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Harsh Ride

coffee_brake

coffee_brake

Guest
Guest
I'm hoping some folks who know their way around suspension more than I do can offer some advice.

I can't do any kind of emulators, sonic springs or anything else pricey. I kinda need some pennytech solutions to a very harsh ride.
Even little bumps make the fairing rattle and the ride is very uncomfortable, increasingly so in the last year.

I just re-oiled the rear shock and put in bronze bushings to replace the needle bearings (thanks for the idea and measurements, T Cro!) and it made a positive difference in the rear end. But the front still shudders and wallows over bumps. Bike has almost 60k on it.

The fork oil is not a year old. I did have Progressive springs in the front but they were entirely too stiff for my 150 lbs. I put the stockers back in and will likely give hubby the Progressives since he weighs so much more than me (and his '99 practically wallows when pushed through the turns, it really needs the springs.) Whereas my bike is so harsh I feel like the front wheel is coming off the ground when it's pushed hard.

I put in regular ATF for shock fluid, and I put in the amount that the manual calls for with the forks off the bike. I have had a fork brace on there since new. The front tire is inflated to spec, and it does have some cupping, but I can feel the difference between a cupped tire and really harsh suspension. The discomfort I feel is not the tire. The suspension settings are set to the manual's "comfy, normal stock riding" settings.

Is there anything I can do so I can bring home my groceries without breaking the eggs on bumps? It's really, really harsh up front. I'm spending a lot of riding effort trying to navigate the smoothest way over normal city roads, and shaking out a lot of fairing bolts....
 
Hey Jenn.  No 'expert', but I've bent a couple things along the way :)

First guess would be the fork is binding, aka stiction.  Second guess would be the forks are over filled with oil.  Another possibility, but it doesn't sound like it in your case, is if you're riding stiff armed you'll feel EVERY little bump in the road.  Loosen your grip, bend your elbows, don't lean on the bars.  Support your torso using your back or use the tank for support.  You can try it - it's free and quick :)  If it helps but is uncomfortable bar risers or a tubular bar adapter might be the 'best fix'. 

First off, check for excessive stiction.  If the forks don't move freely, all the adjustments really don't matter a lot.  Probably your hubby is better for this test.  Have him straddle on the bike and bounce down on the handlebars - HARD!!  Wrap a zip tie lightly around the upper tube.  You want it to move easily, but not on it's own.  Slide it to the top of the 'bug scraper'.  Still straddling the bars, pull up on 'em and let it settle.  It'll be different.  Measure from the top of the bug scraper to the zip tie.  It should be less than 1/2" different. 

Da' Stickies

If it's more and you've got a fork brace on, first step is TAKE IT OFF!  I believe most fork braces cause more problems than they fix.  (y'all that swear by 'em go to another thread for now, k?)  Check the stiction again.  Good?  Check the threads on how to install it so the suspension still moves well. 

Not good?  I'll assume you checked that the upper tubes were straight.  If they're bent, won't ever work right.  Next is check that they're even in the triple clamps.  Even is less than 1/2mm, or within about 1/64th"!  If all those are good, maybe they're pinched or otherwise tweaked out of parallel.  Sometimes that just loosening the axle pinch bolts, the upper clamps, bouncing the front end a couple times and carefully retorqueing everything. 

Other things that can cause the stickies is mismatched springs, the oil level not even between the legs, uneven spring spacers or 'preload' adujsters. 

Setting Sag

Once you've confirmed the forks are moving reasonably well, the first basic setting it to adjust the sag.  It's adjusted with the two rods that come out of the fork caps (or air on the earlier models).  With you on the bike, in your gear, and with whatever stuff you usually carry, the resting place should be about 1/2 way in the suspension travel.  I don't remember how much the front has, but it's should be in your service manual.  Top out the suspension and measure between two convenient places above and below the 'bug scraper'.  Have the hubby measure the same two points with you on the bike.  Turn the adjusters in or out the amount that the measurement is off to get it in the middle.  That's ALL THESE 'PRELOAD ADJUSTER' DO!  They don't effect how stiff the front end is at all unless the travel is way on one end of the travel.  They just move the bike up and down in the suspension travel. 

Setting Damping

Since you're using the stock damping rod suspension, the only thing you can do is change the oil viscosity.  You're using ATF, but I don't know what the viscosity of that is.  From what I read it can vary quite a bit.  If you think it's too harsh, a bit 'lighter' viscosity might help.  You're going to have more bouncing and brake dive along with that, but it might be a good trade-off.

