Topic: front forks seemingly is struggling to hold its motorcycle up

[Redline it]

having read some serious post about oil and springs i couldn't get out of it the answers i'm hoping for. the recent 400f 75 rides so low in the front that going around tight corners in the neighborhood is pretty cool, but when i stop and gonna put the side stand down the bike is just about vertical, and i have to pull on the bar to pull out the tube more, while on level ground. so i have another 400 that hasn't has any weight on it for decades so i thought i'd swap out the springs. only their the same length and the new saggy front end springs are. no oil leaks, shocks are like working like they should, no bouncing. i wonder whats up with that. if it was low on fork oil would it matter, i'm talking about a little low, not out. i think i put atf in it.

[Don R]

 You can add a little PVC pipe to shim the springs. I have a set of cb400F forks with air caps.

[BenelliSEI]

Did you measure the springs and compare to the required free length? New they. should be 16.8” and the service limit is 16.4”.

I helped a friend with his 1981 cb750 Custom that had the same problem. Progressive offered a set of springs for less than a $100 so he bought a pair. They were the SAME length but came with a 6” piece of thick wall 3/4” PVC. We cut in half and added  it on top of the springs (asDon suggests). Problem solved.

[Nurse Julie]

Is it the correct front end?

[carnivorous chicken]

The attachment point for the side stand is notoriously weak on 400Fs, have a look to see if someone didn't bend it back a little too far. They usually bend the other way, usually from people sitting on them with the side stand down...

[Redline it]

Is it the correct front end?

  yes it's all factory stock except for the seat and tires. About measuring, it's the same as all the other 400s I have, what's weird is cylinder wear and transmission also, is nearly identical even though 30000 more miles difference.  I could've swore I put oil in, and just now, drained the left fork tube and black thick murk dripped out, so far less than 1oz. So I put the spring in for a dip stick and it's not showing any. I haven't pumped it yet. I'm looking towards flushing it. I'll report on the right side  after flushing and capping the left tube. It's on the center stand and a little bottle jack can you believe that? I can't.