Side project
Making small parts for a 100km daily commute, then becoming known for the GT-Roller.
GROWTAC | Rubi Workshop
01
GrowtacGROWTAC INC. · TOKYO, JAPAN · SINCE 2009
Couldn't the bicycle
be
a little less restricted?
GROWTAC is a small bicycle parts company in Shinagawa, Tokyo. Its CEO, Masayuki Kimura, was an engineer designing production equipment and special-purpose robots at a major manufacturer, and a racer who rode track at national level as a student and finished the Tour of Japan with a club team.
In 2009, riding 100km to work and back every day, he began making the small parts he needed himself. When his GT-Roller, a roller that moves much like real riding, was well received, he left his job and incorporated the company in 2014. Planning, development, manufacturing and sales are still handled by a small team.
TokyoFounded 2009, Shinagawa, Tokyo
EQUALGROWTAC's bicycle parts line
136gAmong the lightest mechanical calipers in the world
Made in JapanDesigned and made in Japan
FREEDOMMix & match
Parts should be chosen by the rider's taste. EQUAL is a line made so you never have to give up a part you love because of brands, speeds or standards.
NO GRADESOne flagship per use
No top, middle or entry grades. Products are divided by purpose, such as racing or touring and gravel, and each is the flagship for its use.
PERFORMANCENo compromise
Changing the idea that mechanical means a heavy pull and weak braking. Freedom of choice, with no compromise on performance, is the EQUAL principle.
WHY EQUAL
Every time a gear is added or a standard changes, perfectly good parts have to be replaced wholesale. EQUAL began with that frustration.
In the days of downtube shifters, parts could be mixed freely. Today, compatibility rules set by manufacturers narrow the choices. GROWTAC calls changing this the democratization of the bicycle, aiming to give the choice back to riders and shops rather than manufacturers.
That does not mean opposing new technology. Aero, hydraulic discs and internal cables are good choices for those who need them. The point is to keep another clear path open, so riders who don't need them aren't forced to pay for them.
GROWTAC Inc.
He leaves his job and incorporates GROWTAC, a small maker that handles everything from planning to sales itself.
The first EQUAL
The first EQUAL product was the EQUAL Pulley, which let Campagnolo levers run Shimano drivetrains.
Brake & lever
The second product, a mechanical disc brake, is followed by pedals, wheels and the Control Lever.
GROWTAC
Equal
Equal
for every
rider.
THE RANGE IN KOREA
Pick your EqualThe GROWTAC EQUAL range officially imported to Korea by Rubi Company.
01 · BRAKE
Equal Brake
A mechanical disc brake pairing a super duralumin caliper with dedicated cables and pads. Flat and post mount.
- Caliper
- 136g
- Colors
- 7 colors
Kashima Coat
An EQUAL brake with Kashima Coat on the caliper body and piston. A piston that slides without grease.
- Finish
- Kashima
- Includes
- Full set
Control Lever
A drop bar lever whose stepless shifting works with any speed or brand. Road and MTB derailleurs alike.
- Shifting
- 2–13s
- Weight
- 205g
Shiftless
A brake-only lever with the shift mechanism removed. For 1x, single speed and bar-end shifter builds.
- Weight
- 130g
- Standard
- Short pull
02
Equal
BrakeEQUAL Brake · MECHANICAL DISC BRAKE
Rewriting the old belief
that mechanical brakes
are weak.
The EQUAL mechanical disc brake is designed as a whole system, not just a caliper. A dedicated hard outer housing that resists deformation carries the lever's force, a low-friction coated stainless inner cable keeps the pull light, and pads made with Vesrah turn that force into stopping power. That is why it is compared with hydraulic discs.
No oil, no bleed kit, no hose cutting. If something goes wrong on a trip, a cable is all you need to fix it, and the calipers are designed to be taken apart for service. A brake to trust under hard braking in road racing and cyclocross, and on long rides and bike travel.
136g caliper
High-strength super duralumin is precision machined for nearly every part. 136g including pads, and even with cables the system weight is on par with top hydraulic brakes.
