[Notthatbryan]

I've been chasing around the performance of my fork. It's a fox 36 rhythm. Mainly I've been searching for a bit better small bump compliance trying to keep my hands from going numb. After a teardown and rebuild to make sure everything was lubed properly (it wasn't) I'm 95% satisfied.

The issue I'm chasing now is that with the setup I'm on now, the fork has a bit more dive under braking than I'd like.

I'm about 170 lbs with gear on.
I'm running 78psi with compression damping full open, rebound at 6 clicks from closed and no volume spacers.

I've tried one volume spacer at 78 psi, and that felt a little more harsh but had less dive.

I was down at 75 psi with one spacer before the rebuild, but once the fork was moving better after rebuilding that was way too soft.

I'm a little hesitant to increase the compression damping since it may compromise the small bump performance and also the grip damper doesn't have detents so fine adjustments are less repeatable than I'd like.

Any suggestions for tuning before I throw parts at it or replace the fork. I'm not interested in converting to a coil since I'm still working to get lose another 5 lbs so I'd like the ability to fine tune once I get down to my goal weight of 160 w/o gear.

I'm considering a DSD runt or a grip 2 damper to address the dive.

Thoughts?
Thanks in advance.

 

[Chris2fur]

From personal experience, having the same complaints and looking for the same qualities, I found the solution in the Vorsprung Smashpot coil conversion. Yes, you indicated you care more about weight than the final fork performance, but I'm telling you anyway. I had the same concerns but finally put comfort and performance ahead of bike weight. I would never go back.

 

[jimarin]

I'd do the runt. Midstroke support is exceptional. I've got one in my 34 and 38 and have run one in a 36 as well. It's well worth the $200.

 

[alexbn921]

Vorsprung has several solutions. 2 add negative volume and 1 is a coil. Can’t say enough good things about their products.

 

[Cary]

I've been chasing around the performance of my fork. It's a fox 36 rhythm. Mainly I've been searching for a bit better small bump compliance trying to keep my hands from going numb. After a teardown and rebuild to make sure everything was lubed properly (it wasn't) I'm 95% satisfied.

The issue I'm chasing now is that with the setup I'm on now, the fork has a bit more dive under braking than I'd like.

I'm about 170 lbs with gear on.
I'm running 78psi with compression damping full open, rebound at 6 clicks from closed and no volume spacers.

I've tried one volume spacer at 78 psi, and that felt a little more harsh but had less dive.

I was down at 75 psi with one spacer before the rebuild, but once the fork was moving better after rebuilding that was way too soft.

I'm a little hesitant to increase the compression damping since it may compromise the small bump performance and also the grip damper doesn't have detents so fine adjustments are less repeatable than I'd like.

Any suggestions for tuning before I throw parts at it or replace the fork. I'm not interested in converting to a coil since I'm still working to get lose another 5 lbs so I'd like the ability to fine tune once I get down to my goal weight of 160 w/o gear.

I'm considering a DSD runt or a grip 2 damper to address the dive.

Thoughts?
Thanks in advance.

A few things to try before you start throwing parts at the fork:

1) Handlebars- What are you running? An overly stiff set of bars will cause hand numbness. I once spent two years and two forks trying to get a bike to stop making my hands go numb. Turns out it was the bars, an early set of Answer Protaper carbon bars that were super stiff. They were so bad, I threw them on a friend's bike that notices nothing and he came back complaining something was wrong on his bike. Gave them to someone else, they came back. Finally gave them to someone for a DJ bike. Personally, I find the Ibis carbon and Enve M6 bars to have a good ride quality.
2) Grips- Have you played with different grips? Different grips work better for different people. Hand size and grip size have no correlation, there are people with small hands that find large grips work well and vice versa.
3) Rebound- Have you tried taking 2 clicks of rebound out and seeing how it feels? Too much rebound will lead to the fork packing and being in the ramp up portion of the spring curve, which will cause harshness.
4) Air Pressure- Have you tried increasing the pressure 5 psi? It is counterintuitive, but this is the other side of the coin from too much rebound. Too low of a pressure will lead to the fork sitting in the sag at the point where the spring curve is steep and cause harshness. Fox forks seem more sensitive to this than other forks.

