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Shimano Cassettes & Freehubs

by Sheldon "Kah Sept" Brown

This article is also available in German

This article is also available in Russian

7-speed Cassettes | 8-speed Cassettes | 9-speed Cassettes | 10-speed Cassettes

Advantages | Aluminum Bodies | Body Servicing | Body Transplants | Custom Cassettes | Spacing | Cassette Removal/Installation | HyperDrive-C

HG (Hyperglide) | "Road" vs "Mountain" | I.G. (Interactive Glide) | UG (Uniglide) | Upgrading From 7 to 8 or 9 | Wobbly Cassette?

Cassettes for sale from Harris Cyclery

Freewheels and Freehubs ®

Traditional rear hubs came with a standardized set of threads to which a standard freewheel/sprocket cluster could be screwed on. This allowed any brand of freewheel to be mounted on any brand of hub. If you wore out your sprockets, or wanted different gear ratios, you could unscrew the cluster and install a new one. (See also my Article on Freewheels.)

Over the last few years the Shimano "freehub" has largely replaced the conventional threaded rear hub. It is sad to lose the interchangeability that formerly existed, but these hubs work so well that they have come to represent the new "standard."

If you're not sure whether your bike has a cassete Freehub or a thread-on freewheel, I have a separate illustrated article explaining how to tell them apart.

Traditional Threaded Freewheel		Traditional Threaded Hub	Cassette Freehub		Cassette Cluster

Advantages of freehubs

Due to the location of the bearings in a Shimano freehub, the axle is supported closer to the ends. As a result, bent axles are rarely a problem with these hubs. Not all freehub brands share this feature, which is covered by a Shimano patent.

The freehub incorporates the ratchet mechanism into the hub body (although the ratchet mechanism is still replaceable). When you wear out the sprockets on a freehub, you replace the sprockets only, not the ratchet mechanism (which typically lasts much longer than the sprockets).

The sprockets are commonly sold as a set, called a "cassette". The sprockets in a cassette are usually held together by three small bolts or rivets for ease of installation. These bolts or rivets are by no means necessary, they just make it easier to keep the sprockets and spacers in the correct order and position when they are removed from the ratchet body. Individual sprockets are also available.

Some of the high-end cassettes use a "spider", an intermediate metal casting to hold the 4 or 5 largest sprockets. This saves weight, but sprockets that come mounted on a spider cannot be interchanged except as a complete unit.

Cassette Removal/Installation

Modern Hyperglide-type cassettes (everything made since the late 1980s) us a threaded lockring to hold the sprockets onto the splines of the Freehub body. There is a special splined tool that fits the notched hole in the lockring. Some lockring tools have a long handle, others, as shown below, have a hexagonal fitting like a nut, which can either be turned with a large wrench or may be placed in a vise.

The lockring has a normal right-hand thread, turn clockwise to tighten it. When you want to remove the lockring, you need to turn the lockring counterclockwise, but the cassette will freewheel when you do that, so you need a chain whip to hold the cassette from turning.

You can see the 12 spline notches inside the lockring.	Lockring tool and chain whip in place, ready to unscrew the lockring.

Chain Whips and Lockring Tools From Harris Cyclery

Uniglide ®

The older Shimano cassette sprockets used a "twist-tooth" design, called "Uniglide." They had 9 identical splines (tabs) that would slide into matching grooves on the freehub body. Spacer washers would fit between each pair of sprockets. 5- and 6-speeds used 3.65 mm spacers, 7-speed generally 3.1 mm, 8-speed 3.0 mm.

Sprockets smaller than 14 teeth used a built-in spacer, but the other splined sprockets were reversible, so that if you wore out one side, you could flip them over and the other side was just like new! Sprockets with a built-in spacer were available in 5- 6-speed or 7- 8-speed versions.

The smallest sprocket on a Uniglide cassette was not splined, it was threaded. The threads of this sprocket would hold everything else together.

