FreeWheel vs Cassette

Discussion in 'Bicycle Repair' started by Avjzkmvv, Jun 15, 2011.

  1. Avjzkmvv

    Avjzkmvv New Member

    I've read up on the Freewheel but keep hearing or seeing it in contrast to the cassette and am a bit confused by that. Isn't a freewheel simply a device in the hub or attached to the hub; on which a cassette is placed, and allows it to spin freely when the biker is coasting or not using the pedals?

    Many thanks!!
     

  2. srdavo

    srdavo Active Member

    Hi,

    We've got a great bunch of real bicycle mechanics here. Someone will surely chime in with an explanation.

    In the meantime..... put your trust in the late, great Sheldon Brown. (July 14, 1944 - February 4, 2008) He compiled a wealth of information.
    http://www.sheldonbrown.com/free-k7.html
     
    Last edited by a moderator: Dec 15, 2015
  3. loquin

    loquin Active Member

    There are also BMX style freewheels, which are (usually) a single sprocket combined with the thread-on freewheel. BMX freewheels are also available in 'leftie'/'southpaw' configuration, which has left-hand threads, and used on the left side of the wheel (when facing forward.)
     
    Last edited: Jun 15, 2011
  4. TREEWK

    TREEWK Member

    The Common Cassette On Entry Level Bicycles Has A Freewheel Bearing Built Into The Cassette.

    With The "needed" Proper Special Socket (about $7.) You Can Screw The Cassette Of The Bicycle Rear Wheel By Turning It To The Left. The Hub That The Spokes Are Installed In Will Have The Threads Exposed After The Cassette Is Removed.

    Now You Can Screw On A 1&3/8" 24 Threads Per Inch Right Hand Thread Freewheel Sprocket With The Teeth Built In Or A Freewheel Adapter That Lets You Bolt A Much Larger Sprocket To The Adapter.

    You Can Buy Or Build Wheels With Threads On Both Sides And Accomplish Different Things. If The Left Side Has Left Hand Threads You Can Install A Left Hand Adapter And Bolt On A Large Sprocket For Your Motor If It Has A Pull Or Electric Start. I Like The Freewheel Motor Sprocket For Coasting With Motor At Idle. (the Stealth Approach).

    Also there is no engine etc drag when pedaling when you have and engine drive freewheel sprocket.

    Hope This Helps.

    Ron
     
    Last edited: Jun 15, 2011
  5. sparky

    sparky Active Member

    WOW... I had no idea that Sheldon "Coasting Is Bad For You" Brown passed away. I would've loved to drink a beer with that guy. I bought a fixed gear bike because of this page he wrote up --> http://www.sheldonbrown.com/fixed.html

    Anyway, to answer the OP's question. The difference between the two is simply modularity. Freewheels aren't modular, while cassettes are. Cassettes are better because of it. You can replace just the teeth if they wear out, or if you want to try different gear ratios.... and not have to replace the actual "freewheel hub unit" (aka: cassette hub). It's purely for economical reasons.
     
    Last edited by a moderator: Dec 15, 2015
  6. Fabian

    Fabian Well-Known Member

    Cassettes that run on freehubs are beneficial because you can jail-break 2 cassettes (of the same speed type) for a sprocket count that suits your application.

    In my case, i ripped apart two Shimano 9 speed cassettes (11T-32T and 12T-36T) to give me the following custom cassette stack:

    11T - 12T - 13T - 14T - 16T - 19T - 23T - 28T - 36T
     
  7. LR Jerry

    LR Jerry Well-Known Member

    On a freewheel the ratcheting mechanism is in a core with sprockets connected to it and is screwed on to a hub designed for freewheels. On a cassette the ratcheting mechanism is built into the hub. The sprockets are the only part which gets replaced. Although people improperly use the terms interchangeably they aren't the same thing.

    Freewheels are prone to bent axles and the higher quality bikes replaced them with cassettes. It's also a common belief you can custom design a cassette but can't do that to a freewheel. This isn't true on my 5 speed autoshft bike I've got a 34-16 freewheel. I used a Shimano HG-37 core and put Shimano, Falcon and SunLite sprockets on it. I just recently built a 7 speed 34-13 SunLite freewheel. This is what was on it at first: 34, 24, 22, 20, 18, 16, 14. This is what I changed it to: 34, 28, 24, 21, 18, 15, 13.
     
  8. Fabian

    Fabian Well-Known Member

    The issue with the Shimano HG-61 cassette is that it doesn't come with an 11T sprocket, and the problem with Shimano HG-41 is that it doesn't come with a 36T sprocket.
    The other issue when a bicycle is motorized is that the first 3 gears with a (standard) 4 tooth difference between adjacent sprockets is that the ratio is too short between those gears.

    I spent a good deal of time messing around with sprocket sizes to come up with a consistent speed difference between selected gears, giving an 8 tooth count between first and second gear, a 5 tooth difference between second and third gear, a four tooth difference between third and fourth gear, a 3 tooth difference between fifth and sixth gear, a two tooth difference between sixth and 7th gear and a single tooth difference between seventh, eighth and ninth gears.

    Using standard cassette ratios works out completely wrong, when applied to a motorized bicycle application.

    I will agree that an 8 speed (cassette) system is an optimal choice, because you get the vital 11T sprocket with the option of installing the HG-61's 36T sprocket in place of the conventional 34T sprocket.
    That doesn't sound like any meaningful difference, but when you have the optional SickBikeParts 24T sprocket installed on the front chainwheel, it gives you that little bit of extra hill climbing ability, or extra pulling power should you be hauling heavy loads.

    The other advantage of an 8 speed system is that an 8 speed chain is half the price of a nine speed chain, yet eight speed chain lasts equally as long as a nine speed.
     
  9. LR Jerry

    LR Jerry Well-Known Member

    Fabian is right about widening the range between the rear sprockets. On my 5 speed autoshift these are the sprockets on my freewheel: 34, 28, 24, 20, 16. Widening the range improved my acceleration and smooth out the shifting. I've tried different combinations and found what I'm currently using to work best for me.

    https://www.youtube.com/watch?v=pGDGIIdn--s&feature=youtube_gdata_player
     
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