I've always found that moto suspension lecture is not well suited for MTB. On a motorcycle or car you don't move your body a lot. The center of gravity doesn't change that much compared to a bike where you lean back and forth and grip the ground by pushing and loading and unloading with you body. That's what will make big difference in suspension setup because as you lean back the fork won't be loaded equal anymore. Also MTB suspension needs to be incredibly fine and for me I struggle sometimes with mine. For example I just changed my highspeed compression shim to a harder one. This gives me more control when charging hard and ridiculously fast but makes the big super harsh when I ride slower or in the wet. Also when lowering the the air pressure below my usual pressure it made the fork harsher because it was sagged deeper into the stroke and it gave more resistance due to progression. The highspeed rebound also kicked more because I got deep into the travel more often. More pressure made everything more controlled and easier to handle at speed. What I want to say with that is, don't always listen to what people tell you, rather go out and bring a backpack with shock and tire pump and set up to what you need and want. Takes a week but with a friend or group it's a lot of fun and really easy. Get some cones and try different lines and see if you get more extreme with different set ups or if it hinders you. When you're done with it, go ride in the wet and do it all over again
That’s the book I have, it was before air forks so it dates itself, but great book. Agree with this guy, to some degree, Ebike’s weight makes it more valid
I did Rock Shox Zeb coil conversion,cheap! First I took red Zeb air shaft 170 mm,put red part in clamps and unscrewed other side with key 12 anti clock wise. At the top air shaft has two pin holes. In my parts I have few old RS coil shafts,boxxer,domain,lyrik,same diameter 10 mm as Zeb.Simply I knocked out pin at placed coil head and pin on Zeb shaft it fits great. Also I gave a friend air token to work it on lathe,make it bit tighter for coil spring to fit,not to damage air top cap.I left other Zeb shaft parts,sliding ring and rubber bumper. Coil spring if X Fusion Vengeance 170 mm,blue,fit for my 93kg. Travel is 190mm. It works PERFECT!!No more bottoming,its linear,plush and soft on roots and stones. Finally I have my dream fork! Also I can pump a bit of air inside the fork,if I want.From small plastic bottle I have cutted coil spring wrap,not to click inside the fork or to scratch the stanchion inside.
Very exciting to watch your freestyle optimization Video. Definitely learned a couple things. I would add a few things. The lower lock nut of the air spring could be heated up with a heat gun or lighter (carefully or you destroy the little rubber ring inside). That helps in order to reduce opening force. If you have a newer fork and want to save money when altering fork travel you could disassemble the current shaft, buy an old (used) shaft which is 10mm longer than what you wand the fork (with the newest airshaft) to be and just swap the rods. Regarding tight bushings/high friction on lower legs there is this super hero mechanic olivermajewski here on yt. He has two videos about freeing tight bushings and measuring axle width for least friction with attached wheel. As a tinkerer you'll love it. 🙂
@@OtterMTBtech The Runt gives you a second positive air chamber, like forks from EXT, Ohlins and Manitou. Gives you more control over the air spring’s progression.
Here is an interesting experiment: heavier suspension oil (aftermarket by motul, motorex etc...) with less shims. I haven't tried it yet, though I do wonder if that does help with mid stroke support as it shifts the curve of compression and rebound.
You could use kyb k2c which is 5 weight I replaced the S1 in my 17 boxer with great success it calms it down. Don't ask why I needed that 😂 You can also use the kayaba branded k2c it's cheaper and easier to find that the KYC branded oil and it's the same stuff made in the same Japanese factory with higher standards...
@Bjoern_the_Baer if you are referring to how the weights would be (denoted as "wt" like we see on the bottles), I can probably agree to that. Though I'm referring more to a cSt difference of around 4 (so going from 15cSt to 18 or 19cSt) which doesn't seem too significant on paper, though maybe you have done this?
@@brianpham2584 if the difference isn't that big, it won't make the fork feel bad instantly. Problem with changing oil in the damper is that you also chain the other direction as well. Smoother and softer compression can be made with lighter oil. But you'll also make your rebound really fast. I'd stick to a shimstune bushings sizing. With a good tuner you'll most likely get a blend of different oils which will further increase performance but tailored to your needs and preference
For my Rhythm 36, I added a Vorsprung Smashpot coil. Completely transformed the fork. Not a budget upgrade, but still cheaper than a new Fox 38 or RS Zeb.
Great video. Although you had your axles on the lowers on the z1 and the newer 36, which you titled as tight, while you tested the '19 36 without an axle
the air spring is more complicated. What is important is the negative and positive volume, their mutual ratio, the diameter of the pipe and piston, and even the volume of trapped air in the lower legs. Look at the F38 spring. This is an additional pipe with a smaller diameter, identical to the F34, and an increased volume of the lower legs. The F38 has one of the best air springs.
@OtterMTBtech Does this mean I can use the new 2021 Airspring in the older 2019 Fox36? That’s awesome since it’s easier available on the used market here!
Currently have 2 of taken apart. Massive shim stacks, would get lost trying to get changed. And still unable to bleed both of thr float x’s. Tricky stuff
Race Tech's Motorcycle Suspension Bible is great for understanding suspension
I've always found that moto suspension lecture is not well suited for MTB. On a motorcycle or car you don't move your body a lot. The center of gravity doesn't change that much compared to a bike where you lean back and forth and grip the ground by pushing and loading and unloading with you body. That's what will make big difference in suspension setup because as you lean back the fork won't be loaded equal anymore.
