Putting modern hubs on

[Neilson95]

Hi I’m wanting to put modern 450 hubs in my 86 kx500
With the standard suspension as I need to keep it the same to race it in the vmx chapionships
I no I’ll need to get different spaces made but would like to no kf anyone has anymore info or could help me out as to what I’ll need
Cheers in advance

[Sandblaster]

I pulled a 86 swingarm from storage and measured it at approx 8" between the rails where the rear wheel bolts on.
The 89-04 measure approx 7 3/4".
So, there is plenty of room.

On the rear: If you plan to use the 86 brake then there are two issues you need to think about.
1. You will need new adapters to convert the 25mm axle holes in the rear wheel to 20mm.
I have drawings on them for the 89-04 but not the 86. The diameters on the drawing will work but the width will be different.
2. The rear rotor diameter should be 220mm... Double check me on that... If so, the 450 rear rotors are bigger. 06-18 I believe are 240mm and the 2019 and up are 250mm. There is a company that makes a rotor for the 450 that fits on the KX500... But I don't remember who it is... Do some research.

1. On the front wheel you 86 uses a 17mm front axle size. The 450 uses a 20mm.
So adapters will need to be made and I do not have any drawings for that. And like the rear I'm sure the spacing will be different.
Also, the front brake rotor diameter is bigger on the 450 than your 86 500.
I don't know anyone who makes one that will convert.
You can use a 450 rotor but you will either need to make a caliper relocation bracket or have the diameter cut down.
Of course the easy way around all of that is to buy a 450 front end

[Neilson95]

Ok thanks a lot for that info that’s pointed me in the right direction cheers