OCC Chopper Bike Build

I've started work on my new build, an OCC Chopper bike I found in a dirty garage. I've already spent several hours on my projectt and I don't even have a kit!

These things are not perfect for motorizing, as the engine has to be kicked left with the end result being the right rear engine mount stud is close to center of the frame. I could have dropped $40 for a pre-fabbed motormount but I simply don't have an extra penny to spend on this. I've created by own by measuring carefully and drilling holes in thick metal. It's a system of transition plate and muffler mounts that I've used before.

The saddle was trashed! I found some material and worked up a new cover with some homemade rivets. It wil work for a while!

The V-brakes, front and back, are good but the headset cap is trashed. I have to rig up some kind of fix to get a tight setting on the headset.

The handlebars are just weird an I don't want to use them. I'll find a simple straight bar as that will maximize function. In traffic you want narrow bars to sneak through tight spaces.

I patched the rear tube but I cannot inflate the sketchy tire because my floor pump failed. My frame pump that I carry for my push bike commutes to work has mysteriously disappeared from my backpack. It doesn't reay matter though because I bought a very cheap motorcycle tire on ebay as I am told they will fit on the fat rear rim. But, boy, this thing cannot be mounted like a bicycle tire. I am going to have to spend $20 for a motorcyce inner tube and maybe buy a few tire tools. There are some hacks on youtube - not sure how I will settle this. If I use the moto tire I will use a 40 tooth sprocket. If I have to default to the 20" bicycle tire, then it will be 36 tooth. At any rate, there's a lot of work ahead for me before this thing yanks me down the road!

Here are some pics:
 

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Thank you for the comments!

First, about the pedal sprocket: it's a racing cog (Ultegra) that was part of a cassette block of the three biggest rings. They were held together by several small rivets and they took a long time to cut off! The new 25T cog is made of very hard steel. The ten bolts fit perfectly and I use nuts as spacers. Nothing can move as there is nowhere to go. The ring would have to shatter!
I will take you advice and use blue thread lock on the outer nuts.

These sprockets aren't very large. The shaft is 7" (that's what she said) and I was careful to order them specifically for 415 chain. I've test fitted and they are perfect.

I had the a similar experience on my previous motorbike, being forced to carefully grind down each tooth on the one piece crank that wouldn't accept my BMX chain. No fun!

Thanks for the input!
Good great to hear you thought it through!
 
Just out of curiosity, what gas engine do you think will fit that this frame?

_20161013_152500-jpg.75394


I don't see any center mounted gas engine fitting that scary frame.
Have you ever stuck an engine in to see if it will even fit?
And how to expect to start it with no pedals. and how are you going to mount a seat with the frame upside down?
 
Just out of curiosity, what gas engine do you think will fit that this frame?

_20161013_152500-jpg.75394


I don't see any center mounted gas engine fitting that scary frame.
Have you ever stuck an engine in to see if it will even fit?
And how to expect to start it with no pedals. and how are you going to mount a seat with the frame upside down?
He was just rigging it up to see the angle of how it looked, I think his idea is to take a bike and chop shop it to have a similar angle.
 
Just out of curiosity, what gas engine do you think will fit that this frame?

_20161013_152500-jpg.75394


I don't see any center mounted gas engine fitting that scary frame.
Have you ever stuck an engine in to see if it will even fit?
And how to expect to start it with no pedals. and how are you going to mount a seat with the frame upside down?
I think I said in the post, and it is the common use for inverted BMX frames . .
It's a gravity bike. Like this guy's:


I just set it up to see how it looks, and for something inspiring to look at.
You don't sit on these, you lie down. That's why they go 70mph without any engine. ;)
I can't use the fork in other frames because the steerer was cut off very short. It was on my Pashley 24Mz originally (the right way up!). So I chucked it on the old Federal BMX cruiser just to see.
I have a dream of electric motorising this, just low geared for getting it to the top of the hill/s but not really going to happen any time soon.
Yes I have offered up my 66 Crappy Time to all my bikes, and it won't fit this. I can still change my mind if I want to but I am 95% sure I'm doing my 2-stroke build on my Dawes Galaxy Cross. I just need to stay off eBay for two months so I can get the money for the shift kit and extras haha! Hopefully US$ will be nice and cheap by then too (sorry).