Also MTB suspension needs to be incredibly fine and for me I struggle sometimes with mine. For example I just changed my highspeed compression shim to a harder one. This gives me more control when charging hard and ridiculously fast but makes the big super harsh when I ride slower or in the wet. Also when lowering the the air pressure below my usual pressure it made the fork harsher because it was sagged deeper into the stroke and it gave more resistance due to progression. The highspeed rebound also kicked more because I got deep into the travel more often. More pressure made everything more controlled and easier to handle at speed. What I want to say with that is, don't always listen to what people tell you, rather go out and bring a backpack with shock and tire pump and set up to what you need and want. Takes a week but with a friend or group it's a lot of fun and really easy. Get some cones and try different lines and see if you get more extreme with different set ups or if it hinders you. When you're done with it, go ride in the wet and do it all over again
That’s the book I have, it was before air forks so it dates itself, but great book.
Agree with this guy, to some degree, Ebike’s weight makes it more valid
I did Rock Shox Zeb coil conversion,cheap! First I took red Zeb air shaft 170 mm,put red part in clamps and unscrewed other side with key 12 anti clock wise. At the top air shaft has two pin holes. In my parts I have few old RS coil shafts,boxxer,domain,lyrik,same diameter 10 mm as Zeb.Simply I knocked out pin at placed coil head and pin on Zeb shaft it fits great. Also I gave a friend air token to work it on lathe,make it bit tighter for coil spring to fit,not to damage air top cap.I left other Zeb shaft parts,sliding ring and rubber bumper.
Coil spring if X Fusion Vengeance 170 mm,blue,fit for my 93kg. Travel is 190mm.
It works PERFECT!!No more bottoming,its linear,plush and soft on roots and stones.
Finally I have my dream fork!
Also I can pump a bit of air inside the fork,if I want.From small plastic bottle I have cutted coil spring wrap,not to click inside the fork or to scratch the stanchion inside.
That’s crazy, I guess you keep the old air seal on the bottom?
The negative chamber volume and dimple location change how progressive the fork is but it's mostly the volume
Very exciting to watch your freestyle optimization Video. Definitely learned a couple things. I would add a few things. The lower lock nut of the air spring could be heated up with a heat gun or lighter (carefully or you destroy the little rubber ring inside). That helps in order to reduce opening force. If you have a newer fork and want to save money when altering fork travel you could disassemble the current shaft, buy an old (used) shaft which is 10mm longer than what you wand the fork (with the newest airshaft) to be and just swap the rods.
Regarding tight bushings/high friction on lower legs there is this super hero mechanic olivermajewski here on yt. He has two videos about freeing tight bushings and measuring axle width for least friction with attached wheel. As a tinkerer you'll love it. 🙂
Cool on the air spring zzz length, I watched those videos. Was hard for me to follow lol
I bought a DSD Runt for my Lyrik Ultimate. Highly recommend. Easy install and big difference in performance.
What is better?
@@OtterMTBtech The Runt gives you a second positive air chamber, like forks from EXT, Ohlins and Manitou. Gives you more control over the air spring’s progression.
Here is an interesting experiment: heavier suspension oil (aftermarket by motul, motorex etc...) with less shims. I haven't tried it yet, though I do wonder if that does help with mid stroke support as it shifts the curve of compression and rebound.
Makes the fork ride harsh and not enjoyable when cold. Don't do it, rather change the shimstack and get your bushings sized
You could use kyb k2c which is 5 weight I replaced the S1 in my 17 boxer with great success it calms it down. Don't ask why I needed that 😂
You can also use the kayaba branded k2c it's cheaper and easier to find that the KYC branded oil and it's the same stuff made in the same Japanese factory with higher standards...
@Bjoern_the_Baer if you are referring to how the weights would be (denoted as "wt" like we see on the bottles), I can probably agree to that. Though I'm referring more to a cSt difference of around 4 (so going from 15cSt to 18 or 19cSt) which doesn't seem too significant on paper, though maybe you have done this?
@@brianpham2584 if the difference isn't that big, it won't make the fork feel bad instantly. Problem with changing oil in the damper is that you also chain the other direction as well. Smoother and softer compression can be made with lighter oil. But you'll also make your rebound really fast. I'd stick to a shimstune bushings sizing. With a good tuner you'll most likely get a blend of different oils which will further increase performance but tailored to your needs and preference
For my Rhythm 36, I added a Vorsprung Smashpot coil. Completely transformed the fork. Not a budget upgrade, but still cheaper than a new Fox 38 or RS Zeb.
Hmm
Great video. Although you had your axles on the lowers on the z1 and the newer 36, which you titled as tight, while you tested the '19 36 without an axle
I didn’t know that affected it, thanks for pointing out
the air spring is more complicated. What is important is the negative and positive volume, their mutual ratio, the diameter of the pipe and piston, and even the volume of trapped air in the lower legs. Look at the F38 spring. This is an additional pipe with a smaller diameter, identical to the F34, and an increased volume of the lower legs.
The F38 has one of the best air springs.
It can support really high air pressures without getting harsh, too. It's basically a high volume air can inside a fork somehow
@OtterMTBtech Does this mean I can use the new 2021 Airspring in the older 2019 Fox36? That’s awesome since it’s easier available on the used market here!
Not really worth it, allot of work
Love this kind of content. Do you do shocks as well? How hard would it be for a home mechanic to re-shim a Fox Float X for example?
Currently have 2 of taken apart. Massive shim stacks, would get lost trying to get changed. And still unable to bleed both of thr float x’s. Tricky stuff
Do you have a link for the shaft clamps?
ebay.us/vltGmK
@@OtterMTBtech thanks!
Orange loctite ftw!!!
Stuff is great it doesn’t clog the threads