To remove a Uniglide cassette, you need two chain whips, one to hold the cassette, the other to unscrew the smallest sprocket.

To dismantle a Uniglide cassette, turn the smallest sprocket counterclockwise with a chain whip, while holding the cluster from turning backwards with another chain whip, or with the chain of the bicycle. Dura-Ace freehubs used a different, smaller thread, which worked only with Dura-Ace threaded sprockets. (Formerly, you could get an 11 tooth threaded cog for Dura-Ace, but this has been discontinued.)

Uniglide cassettes are no longer available. If you have a hub that uses Uniglide cassettes, the best thing to do is to upgrade the hub by transplanting a Hyperglide body onto it.

Alternatively, you can fit Hyperglide sprockets onto a Uniglide body by grinding or filing off the one wide spline. This is not particularly difficult. You'll still need a threaded Uniglide sprocket for the top-gear position. Supplies of these are getting scanty.

Uniglide ®	Hyperglide ®
Early Hyperglide hubs had both internal and internal threads, so they would work with either style of cassette.

Hyperglide ®

With conventional derailer systems, the shift is accomplished by moving the chain sideways until it can no longer mesh with the sprocket that it is on. It then disengages, and falls on to the next sprocket that is closest to being in line with it.

In the late '80's, Shimano introduced "Hyperglide" a new sprocket design that allows the chain to engage two adjacent sprockets simultaneously. It meshes with the new sprocket before it disengages from the old one. This results in smoother, quieter, faster shifting.

This is accomplished by shaping individual teeth differently on the same sprocket, and by forming ramps into the sides of the sprockets to facilitate downshifting.

To make this work, the rotational position of each sprocket tooth must be aligned to that of the adjacent sprockets. The older "Uniglide" sprockets could be installed on the body in 9 different orientations (18 if you count the flipped-over position!) Hyperglide sprockets only go on one way. This is ensured by the fact that one of the splines (tabs) in the sprockets is wider than the others. This wide spline fits only into a matching wide groove on the Hyperglide body. There is a "^" stamped into the sprocket to help find this wide spline.

Since the rotational position of the sprocket is critical to making Hyperglide work, threaded sprockets cannot be used. All sprockets in a Hyperglide cassette are splined, and a special lock ring screws into internal threads on the freehub body to hold the set together. This lockring uses the same splined tool as is used to remove Shimano and Sachs conventional freewheels.

People like to complain about Shimano making things obsolete for "no reason" but this is not justified in this case. When Shimano designed Hyperglide, they made the freehub body in such a way that the older Uniglide splined sprockets can be used with no problem on the new bodies. Many, but not all, Hyperglide bodies also have the external threads that let you screw a Uniglide small sprocket on.

In addition, the vast majority of Shimano freehubs can be updated by installing a Hyperglide ratchet body. This is an easy and inexpensive modification (see below.)

It is also possible to put Hyperglide sprockets on an older body if you grind away the wide tab from each sprocket.

To provide the Hyperglide functionality, each sprocket must be designed with regard to the adjacent sprockets. For instance, there are 3 different 15 tooth sprockets for 7-speed systems: one version works between a 13 and a 17; another works between a 14 and a 17; another works between a 14 and a 16.

Hyperglide cassettes are commonly sold as a unit, and are designated by a letter which refers to a particular set. There are dozens of different cassette combinations available. Most 7- and 8-speed cassettes are designated by a one- or two-letter code

"Road" vs "Mountain" Cassettes, Derailers and Hubs

When discussing cassettes, the terms "Road" and "Mountain" are marketing terms, not technical ones.

• "Road vs Mountain Cassettes

  Cassettes come in various gear ranges, and the ones where the sizes are close together, with no really large sprockets are commonly referred to in marketing-speak as "road" cassettes. Wide range cassettes, with larger sprockets are commonly called "mountain" or "MTB" cassettes.

