I'll be interested to see how these work out for you. The OEM fork internals are average at best.
Bitubo JBH01V1 closed pressurized fork cartridges
After Installing a XXZ31 rear shock, I found the front cartridges particularly weak on small bump compliance.
They also get very harsh on high compression values.
Several forum members found good improvement of front forks with lower oil level than stock and different grades (5wt, 7.5wt).
Example Oil level curves on damping force from Ohlins NIX22 cartridge for R3:
![Rectangle Slope Parallel Font Plot]()
I wanted to try the same but I need to get new fork springs and a new cartridge with springs is not that far away price wise.
The stock springs are progressive, starting at 0.82 kg/mm and ending at 0.89 kg/mm creating too much static sag for me (~170 lbs)
Among the front fork cartridge options I looked, most of them are standard open cartridge style (similar to stock) but with different materials, piston diameters/designs and separated fork functions (comp & rebound)
e.g. The stock is 20mm. Andreani is ~22mm, Ohlins has NIX22/NIX30 etc..
Typical standard twin-tube fork cartridge design according to Lee Parks Suspension Bible:
![Rectangle Slope Font Line Parallel]()
One big problem with open cartridges is cavitation (esp. on cartridges with both comp and rebound)
A very good demo about it:
The other design used heavily in racing/Motocross is the Spring/Gas pressurized closed cartridge system.
which is supposed to deal with cavitation much better and give consistent damping.
The biggest problem with this style of cartridges is you need to take them to a service center for rebuild if it's gas based.
![Product Font Parallel Rectangle Slope]()
Showa's BFF fork used in GSXR-1000R/ZX-10R, Ohlins NPX in R1M, CBR1000RR-R/V4S/V4R are the OEM pressurized cartridge options I can think of.
There are very limited aftermarket pressurized cartridges on the market with Ohlins FKR, Bitubo JBH/EBH/ECH, Ktech DDS, Andreani pressurized, WP Apex pro 7500, FG Gubellini p.zero, MUPO CSP30 being the options I could find. Unfortunately all these 30mm pressurized kits are very expensive, racing only and require maintenance frequently as suggested by the manufacturer (at around an year/10k miles or 10 hours of track).
Bitubo JBH (previous model ABB) seems to be an exception given it's a simpler and smaller (22mm) design has higher service intervals 20k miles.
I found a service manual for it and looks like the cartridges are closed style, with 22mm pistons and pressurized with nitrogen at 8bar.
The gas and the oil are separated by a floating piston with two rubber o-rings, similar to decarbon style rear shock.
www.yumpu.com
So, I've ordered a set from an Italian retailer with the correct set of springs for me at 0.9 kg/mm which came out to be ~550$ shipped.
motomaniashop.com
I just received them. Will install and report the details after the ride.
![Rectangle Wood Floor Gas Composite material]()
![Tower Skyscraper Camera accessory Camera lens Gas]()
![Font Office supplies Writing implement Parallel Illustration]()
They also get very harsh on high compression values.
Several forum members found good improvement of front forks with lower oil level than stock and different grades (5wt, 7.5wt).
Example Oil level curves on damping force from Ohlins NIX22 cartridge for R3:
I wanted to try the same but I need to get new fork springs and a new cartridge with springs is not that far away price wise.
The stock springs are progressive, starting at 0.82 kg/mm and ending at 0.89 kg/mm creating too much static sag for me (~170 lbs)
Among the front fork cartridge options I looked, most of them are standard open cartridge style (similar to stock) but with different materials, piston diameters/designs and separated fork functions (comp & rebound)
e.g. The stock is 20mm. Andreani is ~22mm, Ohlins has NIX22/NIX30 etc..
Typical standard twin-tube fork cartridge design according to Lee Parks Suspension Bible:
One big problem with open cartridges is cavitation (esp. on cartridges with both comp and rebound)
A very good demo about it:
The other design used heavily in racing/Motocross is the Spring/Gas pressurized closed cartridge system.
which is supposed to deal with cavitation much better and give consistent damping.
The biggest problem with this style of cartridges is you need to take them to a service center for rebuild if it's gas based.
Showa's BFF fork used in GSXR-1000R/ZX-10R, Ohlins NPX in R1M, CBR1000RR-R/V4S/V4R are the OEM pressurized cartridge options I can think of.
