Thinking about building a pit bike.

[Beat nick]

I came on here ages ago because i was gonna buy a pit bike but didn't end up getting one i got a crf230 instead, but have still wanted one. I am doing a wood/metal/electronics technology class in year 11, and i want to build a pit bike frame for a 125cc motor probably a lifan. Has any one on here done this? Ive got this class for the year so i have a fair bit of time to do this in and i can get some of the materials pretty cheap, and i've got a while to save up for a motor and what not. money shouldnt be to much of a problem seeing as i'm working to jobs atm lol. so, any feedback on how to go about this will be good, and i'll keep the thread updated with the progress.

 

[I_THUMP]

Your best bet is to buy a decent bike and mod it, this is a far cheaper option than building one from scratch. As for making the frame good luck with it as China is hard to compete with on price, but as for quality well that depends on how good u are.

 

[ducar.r.spec]

get a normal chinga frame
and replicate with better material
replicate from the replicaters

 

[motoXXX]

yeh way cheaper to just get a 140xr or watev thats got good running gear from stock then build a pit bike but if you want a good custom with all the good parts build one but unless u got about 2g dont bother

 

[Tyrets]

hey dude if you got a good idea in ya head of what you want, a frame is gonna cost fu#$ all to put together as steel is basicly inexpensive its gonna take a bit of time but as you said you got plenty of that build your frame, get some good discriptive pictures of the china bikes to see how they are arranged, and if you take the time to look in the right places on ebay you should have no problem pulling it off for a grand minus motor. when finished though you'll have a kick arse bike that you'll know inside out good luck man, and keep us posted.

 

[unit_mx]

Building a bike is fun , rewarding and can learn much however it costs slighly more as your paying the dealers profit on every part you buy where as on a complete bike your only paying retail on the entire item.
If you do buy a complete bike I would go for a pitpro 140xr then start it , ride it up the street once then pull it down. Regrease all moving parts with blue water proof grease , replace all the bolts / axels / washers /nuts with high tensile or stainless stell items from a fastener wholesaler. Loctite the bolts in with medium strenght once putting together. Once forks are out pull them down and if your unsure of how every thing goes take photo's of the dissasembly process. ONce stripped forks clean em up and replace the oil with decent quality stuff and place sponge between the seals. Now on too the motor pull of the carb and smoothen out that manifold and exhaust port. File out the internal welds in your ehaust header and repack your muffler with decent packing. Then on to your frame bracing and jigging all weak spots , then get it painted. Replace all bearings and grease em up. Replace the swingarm chain buffer and roller with better nylon parts. Piss off the crap chain guides with a decent quality brand one as do with the chain. stick it all back together carefully using a tourque wrench and start the thing up and let the thing idle through a bit and keep the maintnace up to it like dropping the oil staight away in these bikes and gettin better filter on em from stock

 

[coolmodee01]

um hello
the dude wants to do this as a school project
he is wanting to build his own frame regardless of most expence

this is the motovert frame
this pic might not be all that helpfull but it will give you a starting point
you will need to get your hands on a similar frame to get measurments
the hard bit will be getting the right head tube angle

 

[SnItChY]

^^^ i would look at getting a cheapy frame you want to copy

pretty easy to do seen em sell for 30 bucks new

then just a simple copy ,with better quality steel or alloy wich eva u decide
should be cool fun ,keep us uptodate with your progess and we may come up with some ideas u can use as you go

also a walk down to you local bike shope and pics of frames from there stock should also help for referance

remember tho weight is the killer on these bikes so keep it light as possible
but with that you have to give in the strength to attain the weight youll need

but like i said would be fun to do and is then a truly custom bike

 

[Beat nick]

Thanks for the replies, I've scratched this idea for the time seeing as there isnt as much time as i thought I would to do this, but I hopefully will be able to do this at a later time if i ever get around to it, not alot of time to start this anyway because if i'm working on the weekends and threw the holidays ill be helping and electrician most days, so if i do decide to go ahead with i'll bring this thread back.