Motobike Racer...parts bin project

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Inspired by the builds of MplsCoaster, Skipton, and many others, I dug into my parts bin for a vintage-with-modern-components racer of my own. The parts i didn't have on hand, i traded for. Thanks to bartering most of the parts, the only cash out i had were for the cheap tires (soon to be replaced by 700x35c cream kendas).

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Frame is an unknown 1920s/30s 28" motobike, possibly a Hawthorne or Rollfast: It has more than a few problems. It takes a 3/4" seat post shaft, and i have a modern made post of the correct diameter but it is super tough to get it in. Also, when tightening the integrated seat post bolt, a large crack on the left seat stay revealed itself. It looks like a complete break from the top of the seatstay all the way through to the bolt hole. There was more displacement at the break as i tightened the bolt. The bottom segment is OK though. Any ideas on the proper way to fix this while retaining the ability to clamp onto the seatpost?
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Fork is vintage c1980s/1990s japanese 27" suspension fork, possibly Suntour. It looked rusty as heck but the chrome came out nice and shiny after aluminium foil treatment. I really like this fork because unlike more modern suspension forks, this one has a real slim and sexy profile. Though my problem with this fork is that it tilts the frame up a bit, putting the double bars of the frame at a bit of an upward angle. This bothers the bit of OCD in me and i'm still deciding weather to switch to a more level regular fork. What do you think?

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I was able to get a working, shiny Bendix 2 speed on ebay for relatively cheap. Rides very very nice. The 18T cog coupled with the surplus fixie 48T chainwheel made it easy and fast. Low gear is great for the slight inclines around here. I was able to get a very old 1-piece to 3 piece BB adaptor. Basically an axle for cotterless cranks with cones sized to fit US BB cups. Makes use of standard US/BMX bearings.
 
Thanks for the very helpful reply!

Finished this a while back. and this is how it stands now. It's my best rider yet.

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That turned out very cool! If you did want to lower the front a bit Ill bet the fork has a set of elastomers that some can be taken out or cut down if it's a single. What did you do on the seat stay crack?
 
Hey cool, I'll look into that! How do i access the elastomers? New to the newer bike parts. I just had the seat stay crack re-welded and inserted a longer seat post.
 
My guess would be remove the two bolts on the side of the crown and the slider bolt at brake bridge looks like the crown and the legs will seperate the elastomers will be able to be seen probably another bolt under black caps on crown this is just s guess so procede with caution.
Sent from my ADR6350 using Tapatalk 2
 
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