Upgrading question

I own an 8 spd external rover and I am wanting to up grade it to an 10 spd, do I need to get a whole new rear wheel for it or can I just change out the cassette and use the appropriate shifter and derailer.  Thank you ahead of time for any help given.


  • edited December 2016
    The wheel takes standard SRAM/Shimano type cassettes. As you pointed out, you'll also need a compatible rear derailleur and shifter.

    I've read that some 11-speed cassetes are wider than the usual 8/9/10, but you should be ok with a 10.

    You will also need to completely replace your chain, as TT uses 8-speed chain.

    - PaulNM
  • Jamesr, I had the same thought.  Why would you only want a few more gears?  A Patterson crank on the front would double the number of gears and give you more high and low gears.  I don't know the difference in price but that's how I would go.

    A year ago, I went from a 32T front crank to a 38T.  It gave me one more gear but I seldom go much lower than 4th gear in this flat area.  You need to consider what type of terrain you will ride on.  If you want to travel with the trike, make sure you have as many gears as possible are available for all terrains.

  • Another thing to consider is cost:

    10 Speed:
    Cassette ~$30
    Derailleur ~$30
    Shifter ~$15
    Cabling ~$7
    Chain ~$90
    Total: ~$172

    Patterson: ~$272.95

    On the other hand, the Patterson does give you a much greater gearing range than possible from changing the rear cassette. 

    - PaulNM

  • edited December 2016
    You only need a cassette, shifter, and chain. The hub should accept a 10speed cassette the derailleur doesn't care if you are shifting 8 or 10 speeds. You will need a ten speed shifter and 10sp chain. For chain I would use KMC X10 about $20 but you will need two. Match the length of the old chain. Carefully remove the cable and you should be able to reuse it pop on the new shifter adjust and you are good to go. 

    As you are replacing the chain and cassette you could play around a bit with chainring size and cassette ratios keeping in mind changes may affect the length of the chain. Just do not exceed the capacity of the derailleur and you should be fine. 

    The only potential pitfall is service life of the chain and cassette as a 10 speed setup is considerably narrower and less robust than 8 speed. The fact that you will be running a much longer chain should help with chain life. I generally get 4000 miles out of a KMC X10 SL hollow pin chain and roughly 6000 on a 10 speed cassette.   
  • I'm not sure I'd be comfortable re-using the old derailleur. The one TT uses (Mezzano? - forget the name at the moment) is specifically marketed as an 8-speed. There's a good chance the sprocket teeth on the wheels will be wider than what you'd want with 10-speed chain.

    - PaulNM
  • For the last three months I have been running 10 speed on my trek "82" 720 with the original Huret Duopar rear derailleur and it shifts beautifully. The jockey wheels are just along for the ride and to manage chain length so the width isn't an issue.
  • TT ships most trikes with KMC Z72 chains, IIRC
  • the stock chain is 6 7 8 and will not work with a 10 speed cassette
  • I changed my cassett for an 11 to 34 8 speed and went with a patterson altho it cost a bit I can ride up steep hills with ease and hit about 23 mph on the flats. Hope you find a setup that works for you
  • Oh duh, I got things mixed up earlier. It's the exterior dimensions of the chain that narrow in higher speed systems, not the interior. The sprocket teeth will be the exact right size regardless of which "speed" system it's for. 

    - PaulNM
  • 11/34 with Patterson is a good combo and still well within the specs of the KMC Z72 chain the trike came with.
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