• Enter the March CB750 Supply gift certificate giveaway! It's easy... Click here, post something, and you're entered into the drawing!

Forks Dropping

mrbigelow

CB750 New member
Messages
4
Reaction score
0
Points
1
Location
indiana
Hello all!

Question about a CB I picked up recently. The previous owner installed new forks and lowered the with Cycle X springs and a 3 inch spacer.

They're pretty low already at the resting stance (without me on the bike), but when I hop on the bike and put some weight on the bars, the front forks immediately drop. There's almost no clearance at this point -- maybe an inch or so of travel. They bottom out relatively often with the seal covers hitting the triple tree. Obviously not an idea situation.

Here's a before and after of the bike resting without me on it, and then once I hop on:

20200907_204231.jpg 20200907_204316.jpg

I have a CX500 as well and I recently had this same issue. The CX has air shocks, and someone was messing around with the air valve and let some of the air out. When I got on the bike, the forks dropped just like the CB I'm having issues with. So I just added a bit of air in the CX shocks and they're all good now. No more drop when I first hop on the bike.

I'm wondering if the CB shocks just need more oil? Or is there anything else I'm missing? I'm pretty new to the bike scene, so still trying to figure it all out.
 
If the tube is sticking way up in the triple to stick out the top like it looks, lower the fork tubes in the triples.

You can't ride the bike like that regardless of how cool it looks.
 
Sure thing -- agree that this is quite impractical to ride with this much clearance.

My main question though is more so regarding the function of the fork and if it should be dropping like this when I sit on the bike? Is this normal, or does the drop indicate that I might be low on oil? Doesn't seem like the fork should drop this much just from sitting on the bike. It's a quick drop, too. Very deliberate and exact every time. Just slides down and compresses.
 
Measure it. I look for one inch drop with rider weight as normal. It should settle down to be about in the middle of empty travel no oil no spring lock to lock. If you use too much air the seals will die quick; no more than maybe 10 psi air. Normal oil weight is 10 weight there or ATX fluid. Oil amount doesn't matter as drop once done is what it is and spring only affects the level then, oil is doing nothing as it is not moving through orifices at settled condition. Change oil WEIGHT to change settling speed not amount. You do NOT want zero drop at all. that is topping out and just as bad. It takes away rebound as you run over holes.

That fork normally has roughly 6 inches of travel and under normal use will commonly stroke 3.5-4 inches of it.
 
Last edited:
Have you settled it to then jump down on bike to add weight to see if it can go deeper? You may be coil binding spring with that much spacer. Looking at damage if too close to that.

You have another serious issue with how the brake line runs unfastened around the tire sidewall. If tire manages to bite the line you may easily go down over it, I'd be fixing that line higher up before I even got back on it.

And the front tire tread pattern, one chosen that absolutely will cripple handling on one of those. It should act up on rain groove pavement.

Of course, yours and do what you will..............
 
Last edited:
Back
Top