Bonanza BC1300 Restomod 20 years later.

#1
When I was much younger 2000 my Dad would drive by a large shop near our house and my younger brother who has since passed used to point and say there was a mini bike frame outside the shop. At the time I was around 16 and had a 1964 Rupp Continental. I would look late enough to see the handle bars and tell him it's just a rototiller, there were always old trucks, tractors, loaders and other heavy equipment outside the shop. Many months maybe even a years later my Dad stopped by to talk to the owner, we had never seen him stop by this place, it was just me and my Dad. They talked for a bit I have no recollection about what and we stepped inside and there it was just inside the door A MINI BIKE FRAME!!

Going from memory there was a Bonanza frame with the front tag/ logo. No wheels, a rear backing with no shoes and half of a round rusted gas tank! You can look at the pictures and see half of the front forks are rusted away! If I recall correctly he said he was going to fix it up for grandkids. I offered him $20 and it was mine. This was all back in the good old days of being a teenage boy and calling stores only to have the person on the phone say "ok ma'am"

I quickly pulled the ORIGINAL rear "shocks" off and scrapped them :( they were probably pretty rusty. I removed the Bonanza front tag so it wouldn't melt and likely lost it in Ogdensburg, NY forever. I cut the ends off the front forks after trying to remove them with a torch and painted over the damage with Krylon "true blue" so my Dad wouldn't know what i had been up to.

Fast forward to 2020 and the Bonanza frame I've been thinking about building with a hodaka engine is still in NY State and I'm living North of Seattle surrounded by people who hate anything fun involving gasoline. In 2019 my Dad moved the frame with another home made frame from NY to TX. I get laid laid off because of the death of air travel, my younger brother and I both now jobless aircraft engineers move my Dad's belongings from OR to TX and bring home the Bonanza! The pictures in this post were taken in NY in May 2019
 

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#2
Here are wear marks that I think confirm this was a standard BC1300. Wear marks inside the frame at the rear where a round fuel tank would have been mounted.
Wear marks on the outside of the frame in the right side advice the frame where an original exhaust would have been mounted.
 

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#3
When I first got this Bonanza Frame I remember looking for info on the internet and seeing the pictures of Hoss Riding one and all the Hodaka powered ones.
I was always planning to get a Hodaka engine but didn't want to take one from the Hodaka people or original Bonanza people. A few years ago I was planning to get a Suzuki 100cc AX100 engine new manufactured from China, I changed my mind on that too. More on an engine later....
 
#4
Damage due to previous owner!
The Front lower steering bushing was gone and the upper one was missing the flange.
A previous owner drove around with all the engine bolts loose which hammered up the engine mounting plate.
To me it looks like they also drove around with the axle bolt loose. The rear swingarm cracked on one side and it seems like the sprocket or backing plate ate away 1/4 to 1/3 of the swingarm. The adjuster on this side also was changed to a store bought I bolt that they welded the loop closed. They also welded an extra angled tab on because they were perhaps not tightening the axle bolt at all so the little tab was taking the full load!





 
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#5
You've got a decent start there, that's a nice early frame with front pegs (1968 and older). Hell the back fender and fold up pegs are worth good money. Cool story and memories to go with it. I would start collecting the necessary parts off the OldMiniBikes classifieds or Ebay. The parts are out there to put it back together just have to be patient. The eye bolt at the bottom of the top photo looks like an original as well as the one shown on the swingarm.

Is that a Muncie trans and Southbend lathe cabinet I spy on the trailer....?
 
#6
You've got a decent start there, that's a nice early frame with front pegs (1968 and older). Hell the back fender and fold up pegs are worth good money. Cool story and memories to go with it. I would start collecting the necessary parts off the OldMiniBikes classifieds or Ebay. The parts are out there to put it back together just have to be patient. The eye bolt at the bottom of the top photo looks like an original as well as the one shown on the swingarm.

Is that a Muncie trans and Southbend lathe cabinet I spy on the trailer....?
Thank you, I have most of the parts I need and a plan!

I think the tranny is a T5 maybe and the lathe cabinet is for a Harrison!
 
#7
Damage Due to previous storage and me!
There is some pretty serious pitting, none of the pitting will affect functionality.

I cut the forward seat support ends off 20 years ago because it bothered me they hung over the frame. I was even too lazy to fully cut one of them all the way and broke it off lol... so lazy! This won't affect function.

I used my torch here in WA state to remove the lower forks which didn't seem to be that stuck. The springs came out in pieces. I used a punch at an angle to get the upper stops moving. I also filled the handle bar with nuts to add mass. I read a thread yesterday where Manchester1 suggested ball bearings which I had also thought of but didn't have any, genius tho! You can see the fork rusted away badly down to 1/2 an inch!






 
#8
The plan is:
Not an original engine(sorry), it won't be a predator but it will have a lighting coil!
8" Azusa wheels, I know it had 6" originally. New rear wheel and front fork springs were from Hent
Dual 5" drums.
Original-ish sized aluminum fuel tank mounted in original location.
Original style full lights, tail light bracket will bolt on.
Stainless steel lower front forks.

 
#9
Another goal I have is not modifying the original frame in any way. Outside of straightening things, and what I did 20 years ago...

I have a lathe and a mill so making parts isn't too difficult. The problem is I find myself wasting time making parts that aren't needed!
When pressing in the swingarm and spindle bearings I pressed in an extra 1.5" bronze bushing in before the flanged bushing. This provides an extra 3 inches of support but also creates more friction. Even after reaming the bushings to 5/8 the swingarm pivot shaft would just turn in the pivot plate. I machined a 0.12" slot into the swingarm shaft and milled up a little block that engages and prevents rotation.




When i ordered the 13/16 Stainless bar from McMaster i scrolled past the 304 SS and picked the 416 SS because it said easy to machine and I figured it was better until I read about welding it. It turns out it's like Chrome moly steel and requires pre heat, post heat, and specific filler rod.
I had an old weird cutter that happened to be 13/16ish that I used to fish mouth the ends of the forks. I put the extra bar in the lathe and bored thru it to weld on as spacers like the original bonanza forks.


 
#10
The eye bolt at the bottom of the top photo looks like an original as well as the one shown on the swingarm.
Yes and the Eyebolt on the left is one I bought. Also it appears that Bonanza used oversized nuts on the Eye bolt which gives more surface area. I had two in my parts bin for the eye bolt I bought at my local hardware store! It is still not at nice as the original bonanza part!
 
#17
I purchased this sweet drum brake with no sprocket. It was a little too wide for my purposes, so I turned the lip down and probably took about 1/4 of an inch off the width. I also had to countersink the holes so the bolt heads were not poking up, and chamfered the corner off the brake pad.



After all this the backing plate was still poking out too far. At this point I was considering cutting the brake shoes narrower but then any new shoes would not be a drop in fit(ignoring the chamfer lol), and I really didn't want to subject my cutters to such abuse. The brake shoes have quite a bit of play/room between the back of the shoes and the backing plate so I pressed out the pivot pin and cam bushing and machined 0.060" off the backside of the shoulder as highlighted in red in the one picture.

 
#20
For the gas tank I ordered this 4"x7" aluminum tank from BAM manufacturing. I had them install the filler opposite the outlet. I also had them use their "small" cap with no vent.


Here you can see the cap is still too big to turn. It is hitting on the far side.


I used my lathe to turn it down, drill a vent hole and knurl it. Unfortunately I couldn't find a coarse straight knurl to borrow so I ended up with this for now.


 
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