Let’s Suppose I Service My Forks

[Jaybird180]

About March 07, I had a set of forks built by Ed of Trackside Engineering in Wisconsin. Ed has since sold the business and the new owners haven’t returned any of my calls, emails or requests for information, so I now turn to you guys for advice.

 

The forks were built with Racetech 1.0 springs and Racetech Gold Valves part #FMGV S2040nv CTRL# 040297 (from an old email between Ed and myself). I recall talking with Ed about some other kind of pistons, valving, etc. and honestly at the time I was on information overload (in spite of his excellent communication skills). So I’m reasonably sure the RT stuff is on compression side and he used a set of pistons he salvaged from another rider’s setup to use on my rebound side. I have no idea about the brand, weight or oil level used. He also installed new bushings and seals.

 

During our pre-return shipping conversation, I recall him saying something about stiction but I have no recollection of what he was referring. At the time, I was still struggling with suspension vocabulary (and still do apparently) and so I didn’t retain that portion of the conversation. Possibly he was warning me to be aware of it in the future, that he solved the problem or that the problem still exists.

 

At a local hangout I ran into Terrence, an all-around great guy, the proprietor of A&J Cycles, a former WERA racer and AMA Tech Inspector. I spoke with him about some of my handling concerns and trying to articulate the inconsistency I was experiencing.

 

After I invited him over to my bike, he lifted on the front end and when it didn’t return to it’s original geometry he said that I should go inside the forks and find out why it has excess stiction (is this the correct term for this?). Terrence also complained that the 1.0 RT springs may be too stiff for a 233lb dressed weight on my 02 F4i. I haven’t conceded that point yet, as I’ve ridden on this setup with an Ohlins rear (properly sprung by Kyle and verified by Ohlins) since the abovementioned time. I told him that I wasn’t sure of what it feels like, but I believe I may have bottomed the forks a few times on the brakes at Summit Main, so I reasoned that I may have too little spring!?!?

 

Further in the conversation I communicated that at times the bike seems on rails, goes where I point it, at other times it doesn’t want hold the line on exit and other times it falls mid-corner (Michelin Pilot Power tires). I have always blamed either myself for the inconsistency or blamed a recent change in rear preload from fiddling with the adjuster for 2-up rides.

 

Now here comes the ending: Since I just had the shock serviced due to a malfunction, AND since I had this suggestion from Terrence about stiction, AND due to the fact that I’m doing some work to the bike anyhow, I want to service the forks; I want to eliminate them as a variable in my riding results, however I don’t know WHAT to do because of too many unknowns and uncertainties.

 

I haven’t allocated money in this project budget to send the forks out, and besides, whom do I trust to do the work (???), and Terrence is too busy. So I reasoned that changing fork oil can’t be that hard, right? And while I’m doing that, I should be able to visually see if there’s something binding and causing the stiction (which I understand that some of it is normal friction from the bushings and seals).

 

A confused mind can’t make a decision. Can someone help me get un-FusterClucked?

[Jaybird180]

What happened to my spacing in between paragrahps? Isn't this forum WYSIWYG? No wonder, no replies.

[racer]

Yee-aah. I wasn't sure whether to say something about that or not. Thanks in advance for inserting some breaks.

[Jaybird180]

Yee-aah. I wasn't sure whether to say something about that or not. Thanks in advance for inserting some breaks.

Okay, how do I edit and add the breaks? I typed in word and cut/ paste and obviously they didn't transfer over. Makes it hard to read all one paragraph.

 

I recall seeing something about a </BR> Syntax

[Jaybird180]

About March 07, I had a set of forks built by Ed of Trackside Engineering in Wisconsin. Ed has since sold the business and the new owners haven’t returned any of my calls, emails or requests for information, so I now turn to you guys for advice.

 

The forks were built with Racetech 1.0 springs and Racetech Gold Valves part #FMGV S2040nv CTRL# 040297 (from an old email between Ed and myself). I recall talking with Ed about some other kind of pistons, valving, etc. and honestly at the time I was on information overload (in spite of his excellent communication skills). So I’m reasonably sure the RT stuff is on compression side and he used a set of pistons he salvaged from another rider’s setup to use on my rebound side. I have no idea about the brand, weight or oil level used. He also installed new bushings and seals.

 

During our pre-return shipping conversation, I recall him saying something about stiction but I have no recollection of what he was referring. At the time, I was still struggling with suspension vocabulary (and still do apparently) and so I didn’t retain that portion of the conversation. Possibly he was warning me to be aware of it in the future, that he solved the problem or that the problem still exists.

 

At a local hangout I ran into Terrence, an all-around great guy, the proprietor of A&J Cycles, a former WERA racer and AMA Tech Inspector. I spoke with him about some of my handling concerns and trying to articulate the inconsistency I was experiencing.

