Mountain Bike Reviews Forum banner
1 - 20 of 58 Posts

· Registered
Joined
·
1,001 Posts
Discussion Starter · #1 ·
Currently running a Fox 34mm Rhythm on a 2021 SJ Comp carbon.
I found running the front tire 4 PSI less than the rear along with 2 Spacers @ 60 PSI in the Fork makes for a pretty smooth ride, however looking into options for a little more fast speed chatter relief to better match the rear shock. Current weight is 178 lbs.

Which of these would best obtain that (in order from best to worst)

~ Current 34 Rhythm w/Diaz Runt
~ Current 34 Rhythm w/ 150mm Grip Cartridge
~ 34mm GRIP2 @ 140mm
~ 36mm GRIP2 @ 150mm.

I'm happy with the 34 otherwise (flex), but extending to 150mm seems like a better choice for a Fox 36.....Dunno?
 

· always licking the glass
Joined
·
4,428 Posts
Currently running a Fox 34mm Rhythm on a 2021 SJ Comp carbon.
I found running the front tire 4 PSI less than the rear along with 2 Spacers @ 60 PSI in the Fork makes for a pretty smooth ride, however looking into options for a little more fast speed chatter relief to better match the rear shock. Current weight is 178 lbs.

Which of these would best obtain that (in order from best to worst)

~ Current 34 Rhythm w/Diaz Runt
~ Current 34 Rhythm w/ 150mm Grip Cartridge
~ 34mm GRIP2 @ 140mm
~ 36mm GRIP2 @ 150mm.

I'm happy with the 34 otherwise (flex), but extending to 150mm seems like a better choice for a Fox 36.....Dunno?
Free: if you have any tokens in the fork, take them out :) that will help high speed chatter.

Flex: you'll need a 36. Highly recommend it over the 34.
 

· Registered
Joined
·
1,001 Posts
Discussion Starter · #3 ·
Free: if you have any tokens in the fork, take them out :) that will help high speed chatter.

Flex: you'll need a 36. Highly recommend it over the 34.
wondering how the Token removal will aid the chatter as I added the Tokens for that very reason.
Sans Tokens I had two options

1) Plush Fork (18% Sag) and bottom out on 2ft drop + aggressive trail riding.
2) Firm/semi rigid Fork (10%), but ok for bottoming out.

I appreciate your advice but the Tokens will only be leaving If I can find a suitable (preferewably better) option(s) listed above.
 

· Premium Member
Joined
·
8,746 Posts
Currently running a Fox 34mm Rhythm on a 2021 SJ Comp carbon.
I found running the front tire 4 PSI less than the rear along with 2 Spacers @ 60 PSI in the Fork makes for a pretty smooth ride, however looking into options for a little more fast speed chatter relief to better match the rear shock. Current weight is 178 lbs.

Which of these would best obtain that (in order from best to worst)

~ Current 34 Rhythm w/Diaz Runt
~ Current 34 Rhythm w/ 150mm Grip Cartridge
~ 34mm GRIP2 @ 140mm
~ 36mm GRIP2 @ 150mm.

I'm happy with the 34 otherwise (flex), but extending to 150mm seems like a better choice for a Fox 36.....Dunno?
Your pressure appears a bit low for your weight, I would expect to see you at 75-80 psi. Keep in mind that sag is very hard to measure consistently and accurately for the front, and pretty much useless. Stripes recommends removing the tokens because as you add tokens and lower pressure, you get further into the progress part of the spring curve which make the fork harsher, not plusher. Fox forks in particular seem sensitive to this and when in doubt with them, more pressure is better than less. My son's Ibis DV9 has the same Rhythm 34 and it is a surprisingly good fork, but sensitive to setup pressure. I am 200 pounds and originally had it at 80 psi and found it harsh feeling through chatter, which massively improved when I increased the pressure to 90 psi. My son at 170 pounds and more aggressive riding runs the fork at the same pressure.

You don't mention how you got to the pressure you are using or your rebound settings, as excessive rebound can have the same effect. I would suggest you try starting from a baseline again with no tokens and try Specialized recommended settings which are 188 psi shock, rebound 7 clicks out from closed, and 83 psi for the fork and rebound 8 clicks out from closed. Compression settings should be full open. Do this and report back.
 
  • Like
Reactions: stripes

· Registered
Joined
·
1,001 Posts
Discussion Starter · #5 ·
Ok, Ill give it a try.
Maybe I was too quick in adding the Tokens, but unless the Fork has drastically worked itself in, the Fox/Spec recommended setting (for the Fork) was downright stiff and felt like I was riding a rigid Fork.
The rear setting/recommendation was fine and even increasing it 5 - 10 PSI still feels plush (for the 130mm travel).
 