• "Road" vs "Mountain" Derailers

  Similarly, derailers come in long cage and short cage versions. The short cage ("road") ones only work with narrow range ("road") cassettes, because they don't have enough capacity to take up chain slack for use with a wide range cassette. Short cage derailers are also limited in terms of the largest rear sprocket that they can clear without having the jockey pulley rub on the sprocket.

  Long-cage derailers have greater takeup capacity, and work with all types of cassettes. Long-cage derailers are commonly called "mountain" derailers currently, though in the past, this style of derailer was known as a "touring" derailer. (The marketeers retired the use of "touring" as a buzzword in the late '80s when mountain bikes became the hot item.)

  Note, also that rear derailers do not care how many gears you have. You do not need to have a so-called "10-speed" derailer to use a 10-speed cassette. This is true of all Shimano derailers with the exception of 1996 and earlier (pre-9-speed) Dura-Ace units.

• "Road" vs "Mountain" Hubs

  There is no interchangeability issue between "Road" vs "Mountain" cassettes and hubs as long as the number of sprockets matches.

  Also, hubs marked "8-speed, 9-speed or 10-speed will work with any number of sprockets! (Add a 4.5 mm spacer before installing a 7-speed cassette on an 8-, 9-, or 10-speed hub.)

  Any Shimano Hyperglide cassette will fit any Shimano Hyperglide hub with the following exceptions:

  • 7-speed hubs only accept 7-speed cassettes.*
  • 2004-2006, 2007 Dura-Ace 7800 10 speed hubs only accept Dura-Ace 10 speed cassettes.
  • Many older hubs have a problem with 11 tooth sprockets.

  • Capreo hubs and cassettes (special models with 9-tooth sprocket capability) are not interchangeable with anything else.

  Although "Road" and "Mountain" hubs are no different as far as cassette fitting is concerned, they are different in terms of overall spacing. "Road" hubs generally use 130 mm spacing, while "mountain" hubs are 135 mm.

  "Mountain" hubs will likely be slightly better sealed against dirt and mud than "road" hubs, but this is rarely an issue in practice. The wider 135 mm spacing will generally result in a slightly stronger wheel due to reduced dishing of the spokes.

Available Cassettes:

Shimano Standard Combinations

7-speed combinations:

Code	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	32	34
E		12		14		16		18			21			24				28
F				14		16		18			21			24				28			32
G			13		15		17			20			23			26				30
K			13		15		17			20				24					29			34
M			13		15		17		19		21			24				28
H			13		15		17		19		21		23			26
L		12	13	14	15		17		19		21
I			13	14	15		17		19		21		23
J			13	14	15	16	17		19		21
ab	11	12	13	14	15		17		19
ac/aj	11		13		15			18			21			24				28
ad (6-speed)		12		14		16		18			21			24
ai	11	12		14		16		18			21			24
am	11		13		15			18			21			24						30
Megarange	11		13		15			18				22				26						34
Sprockets shown in color are interchangeable with other same-size sprockets shown in the same color.

8-speed combinations:

Code	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	32	34
Megarange	11		13		15		17			20			23			26						34
ak/an	11		13		15		17			20			23			26				30
P		12		14		16		18			21			24				28			32
Q		12	13	14		16		18			21			24				28	Discontinued
R/ah	11	12		14		16		18			21			24				28
S		12	13	14	15	16	17		19		21
T			13	14	15	16	17		19		21		23
U		12	13	14	15		17		19		21		23
V			13	14	15		17		19		21		23			26
W		12	13		15		17		19		21		23		25
Sprockets shown in color are interchangeable with other same-size sprockets shown in the same color.

