Fox 34 rhythms flex?

[PJ27]

I'll just comment on the oil. Let the air out with the pump connected. There is only a little bit of fluid in the DPS to keep the seals lubed. If you let the air out without the pump connected it will come out too fast and pull the oil out too. I set mine for 30% sag which for my light weight do no allow me to use all of the travel. I'm going to try 145 psi my next ride since I'm using almost all of the travel now, weight is 160 lbs with all my gear on. So I'm sort of at the opposite extreme to you. I had to take out the one very small volume spacer that was stock, you might in fact have to add a larger one to make everything work.

Oh I forgot to add it's important that for every 50 psi change that you remove the pump and cycle the shock up and down about 10 times to equalize pressures. The put the pump back on and continue/repeat until you reach whatever set point you are after.

Really appreciate you taking the time to reply and the information - all makes sense. I think you are correct on the spacers, definitely need to add some. and probably over time an upgrade of suspension would also be beneficial.

Happy riding. Thanks again

 

[sdcoffeeroaster]

Really appreciate you taking the time to reply and the information - all makes sense. I think you are correct on the spacers, definitely need to add some. and probably over time an upgrade of suspension would also be beneficial.

Happy riding. Thanks again

My DPS came with the smallest spacer available but even that is too much for my weight. You will probably need a larger one. I've ordered a DVO Topaz T3 shock because I just can't make the DPS work to my liking without being too soft initially. I hope the DVO works better. I plan to borrow a ShockWiz to tune it.

 

[Tooks]

Hi Tooks,

Thanks for the detailed reply. It feels too stiff and like I am floating above the terrain. I adjusted from standard settings which were way off (air pressure was 190PSI).

This was my first ride after adjusting to Fox's recommendations at SHOCK- 2019 FLOAT DPS and DPX2 | Bike Help Center | FOX the first point Fox suggest (as I read it) was to set the air PSI to your body weight in pounds = 227 PSI (I am 6'4 and approx 103kg's with riding gear). To get 28% sag approx 14mm movement when sitting on bike I need to increase PSI to 330 and then rebound to fully closed according to Fox guidelines (as I read/ understood them). Way to stiff and just not a good feeling.

I have let further air out and increased rebound to 3 and it is starting to feel better. (Note: when I let air our of the chamber on the rear shock, oil also came out. In quick research this is normal. Is that correct?)

More trial and error is required this weekend, based on what you are running I am way off and probably need to go down to 237PSI and maybe 5 clicks from closed on rebound. Thoughts?

Thanks again

My new shock arrived with about 200 psi in it, presumably what they’d put in at the factory. First thing I did was let all the air out, didn’t notice any oil, and I had to cycle it on deflation too so that air could escape the negative chamber.

I then inflated to my desired pressure, stopping every 50 psi to cycle air into the negative chamber, otherwise the shock just wanted to stay extended and was very stiff. I followed the guidance exactly as you’ve linked.

The way yours is behaving, it’s like there isn’t enough pressure in the negative chamber? You need to cycle the shock when you let a lot of air out too, otherwise the shock will suck into its travel too early.

I‘d have thought you should be around 240-250 psi and -5 rebound as well.

Just a thought, how confident are you about your pump reporting accurate pressure? I’ve got 2 shock pumps, both very old and they read slightly different! So I’ve had to rely on the one that seems to end up with the correct sag, but the actual pressure in the shock might not be what I’m reading.

 

[PJ27]

My new shock arrived with about 200 psi in it, presumably what they’d put in at the factory. First thing I did was let all the air out, didn’t notice any oil, and I had to cycle it on deflation too so that air could escape the negative chamber.

I then inflated to my desired pressure, stopping every 50 psi to cycle air into the negative chamber, otherwise the shock just wanted to stay extended and was very stiff. I followed the guidance exactly as you’ve linked.

The way yours is behaving, it’s like there isn’t enough pressure in the negative chamber? You need to cycle the shock when you let a lot of air out too, otherwise the shock will suck into its travel too early.

I‘d have thought you should be around 240-250 psi and -5 rebound as well.

Just a thought, how confident are you about your pump reporting accurate pressure? I’ve got 2 shock pumps, both very old and they read slightly different! So I’ve had to rely on the one that seems to end up with the correct sag, but the actual pressure in the shock might not be what I’m reading.

