28 votes

Why do freehub and cassette have only one position that matches?

Early cassettes (Suntour Accushift and Shimano Uniglide being some commonly encountered examples) weren't like this. The splines were all the same and there was no hunting for the little spline or big ...
Nathan Knutson's user avatar
20 votes
Accepted

Freehub pawl system vs star ratchet system

Hope hubs are a very refined, reliable execution of the pawl design. They don't do much to illustrate the disadvantages of the concept that designs like the star ratchet are trying to address. One ...
Nathan Knutson's user avatar
17 votes

What freewheel mechanism designs are used in bicycles?

Standard Pawl and Ratchet Design This design is by far the most common on bicycle freehubs, and as such the least expensive to employ. Mechanism In it's simplest form, this design consists of a ...
Paul's user avatar
  • 1,981
13 votes
Accepted

What's the difference between Shimano HG and SRAM XD free hubs?

The phrase missing here is 'Freehub body'. The freehub replaced the freewheel, mostly, which integrated the sprockets and the ratcheting mechanism. The freehub body is therefore the ratcheting ...
thelawnet's user avatar
  • 4,230
12 votes

What freewheel mechanism designs are used in bicycles?

American Classic Cam Plate Design The full name is "Six Pawl Cam Actuated Engagement System." This design is one of the more complicated ones, but according to American Classic provides a ...
Paul's user avatar
  • 1,981
11 votes

What freewheel mechanism designs are used in bicycles?

Star Ratchet and variations This design in it's simplest form is used by DT Swiss. This design incorporates easily replaceable ratchet plates that offer the added benefit of every engagement point ...
Paul's user avatar
  • 1,981
10 votes

What's the difference between Shimano HG and SRAM XD free hubs?

SRAM's XD and XDR drivers (their term) don't have splines, unlike Shimano and Campagnolo freehub bodies. Instead, their cassettes screw onto the threaded section of the driver as shown in the image ...
Weiwen Ng's user avatar
  • 31.4k
10 votes
Accepted

Swapping Ultegra cassette 11-34 for 11-28: spacers?

There are two kinds of common 11-speed Shimano hyperglide cassettes. The first type of cassettes, "MTB", has a big sprocket that is large. The big sprocket is shaped so that it overhangs the ...
juhist's user avatar
  • 18.7k
10 votes

Which Shimano Freehubs can I use on the WH-R550 wheel?

Shimano provides good official guidance about what the right part is and no guidance about what can be substituted. From the publically available exploded view diagram we know the matching part is Y-...
Nathan Knutson's user avatar
9 votes

What freewheel mechanism designs are used in bicycles?

Sprag Clutch The sprag clutch has existed in industrial applications for some time: being used in motorcycles, helicopters, airplanes, automotive transmissions, and others. As far as I know, Onyx is ...
Paul's user avatar
  • 1,981
9 votes
Accepted

Is there a difference of spacing between cogs on a 7 speed cassette vs a 8 speed cassette?

Yes, there is. Shimano/SRAM & compatible seven speed is 5mm cog-to-cog, and eight is 4.8mm. Generally what you're trying to do here can't be made to work very well. There are some tricks that ...
Nathan Knutson's user avatar
9 votes

Is there a roadside workaround for a freehub that won't engage reliably?

Use strong cable ties or wire/cable to tie the biggest sprocket to the rear wheel spokes. This will eliminate the freewheel, so be very careful when slowing down or going downhill. If cable ties are ...
Michael's user avatar
  • 27.4k
9 votes

Can I put a different manufacturer’s freehub body on my hub?

There are two parts to this question. Generally, you cannot swap freehub bodies between manufacturers. There are some exceptions to this (some hub manufacturers use DT Swiss hub mechanisms, so there ...
Adam Rice's user avatar
  • 30k
9 votes
Accepted

Does a z-shaped cone wrench exist?