9-speed combinations: (Click here for custom combinations)

Code	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	32	34
Dura-Ace	11	12	13	14	15	16	17		19		21
Ultegra 6500	11	12	13	14	15	16	17		19		21
Dura-Ace	11	12	13	14	15		17		19		21		23
Ultegra 6500	11	12	13	14	15		17		19		21		23
XT ar	11	12		14		16		18			21			24				28			32
LX ar	11	12		14		16		18			21			24				28			32
XT as	11		13		15		17			20			23			26				30		34
Dura-Ace		12	13	14	15	16	17	18	19		21
Ultegra 6500		12	13	14	15	16	17	18	19		21
Dura-Ace		12	13	14	15	16	17		19		21		23
Ultegra 6500		12	13	14	15	16	17		19		21		23
HG70 (105-5500)		12	13	14	15	16	17		19		21		23
Dura-Ace		12	13	14	15		17		19		21		23		25
Ultegra 6500		12	13	14	15		17		19		21		23		25
HG70 (105-5500)		12	13	14	15		17		19		21		23		25
Dura-Ace		12	13	14	15		17		19		21			24			27
Ultegra 6500		12	13	14	15		17		19		21			24			27
XTR		12		14		16		18		20			23			26				30		34
XT		12		14		16		18		20			23			26				30		34
Ultegra 6500			13	14	15	16	17	18	19		21		23
HG70 (105-5500)			13	14	15	16	17	18	19		21		23
Ultegra 6500			13	14	15	16	17		19		21		23		25
HG70 (105-5500)			13	14	15	16	17		19		21		23		25
Ultegra 6500				14	15	16	17	18	19		21		23		25
Harris Century Special			13	14	15		17		19		21			24			27			30
Harris Cyclotouriste 13			13		15		17		19		21			24			27			30		34
Harris Cyclotouriste 14				14	15		17		19		21			24			27			30		34
Code	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	32	34
Sprockets shown in color are interchangeable with other same-size sprockets shown in the same color. Individual 9-speed sprockets 16 teeth or smaller are interchangeable between series.

In addition, Shimano makes a special Capreo hub and cassette for small-wheel bikes:	9	10	11	13	15	17	20	23	26

Shimano 8- and 9-speed hubs and cassettes (except Capreo ) are fully interchangeable with one another, so any 8-speed hub can be a 9-speed, or vice-versa. If you select a cassette which includes an 11 tooth sprocket, see the section on Hyperglide C

 

The ak, P, Q & R and most 9-speed cassettes use a spider for the larger sprockets.
This saves weight, but requres replacement of those sprockets as a unit.

10-speed Combinations:

Note: Shimano 8- and 9- and 10-speed cassettes/hubs are fully interchangeable for wheels with steel Freehub bodies.
The only parts that are different in any important way between the 8- and 9- and 10-speed systems are the shift control levers.

The 2004 and later Dura-Ace hub has an aluminum Freehub body, so it only works with 10 speed cassettes.

The 2005 and later Ultegra WH-R600 complete wheels also use an aluminum body, 10-speed only. (Standard Ultegra hubs have steel Freehub bodies.)

Dura-Ace 10 cassettes have titanium sprockets from 18 teeth and larger.

Standard Shimano Cassettes
Part Number	Series	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27
FW0711	Dura-Ace 10	11	12	13	14	15	16	17	18	19		21
FW0712	Dura-Ace 10	11	12	13	14	15	16	17		19		21		23
FW0713	Dura-Ace 10		12	13	14	15	16	17	18	19	20	21
FW0714	Dura-Ace 10		12	13	14	15	16	17	18	19		21		23
FW0715	Dura-Ace 10		12	13	14	15	16	17		19		21		23		25
FW0716	Dura-Ace 10		12	13	14	15	16	17		19		21			24			27

Sprocket Spacing

If you wish to use a cassette/hub with the same number of sprocket (or fewer) with a derailer/shifter of a different system, you may need to replace some of the spacers to change the spacing of the cassette. Modern indexing systems are so forgiving, however, that many theoretically incompatible combinations actually work fairly well.

In particular, for reasons that are not quite clear, 9-speed hubs/cassettes seem to work pretty well with the opposite 9-speed derailer/shifter brand.

"HyperDrive-C" cassettes on conventional bodies.