Oil Level

Recheck it.  It'll probably be low if you pumped the forks dry or drained them overnight.  Even priming them when refilling will leave some air trapped or suspended in bubbles.  Even up the levels too or you can get binding like if you had uneven springs or spacers.

Make sure you're refilling 'em to the correct level.  If there's too much oil the air that's trapped in the top of the fork will compress more quickly and that can make it feel really harsh. 
 
There's books written on this stuff, but sounds like we're not looking to get a perfect setup - just trying to figure out what's wrong.  Stock the Concours has a pretty soft suspension - at least for normal pavement.  For rougher stuff, it needs help, which to fix then you gotta spend the bucks for a fork transplant or aftermarket springs and valving instead of the original damper rod.  Otherwise it's too 'soft' for normal riding. 

It can be done tho'!  I was ok with Vrooomm with OE springs and the original damping setup.  I knew there were compromises tho' and just accepted them and rode it anyway.  It's still better than an early '80s Japanese UJM 'cruiser' I had when I started :)
 
Thanks for the write-up, there are good points in there that I have not considered.
Yep, I'll need Hubby's help to get that front end to move.

I do know I've had the bike since new and did not have the harsh ride for the first few years, and it's never been wrecked, just dropped in the parking lot and once moving slowly in dirt...that's why I think it's something I've done wrong that can be fixed. And I see several things MDR said that I know I need to look at....
 
Mdr covered most everything here, however I would add just a couple more things to check and do.

1) Dump the AFT flush the forks clean of the stuff and use REAL FORK OIL!  IIRC 10W is stock weight.
According to the Big-K manual a dry totally empty fork oil capacity is 379 +/- 4 ml and oil level with fork fully compressed AND without the spring is 171mm (6.75")
2) Check the Spring free length BOTH should be even and measure 543.3mm = 1.375" = 21 3/8" and no less than 533mm = 20.9375"  = 20 15/16"
3) Check your wheel bearings as well.
 
5w will make it more reactive, but also may not be able to controll the spring oscillations.

MDR hit all the point. I'm going to re - touch the high points that causes issues for me on my bike...

1) oil level. set it with the fork fully compressed, springs out. pump out all the air. First time I did this the info didn't state "fully compressed" so I filled the forks to 6" from the top on an extended fork. Talk about harsh - how about solid- no compression at all! Oops THAT didn't work  :eek:

2) fork brace stiction - another big one. I bet 90% or more are installed wrong. I have Murph's -  it took me over an hour to get mine absolutely correct. It has to be shimmed so that when you tighten it down you down push or pull the fork legs apart. Also you do this with the tire / axle already mounted and tight. The brace should help stabilize the legs, but not apply any tension, or you'll get stiction and also compromise your fork seals. HTH, Steve
 
Well gosh the fork seals are the only things I haven't had to replace, let's not screw them up.

All right then I think I know what I gotta do...

and the local dealers are stupid-high on real fork oil, they want $15 or more for a bottle of it.
I guess I can order some from somewhere else, cheaper.
 
My vote is for in correct fork brace adjustment or over oiled also.  Like Steve said it takes a long time to get fork brace right if you use the shims.  I was told that it works better to get it close with shims and then loosen the axle bolts and let the forks find a neutral alignment by themselves.  Anyone want to comment on that?
 
Don't beat yourself up.  None of us came from the womb knowing any of this :)

I thought about this during the <brrr> week.  It's been cold in GA, if I can trust the news.  Cold weather makes oil flow slower and would also make it more harsh.  In PHX, where the temps go from about 30F to 120F, I'd fork oil 2X a year, just to get a different viscosity in there to tame the suspension.  Mostly commuting, so the oil didn't get a chance to 'warm up', if it even does that sort of thing in the bike I was riding at the time (not a Connie - had drain screws - MUCH easier to change).

Regarding ATF, I don't know but I read somewhere that it's viscosity can be a little strange.

Light Auto Engine Oil?

From the 'Hey Bubba, watch me try this' department???

If fork oil is too expensive for just testing a theory, and I can understand that, try some 10W30, 5W30, 10W20 or 5W20 auto oil in there.  (don't know what's available anymore, just throwing out some numbers  :-[ ) For just a test, should be fine???  Might be able to find some light straight weights in the 10 to 20 range??  I wouldn't think those oils had anything in them that would hurt the seals, and there's enough moly and such in the energy conserving blends now you can't use them in anything with a wet clutch so in the forks may be ok for a bit.  At least you'd know what the viscosity was.

