Modifications - Performance Discuss aftermarket and DIY performance modifications

Fork;Springs OK or re-valve needed?

Old 05-26-2008, 10:20 AM
  #1  
Senior Member
MotoGP
Thread Starter
 
smokinjoe73's Avatar
 
Join Date: Jul 2007
Location: NYC
Posts: 4,927
smokinjoe73 is on a distinguished road
Fork;Springs OK or re-valve needed?

I have RT springs valves (not installed yet) For city street use will the springs & oil level be an improvement? I have been told that revalving the honda vaves(by someone good) is the way to go. I live in NYC & ride daily so I cant send them somewhere for valving. I can do the springs tho. Are 90kg springs too heavy for the street?(200# rider & sometimes 2 up). Any help greatly appreciated.
smokinjoe73 is offline  
Old 05-26-2008, 02:03 PM
  #2  
Senior Member
SuperBike
 
drew_c14's Avatar
 
Join Date: Mar 2007
Location: Williamsburg, VA
Posts: 2,455
drew_c14 is on a distinguished road
Sounds like a good setup to me. You should notice a big improvement with springs and good fluid alone.
drew_c14 is offline  
Old 05-26-2008, 02:33 PM
  #3  
OUCH... MY A$$ HURTS!!!
SuperSport
 
joshuatest's Avatar
 
Join Date: Dec 2007
Location: Elba, Ny
Posts: 707
joshuatest is an unknown quantity at this point
Just so you know...

When Greg did mine. I shipped them UPS Ground to him, he had them the next day. He had them complete in one day, and when he shipped them back, I had them next day also...

Now mine where gone longer as I shipped mine out before he had the springs recieved yet, however if you wanted to have him revalve your's, I would imagine if you work out the time ahead of time with him, you could have them back in 3-4 day's total...

just a thought
joshuatest is offline  
Old 05-27-2008, 04:17 PM
  #4  
Sprung
World Champion
 
Hawkrider's Avatar
 
Join Date: Dec 2004
Location: Fulton, MO
Posts: 105,285
Hawkrider will become famous soon enoughHawkrider will become famous soon enough
What Josh said....

Or you could ride up here on a weekend and I'll revalve them while you watch! It takes about 5 hours total.

.90kg/mm springs will overpower your stock rebound and compression damping will still not be correct. I highly suggest a revalve.
Hawkrider is offline  
Old 05-27-2008, 09:38 PM
  #5  
Senior Member
MotoGP
Thread Starter
 
smokinjoe73's Avatar
 
Join Date: Jul 2007
Location: NYC
Posts: 4,927
smokinjoe73 is on a distinguished road
I actually did install the 90kg springs with 130mm of oil from the top. It does seem over sprung, but still an improvement. Are the 90kg too heavy even with a revalve?
smokinjoe73 is offline  
Old 05-28-2008, 08:20 PM
  #6  
Sprung
World Champion
 
Hawkrider's Avatar
 
Join Date: Dec 2004
Location: Fulton, MO
Posts: 105,285
Hawkrider will become famous soon enoughHawkrider will become famous soon enough
That depends on your weight. I was running a 1.05 Ohlins spring at one point. I brake HARD! The spring rate is chosen to match the weight of you and your bike so that you can attain proper laden and unladen sag values.
Hawkrider is offline  
Old 05-29-2008, 02:13 AM
  #7  
Senior Member
MotoGP
Thread Starter
 
smokinjoe73's Avatar
 
Join Date: Jul 2007
Location: NYC
Posts: 4,927
smokinjoe73 is on a distinguished road
So I am about 200#. I brake hard (not HARD). But so far at least I am not bottoming anymore. Is this doable?
smokinjoe73 is offline  
Old 05-29-2008, 03:26 PM
  #8  
Sprung
World Champion
 
Hawkrider's Avatar
 
Join Date: Dec 2004
Location: Fulton, MO
Posts: 105,285
Hawkrider will become famous soon enoughHawkrider will become famous soon enough
Yes, it's doable, but if you want to go one step further then have them revalved.
Hawkrider is offline  
Old 05-29-2008, 04:20 PM
  #9  
OUCH... MY A$$ HURTS!!!
SuperSport
 
joshuatest's Avatar
 
Join Date: Dec 2007
Location: Elba, Ny
Posts: 707
joshuatest is an unknown quantity at this point
I gotta tell you man... I hated to have the bike down any longer since it had already been down because of my crash... But I am glad I went ahead and had Greg just do it all, and do it right...

