Reports of the demise of this Web site are greatly exaggerated! We at thank Harris Cyclery for its support over the years. Harris Cyclery has closed, but we keep going. Keep visiting the site for new and updated articles, and news about possible new affilations.

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Sheldon Brown's Shimano Page
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This page is at an early "under-construction" stage,
but I am putting it up early because other pages link to it.

See also Shimano's Corporate Page.

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Model Names:

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Shimano is the leading manufacturer of bicycle parts. Shimano has come to dominate the industry, and to have a near monopoly on many parts categories. This gets them a lot of bad press, because they are perceived as the Goliath of the industry.

They achieved this position because they have the most successful research and development program in the industry. They pioneered many key technologies:

Unfortunately, their pursuit of high performance has been somewhat at the expense of versatility. For example, to reap the benefits of Hyperglide or Superglide, you need to use one of the specific combinations of sprocket sizes designed to work together. While Shimano offers a pretty good selection, they don't have the perfect combination for every rider.

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SPD Pedal/Cleat Interchangeability
M858 M747 M636 M545 M535 M515 M434 M737 M525 A525 M323 7410 6500 SPD-R
SM-SH70 (No Float ) ok ok ok ok ok ok no no no no yes yes no
SM-SH71 (With Float) ok ok ok ok ok ok no no ok ok yes yes no
SM-SH50, 51 "Single-release" no yes yes yes yes yes yes yes yes yes yes no no no
SM-SH52 "Single-release yes yes yes yes yes yes yes yes yes yes yes no no no
SM-SH55 "Multi-release yes yes yes yes yes yes yes yes yes yes yes no no no
SM-SH56 "Multi-release For PD-M959, PD-M540 & PD-M520 pedals.
SM-SH90 SPD-R (No Float ) no no no no no no no no no no no no no yes
SM-SH91 SPD-R (With Float ) no no no no no no no no no no no no no yes
Table courtesy Eric Salathé

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Shimano Groups

Shimano markets most of their parts as "groups". A group would usually consist of at least a set of hubs, derailers and controls, a crankset and brakeset, all with the same group model name. High end groups often include additional parts, including: headsets, seatposts, pedals, chains, cassettes.

Shimano has many trademarks for different quality levels and technological features/gimmicks.******

1997 Shimano Road Group Hierarchy

  1. Dura Ace
  2. Ultegra
  3. 105SC
  4. RX-100 -- Reported to be the same as the 105 group except for finish.
  5. RSX -- A lower-priced but well-constructed group with drop-bar brake/shift lever: 7-speed rear indexing, and front indexing for triple chainwheels. The front shifter also works with Sachs 3 x 7 internal-gear hubs.

1997 Shimano Mountain Group Hierarchy

  1. XTR
    Ti, Differential Plate Mechanism, hollow cranks
  2. Deore XT
    Parallelogram V-Brakes
  3. Deore LX
  4. STX-RC
  5. STX
  6. Alivio
  7. Acera-X
  8. Altus
  9. Tourney

Other 1997 Groups

Older Group Names

Correspondences between older groups and current groups are only approximate. These data are incomplete. Shimano has gone through many revisions of their groups while maintaining the same name, so comparisions between older versions and newer versions are quite inexact.
105 6-speed version, became 105SC when 7-speed and dual-pivot brakes were added.
200GS Replaced by Altus
300GS Replaced by Acera-X
400GS Replaced by Alivio
500GS Replaced by STX
600 Became 600EX when indexing was introduced, 600 Ultegra (Gray finish) when 7-speed added. When it became an 8-speed group, the 600 designation still existed, but it was usually referred to as just "Ultegra". With the '98 model year, 9-speeds came in and the "600" designation was completely dropped from Ultegra.
Deore Originally an early '80's touring group, designed so that almost all adjustments could be made with a single 6 mm Allen wrench. Evolved into Deore XT MTB group, DX and LX spun off later.
Deore DX Discontinued designation, replaced by LX
Exage ("EXcellence" + "New AGE") This was divided into Exage Country and Exage Trail at one time. The first group to feature front indexing, roughly comparable to Acera-X/Alivio.
Ultegra ("ULTimate" + "IntEGRity") is the second highest level "road" group. The Ultegra name was added as a suffix to 600 when 7-speeds (and the gray paint finish) came in in the early '90s. For the 1998 model year, Ultegra became a 9-speed group, and the 600 designation was retired.

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Shimano Buzzwords and Trademarks

333 ®
An older model, rather unsatisfactory 3-speed hub.


Alfine ®
Pronounced "alfeenay" as in Italian -- Shimano's name for its high-end series of internal-gear hubs and related parts. There are 8-speed and an 11-speed hubs and a front dynamo hub. The 8-speed hub is very similar to the Nexus 8-speed, except that Alfine hubs have a Center Lock fitting for a drum-brake rotor, rather than Rollerbrake splines or a coaster brake.