· Registered
Joined
·
159 Posts
You need to separate spring mod and damper mod. My comment below is only covering spring mods.

Vorsprung Secus improves both initial sensitivity as well as mid-stroke support. DSD Runt only improves the mid-stroke support, and Vorsprung Luftkappe is aiming at the initial sensitivity part (and will add some progressiveness because of reduced positive air chamber volume). As others said, removing all token and run a bit higher pressure will give you more mid-stroke support (with some lost of initial sensitivity), before you spend any money in mod.

When you run low pressure with lots of token in the high speed chatter, the bike would sit deep in the travel and always hit the wall of force from the ramping air spring. More mid-stroke support gives the suspension more “active travel” to handle high speed chatter.

Could you elaborate the comment about too stiff with recommended setting? Is the fork out of balance with the rear when you bounce on the bike? Or is it determined from small bump sensitivity? Could you also share your damper setting?
 

· Premium Member
Joined
·
8,746 Posts
Ok, Ill give it a try.
Maybe I was too quick in adding the Tokens, but unless the Fork has drastically worked itself in, the Fox/Spec recommended setting (for the Fork) was downright stiff and felt like I was riding a rigid Fork.
The rear setting/recommendation was fine and even increasing it 5 - 10 PSI still feels plush (for the 130mm travel).
Try opening the rebound on the fork a few clicks more than the recommendation. You will start to lose traction on the front, add a click at a time back in until you get the traction back. The fork could be packing down from too much rebound.
 
  • Like
Reactions: stripes

· Registered
Joined
·
1,001 Posts
Discussion Starter · #8 ·
You need to separate spring mod and damper mod. My comment below is only covering spring mods.

Vorsprung Secus improves both initial sensitivity as well as mid-stroke support. DSD Runt only improves the mid-stroke support, and Vorsprung Luftkappe is aiming at the initial sensitivity part (and will add some progressiveness because of reduced positive air chamber volume). As others said, removing all token and run a bit higher pressure will give you more mid-stroke support (with some lost of initial sensitivity), before you spend any money in mod.

When you run low pressure with lots of token in the high speed chatter, the bike would sit deep in the travel and always hit the wall of force from the ramping air spring. More mid-stroke support gives the suspension more "active travel" to handle high speed chatter.

Could you elaborate the comment about too stiff with recommended setting? Is the fork out of balance with the rear when you bounce on the bike? Or is it determined from small bump sensitivity? Could you also share your damper setting?
Stiff as in It reminded me of my 80mm Headshok (for harshness).
The Fork and Shock seem in sync when I bounce (or take flight) as the rebound on both seems equal
Rebound setting is four clicks from wide open (for both fork/shock)
 

· Registered
Joined
·
1,001 Posts
Discussion Starter · #9 ·
Try opening the rebound on the fork a few clicks more than the recommendation. You will start to lose traction on the front, add a click at a time back in until you get the traction back. The fork could be packing down from too much rebound.
I did this initally and found the Fork kicked back too fast when wide open. Four clicks in seemed to settle things down and track much better.
 

· Registered
Joined
·
1,001 Posts
Discussion Starter · #10 ·
Still looking at the options in my initial post as I don't believe the recommended PSI setting will make things better as I'll actually loose the small bump (slow speed) compliance I currently have with the 2 Spacers/Tokens.
 

· Premium Member
Joined
·
8,746 Posts
I did this initally and found the Fork kicked back too fast when wide open. Four clicks in seemed to settle things down and track much better.
Sounds like you have the rebound about where it should be. Are you running the compression wide open? Also, how many hours on the fork? Have you serviced it? Also what is your actual front tire pressure, I would expect low 20s, but if it is too high that will also not help the harshness.

The Grip in the Rhythm is surprisingly good out of the box. Not the best, but pretty darn good. If you end up wanting to upgrade and stay in the Fox line, I would go the 36 Performance Elite with the Grip 2 set to 150mm. That said, I would suggest seriously considering a Mezzer Pro if you actually upgrade the entire fork. If you keep the one you have, I would try the Runt. Don't bother changing it to 150mm, it won't change the feel of the fork if you fundamentally don't get along with it.
 