If you've dug into it enough to have went ahead and resprung, why not go ahead and just have him revalve them for you...

I was very happy with the results from Greg, and he worked fast... Was worth the money by far, and outside of a fork swap that I'm sure I'll never do, I'm confident that the bike is right... sounds like your half way there, and since your in the same state, shipping times are quick, shipping prices are low, and in all honestly, Greg is so close to Albany area anyway, it is very doable to just take the ride up and get them done and set up for good..

just my 47 cents....

josh


PS.. Greg, i still get that advertising cut right? lol... just kidding...
joshuatest is offline  
Old 05-29-2008, 08:28 PM
  #10  
Senior Member
SuperBike
 
Thumper's Avatar
 
Join Date: Jul 2004
Posts: 1,015
Thumper is an unknown quantity at this point
Revalve, springs are just half of the equation.

You will be much happier with both......
Thumper is offline  
Old 05-30-2008, 08:06 AM
  #11  
Senior Member
SuperBike
 
RCVTR's Avatar
 
Join Date: Dec 2005
Location: South Lake Tahoe, CA, USA
Posts: 1,689
RCVTR is an unknown quantity at this point
I'd say springs are way less than half the equation. Damping provides the control of supension travel.
RCVTR is offline  
Old 05-30-2008, 08:28 AM
  #12  
Duc Hawk
SuperSport
 
Moto Man's Avatar
 
Join Date: Mar 2008
Location: Malibu's canyons
Posts: 691
Moto Man is on a distinguished road
The PO on my bike says he put Race Tech gold valves in but kept the stock springs. I can't compare to a stock ride but to me it feels like it bottoms out way too easy (eg. when pulling into a driveway at about 5-10mph and hitting a 1 inch lip) unless I have the preload set to 2 lines or less. Then the ride is preetty harsh. Does that sound normal for a 195# rider? I have no idea what weight of fork oil is in there or how much. Guess I'll just have to drain it and refill to be sure. Might as well upgrade the springs while in there.

Last edited by Moto Man; 05-30-2008 at 08:31 AM.
Moto Man is offline  
Old 05-30-2008, 04:53 PM
  #13  
OUCH... MY A$$ HURTS!!!
SuperSport
 
joshuatest's Avatar
 
Join Date: Dec 2007
Location: Elba, Ny
Posts: 707
joshuatest is an unknown quantity at this point
Originally Posted by Moto Man View Post
The PO on my bike says he put Race Tech gold valves in but kept the stock springs. I can't compare to a stock ride but to me it feels like it bottoms out way too easy (eg. when pulling into a driveway at about 5-10mph and hitting a 1 inch lip) unless I have the preload set to 2 lines or less. Then the ride is preetty harsh. Does that sound normal for a 195# rider? I have no idea what weight of fork oil is in there or how much. Guess I'll just have to drain it and refill to be sure. Might as well upgrade the springs while in there.
I would assume that 195 is to much weight to use the stock springs properly...
joshuatest is offline  
Old 05-30-2008, 10:28 PM
  #14  
RK1
Senior Member
MotoGP
 
Join Date: Aug 2007
Location: Way Out West
Posts: 2,547
RK1 is on a distinguished road
Moto Man;

The original equipment fork springs suck for everybody. I had the same problem pulling in the driveway or hitting a pothole. I put a zip tie around one fork tube, shoved it down against the slider, and went for a normal around town surface street ride. When I stopped the zip tie was shoved up against the lower triple clamp. And I weigh almost 50 lbs. less than you. Proper weight fork springs for the VTR were the best $100 I ever spent on a bike.
RK1 is offline  
Old 05-31-2008, 10:22 AM
  #15  
Senior Member
Back Marker
 
Join Date: Mar 2008
Location: Massachusetts
Posts: 229
Dan Cronin is on a distinguished road
RK1,

What springs did you go with and did you end up re-valving?
Dan Cronin is offline  
Old 05-31-2008, 02:30 PM
  #16  
Simi Valley, CA
Back Marker
 
lowell's Avatar
 
Join Date: Mar 2008
Posts: 182
lowell is on a distinguished road
I see that racetech has a chart that will select the spring rate determined by weight . That is probably close unless your 2up or very aggressive.

