Start your RRB Build Off diaries here!
Name to come. (I figure the bike will name itself as I go.) What better reason to finish I project floating in my head than the epic RRBBO! I've been into muscle-bikes and now verging into ol skool BMX, so I thought I'd try to combine the two into a concept of making the earliest looking BMX I can. As if BMX were happening in the 50's with tank bikes.
I'll start with this 50's Stelber 20" tank bike. I love the Stelbers. If you have never seen them, check out the frame. Unique to them as far as I know. They made a 24" with this frame too (wish I had one!) I read somewhere that the geometry let them sell it to the 26" crowd even though it was a 24. Just by raising the seat I guess.
Here it is as bought in a lot of 5 bikes for $25! (Best score ever.)
This was an early concept of it, but everytime I try to use these forks on a build, I get rid of them. Too modern or cheaply made or something.
Here is where I am at with my spare parts as of today. Nothing even bolted yet. Disc brake front rim. Some sweet Demolition Momentum tan walls for the fatness 20X2.35. the seatpost is from a 1950's mixer, which will probably not work out. Looks cool though!
So I'd like to try to make a custom Springer. As if this were the earliest MX bike. Which may be my downfall, but I can always make it a truss if I run out of time.
Here's my Sears Screamer sprung sissy to use for inspiration.
I have a few challenges ahead. One that the seattube is for a wimpy little kid seatpost. Hoping I can just drill that mamma out. Maybe even retaining the the set screw?
Second, the bottom bracket is for pressed bearing little kid cranks. That won't do. It is an odd size though at 35mm. Bigger than english (and not threaded) and smaller than American by a mile. Do you guys think I could get sealed spanish BMX bearings in there? Spanish are 37mm, so two mm bigger than the shell.
The studious among you may have noticed what is special about that rear hub? It is dual drive with a sprocket on both sides. It is for an e-bike. Now don't get too excited. I have a lot on my plate before I start thinking about E-power. But if there is time at the end... this frame would be sweet with that little motor centered in that loop!
Turns out two batteries fit perfectly in the lunchbox on the rear rack! (Which will be level naturally.)
Here is a mock-up with a 26" truss fork. But I am not sure if I want to go that long.
Anyway, I failed to finish last year, but for those who didn't see it, here was the Svelte Spider. It is donating the fork to this build so far.
I look forward to more of the inspiration I am already getting from you guys!! RRB rules.
Last edited by Fisch on Mon Jul 09, 2012 6:54 am, edited 11 times in total.
I like the looks of this set up here. get everything bolted together finish that springer you're working on, give it some ratty grips and patina that rear rack and you'll have a winner. I dig it the way it is! Just my .02.
So many mock-up ideas, I don't know what to comment on. Looks like you have a nice pile of parts to grab from. Have fun and for the love of Steve, FINISH THIS ONE!
Why not cut an english BB off a bike and slide the whole thing into the shell on that bike?
That is a swell idea, you got me excited enough that I had to go measure. Looks like the standard English Raleigh version is 45mm OD outer shell. I measured a mountain bike one and that too was a little over 40mm I think. So we are 5-10mm too wide to slide in. That said, if I slit the Stelber BB along the bottom I might be able to force one in there. Then have the gap welded along the bottom.
Not a bad thought at all. I will have to weigh it against the expense of modern BMX cranks and the pain of having to jam 37mm bearing in a 35mm shell.
Thanks Yoothgeye! And thanks for taking an interest in so many threads. The encouragement helps folks get out there and make progress.
I know you are going for a slick BMX look, but if you do cut the shell and need it welded back, why not have tabs welded on it like an integrated seat post clamp, then you could put 2 bolts down there to cinch the BB in place. It would sure look cool.
You might be able to turn down a set of sealed bearings 2 mm, but that might be tough as they are hardened and not super thick to begin with. You might find that it would be tough to cut them without distorting the heck out of them.
Another alternative might be to epoxy a complete Euro bb in there. It should be just a hair smaller than the ID of your bb, so it should work. That would give you the option of running old school square taper cranks too, instead of Profile type cranks.
Thanks Someguy! There is a lot of stuff happening that doesn't fit yet, things need to be stretched, like the fork to clear the disc brake. I will have to integrate the disc brake mount into the bracket I design to go between the fork and the rods. The seat post is held by gravity at the moment, nothing to even attach it to. But that is the fun of it!
For the final look, I am thinking to keep the rust for now. Maybe some beep pinstriping on the tank.
Springer sketching. I'd love to keep the loop up top to mount a light within. Almost monarkish.
Appreciate it dude!
yoothgeye I like the way you think. I could probably cut half the bb right off along the bottom and cinch the english BB in therewith two bolts. As long as the bolts are in far enough and short enough to clear the spindle and bearings. Something like this.
BMXerpete- very nice thinking as well. If I can avoid welding, that'd be swell! (Don't own a welder) You are right, the bearing cup (the part that screws in) of the english crank is like a mm too small to fit in the current (unthreaded) shell, so it slides around. I like the idea of square taper for the look I am chasing. Heck the Yamaha moto-bike has cottered cranks! You guys make me think I might just figure the biggest hurdle out!
Your idea is perfect, cut the majority of the shell out and bolt your chosen BB in place. Simple, clean.
You lead me there! My worry is whether it could stand up to me standing up and bearing down on those pedals! I have to ride this thing! Some epoxy and some grade 8 hardware might do it though. Could always weld the same concept I guess.
I think it will hold up, grade 8 allen bolts or the pan head allen bolts that you can find all over bikes.
Is this what you meant BMXerpete? Epoxying one of these in there just might be the easiest and quickest solution. Non serviceable. But maybe it could be knocked out with a BFH if the need to replace it arrived.The mountain bike english style beringcup is literally like 1 MM to small for the current bb. So a thin layer of epoxy would fill it easy. Then if I am getting real crafty, a couple of set screws through the bb shell would be pretty slick insurance.
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