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Technical & Reference Section => Tech and Restoration => Topic started by: Vas on August 12, 2019, 09:24 PM

Title: First Build Knowing Size & Measurements
Post by: Vas on August 12, 2019, 09:24 PM

Starting my first build soon but im so confused on what size and measurements i need at the moment i have a GT Air Frame forks and bars was going to respray

But how do you know what size parts etc i need not just for my bike for any bike in general

Hope somebody could help

Thank you Vas

Title: Re: First Build Knowing Size & Measurements
Post by: Spen69 on August 13, 2019, 06:10 AM

Hi Vas, welcome to Rad

Firstly is the frame and forks chrome plated - I'm not sure from the pictures? If it is then don't respect it as the paint won't stick tbh, you're better off reading the stickies in the technical section on chrome cleaning

Next what sizes do you need to know? You bike runs standard 20" wheels, has a set of 1-1/8" threadless forks, most likely a 1" seat post and has a normal front caliper and rear AD brake set-up.

Let us know what specifically your question is and we I'm sure someone o here will have the answer (once they've recovered from their wild weekend in Milton Keynes!)

Title: Re: First Build Knowing Size & Measurements
Post by: griff on August 13, 2019, 10:06 AM

Don't worry about measuring anything - that should fit in any sized skip  :daumenhoch:






















Sorry - couldn't resist :teef:
If chrome not too far gone should clean up ok in a bath of citric or oxalic acid and polish with Peek after - like Spen said look in the tech/resto section for tips
Get it all apart and cleaned and see what you can save/restore - whatever you do don't start chucking money at it straight away as you won't be adding much value

Title: Re: First Build Knowing Size & Measurements
Post by: Vas on August 13, 2019, 07:46 PM

Spen69 my dads stripping it down over the last couple of days but i think its chrome not sure tho looks sort of silver  it really needs new crank arms and sprocket

Griff i totally know mate its a piece of shite but i do love a challenge lol

Title: Re: First Build Knowing Size & Measurements
Post by: Spen69 on August 13, 2019, 09:08 PM

No worries mate, the crank is just a bog standard opc (one piece crank) with a standard 24 tpi (threads per inch) reverse thread, so any crank other than an 80's Mongoose crank will fit.

As for the sprocket, do you mean the front chainwheel or the rear drive freewheel sprocket on the wheel? Either way, count the teeth and let us know as it's likely to be a 44/16 ratio which is standard for BMX's  :daumenhoch:

Title: Re: First Build Knowing Size & Measurements
Post by: Vas on August 13, 2019, 09:35 PM

Spen69 ive just checked with my dad and hes saying its silver more like a powder coated silver

Title: Re: First Build Knowing Size & Measurements
Post by: Vas on August 13, 2019, 09:38 PM

Spen69 thanks ill get back to you soon

Title: Re: First Build Knowing Size & Measurements
Post by: Vas on August 15, 2019, 09:27 PM

Its a gt dyno air i think and is chromoly not sure what that means ?

heres some pics of the same bike but not mine