None of the above working, I would try the DSD Runt. I don't think a Grip2 is going to accomplish what you are after.

 

[ARider]

A coil spring is the best solution for plush off the top and more support in the middle. Can't beat it.

5lbs of body weight won't make much difference. I fluctate by that much over a big day in the saddle.

 

[Notthatbryan]

From personal experience, having the same complaints and looking for the same qualities, I found the solution in the Vorsprung Smashpot coil conversion. Yes, you indicated you care more about weight than the final fork performance, but I'm telling you anyway. I had the same concerns but finally put comfort and performance ahead of bike weight. I would never go back.

The reason I don't want to go coil now is because my weight is changing as I'm working to drop another 5-10 lbs. Since rider weight determines spring weight I want something that will be adjustable for the time being. I may end up with a coil in the future once my weight is stabilized.
I'm not afraid of the weight of a coil.

 

[Chris2fur]

The reason I don't want to go coil now is because my weight is changing as I'm working to drop another 5-10 lbs. Since rider weight determines spring weight I want something that will be adjustable for the time being. I may end up with a coil in the future once my weight is stabilized.
I'm not afraid of the weight of a coil.

That is the one downside upfront on Smashpot is that dialing the right spring is a challenge due to many variables and differences in preference. I have enough springs of different weight ratings to adjust if I were to gain weight--but that wasn't my plan.... You might as well consider spending the money on another spring as to spend money on other products before going with the coil conversion.

 

[Notthatbryan]

A few things to try before you start throwing parts at the fork:

1) Handlebars- What are you running? An overly stiff set of bars will cause hand numbness. I once spent two years and two forks trying to get a bike to stop making my hands go numb. Turns out it was the bars, an early set of Answer Protaper carbon bars that were super stiff. They were so bad, I threw them on a friend's bike that notices nothing and he came back complaining something was wrong on his bike. Gave them to someone else, they came back. Finally gave them to someone for a DJ bike. Personally, I find the Ibis carbon and Enve M6 bars to have a good ride quality.
2) Grips- Have you played with different grips? Different grips work better for different people. Hand size and grip size have no correlation, there are people with small hands that find large grips work well and vice versa.
3) Rebound- Have you tried taking 2 clicks of rebound out and seeing how it feels? Too much rebound will lead to the fork packing and being in the ramp up portion of the spring curve, which will cause harshness.
4) Air Pressure- Have you tried increasing the pressure 5 psi? It is counterintuitive, but this is the other side of the coin from too much rebound. Too low of a pressure will lead to the fork sitting in the sag at the point where the spring curve is steep and cause harshness. Fox forks seem more sensitive to this than other forks.

None of the above working, I would try the DSD Runt. I don't think a Grip2 is going to accomplish what you are after.

I'm running one up carbon bars and do feel like they helped out with my hands. I tried raceface carbon bars before these.

For grips I'm running ergon GA2 Fat grips. I tried PMW grips, and a couple others first.

Rebound I've gone back and forth between 6 and 8 clicks open. 8 feels like the front loses a little traction in bumps. I could probably run with either 6 or 7 clicks open. I think 6 feels a little easier on the hands and a little more balanced with the rear of the bike which is why I ended up there. I don't think the fork is packing down, but could be wrong.

With pressure, I started at 80 psi after the rebuild and dropped down to 78 after a few rides. 78psi gets me just over 20% sag.

 

[Cary]

I'm running one up carbon bars and do feel like they helped out with my hands. I tried raceface carbon bars before these.

For grips I'm running ergon EA2 Fat grips. I tried PMW grips, and a couple others first.

Rebound I've gone back and forth between 6 and 8 clicks open. 8 feels like the front loses a little traction in bumps. I could probably run with either 6 or 7 clicks open. I think 6 feels a little easier on the hands and a little more balanced with the rear of the bike which is why I ended up there. I don't think the fork is packing down, but could be wrong.