The oil flow valves is what I know flow too slow and cause compression lock.

What is the best way to increase flow with out becoming a pogo stick?
lowell is offline  
Old 05-31-2008, 08:31 PM
  #17  
Sprung
World Champion
 
Hawkrider's Avatar
 
Join Date: Dec 2004
Location: Fulton, MO
Posts: 105,285
Hawkrider will become famous soon enoughHawkrider will become famous soon enough
Lowell, I got your PM and replied. The stock valves themselves are okay, particularly with a lighter oil. The problem with using a lighter oil is that the stock shimstacks cannot provide enough damping to properly control fork motion. That's why the revalve is required. With a heavier fork oil the damping is okay but then you get "hydraulic lock" on large bumps (sometimes combined with braking).
Hawkrider is offline  
Old 06-01-2008, 10:36 AM
  #18  
Senior Member
SuperBike
 
RCVTR's Avatar
 
Join Date: Dec 2005
Location: South Lake Tahoe, CA, USA
Posts: 1,689
RCVTR is an unknown quantity at this point
Also, with a higher spring rate, a higher force is required for a given suspension velocity. Therefore, a higher damping rate is also required at that velociy to control the force.

I agree with Greg. No valve modifications required with lighter oil, unless you know what it is you are trying to modify. The stock valves are very good.

Race Tech valves are vastly different than the stock valves. To install Gold Valves without significant shim stack modifications would likely result in far too little high-speed compression damping. With the porting in Gold Valves, all of the high-speed damping must be controlled with the stack. They do not transition to orifice damping.
RCVTR is offline  
Old 06-01-2008, 03:46 PM
  #19  
Simi Valley, CA
Back Marker
 
lowell's Avatar
 
Join Date: Mar 2008
Posts: 182
lowell is on a distinguished road
Would a change to the RC-51 front end be a cure all?

Except for the loss of steering lock of course..
lowell is offline  
Old 06-01-2008, 04:23 PM
  #20  
Senior Member
SuperBike
 
Gregw's Avatar
 
Join Date: Jun 2007
Location: Los Angeles ish
Posts: 1,031
Gregw is on a distinguished road
The CBR1000 fork w/954 triples will keep the lock. Just a couple washers and you're good to go. To be honest, I only lock with the wheel turned left. I haven't tried to the right.
Gregw is offline  
Old 06-01-2008, 05:12 PM
  #21  
Simi Valley, CA
Back Marker
 
lowell's Avatar
 
Join Date: Mar 2008
Posts: 182
lowell is on a distinguished road
did not know that .

Is that combination adjustable?
lowell is offline  
Old 06-01-2008, 05:13 PM
  #22  
Simi Valley, CA
Back Marker
 
lowell's Avatar
 
Join Date: Mar 2008
Posts: 182
lowell is on a distinguished road
Originally Posted by RCVTR View Post

I agree with Greg. No valve modifications required with lighter oil, unless you know what it is you are trying to modify. The stock valves are very good.

So I can just replace the springs and refresh with a lighter oil to get close to correct?
lowell is offline  
Old 06-01-2008, 06:24 PM
  #23  
Sprung
World Champion
 
Hawkrider's Avatar
 
Join Date: Dec 2004
Location: Fulton, MO
Posts: 105,285
Hawkrider will become famous soon enoughHawkrider will become famous soon enough
No, you are not understanding what we are saying.

A heavier spring combined with a lighter oil will throw your rebound damping out the window. It will be a pogo stick.

A heavier spring with heavier oil will allow rebound damping to be sufficient for the higher return spring force, but then you will be much closer to orifice flow (hydraulic lock) on compression to the point that it will be dangerous.

The limit for aftermarket springs with stock valving and oil is about .80kg/mm. That equates to about a 150# rider on the street. Anything heavier than that and you should revalve.