There are very limited aftermarket pressurized cartridges on the market with Ohlins FKR, Bitubo JBH/EBH/ECH, Ktech DDS, Andreani pressurized, WP Apex pro 7500, FG Gubellini p.zero, MUPO CSP30 being the options I could find. Unfortunately all these 30mm pressurized kits are very expensive, racing only and require maintenance frequently as suggested by the manufacturer (at around an year/10k miles or 10 hours of track).
Bitubo JBH (previous model ABB) seems to be an exception given it's a simpler and smaller (22mm) design has higher service intervals 20k miles.
I found a service manual for it and looks like the cartridges are closed style, with 22mm pistons and pressurized with nitrogen at 8bar.
The gas and the oil are separated by a floating piston with two rubber o-rings, similar to decarbon style rear shock.
Bitubo Service Manual.pdf - Motorcycle Insight
Bitubo Service Manual.pdf - Motorcycle Read more about cartridge, piston, bitubo, insert, tube and wrench.
www.yumpu.com
So, I've ordered a set from an Italian retailer with the correct set of springs for me at 0.9 kg/mm which came out to be ~550$ shipped.
PRESSURIZED FORK CARTRIDGES BITUBO JBH01V1 PER SUZUKI KATANA 1000 2019/2020
Bitubo pressurized cartridge, adjustable in compression, rebound and spring preload. It replaces the original cartridge, without any modification.
motomaniashop.com
I just received them. Will install and report the details after the ride.
1 - 20 of 87 Posts
I have finally managed to install the cartridges and it was mostly painless except for compressing the spring to fit the fork caps in the end.
I removed the stock fork internals as per the manual with Traxxion dynamics fork cartridge toolkit and a Biltek KYB cartridge holding tool.
![Tire Plant Automotive tire Automotive lighting Wheel]()
Initially I was worried if the fork bottoms have to be removed, but I was happy to find that the cartridges are direct drop-in.
Cartridge bottom:
![Street light Cylinder Electric blue Auto part Pipe]()
Fork Inside after stock cartridge removal. (I backed out the stock compression screw)
![Automotive lighting Automotive tire Liquid Fluid Automotive design]()
Filled with Silkolene 02 synthetic fork oil (not provided with kit) up to 150mm as recommended.
After riding my favorite twisty, JBH with the 0.9kg/mm springs gave me a huge improvement over stock on small bump compliance.
I've tried higher compression settings as well and they don't seem to make the ride considerably harsh unlike the stock cartridge which was unusable beyond 1.75 round out of compression for me. The nitrogen gas must be helping a lot with small bumps.
I have started with recommended settings comp: 12, rebound : 12, preload: 4mm
After some testing ended up with 9 clicks out on comp, rebound and 10mm of preload which helped reduce brake dive and improved front end feel.
Lower oil level makes a lot of difference in linearity of stroke. I was able to get lower into the stroke without any harshness!
Finally the bike's front and rear suspension are at similar level and the damping feel at the front is now the same at the start of the ride (vs) after 1-2 hours of hard riding unlike the stock which would drop off after hard riding.
The cartridge damping feel is quite linear (similar to stock) unlike the XXZ31 rear shock which is clearly digressive feel with a solid piston TTx style design.
I guess the shim stack is tapered and not preloaded.
A lot of suspension experts seem to prefer the linear feel but I like the initial firmness from a digressive damper.
Showa Damper evolution seems to be going the small piston linear feel route: e.g. Stock GSXR1000 - BPF forks - ~40 mm piston - feels digressive, GSXR1000R - BFF forks - ~25mm solid piston - digressive feel still (but less than the bpf).
![Slope Rectangle Plot Font Parallel]()
Linear damping rate is good for predictability but feels a tiny bit mushy initially during turn-in.
With a digressive rate, you can feel it when you get on the bike and move it with your feet.
The digressive firmness makes it feel like you have less parasitic spring movement energy losses.
I guess the bigger pistons in (~30mm) Bitubo EBH / Ohlins FKR cartridges would give me the firm digressive damping character I was looking for as they move more fluid similar to Showa BPF/BFF forks, but they are too much $$$$
The cartridge upgrade did not completely blow me away like the stock rear shock upgrade to Bitubo XXZ31. Shows you how bad the stock rear shock was.