 

After I invited him over to my bike, he lifted on the front end and when it didn’t return to it’s original geometry he said that I should go inside the forks and find out why it has excess stiction (is this the correct term for this?). Terrence also complained that the 1.0 RT springs may be too stiff for a 233lb dressed weight on my 02 F4i. I haven’t conceded that point yet, as I’ve ridden on this setup with an Ohlins rear (properly sprung by Kyle and verified by Ohlins) since the abovementioned time. I told him that I wasn’t sure of what it feels like, but I believe I may have bottomed the forks a few times on the brakes at Summit Main, so I reasoned that I may have too little spring!?!?

 

Further in the conversation I communicated that at times the bike seems on rails, goes where I point it, at other times it doesn’t want hold the line on exit and other times it falls mid-corner (Michelin Pilot Power tires). I have always blamed either myself for the inconsistency or blamed a recent change in rear preload from fiddling with the adjuster for 2-up rides.

 

Now here comes the ending: Since I just had the shock serviced due to a malfunction, AND since I had this suggestion from Terrence about stiction, AND due to the fact that I’m doing some work to the bike anyhow, I want to service the forks; I want to eliminate them as a variable in my riding results, however I don’t know WHAT to do because of too many unknowns and uncertainties.

 

I haven’t allocated money in this project budget to send the forks out, and besides, whom do I trust to do the work (???), and Terrence is too busy. So I reasoned that changing fork oil can’t be that hard, right? And while I’m doing that, I should be able to visually see if there’s something binding and causing the stiction (which I understand that some of it is normal friction from the bushings and seals).

 

A confused mind can’t make a decision. Can someone help me get un-FusterClucked?

 

 

I talked to the "local" Racetech shop and they say they think there's a twist in the forks causing the springs to bind. Does this make sense?

[Big Willy]

G'day Jaybird,

Racetech have a site where you can check if the springs are correct for your weight.

 

Did the chap mean that he thought your 'forks' were twisted? I have n't heard of 'springs' being twisted but it's possible I suppose.

 

Even though you may have the correct weight of spring, are they the correct spring for your bike? i.e. diameter and length?

 

If they are, bottoming out is usually an indication of insufficient oil level in the forks or not enough compression damping.

 

What can sometimes be mistaken for stiction I have found is too much rebound damping. This keeps the forks in the "harder" part of the stroke and doesn't give them a chance to rebound to soak up new stuff.

 

As for forks twisted, this is possible too and here's the fix..

 

Loosen off the top triple clamp bolts that hold the fork. Place the front wheel between your legs facing the bike and give a yank (no pun intended Racer) on the bars to align them. If they were out, you might hear a "crack". Tighten the bolts to manufactures specifications. This is very important on the lower triple clamps if you have upside down forks as too tight can squeeze them causing some binding on the staunchion. Some prefer to leave them looser than manufacturers' specs.

 

Don't bother with the following steps unless your axle has grease on it. This not only protects it from rust, but it going to help set up the forks.

 

Loosen the lower fork bolts that hold the front axle on the side that DOESN'T have the axle nut. Wedge a little flatbladed screwdriver a little way in to hold the 'clamp' part of the fork open.

Apply the front brake and bounce like mad a few times on the forks. Tighten the lower fork leg (after removing screwdriver d'oh). Check all other nuts and bolts are tight.

 

Some consider that getting the length of the forks exactly the same is critical i.e. lifting or lowering a fork leg a couple of mm so that they are even. But there are forks today that have the compression damping in one and rebound in the other. You can imagine the push/pull effect they have against each other so I don't think 1 or 2 mm is going to affect things too much. That said, it's easy enough to get them perfect if you want by checking how easily the front axle slides in and out and making an adjustment.

 

What I also do is spray a lanolin based lubricant under the dust seal and also onto the fork leg. Many do not realise that when they wash their bikes, they wash the oil film off the staunchions.

 

A zipty around a fork leg is also handy to guage fork travel. Just tight enough to slide on the leg and stay in any one spot.

 

Longwinded I know but I'd try some of these first if you have only recently had your forks done.

[Big Willy]

I forgot, here's a link for you. Your spring rate would seem correct.

http://www.racetech.com/evalving/SpringRat...SpringType=Fork

 

Hope this works for ya.

[Jaybird180]

UPDATE: Sometime after these questions arose, I tucked the front on the brakes (Damn SR). Once I pulled the forks, I found that one was bent & the lower tree looked crooked too. The front had been making a weird noise from movement and now I know where it's from.

 

The suspension shop says that one tube is unrecoverable, so I now need a new plan.

 

This would be the perfect opportunity for me to learn how to disassemble forks. I suppose the best solution is for me to find a set of n-used tubes and transplant them onto my forks along with a n-used lower triple. Then I can also shop around for a bling bling upper triple (Vortex about $140).

 

I saw the Attack Adjustable Triple trees (very nice). How do I know if this is needed, especially at my riding level (novice)? Or do I just stick with stock triples and disregard GMD computrack's ranting about sweet geometry? (Bike worked very well BTW; turned on a dime and stopped hard enough to pop my eyes out of their sockets without the rear dancing)