Hey Tooks,

Again thank you for all your info and guidance, you seem well skilled. In terms of suspension I am an absolute novice. The Jam2 is my first MTB in a long long time, so either trying to remember or learn for first time

I didn't do the cycle through (that's what happens when trying to do it one handed as you other hand has a beer in it !), so you are absolutely right think you could be correct in terms of air negative chamber. I was using my mates shock pump as I don't have one.

I will reduce air pressure to 250PSI and 5 clicks (remembering to cycle through the shock & pump attached) and work from there.

Thanks again. You are a LEGEND.

 

[Tooks]

Hey Tooks,

Again thank you for all your info and guidance, you seem well skilled. In terms of suspension I am an absolute novice. The Jam2 is my first MTB in a long long time, so either trying to remember or learn for first time

I didn't do the cycle through (that's what happens when trying to do it one handed as you other hand has a beer in it !), so you are absolutely right think you could be correct in terms of air negative chamber. I was using my mates shock pump as I don't have one.

I will reduce air pressure to 250PSI and 5 clicks (remembering to cycle through the shock & pump attached) and work from there.

Thanks again. You are a LEGEND.

No worries, these things are great when they’re working properly.

I think you need to borrow your mates pump again, deflate the shock to zero, cycling as you go as the shock shortens its travel.

Starting from zero, inflate to 50psi, then cycle the shock as per the instructions.

Unfortunately, it seems that if you go straight to max pressure, cycling the shock at that point won’t ever equalise the negative chamber pressure, so that could be why you appear to have a very stiff shock.

 

[PJ27]

No worries, these things are great when they’re working properly.

I think you need to borrow your mates pump again, deflate the shock to zero, cycling as you go as the shock shortens its travel.

Starting from zero, inflate to 50psi, then cycle the shock as per the instructions.

Unfortunately, it seems that if you go straight to max pressure, cycling the shock at that point won’t ever equalise the negative chamber pressure, so that could be why you appear to have a very stiff shock.

Do u know the part numbers or a link for the spacers for that suit my rear shock large & small? Also the front 34 Rhythm forks?

 

[Tooks]

Do u know the part numbers or a link for the spacers for that suit my rear shock large & small? Also the front 34 Rhythm forks?

Spacer kit part number for a DPS shock is 803-01-250 I think.

Check the following link though, depending on exactly which shock you have (I’m presuming it’s a 210/55 DPS Evol LV?) some of the spacers shouldn’t be used.

2002-2020 Air Volume Reduction (FLOAT, FLOAT X, FLOAT DPX2 and DHX Air Rear Shocks) | Bike Help Center | FOX

 

[sdcoffeeroaster]

When you do the 50 psi cycling make sure to take he pump off every time you cycle. I didn't do that the first time and pressure bounced around, very high almost instantly when I pumped it up again. Didn't know what was going on at first, lol.

 

[MartinW148]

I made two mistakes when replacing my air shaft on my 2018 Focus Jam2 C with Fox Rhythm 34. I wanted to increase the travel to 150 mm and use a 29" wheel. As flexible as this fork is I decided to go back to 140 mm to try to minimize flex. I'm also unsure as to if this version is OK with 150 mm. I used it that way for months without any apparent issues.
The other mistake is to try to duplicate the huge amount of grease that the factory used on the end of the air shaft. That resulted in plugging all holes as shown in the picture. Months of riding like this did not unplug the holes so I've now cleaned it out and re-installed the stock 140 mm and I'm using one volume spacer. I weigh about 65 kg but still wish I had a higher end, stiffer front fork. No way to test any of this right now since all the trails are closed here in SoCal but someday soon I hope. Stay safe out there! View attachment 28580 View attachment 28581

I'm a similar weight to you, around 67kg. I find the fork has trouble with the small stuff, tends to virbrate over these rather than compress. Maybe that's what is being described as flex, otherwise I don't get any flex. Any tips on set up for the small bumps, I guess it would fall under fast rebound, but I'm no suspension expert

Tx

 

[sdcoffeeroaster]

I'm a similar weight to you, around 67kg. I find the fork has trouble with the small stuff, tends to virbrate over these rather than compress. Maybe that's what is being described as flex, otherwise I don't get any flex. Any tips on set up for the small bumps, I guess it would fall under fast rebound, but I'm no suspension expert

