Rear Cassette and Wheel Hub

[Pauluk]

I have just removed my rear cassette/freewheel in order to remove a loose fitting chain guard. The cassette is a seven speed with what appears to be an integrated freewheel.

Could anyone tell me if its possible to fit a separate freewheel and better quality cassette to this wheel hub or will a new wheel hub be needed to do this.

I don't need to do it now but I wanted to know if I could fit a better quality cassette in the future and what it would entail.

Thanks

 

[compo]

You would need a new hub. You may also need to expand the chainstays outwards to accommodate the wider hub. Do a search for cold settings on these forums and you will find somewhere the measurements you will need to open them up to.

 

[RecordAceFromNew]

What you have is a screw-on freewheel on a disc hub (in the background). I am willing to bet money that your hub has a distance between locknuts (which is the same as the distance between the rear dropouts on the frame) of 135mm. That hub should therefore be able to take pretty much any freewheel you can buy on the market with no modification to either the hub or the frame.

You will only need to change the hub if for whatever reason you want to have a cassette instead of a freewheel at the back. The only significant advantage of a cassette is you can have more "speeds", but then you will also have to change the shifter and perhaps other components to match.

 

[Pauluk]

You will only need to change the hub if for whatever reason you want to have a cassette instead of a freewheel at the back. The only significant advantage of a cassette is you can have more "speeds", but then you will also have to change the shifter and perhaps other components to match.

I was thinking in terms of fitting a freewheel hub and a separate cassette (I thought the freewheel mechanism fixed separately to the hub but I guess its all part of the hub) believing I may be able to source better quality parts in the future.

I don't feel I have a need to change from the 7 cogs I have so from what you are saying, when my rear cogs wear, it sounds like I may as well stay with the type of freewheel/cogs that I currently have.

Just as a side question, why do some bikes have a freewheel hub and cassette and bikes like mine have what I would describe as an all in one freewheel/cog stack (for want of a better terminology).

 

[HovR]

I was thinking in terms of fitting a freewheel hub and a separate cassette (I thought the freewheel mechanism fixed separately to the hub but I guess its all part of the hub) believing I may be able to source better quality parts in the future.

What you currently have is known as a freewheel, where the cogs and ratchet mechanism are all in one, and they screw on to the hub.

What you're thinking of is known as a freehub and cassette (where the ratcheting mechanism that allows you to freewheel is attached to the hub, and a separate "cassette" slides on to it).

If you don't want to upgrade to more than 7 speeds on your bike, there is really no need to move to a freehub (I don't even think you can get cassettes in 7 speed).

Just as a side question, why do some bikes have a freewheel hub and cassette and bikes like mine have what I would describe as an all in one freewheel/cog stack (for want of a better terminology)

The reason some bikes have a freehub is to accommodate more speeds.

The traditional freewheel design (like you have) is unable to accommodate more than 7 speeds, as the screw on mechanism means that only one set of bearings can be accommodated, and these bearings (along with the ratcheting mechanism) have to be at the far end of the freewheel.

As the number of speeds on freewheels increased, so did the width of the freewheel, which put more strain on the bearings and ratcheting mechanism situated at the far end of the freewheel.

A freehub on the other hand has its bearings and ratcheting mechanism placed more evenly along the width of the freehub, meaning that the force from wider cassettes is spread more evenly.

 

[Pauluk]

Thanks for the replies guys and HovR thanks for the explanation, all helps to increase my knowledge.

 

[Sheffield_Tiger]

What you currently have is known as a freewheel, where the cogs and ratchet mechanism are all in one, and they screw on to the hub.

What you're thinking of is known as a freehub and cassette (where the ratcheting mechanism that allows you to freewheel is attached to the hub, and a separate "cassette" slides on to it).

If you don't want to upgrade to more than 7 speeds on your bike, there is really no need to move to a freehub (I don't even think you can get cassettes in 7 speed).

<snip> .

Agree with no real need to swap, but 7s cassettes do exist, I have a few. 7sp freehub bodies seem rarer but that's what spacers are for

 

[HovR]

7s cassettes do exist, I have a few. 7sp freehub bodies seem rarer but that's what spacers are for

Fair enough, learnt something new today.