· always licking the glass
Joined
·
4,428 Posts
wondering how the Token removal will aid the chatter as I added the Tokens for that very reason.
Sans Tokens I had two options

1) Plush Fork (18% Sag) and bottom out on 2ft drop + aggressive trail riding.
2) Firm/semi rigid Fork (10%), but ok for bottoming out.

I appreciate your advice but the Tokens will only be leaving If I can find a suitable (preferewably better) option(s) listed above.
Tokens cause the fork to ramp up faster. The more tokens, the faster the fork ramps up. The more tokens, the rougher the fork feels on high speed chatter.

If you're bottoming out at a two foot drop, add high speed compression (HSC). You don't need tokens to fix a bottom out issue.

What isn't clear to me is what you don't like about your fork. Rather than throwing random options that don't seem to relate, can you tell us what you want to feel better?
 

· Registered
Joined
·
159 Posts
Stiff as in It reminded me of my 80mm Headshok (for harshness).
The Fork and Shock seem in sync when I bounce (or take flight) as the rebound on both seems equal
Rebound setting is four clicks from wide open (for both fork/shock)
I would guess your pump is reading low. Fox recommends 4 click of rebound from open for 86-96psi, which is for 180-210lb of weight. You also mentioned the fork and shock feeling balanced. Combing these observations, your current setting seems pretty spot on and likely close to the recommended setting, but you reach there by feel (fork too stiff and rebound to manage kickback).

I would say try taking out all spacers, run the same pressure, and go test on the high speed chatter starting with HSC fully closed. Gradually open it (as small a turn as you could do, since GRIP is super sensitive for the knob) to get the feel you like. HSC works at the initial portion of travel, but spring works at the end portion. With closed HSC, your drop landing may consume even less total travel than low speed tech.

If no token with high HSC feels better but not enough improvement, you may consider a DSD Runt.
 

· Registered
Joined
·
1,288 Posts
do you have a rhythm fork?

my rhythm has a low speed dial.
GRIP 1 doesn't really have LSC adjust. That big blue knob puts preload on all the shims and has no free bleed so it's kind of like a HSC adjust. Closing it increases both LSC and HSC but in my experience closing it more than about a quarter isn't very useful as the preload means sore hands and the front tyre deflecting of every root on the trail.
 

· Registered
Joined
·
1,001 Posts
Discussion Starter · #17 · (Edited)
Sounds like you have the rebound about where it should be. Are you running the compression wide open? Also, how many hours on the fork? Have you serviced it? Also what is your actual front tire pressure, I would expect low 20s, but if it is too high that will also not help the harshness.

The Grip in the Rhythm is surprisingly good out of the box. Not the best, but pretty darn good. If you end up wanting to upgrade and stay in the Fox line, I would go the 36 Performance Elite with the Grip 2 set to 150mm. That said, I would suggest seriously considering a Mezzer Pro if you actually upgrade the entire fork. If you keep the one you have, I would try the Runt. Don't bother changing it to 150mm, it won't change the feel of the fork if you fundamentally don't get along with it.
Yes, Compression is wide open (unless climbing on road).
There's about 60hrs on the Fork but it's not changed since day one.
I run the Front tire from 18 PSI - 22 PSI (depending on terrain, conditions, etc)

Also, Looks like the Mezz Pro is only offered in 160mm/180mm which is 10mm above the 150mm max. recommended travel.
 

· Registered
Joined
·
1,001 Posts
Discussion Starter · #18 ·
Tokens cause the fork to ramp up faster. The more tokens, the faster the fork ramps up. The more tokens, the rougher the fork feels on high speed chatter.

If you're bottoming out at a two foot drop, add high speed compression (HSC). You don't need tokens to fix a bottom out issue.

What isn't clear to me is what you don't like about your fork. Rather than throwing random options that don't seem to relate, can you tell us what you want to feel better?
Fork is great, just wish it was a bit more plush to better match the shock (they're close but still could be closer).
Adding Compression (blue knob) is a PITA when I have to switch it throughout the ride. If it were just for drops, jumps that would be ok but it also would need to activate it for fast rough terrain.
 

· Registered
Joined
·
1,001 Posts
Discussion Starter · #20 ·
GRIP 1 doesn't really have LSC adjust. That big blue knob puts preload on all the shims and has no free bleed so it's kind of like a HSC adjust. Closing it increases both LSC and HSC but in my experience closing it more than about a quarter isn't very useful as the preload means sore hands and the front tyre deflecting of every root on the trail.
This is what I found also, hence ,y desire to find another solution where I can set and forget!
 
1 - 20 of 58 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top