Postie - Engine and Susp upgrades

[mrtim123]

Hey Guys,

i've been trawling through the pages of you forum for quite a while now....i dont post much on here but do read heaps of threads.
I picked up a late 90's postie bike a little while back for the princely sum of $50. There is absolutely nothing wrong with it but i though to myself "why not chuck a china motor and forks into it".
The long term goal for this bike is for the missus to learn on, so it has to be manual (hence the china motor upgrade) and ideally i would like to rego it again.
I understand that it would require "engineering" but as my brother is in the industry this will not be an issue....
My questions are this:
1. Can i buy an "atomik" or other china from ebay and transfer engine over to it? i know the engine needs an adapter plate to bolt up and a few other little bits - that is cool. If i bought the whole thing then i have wiring, CDI, carby, etc....anything else i need to know?
2. Using the same donor bike, could i replace the triple-clamp and forks in the postie with the china ones? this would give me better (slightly) forks and a disc brake front end (main reason for swap). Even better if the donor had a 17" front wheel, i could use the whole front end then instead of re-lacing the hub onto postie rim.

Basically im trying to do this as cheap as possible. The missus likes the postie so it has to be that bike. I dont want to get a pit-bike for her as she wont ride it....the step-through type design of the postie is ideal for her.

Can you guys see any problems with what im trying to do? I assume its been done before (i know the engine has been) but i cant find much info.

cheers
mrtim123

 

[matty_77]

yes if you are wanting to get it registed, The pit bike engines are 12volt not 6 of the early ct90. I think to solve this problem you would have to buy a complete second hand wiring loom from ebay. Also on the ct90 they run, 6 volt lights, 6volt batteries. Everything electronical on the bike are 6 volt. But if it isnot to get registered The pit bike wiring should be fine.

 

[mrtim123]

ahh sorry mate, when i said "late 90's postie" i mean 1997 model ct110. Its a 12 volt system already

 

[Sabertooth_buterfly]

Hi mrtim
this sounds like a great project, it should work puting a pit bike front end in the only issues I can for see are the steering bearing stem, brake light switch, and the front guard. Bearing stems can be custom made if you have or know someone that has a lathe (I have made a few and they are not dificult) the brake light switch can be rigged from a trail bike master (think xr250 or similar) and then just use the guard from the doner bike. For a doner bike I'd consider one of the atomik bikes (the big wheel pit bike one). You will have to adapt the original honda wiring loom to take the china motor sorry cant help to much with that as I'm not to flash with wireing.
I could imagine that once you got all this done the bike would require an upgrade of rear shocks to maintain its ballance, maybe try looking at the wrecking yards as many early hondas use similar type mounts (maybe old xl185 or 200).
if you go ahead with this keep us updated (with pics I love seeing pics of projects).
saber
PS: I just thought of the speedo drive that could be an issue not sure how to sort that one

 

[mrtim123]

thanks Sabre!
you know what, i hadnt even thought about replacing the rears as well. it seems so obvious now!
I was thinking that the front guard from the doner bike would do, glad you agree. The Atomic with the 17" front will be what i end up tracking down, should get just about all i need from it.
So you may have answered one of my questions here - do you mean the headstem bearings wont fit, or that the stem itself might be too long/thick?.

Whilst waiting to kick this project off, i have painted all the panels in a Kawazaki KX green! When its all stripped down for the powerplant update, ill paint the rest of it. Anything that was red will now be green.

And yes, once parts start arriving i will post plenty of pics. At the moment, its research stage only.
Tim.

 

[Sabertooth_buterfly]

yea there is likely to be a prob with the length or diameter of the steering stem from the china bike but a custom stem should be able to sort this. It sounds like you have either the equipment or know someone who has so that should be an easy fix (famous last works I know), it could be worth looking up the inner diameter of standard china steering bearings and comparing to the honda ones to be sure, or just buy the doner bike and rely on "somehow there will be a way" thats what I often do lol.

 

[clunky64]

why dont you just buy a sachs would be a hell of a lot easier

 

[mrtim123]

where is the fun in that? that and they are fugly too.

 

[timmonds]

hello. for the wiring, assuming it is a kick start. wouldn't it be easy to wire up a voltage divider for 50/50 (6v and 6v) stuff from high school electronics. run that from the 12v of the motor. i have done lots of these for small circuits, however not tested on something like a bike, sure it would work the same. hope this helps. (this is essentially adapting the china one to honda one like Sabertooth_buterfly suggested.)