Overall the upgrade is fantastic for ride quality and consistency of damping. Maybe I would have picked 0.95 kg/mm springs if I were to order again.
I would highly recommend this to anyone that wants a quality (20-22mm class) cartridge kit for sub 600$
I removed the stock fork internals as per the manual with Traxxion dynamics fork cartridge toolkit and a Biltek KYB cartridge holding tool.
Initially I was worried if the fork bottoms have to be removed, but I was happy to find that the cartridges are direct drop-in.
Cartridge bottom:
Fork Inside after stock cartridge removal. (I backed out the stock compression screw)
Filled with Silkolene 02 synthetic fork oil (not provided with kit) up to 150mm as recommended.
After riding my favorite twisty, JBH with the 0.9kg/mm springs gave me a huge improvement over stock on small bump compliance.
I've tried higher compression settings as well and they don't seem to make the ride considerably harsh unlike the stock cartridge which was unusable beyond 1.75 round out of compression for me. The nitrogen gas must be helping a lot with small bumps.
I have started with recommended settings comp: 12, rebound : 12, preload: 4mm
After some testing ended up with 9 clicks out on comp, rebound and 10mm of preload which helped reduce brake dive and improved front end feel.
Lower oil level makes a lot of difference in linearity of stroke. I was able to get lower into the stroke without any harshness!
Finally the bike's front and rear suspension are at similar level and the damping feel at the front is now the same at the start of the ride (vs) after 1-2 hours of hard riding unlike the stock which would drop off after hard riding.
The cartridge damping feel is quite linear (similar to stock) unlike the XXZ31 rear shock which is clearly digressive feel with a solid piston TTx style design.
I guess the shim stack is tapered and not preloaded.
A lot of suspension experts seem to prefer the linear feel but I like the initial firmness from a digressive damper.
Showa Damper evolution seems to be going the small piston linear feel route: e.g. Stock GSXR1000 - BPF forks - ~40 mm piston - feels digressive, GSXR1000R - BFF forks - ~25mm solid piston - digressive feel still (but less than the bpf).
Linear damping rate is good for predictability but feels a tiny bit mushy initially during turn-in.
With a digressive rate, you can feel it when you get on the bike and move it with your feet.
The digressive firmness makes it feel like you have less parasitic spring movement energy losses.
I guess the bigger pistons in (~30mm) Bitubo EBH / Ohlins FKR cartridges would give me the firm digressive damping character I was looking for as they move more fluid similar to Showa BPF/BFF forks, but they are too much $$$$
The cartridge upgrade did not completely blow me away like the stock rear shock upgrade to Bitubo XXZ31. Shows you how bad the stock rear shock was.
Overall the upgrade is fantastic for ride quality and consistency of damping. Maybe I would have picked 0.95 kg/mm springs if I were to order again.
I would highly recommend this to anyone that wants a quality (20-22mm class) cartridge kit for sub 600$
Likewise.
Sweet! Thx I did a bunch of cross-referencing of parts in the OEM forks this morning, 2022 internals are the same as 2017- so looks like no problem with compatiblity. Will be an adventure, I've only ever been inside 80's vintage forks...
I did a bunch of cross-referencing of parts in the OEM forks this morning, 2022 internals are the same as 2017- so looks like no problem with compatiblity. Will be an adventure, I've only ever been inside 80's vintage forks...
Cogent Dynamics
33 Meadow Brook Dr.
Fletcher, NC 28732
www.motocd.com
They were the go-to suspension shop on the old Maximum-Suzuki forum- lots of Bandit folks sent shocks down there (me included) for gold valve replacements and so on.
33 Meadow Brook Dr.
Fletcher, NC 28732
Cogent Dynamics | Made in USA Made Motorcycle Suspension | Forks, Shocks, Springs, Accessories
Cogent Dynamics designs & builds custom motorcycle suspension upgrade solutions: Shocks, Springs, Dampers & more. Located in the mountains of Asheville, NC.
www.motocd.com
They were the go-to suspension shop on the old Maximum-Suzuki forum- lots of Bandit folks sent shocks down there (me included) for gold valve replacements and so on.
1 - 20 of 87 Posts