Shimano uses the trademark "HyperDrive-C" to designate a system involving an 11 tooth sprocket. (The "C" stands for "compact". These systems are usually used with smaller than standard chainwheel sizes.)

Due to clearance problems, the cutaway between the splines on 11-tooth sprockets only goes halfway through the sprocket. The matching splines on HyperDrive-C bodies don't go all the way to the outer end of the body.

Hyperglide "C" body       Non-compact body

If you install a cassette with an 11 tooth sprocket on an older, non-compact body, the cassette will not be properly secured, and the sprockets (other than the 11) will be loose and wobbly.

There are two ways around this problem:

• You can use HyperDrive-C cassettes on conventional bodies by adding a 1 mm thick spacer to the body before installing the cassette. This is a standard spacer commonly used for fine tuning chainline with conventional freewheels. It may be necessary to add a spacer to the right side of the axle in some applications, especially if you wish to make the wheel interchange with other wheels without needing to re-adjust the rear derailer.

• Alternately, you can grind a bevel on the ends of the splines of an older body. This is a five minute job if you have access to a bench grinder.

Note, if you install an 11 tooth sprocket on an existing cassette that had a larger top gear, you must also replace the Hyperglide lockring with a Hyperglide-C lockring. The lockrings made to work with 11 tooth sprockets have a smaller outside diameter. If you use a larger lockring, the side plates of the chain will hit the edge of the lockring, and the chain will not run properly on the 11 tooth sprocket. (Hyperglide-C lockrings are compatible with all sprocket sizes.)

Building Custom Cassettes

Shimano wants you to use one of their standard combinations, and they offer a wide enough choice to suit the needs of most cyclists, but you don't have to if you don't want to! It is not difficult to customize Shimano cassettes. If you substitute an un-approved cog, Uniglide or Hyperglide, it will still work, but the shift to/from that cog will probably not be as smooth as a Hyperglide shift normally is. Since people managed without Hyperglide for several decades, this shouldn't scare you off. In particular, if you substitute the top or bottom sprocket, you will only have one shift that isn't HG; shifts to or from the extreme sprockets tend to be less troublesome than intermediate shifts anyway.

For example, Shimano doesn't make any true "corncob" (one-tooth-jump) cassettes for time-trialists or flatland riders. In 7 speed, the closest is the J (13/14/15/16/17/19/21).

If you remove the 21 tooth sprocket from a J, you can make it into a 13-19 corncob by buying an 18 to put between the 17 and the 19. Altenately, you could make it into a 12-18 by removing the 19 and the 21, and buying a 12 and an 18.

Similar modifications can be done with other ratios. Generally, the smallest sprocket needs to be one with a built-in spacer, designed for the top-gear position. While you can't insert or remove a sprocket within a spider module, you can add sprockets on either side of these modules.

For example, if you want a 13-32 9-speed, you can start with a 12-27:

• Replace the 12 and 13 with a top-position 13.

• Add a spacer and a 32 after the 27
  (you don't need to buy the spacer, because you can use the spacer that came between the original flat 13 and the 14.)

Shimano cassettes that don't use spiders have most of the sprockets held together by 3 small bolts, or, in some cases, 3 long rivets. These bolts/rivets are not essential. Their function is convenience, in allowing the cassette to be installed slightly more easily. To make a custom cassette, you will often need to remove the screws or rivets. Just discard them, they are un-necessary in practice.

• Some cassettes use screws have a 4 mm hex head. These can be removed with an adjustable wrench.

• Some cassettes use screws with a 2 mm Allen head. These are frequently mistaken for rivets.

• In the case of cassettes that are actually rivetted together, the easiest way to remove the rivets is to grind off the heads where they protrude from the largest sprocket. I generally do this on a bench grinder.

There is no problem mixing, say, 9-speed or 8-speed sprockets into 7- or 8-speed cassette. The smaller sizes (11, 12, 13) that feature built-in spacers should, ideally be matched, but even this isn't generally a problem in practice.

