Help to purchase front Suspension Fork

Started to assemble a new ebike as the old one been stollen yesterday, unfortunately...
So, question who can explain or maybe give links because my google search got me nowhere.
My old stolen ebike had this fork- 

https://a.aliexpress.com/_u8Tj1j

Did use a 26inch fat tire wheel on it.
If I want on my new ebike smaller wheels, let say 24" or smaller - I have to buy a long fork or have to purchase a longer "head tube" for it. I believe if the answer is yes then the fork needs to be without that tube or not "permanently" fixed or soldered to the fork... So I can attach any head tube?

Or I absolutely wrong?

Any help would be appreciated.

No to longer head tube, 24 smaller wheel will put crank bottom bracket 1 inch closer to ground easier hit things , but these forks quite tall anyway ,long travel so probly even it out there is bit of adjustment on forks possible to raise ride height a bit aswell if need, has your frame got a straight head tube because that's what these forks are for as they have straight steerer tube other kind is called taper, did you like these forks when you had them? I am thinking getting some,

serginho007 said:

Or I absolutely wrong?

Click to expand...

Probably.

The head tube is part of the bike frame. It's the short tube that the fork's steerer tube fits into. The steerer tube is cut to length to fit the head tube, plus the additional length to include the headset, the stem, and any spacers you use to adjust the height of your bars.

You could use a longer travel fork or go with a fork designed for a larger wheel (27.5, 29) to make up the length from going to the smaller wheel, but if you are riding on rough terrain, you may want to limit the travel if you go with the longer travel option.

Thank you very for your help as now I know what exactly to order...

Thanks again all