Tx

Once I get my new DVO Topaz I plan to borrow a Shockwiz and run it on the front and back I'll post when I get some results. I had a very costly crash about 1 1/2 years ago on my Giant Anthem 2 that also had this fork. The last thing I remember is the fork chattering across some very small ripples in the trail. I cut a corner too sharp, up the side of the slope and slid out on my shoulder almost instantly at 20 mph. Lots of damage but I really remember the fork doing that in a big way as I went down and it was almost violent just like a nasty vibration. Maybe rebound dampening set too high not sure? I was running one volume spacer and compression dampening open, maybe 10-11 clicks of rebound at that time.

 

[PJ27]

Hi
I am a little confused (quite easy I know), can someone please confirm the correct volume spacers and part number for the 2020 Jam2 6.8 Nine. The ID on my fork is DSDY.

Is the part number;

234-04-953 (green, 10cc) Fox Rythym 34 or
234-04-811 (blue, 8cc) Fox 34 e-bike+

I believe the forks on the bike are just the Fox 34 Rhythm not the 34 e-bike+ arent they? (If thats the case why would they put the e-bike specific forks?)

Thanks

 

[MartinW148]

Question on volume spacers. If I were to add avolume spacer, could I run less air pressure to make the ride more compliant at slow speed and for high frequency bumps, letting the volume spacer protect the fork from bottoming out at full travel?

I previously had only thought of volume spacer for agreesive riding?

Thanks
M*

 

[sdcoffeeroaster]

Hi
I am a little confused (quite easy I know), can someone please confirm the correct volume spacers and part number for the 2020 Jam2 6.8 Nine. The ID on my fork is DSDY.

Is the part number;

234-04-953 (green, 10cc) Fox Rythym 34 or
234-04-811 (blue, 8cc) Fox 34 e-bike+

I believe the forks on the bike are just the Fox 34 Rhythm not the 34 e-bike+ arent they? (If thats the case why would they put the e-bike specific forks?)

Thanks
View attachment 30262

It should be the green one. My 2018 came with one spacer and it was 140 mm travel. I did try the 150 mm air damper but from what I read the 27.5+/29" version of the Rhythm fork is supposed to be limited to 140 mm. I see that Focus did in fact put the 150 in this new bike so maybe it's OK. I just found that with sag set close to the spec, and with my weight I never came close to using all the travel. With about 50 psi and no volume spacer I do use most of it on harder rides so I'm close. I also found that the air damper is usually plugged with bunch of grease blocking most if not all of the holes. I'm not sure how that affects the performance but I did correct that.

Look up the 4 digit number on your fork on the Fox website. Mine is: DBLS

2018, 34, A, FLOAT, 29in, Rhythm, 140, Grip, Sweep-Adj, Matte Blk, No Logo, 15QRx110, 1.5 T, 51mm Rake, N/M OE

 

[sdcoffeeroaster]

Question on volume spacers. If I were to add avolume spacer, could I run less air pressure to make the ride more compliant at slow speed and for high frequency bumps, letting the volume spacer protect the fork from bottoming out at full travel?

I previously had only thought of volume spacer for agreesive riding?

Thanks
M*

Yes but if you are a lighter rider like me then you might not ever use the last 20-30mm of the travel. That's the result of too many volume spacers and maybe less aggressive riding. I'm 150-160 lbs with all my gear and currently don't think I even need one spacer. I have thought of changing the seal to one that says it's "low friction". I'm not sure it's any different from the one that comes stock with the Rhythm 34 but Fox advertises them as if they are improved over stock....does anyone know?