Total system
Dedicated hard outer housing, low-friction inner cable and Vesrah EVO RESIN pads: everything braking needs comes in one set.
Brake feel adjustment
Change the leverage to match braking character to your weight and taste. Set it up for control, or for stronger initial bite.
Cable routing
The cable path into the caliper is refined to cut friction. A lighter lever, easier installation and a cleaner look.
GALLERY
DRAG →Equal on the roadRace · gravel · touring · workshop
HOW IT WORKS
Inside the systemThree things behind EQUAL's stopping power
Housing that doesn't compress
Ordinary housing compresses the harder you squeeze, and force is lost. EQUAL's hard housing reduces that deformation and carries the lever's force to the caliper. When installing, it is best to replace the old housing and run the full line with the included housing.
Pads made with Vesrah
A resin-based ceramic semi-metallic compound (EVO RESIN) on aluminum backplates, for high braking power and durability. Shimano road-type pads also fit when it is time to replace them.
Leverage tuned to your weight
Change the leverage at the actuator arm to tune braking character. We recommend starting on the softer setting and increasing it to suit you. An indicator on the arm shows when the cable tension needs resetting.
Flat
or Post?
or Post?
Flat mount is common on road and gravel frames; post mount on MTB, touring and earlier disc frames. EQUAL makes both with the same performance. The adapter you need depends on your frame and fork mounts and rotor size (140 / 160mm). If you are unsure, send us your bike details before ordering and Rubi Workshop will check.
COLORS
Seven colorsGray · Red · Blue · Gold · Black · Silver · Clear Purple, plus Kashima Coat
Flat mount shown. Post mount comes in the same colors.
Equal BrakeSPECIFICATION
A set with front and rear calipers (pads included) and two dedicated cable sets. For short-pull levers only; not compatible with long-pull V-brake levers.
View EQUAL Brake →| FLAT MOUNTFlat mount | POST MOUNTPost mount | |
|---|---|---|
| Caliper weight | 136g | 137g |
| Type | Mechanical · single piston | Mechanical · single piston |
| Material | Super duralumin, CNC | Super duralumin, CNC |
| Lever | Short pull (road · cantilever) | Short pull (road · cantilever) |
| Rotor | 140 / 160mm | 140 / 160mm |
| Pad | Vesrah EVO RESIN | Vesrah EVO RESIN |
| Colors | 7 colors | 7 colors |
| Cable | Dedicated hard housing · inner | Dedicated hard housing · inner |
| Hardware | Front adapter · rear bolts | 2 mounting bolts |
Units mm, g. Weight per caliper, pads included. Colors: gray, red, blue, gold, black, silver, clear purple. Figures from the official GROWTAC site and may vary by production run.
03
Kashima
CoatKASHIMA COAT · EQUAL BRAKE SPECIAL FINISH
Instead of color,
dressed in hardness
it is EQUAL.
Kashima Coat is a surface treatment that combines hard anodizing with molybdenum disulfide, a solid lubricant. Hard and low in friction, it has long been used on MTB suspension parts that slide and take repeated contact. The EQUAL Kashima Coat version applies it not only to the caliper body but also to the piston and the parts around the pads.
Its high surface hardness resists the scratches and marks of riding and maintenance, keeping the caliper looking new for longer. Less wear on sliding surfaces also keeps the braking feel consistent over time. A specification that puts performance and durability ahead of colored anodizing.
GREASELESS PISTON
A piston that slides
A piston that slides
without grease
Kashima Coat on the sliding surfaces of the piston assembly lets it move smoothly without grease. With less risk of grease or oil reaching the pads and rotor, braking power is protected from contamination.
Available in flat and post mount, only as a full set with front and rear calipers and cable sets.
KASHIMA COAT
Kashima CoatSPECIFICATION
Weight and mounting are the same as the color versions; the surface treatment and piston design differ.