Custom Cassettes for sale from Harris Cyclery

I.G. (Interactive Glide)

The newer Shimano 7-speed cassettes have carried the Hyperglide principle even farther, by adding ramps and contouring to both sides of the sprockets. To do this while maintaining the full thickness of the teeth, the designers had to make the sprockets thicker. Since the sprockets are thicker, the spacers must be thinner to maintain the correct spacing. Also, since the sprockets are thicker, Shimano says you shouldn't use H.G. chains on I.G. cassettes. Sachs chains are compatible with both types.

Shimano says that you shouldn't mix I.G. and non-I.G. sprockets, but if you use one I.G. spacer per I.G. sprocket, you should be all right. Some experimentation may be required for best results with a mixed setup.

Body Transplantation.

Virtually all Shimano freehub bodies are interchangeable. The exceptions are:

• Very early freehubs (identifiable by the absence of the typical bulge on the right end of the hub barrel) which have non-interchangeable bodies.

• Hubs that use the new "silent clutch" mechanism.

• Pre-1997 Dura-Ace freehubs, which only take pre-1997 Dura-Ace bodies.

To remove the freehub body, first remove the axle. Insert a 10 mm Allen wrench into the fixing bolt in the middle of the body. Unscrew the hollow fixing bolt (conventional right thread, counterclockwise to loosen). The body will lift off, it is secured to the hub shell by the hollow bolt and a set of splines that keep it from rotating.

Dura-Ace bodies require a special spline wrench, Shimano tool #TL-FH10 to remove the body from the hub. See my page on Dura-Ace Interchangeability for more details on this.

The very earliest Uniglide Freehubs, 1970s and very early '80s, used a different system, see below.

Although most bodies are interchangeable at the hub shell, you may have further complications due to incompatibility between your right side cone and the dustcap that comes with a replacement body. The dust caps can usually be pried out and interchanged, or you can buy an appropriate right cone to match your new ratchet body.

A frequent reason for body transplantation is to convert a 6- or 7-speed Freehub to use 8-/9-/10-speed cassettes. This generally will increase the over-locknut dimension. As a result you will usually need to re-dish the wheel after doing this upgrade.

New Axle Not Needed!

Some folks will tell you that you also need to install a longer axle when doing this, but that's not correct. Typical rear QR axles are 11 mm longer than the over-locknut dimension of the hub, so there's 5.5 mm of axle sticking out past the locknuts. That's way more than is actually needed. If you are converting a 126 mm OLD 7-speed Freehub (137 mm axle length) to 8 or more speeds, it goes to 130 mm. That will leave you 3.5 mm of protrusion on each side, once you move the right cone over to even things out. That's plenty.

In fact, no protrusion is truly necessary, but it's a convenience in wheel installation to have some protrusion. I once set up a bike with zero protrusion, where the axle was flush with the locknuts. (This was a fixed-gear with vertical dropouts, and I did it to give me a bit more chain tension adjustability.) I put a lot of hard miles on that bike, it never gave me a lick of trouble.

Non-Shimano Hubs

Generally speaking, off-brand "Shimano type" freehub bodies are not available, if they're even removeable. Many of the off-brand hubs have the body rivetted onto the hub shell.

Some "premium" off-brand hubs use aluminum bodies to save weight. This is a Bad Idea because the standard Shimano spline pattern is not designed for this material. The steel sprockets are liable to cut notches into the edges of the splines, which can make it very difficult if not impossible to remove the cassette from the damaged body.

Shown here is an aluminum body that has suffered this sort of damage. Someone has filed down the burrs to make it re-usable after a fashion.

For the 2004 model year, Shimano started using aluminum bodies for the Dura-Ace 10-speed model. To avoid this problem, Shimano changed the spline pattern, making the aluminum spline ridges significantly taller for better support. The downside of this is that those hubs will accept only 10-speed cassettes.

See my Dura-Ace Article for details on this.

