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I wish I knew that before. The zeb comes with a complete bike.
When you are shopping for a enduro bike with <64 HA, they usually come with a 170 fork. I wish there are more enduro bikes using 160mm
Did you ever get an answer to your question?
I just want to share, I have 2 Zeb ultimates with buttercup stock. one is a 170mm and the other is 180mm. A few months back, I also got the issue where my forks can't reach past 25mm below the max travel line on the stanchions. I tried letting all the air out by pressing the pin on the valve core but still the same.
Last night, I removed the valve core and pressed the bleed valve on both lowers while applying a slight downward pressure on the handlebar and viola, the fork reach full travel, it even passed the max travel line on the stanchion a bit.
Hello everyone,
I read through all of the messages in this thread and it has been very helpful, by pointing out the options to make the fork less progressive.
My fork is a MY 23 Zeb Ultimate and I haven't been able to get it too work 'right' in two seasons of riding. I weigh 80 kilos and have been trying my best to become fast enough to keep pace at my local enduro races. The best setup I have found so far is 70 psi and zero tokens -- compression doesn't seem to matter that much imo; I usually leave it in the middle or fully open 🤷♂️
Other people here were able to perfectly explain what is happening (on some rides): deeper in the travel, at around 150 - 160 mm, I hit a wall of compression that I can't deal with. My local trails are mostly just extremely steep and I don't seem to hit the wall there. But this week I went into the alps and here it became oh so apparent. Lots of deep steps and large rocks. When I try to plow through these I hit the wall, hard. I ran an experiment mid trail: I set the air spring to 55 psi. That allowed me to plow through the same section, as mentionend before here, but left me with a poor ride height. Can someone explain to me why the very low pressure would affect the progression? I don't fully understand that.
Here's my todo list for getting the fork to work better for me:
- checking the airspring for excess grease -- I can do this myself once I get home
- I will install fresh SKF seals and make sure that I have the proper 7wt oil volume -- I can do this myself too, once I get home
- I contacted SRAM support. I will let you know what they tell me
- I ordered the Trutune. Atm the only have the short one
- At the end of september, I wil have my charger upgraded to the charger 3.1. I am curious what that will do to the fork
- I will check my bushing. Can I do the burnishing myself? Or should I have my local service center do that? How is that done? I am curious
I am a big fan of rockshox products. Hopefully, I can get this fork to work for me, somehow. But unfortunately, this fork has not worked at all for me during the last two season and all this time I was convinced that I just suck
It is most likely just air build up in your lowers, if you open up the bolts at the bottom (with 0 psi in main chamber), you might see results straight away. Then you might need to take some of the steps you mention to prevent the fork from getting harsh again over time.
I last did this at the start of the year and my fork was great until the end of summer, I went to a bike park 2 weeks ago at 2000m of altitude and could not get the fork past 160mm travel (180mm version).
It ramps quicky because spring rate gets firmer deeper in the stroke as all chambers get smaller and smaller (air spring, left and right lower leg). Bushing burnishing is not hard if you have the tool and I guess you don't so that is that. It makes a big difference, yes. But running too soft air spring to compensate for something else is always compromise that is not worth it as it makes more things worse than better.
@rpsteiger "Can someone explain to me why the very low pressure would affect the progression? I don't fully understand that."
The lower the pressure, the lower (deeper in the travel) your sag, both static and dynamic (dynamic ride height) will be. As air springs are naturally somewhat progressive, no matter how well developed they are, that just means you are operating in the progressive part of the characteristic vs. when running a higher pressure. That of course means that a given bump will be handled by less travel as the force will ramp up quicker.
It has been discussed in the past here on Vital, probably mentioned by either Darren Murphy from Push on Vital MTB podcast or by Jordi in Fox's Dialed series (or both actually), etc., but if you feel your fork is too stiff or harsh, removing the pressure is quite likely not the right way to solve things. Adding pressure is the correct way. This raises your ride height and moves you to a more linear part of the air spring. Opening rebound damping can also help as it enables the fork to rebound higher in the travel and not get packed down in the more progressive part of the travel.
Thank you for your reply. Exactly what you say is what I expected to happen: the deeper I run into the travel (deeper with 55 psi), the harder I should experience the end of stroke. Paradoxically, in my experiment the opposite happened. The fork feels way less progressive when riding through rock gardens on 55 psi, compared to 70. Obviously, there is no point in running the fork at 55 psi, since the ride height is poor.
Thabk you for your reply. They have the proper tool in my local bike shop. I will report back afterwards 👍
Thank you for your reply. I don‘t quite understand what you mean with air build up. I should be able to remove that by pressing thw bleed ports. Also my issues with the progression have remained constant over two years. Even after a full rebuild it was there.
Can someone explain to me why the very low pressure would affect the progression? I don't fully understand that.
Technically the progression is always the same regardless of pressure. As you said, at lower pressure you have more access to full travel but the mid stroke is also less supportive. So the difference between the mid and end stroke is about the same at both pressure settings.
To change that requires increasing the size of the positive chamber. Trutune and the Luft Fusion are two ways to do that. They can also work togheter very well, I have some customers using both on the ZEB and their feedback suggests the LF is more effective for linearizing the travel, and not just the end stroke.