View Kashima Coat →| FLAT MOUNTFlat mount | POST MOUNTPost mount | |
|---|---|---|
| Caliper weight | 136g | 137g |
| Finish | Kashima Coat | Kashima Coat |
| Piston | Greaseless | Greaseless |
| Lever | Short pull (road · cantilever) | Short pull (road · cantilever) |
| Rotor | 140 / 160mm | 140 / 160mm |
| Pad | Vesrah EVO RESIN | Vesrah EVO RESIN |
| Includes | Full set (F · R) | Full set (F · R) |
Units mm, g. Weight per caliper, pads included.
04
Control
LeverEQUAL Control Lever · STEPLESS SHIFTING
Any drivetrain,
if a cable can pull it,
it moves.
The EQUAL Control Lever is a drop bar brake and shift lever that began with a question: couldn't bicycles be less restricted? Its stepless (friction) action moves the cable exactly as far as you push the lever, with no clicks, so it runs any mechanical derailleur from 2 to 13 speed, free from brands, groupsets and speed counts.
Pair a 9-speed derailleur with an 11-speed cassette, run a wide-range MTB cassette on drop bars, or bring treasured vintage parts back into service. Instead of the shifter dictating the drivetrain, you choose the parts you love first and fit the lever to them.
Stepless shifting
A feel unique to GROWTAC, like working a marionette, with no clicks. The more you use it, the more at one with the bike you become.
Road and MTB derailleurs
Swap cable pulleys from 17mm to 24mm to match the pull ratio. Road derailleurs, MTB derailleurs and internal gear hubs alike.
Modular design
Up to three shift levers and two cables per side. Remove the sub-levers you don't need and keep only what you use.
Click Plate
If stepless feels unfamiliar, the optional Click Plate adds a familiar click, while keeping the freedom to combine.
THE LEVERS
DRAG →Standard & Shiftless
Mix
L / R
L / R
Standard and Shiftless can be combined freely left and right. For a 1x build, Standard on the right and Shiftless on the left. For a classic build that leaves shifting to bar-end shifters, Shiftless on both sides. The slim ergonomic hoods are easy to grip even for small hands, and reach adjustment fits the lever to your hand.
GALLERY
DRAG →On the barHoods · drops · sub-levers · builds
Control LeverSPECIFICATION
Drop bars only; not for flat bars. For mechanical (cable) drivetrains only, not compatible with electronic groups. Brake and shift cables sold separately.
View Control Lever →| STANDARDShifter | SHIFTLESSBrake lever | |
|---|---|---|
| Weight | L 210g · R 205g | L · R 130g |
| Shifting | Stepless (friction), 2–13s | - |
| Drivetrain | Road · MTB · internal gear hub | - |
| Cable pulley | 17–24mm included | - |
| Brake | Short pull | Short pull |
| Handlebar | Drop bar | Drop bar |
| Reach adjust | Yes | Yes |
| Option | Click Plate | - |
Units mm, g. Weights are reference weights per lever. Versions for dropper seatposts and SRAM Blips wireless shifting also exist; ask Rubi Workshop if you need one.
05
ShowroomORDER · INSTALL · SERVICE
Build it
with Equal.
The adapters and cable lengths EQUAL brakes need depend on your frame and fork mounts, rotor size and levers. At Rubi Workshop we work out the setup for your bike and install it with a fresh cable run in the dedicated housing.
We also handle servicing such as leverage setup, pad replacement and cable tension checks. For a custom build around the Control Lever, tell us the parts combination you have in mind first.
- ADDRESS
- Rubi Building, 320 Sinbanpo-ro, Seocho-gu, Seoul
Rubi Workshop - HOURS
- Mon–Fri 12:00–18:00
- CALL
- 1551-5320
- help@rubi.kr
FOR DEALERSEqual in
your shop
Rubi Company is the official importer of GROWTAC in Korea. Bike shops interested in stocking EQUAL brakes and Control Levers, please contact Rubi Supply.
GROWTAC at Rubi Supply →DEALER INQUIRIES · +82-2-516-8465