I'm not trying to sell anything here. I'm telling you the proper way to do this.
Hawkrider is offline  
Old 06-01-2008, 06:38 PM
  #24  
Senior Member
SuperBike
 
Gregw's Avatar
 
Join Date: Jun 2007
Location: Los Angeles ish
Posts: 1,031
Gregw is on a distinguished road
Originally Posted by lowell View Post
Is that combination adjustable?
I have the '04-'05 forks which have preload, compression and rebound adjustments. Probably all years do, but not having looked at them, I'll not comment on them.
Gregw is offline  
Old 06-01-2008, 06:44 PM
  #25  
Sprung
World Champion
 
Hawkrider's Avatar
 
Join Date: Dec 2004
Location: Fulton, MO
Posts: 105,285
Hawkrider will become famous soon enoughHawkrider will become famous soon enough
04-08 1000RR forks are fully adjustable. 04-05 have about .93kg/mm springs and 06-07 have 1.0kg/mm springs with better valving.
Hawkrider is offline  
Old 06-01-2008, 07:04 PM
  #26  
Senior Member
SuperBike
 
Gregw's Avatar
 
Join Date: Jun 2007
Location: Los Angeles ish
Posts: 1,031
Gregw is on a distinguished road
I bought a stock CBR spring thinking it was .88kg. I saw that on the racetech website. Their spring calc said I'd be in the .89kg range so stock was closest. Now ya' got me wondering if I gotta start eatin more.
Gregw is offline  
Old 06-01-2008, 07:09 PM
  #27  
Simi Valley, CA
Back Marker
 
lowell's Avatar
 
Join Date: Mar 2008
Posts: 182
lowell is on a distinguished road
I just need a solution soon. not riding the bike much till I get this front end dialed in. way too scary and twitchy
lowell is offline  
Old 06-01-2008, 09:21 PM
  #28  
Sprung
World Champion
 
Hawkrider's Avatar
 
Join Date: Dec 2004
Location: Fulton, MO
Posts: 105,285
Hawkrider will become famous soon enoughHawkrider will become famous soon enough
You can ride the bike with stock suspension, just don't ride it fast!

Set your sag and rebound damping, front and rear for the time being.

If you insist on not riding it with stock suspension, with the RC51 fork swap you'll probably have the bike down for a while. It takes a while to collect all those parts, the clip-ons being the biggest hurdle.
Hawkrider is offline  
Old 06-01-2008, 10:43 PM
  #29  
Duc Hawk
SuperSport
 
Moto Man's Avatar
 
Join Date: Mar 2008
Location: Malibu's canyons
Posts: 691
Moto Man is on a distinguished road
This a great thread! One more question for you guys with the gift of deep suspension knowledge. Since I (supposedly) already have gold valves I should be able to run heavier oil once I switch the springs and should also set the stock shim stacks to ??? to control high speed dampning?
Moto Man is offline  
Old 06-02-2008, 08:23 AM
  #30  
Senior Member
SuperBike
 
RCVTR's Avatar
 
Join Date: Dec 2005
Location: South Lake Tahoe, CA, USA
Posts: 1,689
RCVTR is an unknown quantity at this point
Greg's shim stack should keep you away from the region where the Gold Valves will "blow off" (meaning the damping curve goes horizontal). He may also have something that is designed for Gold Valves specifically. I very much doubt he'll just publish his stack. And the shim kit is about $200. My recommendation is to have him do the work, because he's done enough research and testing to know what works (and no, I don't work for him).

This should keep you away from having to care what valve you have, for most situations. Then you can run a lighter oil and have better control over the low speed region. The very high-speed damping, such as when you hit a big bump when hard on the brakes, or under heavy cornering loads may never be as well handled with Gold Valves. But the jury is out on that one. Some people swear by them. Others won't use them.

If you are someone who does get into a situation where the stock valves ramp up too quickly (on a particular section of road or track) after taking these first tuning steps, then you can increase the orifice size in the valve bodies. But I don't believe that would be recommeded as a first step.

Last edited by RCVTR; 06-02-2008 at 08:30 AM.
RCVTR is offline  

Thread Tools
Search this Thread
Quick Reply: Fork;Springs OK or re-valve needed?


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.