poop's tuscaloosa dumplin'!

[Poop]

i just realized with that last pic, that i've skipped over also the mounting of my seat shock. that's actually a pretty big deal for me, because it involves another problem i've seen discussed here and elsewhere often, and offers a solution you don't see a whole lot. well, i've seen it more since i cooked it up in my garage, but it just took me too long to finish the rest of my bike. besides, i haven't seen ANY use the type of shock i used, so i still have a chance to say something about it.

several years ago some people asked about using mountain bike shocks for the seat spring. they had become readily available, as many wal-mart bikes even are full-suspension. the conventional wisdom held that they were too stiff to use, but this neglected one potential design variable: if the shock is mounted at an angle, then its spring rate is divided greatly, depending on the angle of seat travel and the angle of the shock travel. if the seat travels two inches while the shock travels one, then the spring rate has been cut in half.

so this had been my plan, to use a cheap ass throwaway mountain bike shock, do the math i was once a whiz at to figure out the right angle necessary, then execute a seat shock design that was perfectly sprung using a cheap ass shock.

then i found this sweet little number. it's a rock shox mountain bike shock, fully adjustable air/oil number with on-the-fly adjustable damping (dampening?) and gate valve positioning. this means i can set the spring rate using air pressure, then turn one wheel to adjust rebounding quickness, and adjust the maximum of how far down she'll compress with another wheel. all for about a hundred bucks. it would put primo suspension technology under my ass for much cheaper than that chopper shox mess, with much more adjustability. no brainer for me. i haven't finished playing with all the adjustments since the bike is done, but so far, it's very comfortable, not even fully dialed in. so cool to have so much comfort built into a seat that looks, well, damned uncomfortable. it makes me look tougher than i am.

[Poop]

here are some reviews of the shock:

RockShox Pearl 3.1 Rear Shock Reviews

[sdicato]

poop so happy for ya....best of luck in life....im enjoying the thread and the build looks kickass

[Poop]

thanks, sal! miss seeing you around here as much. hope all is good for you. one day i'll buy you a beer, i hope. and really, thanks.

[Poop]

here are a few final looks at the fender mounts before powdercoat. first, the right one, still needing a little more smoothing out.





this next pic is of the left mount, which includes an extra piece of plate for the tag mount. using a piece of plate here eliminates the use of a bung, which is a weaker joint than two plates bolted together. i chose this to address vibration issues that plague so many tag mount applications. i think it's pretty damn bulletproof; time will tell.

[Poop]

the next piece is a small one that not many people will notice, but was cool for me because it was my first time using a lathe "all by myself." i realized that to ditch the speedo drive on the front axle, i'd have to machine a spacer with a few critical dimensions to take up the space. with a little guidance from my buddy the aircraft mechanic, i spent a saturday morning turning this free chunk of aircraft aluminum into a nice little spacer. it's a cool touch of detail on a small part, that i'd almost forgotten about. all i have are these crappy cell phone pics. feel free anyone to ask questions, if there's something i can tell about it.




oh yeah, i turned it on a 100+ year old watchmaker's lathe, driven by a leather belt that was busted and patched together with rivets and a piece of thin aluminum plate. so my work that day was to the rhythm of a very constant "fap, fap, fap," different from the "fap, fap, fap" i usually work by at home.

[Poop]

front brake time!

i'm one of the oddballs that started his chop on a bike that already had the front brake deleted, and went out of my way to find a brake setup to work on it.

this part of the build started when a young kid who works in the local bicycle shop mentioned that his dad had an old cb450, which shares a lot of parts with my bike, leaning against a tree in the back yard for many years. clint is just a super nice kid, and said if i ever needed anything off of it, to let him know. i have had a parts bike the whole time, and didn't think i'd need to take him up on it, but when i started looking for a brake disc, i realized that had been removed from the parts bike already, as well. so clint said c'mon and pull it off, it was mine to have, and anything else i wanted from it. i strongly considered pulling the caliper and bracket for it, but the caliper was badly seized.

the more i read old reviews of the bike, the more i learned the reputation this caliper carried for seizing under the slightest adverse condition. one reviewer said if the temperature dropped ten degrees and you looked at it funny, it would seize. or something to that effect. so, i became less interested in using it, and decided i'd find something and adapt it, now that i was picking up some skills.