With pressure, I started at 80 psi after the rebuild and dropped down to 78 after a few rides. 78psi gets me just over 20% sag.

Seems like you have done about all you can with the no cost options. Tire pressure is the only other. I would do the runt.

 

[Notthatbryan]

Seems like you have done about all you can with the no cost options. Tire pressure is the only other. I would do the runt.

I basically am a professional trouble shooter, I'm in Testing and Evaluation so I thought I'd worked through all the options before posting here.

I'm running 20 psi front in a DHF maxterra /EXO.
Rear is 22 with a Dissector, also maxterra /EXO

 

[Cary]

I basically am a professional trouble shooter, I'm in Testing and Evaluation so I thought I'd worked through all the options before posting here.

I'm running 20 psi front in a DHF maxterra /EXO.
Rear is 22 with a Dissector, also maxterra /EXO

It seems like you have covered all the issues methodically. You might also consider a DVO Diamond. If you soften the high speed stack (the default stack is very stiff and works well only for very aggressive or heavy riders, but is easily tuned) you have a very plush fork off the top as you can use the OTT adjustment to control the feel right off the top and for the initial travel and low speed to control dive.

 

[Notthatbryan]

It seems like you have covered all the issues methodically. You might also consider a DVO Diamond. If you soften the high speed stack (the default stack is very stiff and works well only for very aggressive or heavy riders, but is easily tuned) you have a very plush fork off the top as you can use the OTT adjustment to control the feel right off the top and for the initial travel and low speed to control dive.

If I replace the fork the DVO is high on the list for the reasons you stated. I've reshimmed dampers before but it's been 20 years and they were Cannondale head shocks.

 

[mikesee]

Since it's cheap (potentially free) and easy to do, as well as easily reversible, why not add a stack of volume reducers and then fine tune your pressure accordingly?

 

[cassieno]

Under what conditions do your hands go numb?

 

[Notthatbryan]

Since it's cheap (potentially free) and easy to do, as well as easily reversible, why not add a stack of volume reducers and then fine tune your pressure accordingly?

The fork came with 3 volume reducers. I rode it that way for a while and never used more than 100mm of travel. And the fork always felt harsh and didn't smooth out small bumps well at all. after pulling it apart I'm sure the excess grease was not letting the negative chamber equalize properly. I dropped to 1 volume spacer before rebuilding the fork. After rebuilding the fork I have tried 0 and 1 with pressure between 77 and 80 psi.

I find the best overall feeling with 0 reducers at 78 psi but would like to limit the brake dive. 1 spacer at the same pressure limits dive a bit more but feels more harsh in my hands. I don't bottom out on either setup on most rides.

 

[Notthatbryan]

Under what conditions do your hands go numb?

Mainly on rolling technical terrain, lots of roots and rocks but not super steep big climbs or descents. Technical blue to moderate black trails. I'm quick enough to keep up with a couple of buddies on ebikes but I don't know how fast I really am at this point.
On longer climbs I change my hand position up and can keep it at bay.

I'm in GA and ride mainly at Allatoona Creek park (luckily right out my back door about 20 yards) and Blankets Creek.

 

[cassieno]

Do you notice it on steep downs also? Or just on technical rolling terrain? What bike is it on? Have you had this issue before on other bikes? What bike were you riding before and did you have the issue.

I am wondering if some of it comes down to bike fit. i.e. Steeper seat tube angle puts more weight on your hands when sitting on rolling terrain. Steep SA work really well for straight up and down, but can be less ideal in rolling terrain depending on your body proportions.

 

[commplex]

I weight 175 and run mine at 85 psi with no tokens. Like someone said earlier it seems counterintuitive to add more psi but it actually made a big difference for me. Small bump is good, no brake dive and plenty of mid stroke support.

 

[jeremy3220]

Mainly on rolling technical terrain, lots of roots and rocks but not super steep big climbs or descents.

And this is also the same terrain you're having brake dive issues on?