Upgrading From 6-/7-speed (126 mm) to 8-/9-speed (130 mm)

Most Shimano 6- or 7-speed cassette Freehubs can be upgraded to 8-/9-speed by replacing the Freehub body, as described above.

6- and 7-speed hubs generally use 126 mm spacing, while 8-/9-speed hubs use 130 mm (road) or 135 mm (MTB/Hybrid).

Many people will tell you that this requires a new axle, but if you're only going from 126 to 130, this is not true. The 137 mm long axles commonly supplied with 126 mm hubs are plenty long enough for use with 130 mm spacing. There is absolutely no risk to this.

If you do re-space your hub, you'll also need to re-dish your wheel, because the extra space will all be added on the right side by installing the wider Freehub body. You'll need to tighten spokes on the right, possibly also loosen some on the left, to move the rim 2 mm to the right so that it will once again be centered in the frame.

In going to a wider hub spacing, you'll also need to deal with the frame spacing, but this is not as difficult as you might suppose. For details on this, see my article on Frame Spacing.

Freehub Bodies for sale from Harris Cyclery

 

8 Of 9 On 7

If your 126 mm frame is carbon fiber or held together by glue, you probably shouldn't try to spread it. That still doesn't mean that you're stuck with 7-speeds!

Any 7-speed Shimano Hyperglide Freehub will actually work with 8 sprockets, without any modification! What you need to do is to use 8 of the sprockets from a 9-speed cassette, with the 9-speed spacers.

To make this work, you'll also need to use a 9-speed chain and shifters. Your old 7-speed derailer should work OK if it isn't too badly worn. The limit stops on the derailer will cause the useless 9th position on the shifters to be locked out, so this will work as a perfectly normal 8-speed rig.

Shimano Freehub ® Body Servicing

Generally, Freehub ® bodies are not repaired when they fail, because the labor cost of servicing them is often greater than the cost of buying a brand-new body. If you really want to take one apart and overhaul it, they may be serviced in the same way as conventional freewheels. You'll need a fairly hard-to-find old-style Shimano special tool (TL-FH 40) to unscrew the cup, which is also the cone for the main bearings.

Special Purpose "Uniglide" Cassettes

Shimano lists 11 old-style "Uniglide" cassettes in their 1997 catalog. These are mostly oddball combinations, (too rare to be worth tooling up for a Hyperglide version) and you will not find them at your Local Bicycle Shop. Although these are listed in the catalogue, they don't seem to be obtainable in practice.

8-speed:

14	15	16	17	18	19	20	21	22	23	24
14	15	16	17	18	19	20	21
14	15	16	17	18	19		21		23
	15	16	17	18	19	20	21		23
		16	17	18	19	20	21	22	23
		16	17	18	19	20	21	22		24

7-speed:

14	15	16	17	18	19	20	21	22	23	24
14	15	16	17	18	19		21
14	15	16	17		19		21		23
	15	16	17	18	19		21		23
		16	17	18	19	20	21	22
		16	17	18	19	20	21		23
				18	19	20	21	22	23	24

Early Uniglide: 1970s-early '80s

Shimano Freehubs dating from the mid 1980s onward have replaceble bodies, held onto the hub shell by screw threadsand, usually splines. This is explained above in the transplant section of this article.

The earliest Shimano Freehubs, however, used a more primitive construction. There was a set of splines to keep the body from rotating on the hub shell, but instead of a hollow bolt to secure the body to the shell, there was a smooth cylindrical projection past the splines, and the corresponding Freehub body was a slip fit over this projection. The axle held the assembly from falling off, but it was not a fully satisfactory design. See the photos below, kindly provided by David Landsberg.

Note that replacement bodies are not available for these early hubs. These hubs date from the late 1970s and very early 1980s. They can be identified by the narrow barrel, without the chracteristic bulge on the right end. (The bulge is to accommodate the threading for the hollow bolt used on newer Shimano Freehubs.)

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