 

[dobbyhasfriends]

I found the 34 rhythm on my levo (150mm) is way way better since I added 2 more spacers and ran less pressure, better small bump response and only bottoms out on the hardest landing or decent size jumps.. im 100kg in kit.
for example, there is a section of trail I ride here that is all bedrock drop offs, around 2 - 2-1/2 feet onto loose stone over bedrock, its a fast section and I was bottoming the fork out every time I went down it. after adding the spacers it feels more plush, it feels like im using the same amount of travel but in fact I still usually have 20-30mm left and a much more stable ride.
from memory I have 95 psi in the fork

 

[NULevo]

I found the 34 rhythm on my levo (150mm) is way way better since I added 2 more spacers and ran less pressure, better small bump response and only bottoms out on the hardest landing or decent size jumps.. im 100kg in kit.
for example, there is a section of trail I ride here that is all bedrock drop offs, around 2 - 2-1/2 feet onto loose stone over bedrock, its a fast section and I was bottoming the fork out every time I went down it. after adding the spacers it feels more plush, it feels like im using the same amount of travel but in fact I still usually have 20-30mm left and a much more stable ride.
from memory I have 95 psi in the fork

Hi Dobby, did your fork come with any spacers fitted? what colour fits the 34'f fitted to the Levo's? I can't find if its the blue or green.

 

[dobbyhasfriends]

Hi Dobby, did your fork come with any spacers fitted? what colour fits the 34'f fitted to the Levo's? I can't find if its the blue or green.

one spacer and the right one for this fork is green

 

[NULevo]

one spacer and the right one for this fork is green

Thanks Dobby, I'll get some more and have a play

 

[PJ27]

Hi

I found the 34 rhythm on my levo (150mm) is way way better since I added 2 more spacers and ran less pressure, better small bump response and only bottoms out on the hardest landing or decent size jumps.. im 100kg in kit.
for example, there is a section of trail I ride here that is all bedrock drop offs, around 2 - 2-1/2 feet onto loose stone over bedrock, its a fast section and I was bottoming the fork out every time I went down it. after adding the spacers it feels more plush, it feels like im using the same amount of travel but in fact I still usually have 20-30mm left and a much more stable ride.
from memory I have 95 psi in the fork

Hi Dobby, thanks for the info that's great. I am approx. 103kg in full riding kit so very similar.

Thanks again

 

[PJ27]

It should be the green one. My 2018 came with one spacer and it was 140 mm travel. I did try the 150 mm air damper but from what I read the 27.5+/29" version of the Rhythm fork is supposed to be limited to 140 mm. I see that Focus did in fact put the 150 in this new bike so maybe it's OK. I just found that with sag set close to the spec, and with my weight I never came close to using all the travel. With about 50 psi and no volume spacer I do use most of it on harder rides so I'm close. I also found that the air damper is usually plugged with bunch of grease blocking most if not all of the holes. I'm not sure how that affects the performance but I did correct that.

Look up the 4 digit number on your fork on the Fox website. Mine is: DBLS

2018, 34, A, FLOAT, 29in, Rhythm, 140, Grip, Sweep-Adj, Matte Blk, No Logo, 15QRx110, 1.5 T, 51mm Rake, N/M OE

Thanks again for the info. Looking up the below information on my specific fork is where I get the slightly confused. The volume spacer details on the Fox website under my code gives information on all 32-34mm forks. The spacer details for the 34mm's provides both for the 34 and the 34 e-bike+ and the spacers are different. In the description to my fork code it says E-Bike (not ebike+). I suppose I could have a look inside as according to the website the 34 Rhythm do not have any factory fitted spacers and the e-Bike+ come with 2.

Do you need the the Fox Fork Top cap to open the fork?

I did look up my code: DSDY and it says;

2020, 34, A, FLOAT, 29in, Rhythm E-Bike, 150, Grip, Sweep-Adj, Matte Blk, No Logo, 15QRx110, 1.5 T, 51mm Rake, OE

 

[sdcoffeeroaster]

Thanks again for the info. Looking up the below information on my specific fork is where I get the slightly confused. The volume spacer details on the Fox website under my code gives information on all 32-34mm forks. The spacer details for the 34mm's provides both for the 34 and the 34 e-bike+ and the spacers are different. In the description to my fork code it says E-Bike (not ebike+). I suppose I could have a look inside as according to the website the 34 Rhythm do not have any factory fitted spacers and the e-Bike+ come with 2.

Do you need the the Fox Fork Top cap to open the fork?

I did look up my code: DSDY and it says;

2020, 34, A, FLOAT, 29in, Rhythm E-Bike, 150, Grip, Sweep-Adj, Matte Blk, No Logo, 15QRx110, 1.5 T, 51mm Rake, OE

I see you do have the 2020 version and it does say e-bike. But it's still a 34mm so I don't see why the 34mm green volume spacers would not work but I could be mistaken. I wonder if they beefed up the lower legs or the ID the 34mm tubes for e-bike use? If the later is true I could see where maybe the volume spacer might not fit.