See also the Nexus and Alfine page.

Biopace ®
A type of non-round chainwheel introduced by Shimano in the 1980's. It is designed to provide a more natural motion of the foot, better off-road traction, and to reduce stress on the knee.

See my article on Biopace for more details.

Center Lock ®
Shimano's proprietary splined attachment for a disc-brake rotor.
Crane ®
Top-of-the-line touring derailer of the 1970's.
Di2 ®
Shimano's trademarked name for electrical shifting.
Dura-Ace ®
The jewel in Shimano's crown, the flagship road racing group.

There are interchangeability issues with older Dura-Ace parts, and I have an article on Dura-Ace interchangeability. See also the 1973 Shimano Dura-Ace Catalogue on this site.

Dyna Drive ®
In the early '80's, Shimano introduced a special crank/pedal set, which used much larger diameter threading where the pedal screwed into the crank. This allowed them to build the bearing into the inside of the pedal thread, eliminating the need for a pedal axle. The purpose of this was to improve the biomechanics of the pedal by placing the bottom of the foot below the pedal axis.

This was rather a good idea biomechanically, but never caught on. In practice, the pedal bearings turned out to be underengineered for the loadings they had to deal with.

See the 1982 Shimano Catalogue on this site.

Dyna-Sys ®
A MTB derailer, cassette and shifter combination introduced in the 2011 model year. Cable travel is longer than with other Shimano systems. The 10-speed cassette has the same spacing as other Shimano 10-speed cassettes but may have a 36T large cog. Double chainwheels are used instead of triple.
Eagle ®
A beefed up version of the Lark , including an extra thick mounting claw and a built in bumper to protect the derailer from impact. Probably the strongest derailer ever made before the 21st century models such as Saint and Hone
Exage ®
"EXcelence + "new AGE"
EZ-Fire ®
EZ-Fire Plus ®
Front-Freewheel System (FFS ®)
Front Freewheel System. The freewheel was built into the bottom bracket, so that the chain would turn even when the rider was coasting. This was to allow shifting while coasting--a solution in search of a problem.

See the 1982 Shimano Catalogue on this site.

Freehub ®
A rear hub in which the freewheel mechanism is built into the hub itself, rather than being part of the sprocket cluster. Most freehubs use a cassette of sprockets.

Shimano's patented design places the right cone much closer to the end of the axle than does a conventional hub, greatly reducing the chance of bending or breaking axles. For more detail see my article on Shimano Cassettes. k7hub

A derailer with a mid-length cage, generally usable with cogs up to 32T but only an intermediate chain-wrap capacity; cannot accommodate wide-range chainwheels on all cogs..
Heavy-duty "downhill " component set
HG (Hyperglide ®)
Hyperglide ®
Hyperdrive-C ®
Shimano's name for Compact Drive. See the Shimano Cassette Freehub page for details.
IG ®
Interactive Glide. See the Shimano Cassette Freehub page for details.
Lark® -preselector
Light Action ®
Low Flex ® Cantilever
Nexave ®
A line of equipment intended for derailer-equipped "comfort bikes" including cassettes, hubs, cranksets and dynamo front hubs.
Nexus ®
Shimano's line of components intended for urban and utility cycling, including internal-gear hubs, Rollerbrakes and dynamo front hubs.

See also the Nexus and Alfine page.

Octalink ®
See Octalink Glossary Entry
Parallax ®
This term refers to hub shells with a larger diameter barrel, generally marketed as "mountain bike" parts. Primarily a cosmetic issue.
Positron ®
This was Shimano's first attempt at indexed shifting. The indexing "clicks" were built into the derailer, not the lever. The positron system didn't have a return spring; some models used a double cable to pull the derailer back and forth; other models used a single, semi-rigid push-pull cable.

Positron was a valuable learning experience for Shimano. Their original theory was that experienced cyclists already knew how to shift, but that beginners could benefit from a system that didn't require fine-tuning of the shift lever position. For this reason, Positron was offered on entry-level bikes, often department-store models. This marketing theory turned out to be unworkable. The parts had to be made very cheaply to meet the price points required. This caused less-than-impressive performance. In addition, the fact that Positron was only supplied on bottom-end bikes caused it to acquire a poor connontation, as something to be outgrown, and not to be considered by a "serious cyclists."

Shimano went back to the drawing board, and the next time they tried indexed shifting, in 1984, they started at the top of the line, with Dura-Ace S.I.S. Cyclists were initially dubious about this feature, but it worked so well that most resistance was overcome. Once the pros started using it, this now-glamorous feature rapidly trickled down to the hoi polloi. The result was Shimano's complete domination of the bicycle parts market, much as Microsoft dominates the computer software market. By 1986 it had become almost impossible to sell a bike that didn't have indexed shifting.