No, its not not needed. Remove the cone from the non-drive side, and the axle slides out the drive side. Assembly means setting the position of the drive side cone and locking it with the lock nut, ...
mattnz's user avatar
  • 50.5k
8 votes

Servicing a Vuelta XRP Disc Hub

I don't have specific experience with this one, but the pictures suggest it works one of two ways: From where you're at now, you bonk the end of the axle on the non-drive sufficiently hard and the ...
Nathan Knutson's user avatar
8 votes

(Apparent) chain slippage causes on new bike - usual culprits already eliminated

If everything is shifting smoothly and the hanger is aligned, it's very likely the freehub body slipping intermittently, which feels much like the chain slipping. Usually it takes a visual to be sure ...
Nathan Knutson's user avatar
8 votes
Accepted

12 speed cassette touching spokes

Sounds like the easy solution is going to be get an extra long lockring. Wheels Mfg and another company I can't remember both used to offer them. I believe current Chris King ones are longer than ...
Nathan Knutson's user avatar
8 votes
Accepted

Cassette with more gears on same wheel?

Since current >7 speed cassettes have so fine spacing between the gears, about the only reason why you'd want to install a cassette with more gears is wanting to get more range. A 9-speed freehub ...
juhist's user avatar
  • 18.7k
8 votes
Accepted

How to achieve a 200 Nm tightening torque when installing a freewheel body?

Shimano's torque ratings are best interpreted as a "ballpark" in the extreme high and low ranges. It's only the 2-20Nm range or so where you should respect the precise numerical value. If ...
MaplePanda's user avatar
  • 15.5k
8 votes

How to achieve a 200 Nm tightening torque when installing a freewheel body?

You could measure your lever length and put known weights on the end. Clamp the tool to a vise in a way that the wheel is upright. If your wheel has a 311mm radius you now need to put a 50kg to 65kg ...
Michael's user avatar
  • 27.4k
7 votes
Accepted

What tool do I need to remove this Joytech freehub?

I believe this one is a 12mm allen inserted through the non-drive side. 11mm is out there too. Usually what I do is clamp an L-type one in a vise, long end up. A long socket would also work but it ...
Nathan Knutson's user avatar
7 votes

Could I replace a hub on a wheel?

Simple answer: yes, but it’s not worth doing. Cost of hub, spokes, nipples and having wheel rebuilt will exceed the cost of a new wheel. Even if you re-use the spokes a new wheel will still be ...
Argenti Apparatus's user avatar
7 votes

Could I replace a hub on a wheel?

Yes - I have personally done this, by installing an 8 speed cassette freehub into a wheel that had a 6 speed freewheel. The donor was a 26" MTB wheel, and the recipient was a 20" wheel for my folding ...
Criggie's user avatar
  • 124k
7 votes
Accepted

Is Shimano the only company with a sealed ratchet mechanism in their freehubs?

Do any other manufacturers use internal ratchets in their freehubs? Many other companies manufacture freehubs with internal ratchets, both clones that are Shimano compatible and variations of their ...
DecSim's user avatar
  • 171
7 votes

Should the tightness of the QR skewer (rear wheel) affect the freewheel

You just noticed that quick release tightness affects the bearing preload. If your hub has cup and cone bearings, you can adjust the bearing preload so that you are able to tighten the QR skewer to ...
juhist's user avatar
  • 18.7k
7 votes
Accepted

How do I remove the rear sprocket from a Gates Belt drive system

It's probably stuck because it's digging in to the freehub body splines. Install just the lockring without any spacers. Use your cassette lockring tool to immobilize the freehub from turning, and use ...
Nathan Knutson's user avatar
7 votes
Accepted

How do I get off my totally stuck freehub body?

Just to be clear, the part shown on your pictures is called a freehub body (black cylinder with splines). It incorporates the ratchet system enabling the hub to engage one way and to disengage the ...
olliebulle's user avatar
  • 4,119
6 votes
Accepted

Freehub: why are the pawls on the inside surface not the outside?

I am going to combine the comments into an answer - feel free to improve. The main benefit is the larger circumference of the ratchet surface. This means for the same torque on the wheel, there is ...
mattnz's user avatar
  • 50.5k
6 votes

Shimano FH-6800 rebuild or replace?

There are no thru axle FH-6800 or WH-6800 versions. The next/new Ultegra will have some, but as of now I don't think think any thru axle hubs or wheels that say Ultegra on them are really out in the ...
Nathan Knutson's user avatar
6 votes
Accepted

What model/make are this Freewheel and Freehub?

It looks like a Helicomatic. Once you know the name, there is plenty of information on the Internet.
ojs's user avatar
  • 22k

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