stretch pocket rocket

[ironman]

Hey new to the sight. just stated a new project. decide to customize my sons pocket rocket plans go as followed
Streching the rear 6'' buiding a swingarm for it.
Going with a chopper style frontend so bring the front out by 9''
Rasing the clip-on up about 3''
Gas tank will be under the seat
Will have have front and rear foot pegs
i know dont look like much but in my head i know my
son is going to love the style.
will post up some pictures tonight of it.

[crazycart]

Sounds awesome be sure to post lots of pics.

[ironman]

http://i206.photobucket.com/albums/bb106/jamieandterry/000_1108.jpg
http://i206.photobucket.com/albums/bb106/jamieandterry/000_1107.jpg
http://i206.photobucket.com/albums/bb106/jamieandterry/000_1106.jpg

here is a few pictures just using some scrap metal to get an idea of what im going for first day on project will be showing more as time goes on.

[robertdjung]

cool project! keep the pics and the descriptions coming!

[2or3wheels]

Wow thats gonna be a cool bike when its done.

[ironman]

ok fist day of working on bike everything went wrong.
welded up the rear swing arm was off about a 1/ a inch rear spocket hits the swing arm frame.
try to blend it out a little weld broke. back to the cutting and welding to try again.

[ironman]

day 3 alot better here is where i am at now


http://i206.photobucket.com/albums/bb106/jamieandterry/000_1112.jpg
http://i206.photobucket.com/albums/bb106/jamieandterry/000_1113.jpghttp://i206.photobucket.com/albums/bb106/jamieandterry/000_1114.jpg
http://i206.photobucket.com/albums/bb106/jamieandterry/day3minichoppe.jpg
need to find a chain that will fit now,hook up the exhaust build the tank and so on. will keep you guys updated on the min rocket chopper.

[kibble]

LOL, had to read the first post over again to figure out what was going on and why some parts of it looked commercially made and others home made.

Looking good though!

[my_mini_bike]

im liking what im seeing. keep up the good work lol. possibly a longer front end to give it that full on chopper look? or u still want it to be functional

[gustopf]

looks very nice, should be a crowd pleaser haha, any clue who makes them dang things, we had a few people in last year trying to order parts. and no one seems to know who made em :rolleyes:

[2or3wheels]

chinese chonda wanna bees, its look in good, long *** chain.

[ironman]

yea i know chain is going to be long going to have to put two chains together and buy two master links. Over all chain size is about 14 inches longer

[2or3wheels]

gonna be flippin cool

[ironman]

ordered chain wensday and ordered two master links trying to figure what to do with the gas tank how to make it .

[gustopf]

maybe mount it in the back, and look around for like a riding tractor tank, with like 2 gallons, you could cruise for hours :D your son would get tired before he ran out of gas

[ironman]

heres a update on the bike.
Tank has been moved to the back rear wheel adjusters been put on .
Have to wait to mount brake calipers until i get the chain in.
Added on a pipe for the exaught

http://i206.photobucket.com/albums/bb106/jamieandterry/bp3.jpg.
know starting to work on a seat design

[gustopf]

looks nice, how are the front arms holding up with someones wight on it? youll have to lets us know how she handles :p

[jr dragster Tyler]

I bet that exaust sounds good but be careful 2 strokes need back pressure or else your just loosing power trying to gain some with a straight pipe. And i heard lack of back presure is hard on the rings and stuff maybe Russ could explain this theory?

[crazycart]

Straight pipes in general arent good for 2 strokes,The best exhaust for them is an expansion chamber.Like this:
http://upload.wikimedia.org/wikipedia/commons/5/52/Arbeitsweise_Zweitakt.gif

[Russ2251]

One of the easiest ways to boost power on a 2 cycle engine is to improve cylinder scavenging by way of exhaust system. Expansion chambers work best. The reason is easy to see (crazycarts post).

A straight pipe helps a little and won't hurt at all, but, efficiency is diminished by a few percent (unburned fuel exits pipe).
Next to expansion chambers, a long tapered megaphone works best for me, and, again won't hurt. Noise levels are really impressive too...and I do mean Impressive.
Most of the time I just use an over sized 4 cycle muffler on a short pipe to appease the neighbors.
4 cycle engines are much more prone to damage than 2 cycles. Zero exhaust back pressure can ruin valves and eventually will burn valve seats. Won't hurt 2 cycles...just wastes fuel.
Back in the '60's we used to run Clinton Panthers with exhaust just pouring out of the exhaust port. Looked really awesome at night.

[crazycart]

Also,the fuel escaping out a straight pipe on a 2 stroke can cause a lean mix that can make the engine seize or melt down.

[Russ2251]

Also,the fuel escaping out a straight pipe on a 2 stroke can cause a lean mix that can make the engine seize or melt down.

How so???

[robin]

my frend has just spen over 200 on a race exhaust for his rs 125 standard it did 95 now it dose about 105~110 and acceleration is much better

[crazycart]

How so???

The gas escaping out the pipe=less gas in the cylinder=less lubrication=more friction and heat that can result in a seize and/or melted piston

[ironman]

wow lots of good enough thanks for the input .
When i get the chain on i will start it up and see how it does.

[ironman]

looks nice, how are the front arms holding up with someones wight on it? youll have to lets us know how she handles :p
I'm about 195lbs. and seem to hold the weight fine. i went with a thicker tubing so should do good.

[Russ2251]

The gas escaping out the pipe=less gas in the cylinder=less lubrication=more friction and heat that can result in a seize and/or melted piston

This statement is just plain wrong. What is your experience to enable you to make this claim? I need hard data! I would strongly recommend reading "Two Stroke Performance Tuning" by A. Graham Bell. Good for basics and high end engine builders.

[crazycart]

Sorry i was more referring to engines that were made for a expansion chamber pipe (such as most snowmobiles) and if the expansion pipe is taken off them there is a large power loss and you run a higher chance of burning it up.And thank you i will have to check that book out.

ANYWAY,ironman,i once made a pedal bike similar to your pocketbike and had the fork bent like yours,the steering was pretty bad and the frame would swing,i'd recommend bending the forks back straight and bust cut the frame and bend it out more like a chopper has.

[Russ2251]

Another excellent book:
"The Two-Stroke Cycle Engine: Its Development, Operation, and Design"
by John B. Heywood who is a professor at MIT.
Find it here: http://www.routledge.com/shopping_cart/products/product_detail.asp?sku=&isbn=9781560328315&pc=

[ironman]

ah, what a great night last night got the bike together took it around to check it out for my son.
{still need work to be safe}added front foot pegs on the front wheel for him and need to make the forks a little more steady.

by the way love the sound of the straight pipe i but on it.{next door people hate it lol}

[2or3wheels]

thats sweet

[dirtrider69]

post some pics of it....

[sayre315]

where'd you get the engine?

[ironman]

came on the pocket rocket but you can get them on ebay and just about any were else to around 50.00 i think