See the 1982 Shimano Catalogue on this site.

Many Positron-equipped bikes also featured the Front Freewheel System, but this was not a specific linkage...either of these systems could and did function without the other.

Power Modulator ®
As bicycle brakes have improved in recent years, there has arisen the perception that some front brakes are "too good" as if such a thing was possible.

As a result, some manufacturers have taken to adding devices that deliberately sabotage the functionality of the front brake, out of fear that an unskilled rider will take a header as a result of improper use of the front brake.

These sabotage devices are commonly called "power modulators" and sometimes are marketed as if they were a version of ABS braking as used on newer cars.

This is a very foolish approach, probably driven by the common superstition that the use of the front brake is inherently dangerous. The result is increased stopping distance. This is a "safety" feature that is actually more likely to be a detriment to safety.

See also my article on Braking and Turning

RF ®
RapidFire ® Shimano's first "below the bar" shifting system, early '90s. It used two buttons operated by the rider's thumb, one for upshifting, one for downshifting. This caused confusion since the ushifting and downshifting motion was done with the same digit, in the same direction.
RF+ ®
RapidFire Plus ® Successor to RapidFire, used a thumb button to select a larger sprocket/chainring, and an index-finger "trigger" to select a smaller one. This solved the ergonomic problems of the original RapidFire, and remains Shimano's flagship shifting system for upright handlebars.
RapidRise ®
This is Shimano's trademark for "low-normal" rear derailers.
A Shimano drum brake with three cam-operated shoes, and a proprietary splined connection to Nexus hubs and some Nexave hubs.

Also see the Rollerbrake page.

Heavy-duty "downhill " component set
Selecta ®
Selecta was an early Shimano ® attempt at a splined crank/bottom bracket system, dating from the late '70s or early '80s.

The spline pattern was chosen to premit the spindle to fit through a Front-Freewheel bearing set, which wouldn't permit a standard sized square tapered BB spindle to fit throgh the front freewheel bearing assembly.

These turned out to be rather unreliable, due to the small diameter of the splines, and Shimano abandoned the system. The did continue to supply spare parts for many years thereafter, but these are no longer available.

Servo Wave ®
Brake lever with variable mechanical advantage. Low MA at the beginning of the stroke brings the shoes to the rim quickly, higher MA later in the stroke provides more braking power.
A long-cage rear derailer.
Silent clutch ®
A roller clutch, used in some Freehubs and high-end internal-gear hubs.
Shimano Indexing System ® Shimano's brand of indexed shifting.
Shimano Linear Response ® A constellation of brake improvements primarily aimed at reducing friction. Includes the use of lined cable housing and lightly sprung calipers/cantilevers, accompanied by levers that also contain a return spring (a Dia Compe invention.) SLR was introduced with the 105 group in the late '80s.
Shimano Pedaling Dynamics. First commercially successful clipless shoe/pedal system with a recessed cleat for walkability. (Cyclebinding was an earlier walkable system that never caught on.)
Super Plate ®
Ultra-wide range non-indexing derailer, notoriously fragile. Similar to the Hurét Duopar. Early-mid '80's
System Total Integration ® Originally referred to any combined brake/shift lever assembly, but in current usage, this term generally refers only to drop-handlebar brifters.
Super SLR ®
Titlist ®
Inexpensive steel front derailer of the '70's
Ultegra ®
"ULtimate inTEGRity"
Uniglide ®
Older Shimano freewheel and cassette sprocket design, using twisted teeth for improved shifting. Uniglide cassettes used a single threaded sprocket as a lockring to hold the larger sprockets to the Freehub body. Uniglide was superceded by Hyperglide in the late 1980s.
V-Brake ®
Year Month
A 1976 2002 A January
B 1977 2003 B February
C 1978 2004 C March
D 1979 2005 D April
E 1980 E May
F 1981 F June
G 1982 G July
H 1983 H August
I 1984 I September
J 1985 J October
K 1986 K November
L 1987 L December
M 1988
N 1989
O 1990
P 1991
Q 1992
R 1993
S 1994
T 1995
U 1996
V 1997
W 1998
X 1999
Y 2000
Z 2001

See also the 1982 Shimano Catalogue on this site.

See also the 1973 Shimano Dura-Ace Catalogue on this site.

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Articles by Sheldon Brown and Others

Reports of the demise of this Web site are greatly exaggerated! We at thank Harris Cyclery for its support over the years. Harris Cyclery has closed, but we keep going. Keep visiting the site for new and updated articles, and news about possible new affilations.

Copyright © 1996, 2008 Sheldon Brown

Harris Cyclery Home Page

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Last Updated: by Harriet Fell