Hi,

I am currently putting together a 24″ hard tail for my son. I have the opportunity to use a 100mm travel 26er fork. A2c on bike is currently 420mm and the new fork is 470mm. If I include a 40% sag this drops to 430mm doesn’t it?

Is this acceptable? Will it screw up the handling? Bike is an all rounder so good climbing characteristics is important.

Thoughts?

No, that would be 430mm. But anyway 40% is too much. How about reducing the fork to 80mm, then running 25% sag. Still 430mm, but will feel much better climbing and out of the saddle. Still slacker than the original though. Guessing between 0.5 and 1 deg? (not done the maths)

(sorry – either I mis-read or you have ninja-edited!)

There isn’t much point running 40% sag though…. (presuming all else works geometry wise) because you’ll also be running really low pressure for the kids weight and the remaining 60mm are likely going to be sucked up.

You might be better biting the bullet and buying some F1rsts…(£150)
https://www.bike-discount.de/en/buy/f1rst-air-24-mtb-suspension-fork-51499?lang=en

I know you can get away with a 120mm SID on a FS Frame designed for a 100mm (e.g. Ripcord) but I think you’d be really pushing the envelope trying to get the extra 30mm… on a kids HT frame.

Out of interest what 26er fork have you got?
(Reason I’m asking is I’m going to be changing a 26″ fork on a Norco I just bought and I’m looking at used SID’s or REBA)

Could quite possibly cover the cost of buying the F1rsts … (just typing as I think)

my eldest is using a reba dual air. Got extra spacers in there, but also have the -ve chamber charged up to pull the fork down and make it more compliant for the little weight. She loves it.

I’m going through the same process at present…little one is only 8…I’ve gone with carbon forks based on the fact the weight saving will probably be more benificial to her at this time than suspension…guess it depends on where you’ll/they’ll be riding.

Thanks all. So unless I can convert them to 80mm it’s not advisable.

The F1rst forks do look good. Will give them some thought although it is a big budget creep.

I have some very cheap fox float F100s available to me mates rates so not mine to sell on unfortunately.

Last point, I would happily put some rigid forks on for my son (also 8) but he is desperate for bouncy forks like mine. If it encourages him to ride then I’ll happily go with it!

Thanks all.

If it helps … the F1rsts are worth it…
They are pretty basic (easy to service) but they do work unlike spring forks for kids and also only 1680g or so.

I know people have externally modified various 26″ forks to fit but honestly I think it needs to be your hobby to go down that route… (involves cutting and grinding and sticking them back together with epoxy and I don’t think twice before shortening cranks… but this all seemed way to far out for me)

Also if you don’t modify the internals the adult forks are unlikely to really work “that well” … you end up with insanely low pressure that won’t then decompress so people end up modifying the needle valve.

I have some very cheap fox float F100s available to me mates rates so not mine to sell on unfortunately.

Worth taking into account if they need a service and what that would cost ??

I put some 80mm Floats on my lads 24″ HT. IIRC the AC difference was about 15mm between the sprung RST’s I took off and Floats.