lowering bike ?

[riggy]

I was thinking about lowering my crf450x butt have some question . would I need to cut the fork spring or just install spacers to lower ?

[todd35]

No you don't have to cut the springs on the Showa forks you can machine a new snap ring groove to raise the spring seats. If you cut the springs it makes them a stiffer rate. PM me if you need someone to cut the grooves or if you need lowering spacers

[riggy]

If i wanted to lower 1inch would i machine the snap ring groove 1 inch higher ? Thanks the info todd .

[MX Tuner]

You can also get springs made in the rate you want in the length you want without having to find someone qualified to accurately machine new circlip grooves. If you just add spacers with the stock length springs/grooves, you'll end up with *way* too much fork spring preload which will ruin any plushness.

[UMan]

This is how the forks on my son's CRF250X were lowered.

Ron

[riggy]

Awsome Thank you for the pic ron it helps me get a better idea of what i need to do . . how much did u lower his ? have u had a problems with bottoming or negatives looks like maybe u lowered 2 inches ? I would love to lower mine 2 inches im just worried it would bottom out butt 2inches would be great for my short legs .

[riggy]

what was used to cut the groove ? would a hacksaw blade work and I assume the new groove is towards the top of the forks ?

[riggy]

what di you use as a spacer ? and to lower 1inch would u make a 1inch spacer , and so on 2inch would it need a 2inch spacer ?

[todd35]

I use 3/4 od Delrin and I drill a 1/2 hole thru it. Just make your spacer the length you want lower it and move the snap ring groove up that distance. Anyone with a lathe can cut the grooves in about 5 min. I have heard of people using a triangle file but i would be careful with a hacksaw blade, you could easily cut thru it. It is much cheaper and easier then new springs and it is easy to convert back to stock height. I wouldn't hesitate to lower it 2 inches. My dirt track bike is lowered 5" and I race TT which always has a jump and it never bottoms

[riggy]

Thanks a " TON " for the info todd . Thanks guys . I will touching the ground soon sweeet !

[riggy]

Thanks a " TON " for the info todd . Thanks guys . I will touching the ground soon sweeet !

[UMan]

Awsome Thank you for the pic ron it helps me get a better idea of what i need to do . . how much did u lower his ? have u had a problems with bottoming or negatives looks like maybe u lowered 2 inches ? I would love to lower mine 2 inches im just worried it would bottom out butt 2inches would be great for my short legs .

The 250X was lowered 2" by the previous owner. I de-lowered the bike when I bought it, so I don't know how it rode.

Ron

[riggy]

how about the rear shock spacer , what size spacer to lower 1 inch or 2 inches ?

[chadk66]

best way I've found to lower the seat height on crf's is use the stock crf shock but use an 07-10 kxf250 lower shock clevis. this will shorten the shock about 5/8". And will lower the seat about 1.5 inches. Then just put 1.25" spacers in the forks and raise the fork spring seats as mentioned above.

[kawamaha]

best way I've found to lower the seat height on crf's is use the stock crf shock but use an 07-10 kxf250 lower shock clevis.

this will raise the rear wheel, no matter if its extended or compressed. so the rear fender is used as mechanical end stop?

[chadk66]

this will raise the rear wheel, no matter if its extended or compressed. so the rear fender is used as mechanical end stop?

bottoms out on the shock rod long before the fender.

[kawamaha]

best way I've found to lower the seat height on crf's is use the stock crf shock but use an 07-10 kxf250 lower shock clevis. this will shorten the shock about 5/8". And will lower the seat about 1.5 inches. Then just put 1.25" spacers in the forks and raise the fork spring seats as mentioned above.

ok, beeing interested in linkage designs for a long time, I did a drawing...

due to the progression the max. lift of the rear wheel is less than the the 1.5 inches. its about 5/8 inches that the rear wheel lifts more than stock.

with a shorter clevis the linkage moves more to its fully extended position, results in more progression at the end of the stroke.

with a 5/8 inch shorter shock I won't reach a fully extended linkage, which would limit the max. possible rear wheel lift. but when I removed the shock of my KX450F to check the chain sag, I remember that the swingarm lift was limited by the chain clamped between the swingarm and the chain roller.

so if I would use a shorter clamp I would check that.

I don't know if a stock CRF has a 5/8 gap between the tire and the rear fender, but as I explained, its also possible it stops at the

chain roller or somewhere else -

could be the shock rod, could be something else - just my 2cents...

[chadk66]

It wasn't an issue with this bike. Not sure what to tell ya.

[kawamaha]

It wasn't an issue with this bike. Not sure what to tell ya.

I don't want to offend you and I don't say there's an issue.

just some theory...

[chadk66]

no offense taken. granted the kid is 120lbs and probably never used the whole stroke.