a few years ago, there was a local shop i sold nylon panel fasteners to, for sport bike fairing repair. when i asked about a possible caliper to use for my chop, he welcomed me to check his used parts shelves in the back for anything i could use. i found a two piston tokico from a sport bike rear brake, and he said have it, and refused any money. i gave him that month's box of panel fasteners for free, and went home to figure out how to make it work.

here's a peek:

[Poop]

have i mentioned how freakin' awesome it is when someone who knows what the hell they're doing takes the time to pass along a little knowledge? even better, when they take the time to teach you how to begin a particular process, explain it in twenty minutes, giving you an outline to work from and discover for yourself how to make it work?

a good friend of mine i met because he works at a customer i picked up a few years ago. it's the place i've mentioned here already several times, that executes world-class restorations of vintage warbirds. let me tell you, those mechanics are freakin' awesome. they're not just any aircraft mechanics (a group which already has a pretty impressive skill set). these guys are fanatical students of the way scores of planes from more than half a century ago were built, and why. this makes them students of industrial and engineering history, and often it means they have to resurrect old processes of manufacturing parts just to use a period correct technology. this, of course, makes them master fabricators in various media.

needless to say, kurtz is way overqualified to give me advice on whatever the hell i'm working on. one time when he stopped by my garage to check progress on my build, i showed him my challenge with the brake, and he broke it down real simple. he asked if i had a jig saw and some thin plywood--i did--and explained that i just needed to make the part out of plywood, using washers for shims, and held together with drywall screws. once i had a part that held the brake in the right place, then i had a pattern from which to mill the bracket from aluminum. i was also worried about the cost of a chunk of aluminum that big, but he said not to stress that now.

so, on to my plywood bike parts. (by the way, my friends still joke about the parts i made out of plywood. they thought i was off my freakin' rocker, i think. of course, i was. but the brake bracket plan was solid.)






the following picture was taken down the street, at another shop i had access to. bill gwynn was a widely acclaimed drag race engine builder in my hometown. when he passed a few years ago, there were scores of exotic engines in his shop, sent from around the world for machining and rebuilds. two of them were for some sheik's powerboat, i heard. regardless, tons of knowledge and equipment still remain at that shop, and i consider myself extremely lucky to have had access to that equipment and the generous people there. so, here's my first milling project...






right about now, i'm grinning like a possum, feeling like there's nothing i can't figure out with the help of friends and maybe a long amount of thinking on it. i'm starting to realize how nice this bike will turn out has a lot less to do with how much money i can scrounge up, as it does with how much time i'm willing to do it, how much attention i spend on details, and how much i'm willing to learn from generous friends. at this point, it got hard to explain to folks just how much this build means to me, so i really didn't even try. i believed one day it would explain itself, as long as i kept it a priority.

[Poop]

here she is now, after i powdercoated the bracket, shaved a tab off the leg and powdercoated that, and had my stock 7mm disc (the old ones were thick) drilled and ground down thinner to accept a modern caliper.



next up:




woohoo!

[Poop]

oh yeah, one more thing about that brake before i hit the sack. it wasn't until after i finished this piece that i heard about the existence of screw-in transfer punches. that's what a professional would use to transfer the hole positions from the existing part (fork leg mount tabs) to the new part (blank caliper bracket). being unaware of the existence of such a part, i made the equivalent by grinding hardened set screws down to points and screwing them into the holes of the fork leg. it cost about a nickel, at most, and took maybe four minutes.

[Poop]

and with that, goodnight! i'm tired just writing about it.

[Barefoot Choppa]

Very cool poopalicious!!! Glad to see this all worked out for ya and sounds like your surrounded with the right friends with the skillsets and equipment to make this happen. You did good my friend!!!! Oh, and keep it up man.....little long winded but great build thread!!!

[Poop]

thanks, rick. I think that's the first time i've been called long winded.

oh wait, i meant the millionth.

really, thanks. means a lot coming from friends.

[kenart]

Awesome! I am votin for ya.........

[hanger]

Awesome build Poop! You've done an outstanding job on this build and I'm always looking for your updates. Keep the pics and writing coming.