21 speed still ok?

Discussion in 'Mountain Bikes' started by swipeys, Aug 31, 2004.

  1. swipeys

    swipeys New Member

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    I bought a used Trek 4300 for a song and dance to get into upgrading, and tooling around with the bike; more or less to learn about hjow to work on my other bikes etc. My question is: its a 21 speed with entry level Shimano shifters derailleurs etc. I have no particular desire to upgrade to a 9 speed cassette, and the guy at my LBS said this really isn't possible anyway: the cassette wouldn't fit. He also said that 7 speed cassettes are practically extinct, and new cassettes with 7 speeds are junk. I consider myself an intermediate rider, with no desire to ever become a serious mountain biker. Are his remarks geared toward high end mountain bikers as opposed to a hack like me? Should I worry that soon I won't even be able to find a 7 speed cassete, and a non-9 speed chain to go with it? Just wondering, before I spend too much time playing around with this trek. Thanks!
     
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  2. dabac

    dabac Well-Known Member

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    AFAIK decent 7-speed cassettes are still quite available. There are good chances that a 9-speed chain will work in a 7-speed rig if it ever comes to that. I've ridden 7-speed much longer than my pals, and the only times I've ever really suffered from that have been in the Alps. During that kind of extreme climbs/descents the 7-spd left me wishing for a wider span. In XC riding there are (IMO) so many other things going on that maintaining the perfect cadence isn't really possible anyhow, so a lesser number of ratios isn't such a big deal.

    Check out http://www.sheldonbrown.com/k7.html for more tips and tricks about cassettes.
     
  3. swipeys

    swipeys New Member

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    One additional question: you said a 9 speed chain would work, but not a 9 speed cassette?
     
  4. bwgride

    bwgride New Member

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    I have four bikes, three 7 speed cassettes and one 6 speed freewheel. All work fine and I can still find all the parts I need. My opinion -- and no doubt many will disagree with me here -- is that component manufacturers introduced more speeds as a marketing strategy, not because 7 speed was inherently inferior. Maybe, due to the small spacing difference and narrower chain, 9 and 10 speeds shift faster, but the difference is very minor. The actual differences between a 7 speed option and 8/9/10 are very little in my experience.

    As for the bike shop person telling you the 7 speed cassettes are junk, that's crazy. Ask him what he means by that. Is he trying to sell you an 8/9/10 speed component combo? Lets suppose that he is correct and that the new 7-speed cassettes are junk and they last only 5,000 to 10,000 miles -- so what? That's a lot of bicycle riding. Buy another cassette when the "junk" cassette is worn out. Here are a few places to find 7 speed cassettes. If you are concerned about 7 speed cassettes becoming extinct, go ahead and buy a couple now.

    www.Nashbar.com (Nashbar has the Shimano HG50 7 speed cassette for $15, Shimano IG60 for $25, , and they have their on version for $10 which I have not tried yet)

    Other companies selling 7-speed cassettes include:

    http://store.airbomb.com
    www.performancebike.com
    http://bikepartsusa.com/
    http://www.loosescrews.com
    http://aebike.com

    and the list goes on.

    By the way, I don't believe you want to use a 9/10 speed chain on 7 speed, although one made for 8 speed is fine since most 8 speed chains are marketed as 7/8 speed anyway (I currently use SRAM PC48 chain on one 7 speed bike and Shimano HG50 on two others). Nashbar.com sells both SRAM PC48 and Shimano HG50 chains for under $10 right now.
     
  5. swipeys

    swipeys New Member

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    I appreciate the comprehensive reply. The bike shop guys start talking me in circles, and I tend to just nod along as they talk. His argument was that all of Shimano's top o the line componentry is 9 speed nowadays, and they just make enough crap 7 speed stuff to placate people who don't want to get a new bike.

    Again, thanks for the response. Very helpful!
     
  6. dabac

    dabac Well-Known Member

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    Check out the Sheldon Brown site for all the details. But basically: the 9 spd chain is narrower than the 7 spd. Usually this is not a problem, 'cause the 7 spd sprockets will still fit within the chain and since the RD engages the chain from "inside" it should shift OK. Things might be a bit more touch and go at the front, but there's still a good chance of functionality. The 9 spd cassette doesn't fit a 7 spd body, it's too wide. 8 out of 9 will fit a 7 spd body, but then you either need non-indexing shifters, or switch to a 9 spd shifter and block one of the positions out at the RD.

    If you would ever run out of 7 spd cassettes, there shouldn't be too much trouble gettiong hold of spacers and then simply use an 8/9 spd for parts.
     
  7. swipeys

    swipeys New Member

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    Can you explain that to me a little more? You mean if 7 speed cassettes ever become exctinct I could use a 8/9 speed cassette?
     
  8. Banatean

    Banatean New Member

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    Hi,i was wondering if you're talking about Freewheel or Freehub ?,you see my wife's Specialized that we bought less than a year ago came with a 21 speed Freewheel,i didn't like at all ;it had that crazy clicking sound,only seven speeds and it came with chezzy Alex crap rims...so i yanked them out for a set of Sun Rims with Freehub set-up,then i got an 8 speed cassette and a 8 speed shifter i transformed the bike :) ,now it doesn't make that clicking sound,got an extra gear...it's beautiful :D .
    Just an idea in case you wanna convert to a 8 speed cassette :eek: .
    Dan
     
  9. swipeys

    swipeys New Member

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    Dan--I'm too much of a novice to know the difference. How can I tell which it is?
     
  10. Banatean

    Banatean New Member

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    I'll try to describe best i can what to look for.With the wheel off the bike look at it closely and if you see two dimples at oposite sides in the front of your cassette (cassette term is mostly used for Freehub...) near the smallest gear with the big nut in the midlle then you got a Freewheel,those dimples are for a wrench,on the other hand (and if you want to take the cassette off you need a special wrench,the'r cheap) if you don't see those dimples that means you've got a Freehub.Back a few years only the higher end bikes offered Freehub but now it's getting to be quite common.To help you save $ :) i'dd go to a bike shop or a book store and purchase The Haynes Bicycle Book 10100,they are about $ 20 in Canada and much cheaper down in the states.The book it's worth every penney ;) specially that it has tonnes of colored pictures and step by step instructions on everything a DIY needs to know.
    Good luck and let me know if i can be of more help.
    Dan :)
     
  11. dabac

    dabac Well-Known Member

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    A cassette is primarily held together for convenience. It can be broken down into separate spacers and sprockets. An 8/9 cassette should be possible to cannibalize for parts. These parts can then be used to assemble another cassette according to your wishes, and some mechanical requirements. Look at http://www.sheldonbrown.com/k7.html for details. As long as sprocket thickness and spacer thickness are reasonably matched up to provide the spacing between the sprockets that your chain and shifter(if indexed) needs you should be good to go.

    The site also has pics to let you separate between freewheel and freehub.
     
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