I ran the front fork with shockwiz today and ended up with 4 clicks from fully closed for the rebound and 40 psi for my total rider weight of 160 lbs with gear. I started with 6 clicks and 50 psi. I'll probably go with 45 psi as a compromise since that is a lot of sag. Oh and no volume spacers is correct for me as I figured. Once I get my new DVO topaz shock I'll tune that and then tune the front forks again. I may even try 150 mm travel someday again.

This link might be helpful: FOX 34 e-bike optimised fork - what's different? Read our first impressions.

So if I read the article correctly, the ebike version is using the 32mm air damper because the id of the tubes is larger. So maybe a 32mm volume spacer is what you need as well. Oh you just need a 26mm socket to remove the air side cap. Just remember to let all of the air out first.

 

[PJ27]

I see you do have the 2020 version and it does say e-bike. But it's still a 34mm so I don't see why the 34mm green volume spacers would not work but I could be mistaken. I wonder if they beefed up the lower legs or the ID the 34mm tubes for e-bike use? If the later is true I could see where maybe the volume spacer might not fit.

I ran the front fork with shockwiz today and ended up with 4 clicks from fully closed for the rebound and 40 psi for my total rider weight of 160 lbs with gear. I started with 6 clicks and 50 psi. I'll probably go with 45 psi as a compromise since that is a lot of sag. Oh and no volume spacers is correct for me as I figured. Once I get my new DVO topaz shock I'll tune that and then tune the front forks again. I may even try 150 mm travel someday again.

This link might be helpful: FOX 34 e-bike optimised fork - what's different? Read our first impressions.

So if I read the article correctly, the ebike version is using the 32mm air damper because the id of the tubes is larger. So maybe a 32mm volume spacer is what you need as well. Oh you just need a 26mm socket to remove the air side cap. Just remember to let all of the air out first.

Thanks again for all your help and information - you are a LEGEND.

I opened up the front forks on the weekend and there was one spacer factory fitted and it was Green (10cc)!!!!!

Its a bit weird as in the table ( FORK- 2020 32mm/34mm | Bike Help Center | FOX ) for my shock code DSDY doesn't line up. The table advises for the 34mm Rhythm 150mm travel there are 0 factory fitted spacers and for the 34 e-bike+ (which mine is marked) there should be 2 Blue spacers (8cc). What would the difference be? Should I order Blue and swap out the green or just stick with green?

I wish things were simple!

 

[sdcoffeeroaster]

Thanks again for all your help and information - you are a LEGEND.

I opened up the front forks on the weekend and there was one spacer factory fitted and it was Green (10cc)!!!!!

Its a bit weird as in the table ( FORK- 2020 32mm/34mm | Bike Help Center | FOX ) for my shock code DSDY doesn't line up. The table advises for the 34mm Rhythm 150mm travel there are 0 factory fitted spacers and for the 34 e-bike+ (which mine is marked) there should be 2 Blue spacers (8cc). What would the difference be? Should I order Blue and swap out the green or just stick with green?

I wish things were simple!

I think if the green ones fit and you need more just order the green ones. According to Fox that ebike 34mm ID should be smaller and takes the air shaft for the 32mm fork because of that. So I would have thought the green volume spacers would not fit either but apparently they do so just go with those. If you are bottoming out with the right sag set, add another volume spacer. You could try to contact Fox to get better information about your fork. I did learn that my fork should be OK with the 150mm air shaft so I might just put it back on.

 

[PJ27]

I think if the green ones fit and you need more just order the green ones. According to Fox that ebike 34mm ID should be smaller and takes the air shaft for the 32mm fork because of that. So I would have thought the green volume spacers would not fit either but apparently they do so just go with those. If you are bottoming out with the right sag set, add another volume spacer. You could try to contact Fox to get better information about your fork. I did learn that my fork should be OK with the 150mm air shaft so I might just put it back on.

Thanks again for your help and reply. Maybe both the blue and green will work!! Will probable get the green.

I sent Fox an email 12 days again and a follow-up 5 days ago with no reply!