Too Tall, Dark and Ugly

[Jeffro]

There's so many ways to skin a cat I can't decide how or what will best tackle my ergo and mods.

At 6-2, ~255 my I'm focusing on suspension and fit. One thing i've noticed is that after I hit a few bumpy roads the forks fade and seem less willing to turn. I tried home-made preload spacers but both times got the ID wrong. What I did notice was after putting the caps back on, dropping the bike to floor height (meaning forks were fully extended when caps went on) the front end handles GREAT and I feel like Kenny Roberts driving around the back roads looking for another sharp turn. But after a few hours or good bumps it's back to feeling mushy under my weight.

My cheapo fix (and off road mentality) is to buy the fleabay preload caps but I also want air bleeder caps. This way (I hope) I can get that proper balance. If anyone has any words of wisdom... I searched high and low and couldn't find anyone discussing air bleeders on the forks caps. It appears I can't have my cake and eat it too though.

Will update after this weekend with pictures. Trying homemade preload and drill/tap caps for air valves first. That way if I destroy the caps I can fall back on the fleebay caps with preload adj.

 

[Junkie]

If the front end feel is changing after use on bumpy roads, I suspect your fork oil is overdue for a replacement. Suspension use warms the oil, which results in it thinning out, which explains the change in feel.

The stock fork springs are awfully soft. While spacers are an improvement over stock, your best (moderate budget) option for the forks is new springs and Gold Valve Emulators. There might be a company other than Racetech doing something similar to the GVEs, not sure. Springs are $130, GVEs $180, oil 2L @ $14/L. You might be able to find a better deal through a friendly local shop vs direct - I know I've had luck with that.

Proper springs and GVEs are a huge improvement over just spacers.

 

[drdubb]

Cogent dynamics has a drop in valve and will supply springs to your weight and riding style. I've put them in my NC and also had them on my old DR650. They supply directions for the amount of oil and spacer length.
I also went with a shock. $$$, but worth it.

 

[MZ5]

It’s interesting that you would experience damping fade from the forks but not the shock. The forks don’t heat their oil much at all, so it’s very difficult for them to fade from an oil viscosity change. Shocks like ours, on the other hand, heat their oil quite easily on nearly any surface other than smooth asphalt.

Any chance that what you’re experiencing is actually shock fade, and the consequent impact that has on the front end?

 

[Jeffro]

If the front end feel is changing after use on bumpy roads, I suspect your fork oil is overdue for a replacement. Suspension use warms the oil, which results in it thinning out, which explains the change in feel.

The stock fork springs are awfully soft. While spacers are an improvement over stock, your best (moderate budget) option for the forks is new springs and Gold Valve Emulators. There might be a company other than Racetech doing something similar to the GVEs, not sure. Springs are $130, GVEs $180, oil 2L @ $14/L. You might be able to find a better deal through a friendly local shop vs direct - I know I've had luck with that.

Proper springs and GVEs are a huge improvement over just spacers.

Bike is new, still less than 500 miles so i'd hope the oil was fresh and set proper. I've had f&r racetech springs in my last two bikes, never messed with the valves though. I might get there but I like to try the cheap garage tweaks with oil and preload before I drop $300+. The rear is easy. I don't know why but it feels dialed in even on my weight. All I did was take the preload screws down a turn. (all i had room for but it good)

 

[Jeffro]

No it's definitely the front getting squishy. I can lean over and just about bottom the front out just pushing down when the bike's not moving.

 

[dduelin]

In my opinion for performance riding the stock springs are inadequate for any rider over ~160 lbs. Preload does not affect spring rate, or "stiffen" the forks. It only affects ride height. I can't explain the description of the forks changing behavior after hitting some bumps but based on the first post new springs based on rider weight are in order. Racetech and Cogent Dynamic and others make cartridge emulator kits that changes the fork design from a basic damping rod to a hybrid of damping rod and cartridge damping. These do work pretty good for the basic fork design.

Suspension tuning is a blend of art & science but you cannot take out the science part.

 

[Jeffro]

In my opinion for performance riding the stock springs are inadequate for any rider over ~160 lbs. Preload does not affect spring rate, or "stiffen" the forks. It only affects ride height. I can't explain the description of the forks changing behavior after hitting some bumps but based on the first post new springs based on rider weight are in order. Racetech and Cogent Dynamic and others make cartridge emulator kits that changes the fork design from a basic damping rod to a hybrid of damping rod and cartridge damping. These do work pretty good for the basic fork design.

Suspension tuning is a blend of art & science but you cannot take out the science part.

And luck. (like that 5'7-10", 130-150 lbs and in marathon shape luck)

I'm guessing but after today I suspect that the extra air in the fork was helping the spring out. For a little bit. Then a few good bumps and brakes and the forks, not being 100% sealed or designed for holding extra air push the once positive pressure out and they're at normal operating psi's. Then the forks are back to behaving as they would when a 250 lb guy dives on them. They aren't fading, they're crying.

Sounds like it can't hurt to give it a little more preload for now but if I want to get seriously dialed in it'll need the right internals.

 

[TacomaJD]

Fork oil could be cavitating over bumps? But I just wouldn't think you could ride an NC hard enough for that sort of extreme thing to occurr. Maybe you can try putting a little thicker weight fork oil in the forks, this will increase rebound and compression damping.

Also, I'm sure you already checked, but it isn't low on fork oil is it? Maybe leaky seal?

There ain't too many factors that can make it get mushy after hard use, should be fairly easy to target.

Sent from my SM-G930V using Tapatalk

 

[Jeffro]

I ordered some fork boots awhile back so when I put those on I'll replace the oil with a 7.5wt that's always worked for me. Then I'll get the springs, play with the oil level and see how it feels. Can't believe I was going to put bleeder valves on the caps.

 

[Rapturee]

at 6'6" and 235lbs i have not seen that issue with mine yet and i've ridden it pretty hard at times... Watching with interest to see how you overcome this issue. :{)

 

[Jeffro]

I think it was all about having the front wheel off the ground when I put the caps on. If I could find a way to keep that extra air all the time it would swallow all the stutter bumps and road buckles around here. It normalizes or goes back to normal after a few miles. I'm just getting used to the shorter travel. My last bike could ride over telephone polls at 20 mph.