It will be there unless you close off the lowers in compressed position. Or press the bleeders with fork compressed (with rag covering them so oil won't squirt on your.brake rotor/caliper)
@Eoin @Jakub_G: there was air in the lowers. After letting out all the air and then pressing the bleed ports (while slightly pressing on the crown) the fork finally reached full travel 😄 You guys were right.
Swarf in new forks is a thing alright... I bought 2 x bikes with Rockshox at the start of the year (Zeb and Sid) and this is what was inside brand new forks. Had better pictures but can't find them on my phone...might be on my DSLR
Small update on my troubleshooting quest. I removed the lowers today. The air spring looks fine. There does not seem to be excess grease on the air spring, see the images below.
However, it was very hard to remove the lowers. I had to hammer lots on the screw to get it loose. I wonder if that is an indication of tight lower bushings 🧐
"I had to hammer lots on the screw to get it loose. I wonder if that is an indication of tight lower bushings"
It is not.
Hi everyone
Yesterday, I received my trutune insert and managed to go for a short ride. The conditions weren't optimal: it was greasy and dark.
Installation was super straight forward and quick. As advertised, it behaves like a token.
The trutune does exactly what it said it would, it's quite mind boggling to me. It completely transformed the fork. Straight away, it felt way better 🥳
I did not hit a wall of progression in the mid stroke. I had to reduce the stack height, which I did not expect.
I will need some more time to trust the fork completely. I only tried one air spring setup: I went straight to 74 psi (from 70), which felt great. The damper setup felt perfect with LSC in the middle and HSC at minus 1.
Quick update: unfortunately I was not able to do more riding in the meantime. I am currently on holiday with my wife. I brought the zeb to a shop for bushing burnishing and also had them install the charger 3.1 upgrade kit. I will report back after my first ride with those changes.
I got the fork back from my shop. They
- burnished the bushings (only on one side the other was fine)
- upgraded the charger damper to charger 3.1—charger 3.1 should come with more oil flow for HSC. This is visible apparent when comparing the two thingies—I dont' know what that thing is called.
- I did not request it but they went with 5wt Motorex oil instead of 7wt Maxima Plush.
On the first ride, I tested the upgraded fork without the trutune insert at 70 psi. The initial impression was that it felt less harsh on square hits. On charger 3.0 I liked HSC at -1 but on charger 3.1, I prefer -2. Overall, I was under the impression that the change to the damper made the fork ride better, but it still felt too progressive.
Today I went on another ride with the trutune insert at 74 psi. I kept compression and rebound the same. I will need more testing but it feels pretty smooth now. Maybe I can lower the pressure with the trutune even further to 72 psi, I will see where that puts my sag at. I only measured sag without trutune at 70 psi which came out to 22-24%. Because of that I am scared of dropping my pressures lower.
To conclude: I think both the trutune and the charger upgrade make the fork better. I think you definitely want the charger upgrade, since it really helps with the harshness from square hits. The trutune really helps with the very progressive nature of the fork, but that might not be a problem for all riders.
EDIT: Two days ago, I tested my friend's Fox 38. It felt a lot less harsh in the mid to end stroke. Basically, it had exactly the feeling that I can't get out of my Zeb. I am pretty gutted at this point. I could still geld the lighter tune for the charger 3.1. However, I think the problem is the air spring ...
After going mad, I was looking online for information how the pro's run their Zeb. I came across this clip where Jack Moir says that he runs a light tune on this 2023 Zeb.
We did it! Complain enough and someone will listen.
What does the downtube say?
And a comparison with the Fox 38:
It says smack! My thoughts exactly. From MRP:
"The Noken is 10-13mm taller than standard damper control knobs, so it’s important to confirm downtube clearance before installation"
Looks like MRP ntoiced too https://mrpbike.com/products/riser-crown-race
I haven't seen a problem yet though. Here's two of my bikes for reference. Regular crown races.
It's interesting that MRP came out with a product too. I am beyond confused on the topic of the newer RockShock stuff. Since my last post I bought a Manitou Mezzer and it is a lot better. I was able to set it up well in three rides and my bike rides balanced for the first time in 1.5 years.
At that point, I was convinced that my Zeb had been defect all this time. I sent it back to the factory, but they sent it back without any useful message (the warranty just expired 2 months ago). It would have liked to know whether is was fine or not, but I understand why they sent it back.
I hope I get an opportunity to borrow another Zeb from my shop to ride on my bike. It is highly unlikely that I will choose it over my Mezzer, but I would really like to know if the current Zeb is super harsh — and I would say unusable for most riders.
Have you checked for lowers binding?
Question to the panel: in your experience, does a 38 have as much built-in progression as a Zeb with the same amount of travel?
Absolutely not
I’ll second that, much less built in ramp with Fox38
I haven't noticed one being particularly more progressive than the other - the zeb is a max 190mm fork so that reduces the progression when you drop it down to 170 or 180 since you aren't using the whole air chamber. The fox has extra volume around the air spring tube though so it seems to balance out.
People need to realise that not using all the travel doesn't only mean it's too progressive- there could be a number of reasons for that
I can't find the data right now, but the Zeb is more progressive than the 38. IIRC, a big part of that is lower-leg ramp effect.
Post a reply to: Attn Fellow Suspension Nerds - 180mm Zeb won't get full travel?