CLASS question

[Guest Ken8143]

OK - so the motorcycle guy replaces the front fork springs. Compressor runs, pressure builds up nicely and holds - BUT - there is no difference between low and high pressure on the front suspension. Front end bounces down just as easily on high pressure (17 psi) as on low pressure (7 psi)

 

Previously I could see the forks extending when the pressure went up, and theren was a noticble differencem but not now. No error messages on the computer read out. 1987 venture royale.

 

Any ideas about what went wrong? Or what to do for a fix?

[StuD]

Stock springs or proggressive springs?? I have read that if you replace with progressive springs you do not need to use front fork pressure. :confused24::canada:

[Skid]

The difference is as much as night and day,

also changing to Progressive Springs is very easy and takes little time.

[Black Owl]

Is the solenoid valve for the front shock opening?

 

You may have a cold solder crack and no signal being sent to the solenoid. The readout will show pressure building in the chamber, but if the solenoid valve is not opening, the air is not being routed to the shock.

 

Also, you will not receive an error message.

[Guest Ken8143]

Somewhere I read there is a technical article about the CLASS and progressive springs in the front - a work around if the CLASS doesn't work right for the front forks.

 

Can't find that article. Anybody know about where it is?

 

Another question - do you actually need the air suspension adjustment when you have the progressives installed?

[Marcarl]

Somewhere I read there is a technical article about the CLASS and progressive springs in the front - a work around if the CLASS doesn't work right for the front forks.

 

Can't find that article. Anybody know about where it is?

 

Another question - do you actually need the air suspension adjustment when you have the progressives installed?

You don't need air with progressives. My guess is the same as Black Owl, air is not getting to the forks. How long does it take to pump up 17 lbs?

[Guest Ken8143]

You don't need air with progressives. My guess is the same as Black Owl, air is not getting to the forks. How long does it take to pump up 17 lbs?

 

It jumps up to 17 pounds just as fast as it used to - pretty quickly

[Marcarl]

It jumps up to 17 pounds just as fast as it used to - pretty quickly

You may want to compare the time to another 1st gen if that is possible. The back takes a lot longer to fill than the front, (higher pressure), but I remember that the front does take a little time. This might indicate a blockage in the system or maybe the solenoid is not working. You should see some rise in the front, especially when you're sitting on it.

[cecdoo]

I am not very far from you if you want to meet to compare fill-up times. Craig

[Gearhead]

With progressives in the front I no longer need air in the forks. With no air I am sitting right around the 33% static sag that I've seen as a rule-of-thumb. However, the air does still work - adding air does jack up the front end. But - I think it is less noticeable than with the old, sagged stock springs. With the stouter springs in there the air pressure is a smaller percentage of total fork "effective spring rate" than before, which means it would have a smaller effect.

 

Jeremy

[Guest Ken8143]

You may want to compare the time to another 1st gen if that is possible. The back takes a lot longer to fill than the front, (higher pressure), but I remember that the front does take a little time. This might indicate a blockage in the system or maybe the solenoid is not working. You should see some rise in the front, especially when you're sitting on it.

 

 

Thanks for the info, guys -

 

When I said quickly I probably misrepresented things. It does not take forever - it is the same amount of time it used to take when I could see the front forks rising. And when I take it from 17 down to 7 I can hear some air hissing out, I assume from a release valve.

 

We will get it figured out one of these days! Like a number of you have mentioned, the air may not be needed. I just am confused why the air did not work after they replaced the fork seals, and again after they went back in to see what the heck was going on - and I told them to put progressives in.

 

One good thing - the shop did not charge me extra labor - just the cost of the progressives. The bad part is that I can't ride my bike!

[GeorgeS]

I think I would drain the Oil out of the tubes into a Container, and see just how much Oil the guy put in after the work.

 

Should be about 13 oz of oil in each side.

[calperin]

I have progressives on the front, and I never put more than 7 psi on the fronts. If I do that, I can fell the street on my hands as if I'm riding on top of a rock. (Flintstone's bike)

 

And the back, with the standard one, allways take two o three times more than the front ones.

 

Regards,

[wild hair 39]

fork oil,had to use 5W,on mine,to get the rid of the harsh ride,after that,rides great

13 oz fork may be to mutch oil,prog are larger,and don't need as mutch,forks claped,5.5"from the top.prog spec,

[GeorgeS]

My thinking was, how much "oil " if any, did the guy who worked on it put In,

 

And what wgt. If the thing is bottoming out and unridable, I'm wondering if the guy put in any oil at all. ???

 

Sounds pretty strange. Even with No Air pressure in the front forks, It should be ridable.

[Gearhead]

"13 oz fork may be to mutch oil,prog are larger,and don't need as mutch,forks claped,5.5"from the top.prog spec,"

 

 

 

On my 87, 13 oz of oil still leaves over 6" of space to the top of the fork tube with fork collapsed and spring removed, thus, it should be OK.

 

Jeremy

[GeorgeS]

I was wondering if the mech who worked on it, Put Any Oil at all in it. If its bottoming out, with air, sounds like some parts were reinstalled wrong, or maby, the guy forgot to put in Any Oil at all. ??