[rlfrost4015]

I just purchased a 2020 CRF 125f big wheel for my son. Looking to upgrade suspension - specifically to inverted front forks. I know with other 125’s you can slip in fork tubes from different models with better suspension. Did I happen to buy a bike this isn’t possible? Let me know what others have done - I scoured google all the sites I could with no real answer on how to do the inverted fork upgrade, thanks very much for the information in advance!

[JimDirt]

Welcome to the site !!

About the only thing you could do is try getting a set for a CRF150R and trying to adapt the stem to fit the size of yours (length of stem and bearing O.D.) , and have the length of the tubes ( you can install limiters) so the overall length is the same as your bike stock to keep the geometry and balance of the bike the same and safe ... Emig Racing (Jeff Emig the retired MX'er/Announcer) sells a kit for the CRF230 , but not sure if it will adapt or work with the 125F http://www.emigracing.com/crf230f-crf250450f.html , but its not cut and dried , like bolting the kit on and going , there is a lot of other things to consider , maybe look into that and decide if it is worth the effort , or to just buy a CRF150R or similar ... and be done with it .... , unfortunately , the F bikes are basic and don't have the options of the other bikes to keep costs down , like inverted forks , the conventional forks are much cheaper to manufacture , maybe Ray can chime in with something he may know , as he is the small bike Guru around here .... , but I am thinking you may end up going the route of the 150R

[Aussiecrf230]

Well I wouldn't rush out and buy anything until you have done lots of measuring.
Current fork diameter and length as well as stem height and diameter.
Troll through the parts fische the bearing part numbers will help identify what might swap.

I believe the 125F are 31mm forks the 230F are 37mm.
So there is probably limited room to go to larger fork without having to mess around with axle length. That is why people graft a whole front end where they can.

You will find the right way up fork to be plusher for trail riding and having the springs at right rate with correct weight oil might make it handle better than you may think.

As Jim said, anything is possible it is just finding what fits best.

[rlfrost4015]

Thanks for the information. My son is 12 and runs harescrambles so trying to get a decent suspension for him. Unfortunately he isn’t quite ready for a 85 - he leans more toward the 4 stroke power characteristics. We didn’t have many options with his size and capabilities right now so figured the 125f for power and can do a big bore when he is ready for more. The crf150RB wasnt an option for him as we really wanted him to have e start - he can kick a bike but figured it would give him one less thing to worry about at races. Basically we are trying to get the suspension of a 85 but with the 125f motor. I know the klx140 you can pretty much use the front end of a kx85 and same with the ttr. I guess you know what they say about assumptions...... and me assuming CRF125f would be the same!! Will do some research- I just thought it was a little weird I couldn’t find any threads on this already as I am sure others have tried (and maybe failed) at the same.

[JimDirt]

Yes , unfortunately as I had mentioned about Emig , they have stuff for the 230 , but it does not mention the 125 , it most likely could be for those very reasons Ray mentioned , also when I said "but I am thinking you may end up going the route of the 150R" , what I meant was switching to that bike ........ but if the button is a issue , you might end up having to go the route of the KLX140 , it is basically just what you are looking for , and as I mentioned , if height is a issue , then you can always have the suspension lowered to make it fit better , then as he grows you can adjust that to fit , and/or switch brands or models when he is ready ..... if the 140 power is too much at this time , you can also have the throttle limiter to curb the power till he is more comfortable on the bike , but if he is already racing then I think he will have the throttle control to regulate any power differences from the 125F to the KLX if any ....

Good luck .....

[Aussiecrf230]

I believe RH Moto Worx have done a conversion for USD forks.
Not sure on what this would cost, but looks like CR80 front end.

Think was for XR100 or the like
Fork swaps may raise bike so maybe an issue.