'93 CB250 (custom) SUSPENSION IMPROVEMENT RECOMMENDATIONS?

[LePegase]

Hey guys,

Lately I've been feeling a weak suspension on my CB250, specially when I go over train tracks or bumps. Any recommendations that have worked for you in the past other than replacing the shocks? Also, if it comes the replacing the shocks, any brands you'd recommend for this model?

 

[LongDistanceRider]

I would start with draining the forks and refilling with 10w fork oil, see FSM for quantity. There's a small 10mm head bolt at the bottom outside of each for that's the drain screw. You'll need to support the bike because you're going to remove the top fork nut that holds the spring in, so good support with front wheel off the ground.
For the rear short of replacing the shocks you want to remove them and move the swingarm by hand thru it's range of motion, it should move smoothly. Easier with the wheel removed also. Range of motion is only 3-5 inches. I don't know for sure but there should be grease zert fittings that should be cleaned and then lubed. Not reassemble with the shocks at their lowest preload setting.
Make sure your tires are not over inflated, there's a decal somewhere usually with the suggested pressure for the original tires and that's a good start point.

 

[ancientdad]

Hey guys,

Lately I've been feeling a weak suspension on my CB250, specially when I go over train tracks or bumps. Any recommendations that have worked for you in the past other than replacing the shocks? Also, if it comes the replacing the shocks, any brands you'd recommend for this model?

Moved to SOHC Twins Suspension section

 

[Alan F.]

First of all how many miles are on your bike?
What do you weigh with your gear on and do you carry anything with you when you ride, tank bag etc?

If you've just got a worn out stock suspension it's time to rebuild your forks and make sure your fork springs are in spec and appropriate for your weight. New springs may be needed.
Rear shocks are easily replaceable, I'd measure their length center of top eye to center of bottom eye and look for replacements based on that.
Even the cheapest new shocks will be worlds ahead of your worn out stockers, you can spend from a little up to a stupid amount of money on shocks, I'd start low.

Definitely check out your swingarm pivot, if it's never been apart...its time now. Disassemble, clean, grease & reassemble at very minimum.
If they fit loose when reassembling, or you can feel the back end of your swingarm moving side to side after reassembling, you may need new bushings and a new pivot bolt, loose fit will affect handling.

Also your steering bearings may need some attention. With the front wheel raised off the ground, turn steering fully from side to side, do you feel a notch in the middle? Time for new bearings.
Stock are ball bearings, nothing wrong with that, there are tapered roller bearing kits out there but I'd recommend simple disassembly, cleaning & reassembly with plenty of new grease.
This isn't a GP bike, you just want to improve what you have right?

 

[LePegase]

I would start with draining the forks and refilling with 10w fork oil, see FSM for quantity. There's a small 10mm head bolt at the bottom outside of each for that's the drain screw. You'll need to support the bike because you're going to remove the top fork nut that holds the spring in, so good support with front wheel off the ground.
For the rear short of replacing the shocks you want to remove them and move the swingarm by hand thru it's range of motion, it should move smoothly. Easier with the wheel removed also. Range of motion is only 3-5 inches. I don't know for sure but there should be grease zert fittings that should be cleaned and then lubed. Not reassemble with the shocks at their lowest preload setting.
Make sure your tires are not over inflated, there's a decal somewhere usually with the suggested pressure for the original tires and that's a good start point.

Thanks a lot for your input. I will try this!

 

[LePegase]

 

[LePegase]

Moved to SOHC Twins Suspension section

Thanks!

 

[LePegase]

First of all how many miles are on your bike?
What do you weigh with your gear on and do you carry anything with you when you ride, tank bag etc?

If you've just got a worn out stock suspension it's time to rebuild your forks and make sure your fork springs are in spec and appropriate for your weight. New springs may be needed.
Rear shocks are easily replaceable, I'd measure their length center of top eye to center of bottom eye and look for replacements based on that.
Even the cheapest new shocks will be worlds ahead of your worn out stockers, you can spend from a little up to a stupid amount of money on shocks, I'd start low.

Definitely check out your swingarm pivot, if it's never been apart...its time now. Disassemble, clean, grease & reassemble at very minimum.
If they fit loose when reassembling, or you can feel the back end of your swingarm moving side to side after reassembling, you may need new bushings and a new pivot bolt, loose fit will affect handling.

Also your steering bearings may need some attention. With the front wheel raised off the ground, turn steering fully from side to side, do you feel a notch in the middle? Time for new bearings.
Stock are ball bearings, nothing wrong with that, there are tapered roller bearing kits out there but I'd recommend simple disassembly, cleaning & reassembly with plenty of new grease.
This isn't a GP bike, you just want to improve what you have right?

The guy that I bought it from had installed a new electronic odometer but I'm guessing at least 15k miles.

I weigh about 145lbs + 10-15lbs of gear

Thanks, will definitely try this too... and no, not a GP bike haha

Btw, your '65 CB160 story is awesome!