run on injection and not a carb.. that would be a let down!!! haha.
I was going to run injection but I think in order to make it "clean" in going to use a carb.
 
#80 ·
Re: 1940 SS Knuckle

Amazing work man, your attention to detail and the obscene baffles me. That's seriously skinny. Like Rezi I've modified kickers to be angled inward and less obtrusive but your level of detail is unreal.

Cannot wait to see this beast together. I hope it's going to run on injection and not a carb.. that would be a let down!!! haha.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top