I did say I've never tried this and if you have to replace the seals I didn't say anything, didn't I?  O:)
 
Unfortunately Jenn, $15/qt is the going rate for real fork oil.
I'd try ATF if cash is tight though.
 
Zorlac said:
Unfortunately Jenn, $15/qt is the going rate for real fork oil.
I'd try ATF if cash is tight though.
Click to expand...

But what is more expensive? Doing it right? or doing it over again?
 
This I understand, the cost of doing it over.

But I'll add this: for the amount and aggressiveness of my riding, I am not sensitive much to my suspension. As in, all I can tell is "too harsh" or "spongy." Ten years of riding and I can't tell the difference after I supposedly set my sag, I just know if I need more ground clearance or not!

So I was hoping I would be blissfully unaware if ATF was a shade different than 10W fork oil. I'm not asking for Cadillac, I just want to quit shaking my spine (and my eggs in the groceries) to pieces!
 
Try some synthetic fork oil like Amsoil.  Yes they do make a oil just for forks.  It will be less sensitive to temperature changes than "real" oils.
 
2linby said:
Zorlac said:
Unfortunately Jenn, $15/qt is the going rate for real fork oil.
I'd try ATF if cash is tight though.
Click to expand...
But what is more expensive? Doing it right? or doing it over again?
Click to expand...
I don't worry about stuff like that, ATF works for a lot of folks and you're not getting raped at the parts counter.
If my seals ain't leaking, and my forks bounce, I'm good.  ;)
 
I would guess too much oil in the front shocks or a mis-fitted fork brace. The PRE-94's  oil must be measured by volume. I'm not sure what year the fork tubes were machined where the fork braces attach.  But before that they needed to be shimmed for proper fit.
 
I've been using ATF in my bikes for years. No complaints.
ATF is a non foaming hydraulic fluid. Fork fluid as a non foaming hydraulic fluid.
May not be exact fluid but is fine.''

You said that you had fork brace. When was it installed?
What year is your Connie?
The earlier Connies had differences in the diameter of the fork leg where the fork brace is mounted. (Pre 98 I think)
Those should be adjusted (as needed) to keep everything lined up.
In some cases, the fork brace pulls the legs together or pushes them apart.
Result is sticking forks....

Go to Murphs site. Look at his fork braces. he has one for earlier years and 1 for later years i think. If not call and ask him. He is the one that advised and helped us when my Buddy bought his for a 97. We added a piece of thin aluminum (ie. piece of a beer can) to align Kens forks...

Easiest way to see if you have sticking forks is to raise the front end off the ground and remove the fork springs. Rais the forks to full compression and let them drop. They should slide down smoothly.
Also loosen your axle andsee if thatmakes a diofference. if it does, I would suspect the fork brace.

Since your only 150, I'd go back to stock springs while your at it..
PS: THe best way to adjust how much fluid is in your forks is NOT by measuring the volumn.
The best way is to measure the fluid height in both forklegs"You do this when the forks are compressed and with out the springs. Since your so light I suggest a setting of 7".
If you opt to do this, send me a note and I'll send more detailed instrucions on a cheap way to do it... (ie. Turkey Baster method)

Ride safe, Ted

 
Thanks, the fork brace is appropriate for the year (05) and came from Murph's. I really don't think it's the brace, I think I must have too much oil in the forks. I have the Motion Pro oil level setting thing but I still think there's too much in there.
I thought I said already that the stock springs are back in there...maybe I forgot, sorry...

I'm very anxious to get in there and fix the problem but a stupid VFR is up on the lift and has been for weeks while I sorted out ITS front end problems! I'm still waiting on the right parts to get the darn thing done, THEN I can pull the Connie off-line. One bike on the lift at a time...that's the rule....this VFR has taken way too long already.


 
Just an update....starting with the easiest stuff first, I had to tighten up the neck bearings so while I was in there, I removed the fork caps and took out a couple ounces of fork oil from each tube, not removing the tubes from the triples. I just kept the front end straight and made sure I was getting the same amount from each leg.

MUCH better ride. Now when I hit a bump, the whole front end doesn't rattle and my teeth don't shake. The 115 miles to the International Motorcycle Show this weekend in Greenville was noticeably more comfortable than the previous few months' riding.

I'm hoping that at the next wrenching session, I can get a little more knowledgeable help with setting up the suspension.

Thanks much for all the advice...

 
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