Anyway.. totally off topic now. ;) I only posted the pic as we were talking about using mountain bike forks at weird angles that they don't really have the rake (forward offset) for.
 
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I think I said in the post, and it is the common use for inverted BMX frames . .
It's a gravity bike.

I just set it up to see how it looks, and for something inspiring to look at.
You don't sit on these, you lie down. That's why they go 70mph without any engine. ;)
Just checking as I see no way to put a gas engine in it.
So a gravity bike, like a soap derby, I can see 70mph with a steep and long enough hill, and I bet not single one relies on just a coaster brake to stop them ;-}
 
I think I said in the post, and it is the common use for inverted BMX frames . .
It's a gravity bike. Like this guy's:


I just set it up to see how it looks, and for something inspiring to look at.
You don't sit on these, you lie down. That's why they go 70mph without any engine. ;)
I can't use the fork in other frames because the steerer was cut off very short. It was on my Pashley 24Mz originally (the right way up!). So I chucked it on the old Federal BMX cruiser just to see.
I have a dream of electric motorising this, just low geared for getting it to the top of the hill/s but not really going to happen any time soon.
Yes I have offered up my 66 Crappy Time to all my bikes, and it won't fit this. I can still change my mind if I want to but I am 95% sure I'm doing my 2-stroke build on my Dawes Galaxy Cross. I just need to stay off eBay for two months so I can get the money for the shift kit and extras haha! Hopefully US$ will be nice and cheap by then too (sorry).

Anyway.. totally off topic now. ;) I only posted the pic as we were talking about using mountain bike forks at weird angles that they don't really have the rake (forward offset) for.


You COULD mount the 2 stroke below the down tube with custom built motor mounts. Anything is possible. Would look extraordinary and perform well!
 
You COULD mount the 2 stroke below the down tube with custom built motor mounts. Anything is possible. Would look extraordinary and perform well!

Yes, that idea hadn't escaped me. I could probably use an inverted 66 mounted to what is now the down tube using Stingray mounts. Unfortunately all gas engines are illegal on public roads here and you're even supposed to pedal electric bikes.
I don't own a truck or van so it would be great to get this thing electric powered. Also probably a bit easier to find a chain line that works.
I will probably get the original fork back on and just improvise a disc caliper mount. Means I don't get to use the same wheel of course..
But the whole thing is basically going to be a living room ornament for a while. I have enough other bikes to spend time and too much money on!
 
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OCC Chopper Build Update

It wasn't real cold in the garage to I did some more work and evaluated the status of the project. My first step was to reattach the original 24" wheel and do some tests for proper trail which means proper handling. All good! The bigger rear wheel fixes everything; the bike rolls steady and tracks well with a very good turning radius.

My efforts to bolt a bigger sprocket to the freewheel failed. Still, I attached the pedal chain and, with a little hard plastic kicker, I should be able to get the pedal chain off the rear tire. I have a design in mind. Should be a simple solution.

I noticed my motor mounts are not quite finished: I need to fit the motor and make the precise measurements to drill holes for the front motor studs. No big deal. I will probably drill holes tomorrow then add my jackshaft.

I can't get my front fork bearings properly set. Need to figure out what's going on there.

I'll need to experiment with handlebars and get a new seat post and saddle. I am almost ready to order my kit. Still haven't decided on the size of my drive sprocket.
 
View attachment 75473 OCC Chopper Build Update

It wasn't real cold in the garage to I did some more work and evaluated the status of the project. My first step was to reattach the original 24" wheel and do some tests for proper trail which means proper handling. All good! The bigger rear wheel fixes everything; the bike rolls steady and tracks well with a very good turning radius.

My efforts to bolt a bigger sprocket to the freewheel failed. Still, I attached the pedal chain and, with a little hard plastic kicker, I should be able to get the pedal chain off the rear tire. I have a design in mind. Should be a simple solution.

I noticed my motor mounts are not quite finished: I need to fit the motor and make the precise measurements to drill holes for the front motor studs. No big deal. I will probably drill holes tomorrow then add my jackshaft.

I can't get my front fork bearings properly set. Need to figure out what's going on there.

I'll need to experiment with handlebars and get a new seat post and saddle. I am almost ready to order my kit. Still haven't decided on the size of my drive sprocket.
What went wrong regarding the sprocket?
 
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