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  1. #1
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    Freewheel 'upgrade'...

    I was unsure where to post (thought about the beginners place as I am very, very green), but I believe this is the best forum for this question... I currently have a 7 speed freewheel and I'm thinking of getting the biggest cog I can fit, so my question is if I can fit an 8, or even a 9 speed freewheel with the available space?
    Thank you in advance.

    Paul

  2. #2
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    Freewheels are 5,6,7 speeds.

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  4. #4
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    Sheldon says a 7 speed freewheel is 32.8 mm wide. You might want to measure yours.
    He says a 8 speed is 36.8 mm wide.
    Do you have 4 mm of available space before the chain would interfere with the dropout/chainstay?

  5. #5
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    Quote Originally Posted by vanamees View Post
    Freewheels are 5,6,7 speeds.
    You can get 8, 9, and 10 speed freewheels these days (maybe even 11), not to mention the one with a single gear that have been around for...a hundred years or so.

    You will likely have to re-dish your wheel to make an 8 speed freewheel work, not to mention compatibility issues with your shifter.

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    Quote Originally Posted by big_papa_nuts View Post
    You will likely have to re-dish your wheel to make an 8 speed freewheel work, not to mention compatibility issues with your shifter.
    A re-dish would only be necessary if the axle length or spacers are modified.

  7. #7
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    Interesting. I hadn't seen that before.

    OP, it sounds like you have to be ready to try it and maybe do some tinkering. You'll most likely need a new shifter. It's possible that this part simply won't fit, or it might go right on. Certainly a lot of bike parts don't maximize their use of available space, so I wouldn't be shocked if SunRace figured out how to sneak another cog into the same total width of that threaded interface and clearances.

    Other options would be a 7-speed freewheel with lower gearing, a smaller granny ring, a wheel built with a freehub, and a nicer bike to start with. Really depends on what your goals and budget are, and what you have now.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  8. #8
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    Quote Originally Posted by Slash5 View Post
    A re-dish would only be necessary if the axle length or spacers are modified.
    So, for what I can understand, as long as there's clearance, I can swap between sizes? I do have (more than) the above mentioned 4mm...

  9. #9
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    Quote Originally Posted by AndrwSwitch View Post
    Interesting. I hadn't seen that before.

    OP, it sounds like you have to be ready to try it and maybe do some tinkering. You'll most likely need a new shifter. It's possible that this part simply won't fit, or it might go right on. Certainly a lot of bike parts don't maximize their use of available space, so I wouldn't be shocked if SunRace figured out how to sneak another cog into the same total width of that threaded interface and clearances.

    Other options would be a 7-speed freewheel with lower gearing, a smaller granny ring, a wheel built with a freehub, and a nicer bike to start with. Really depends on what your goals and budget are, and what you have now.
    Fair enough.
    Budget is the main question in my (re)build. I bought it used because I liked the frame format compared to other alternatives (budget was also a big concern here). I've owned it for a tad more than a month and already upgraded a few things as I'm slowly learning about this world - more familiar with motorcycles - and new brakes are already being researched.
    I'm running a 28 and I definitely feel like a 30/32 would really help when climbing...

  10. #10
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    I feel like I'm dropping into the middle of a conversation here.

    I don't know what bike you have, what crank you have, or what kind of riding you're doing.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  11. #11
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    Quote Originally Posted by AndrwSwitch View Post
    I feel like I'm dropping into the middle of a conversation here.

    I don't know what bike you have, what crank you have, or what kind of riding you're doing.
    Please do, I really am trying to have a broader understanding of all this...

    I don't have much info on it since the previous owner was very vague in terms of parts - now I understand why - but if it helps, I have a recent image:

    Freewheel 'upgrade'...-1.jpg

    I (mostly) ride on road with some sporadic off-road incursions.

  12. #12
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    Huh. No branding I can see on the frame.

    How big is your rear tire? Look for a label saying something like "26x4.0."

    You can count the teeth on your chain rings or look for a stamped label. How many chain rings do you have?

    Are you comfortable pedaling out of the saddle?
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  13. #13
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    Quote Originally Posted by AndrwSwitch View Post
    Huh. No branding I can see on the frame.

    How big is your rear tire? Look for a label saying something like "26x4.0."

    You can count the teeth on your chain rings or look for a stamped label. How many chain rings do you have?

    Are you comfortable pedaling out of the saddle?
    I see and am aware of no brand either.
    Tires are indeed 26x4.
    It has occurred to me to 'simply' replace the chainring, but will that change the ratio more dramatically, should I say?
    That is the reason for wanting a different gear ratio, particularly at the low end... I like to stay on the saddle...

  14. #14
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    I don't know whether changing your chain ring or your cassette will make a bigger difference. How big is your chainring? Just one?

    Learn to ride out of the saddle. Sooner or later, there are always hills too steep to climb in the saddle. Sometimes it's a balance problem more than a gearing problem.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

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    Quote Originally Posted by AndrwSwitch View Post
    I don't know whether changing your chain ring or your cassette will make a bigger difference. How big is your chainring? Just one?

    Learn to ride out of the saddle. Sooner or later, there are always hills too steep to climb in the saddle. Sometimes it's a balance problem more than a gearing problem.
    Just one (I have also considered the possibility of a double chainring).
    When I ride out of the saddle, I tend to chose heavier gears, am I correct on doing so?

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    It's fairly typical that people prefer higher pedal force and lower cadence when they're out of the saddle.

    I don't know if you're really choosing a good gear for you. If you're unsure, try a lighter gear or a heavier gear. Go with what feels right.

    It takes getting used to, but I can climb out of the saddle for a pretty long time if I have a good rhythm.

    How many teeth are on your one chain ring? It makes a really big difference. Can you post a pic of your crank?
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  17. #17
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    Just checked: 44 teeth
    Crank is probably cheap, it's already creaking...

  18. #18
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    44t is a ridiculously large chain ring to use for single ring applications.

    It would make a bigger difference to use a more appropriately sized chain ring. Say, 32t. That would lower the speed you could go by pedaling at 90 rpm to just under 19 mph. I'm not sure if that's a problem for you.

    Check out this gear calculator...
    Sheldon Brown's Bicycle Gear Calculator

    You can play around with different options. The "MPH at xx RPM" is the one I find most intuitive. I've ridden with a speedometer some and use a GPS to record my rides, so I have some sense of what speeds I can ride on different kinds of terrain.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  19. #19
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    Quote Originally Posted by AndrwSwitch View Post
    44t is a ridiculously large chain ring to use for single ring applications.

    It would make a bigger difference to use a more appropriately sized chain ring. Say, 32t. That would lower the speed you could go by pedaling at 90 rpm to just under 19 mph. I'm not sure if that's a problem for you.

    Check out this gear calculator...
    Sheldon Brown's Bicycle Gear Calculator

    You can play around with different options. The "MPH at xx RPM" is the one I find most intuitive. I've ridden with a speedometer some and use a GPS to record my rides, so I have some sense of what speeds I can ride on different kinds of terrain.
    Fantastic info, thank you!
    After playing with it for a few minutes, I'm even more convinced I am doing the best choice by upgrading the gear set; with a 11-32 set (8 gear) over a 32 chainring, I will lose a mere 2mph at the low end, but gain almost 11mph at the top end, which is something I see with pleasure now that I'm starting to have more strength in my legs (I've only been riding for just over a month)...

  20. #20
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    DNP Screw Thread 10 Speed Bike Freewheel Cog 11-32T/ 34T 10S for Shimano Z20 /21 | eBay

    From the seller:

    " Description Of DNP Epoch 10 Speed Freewheel Cog 11-32T/ 34T 10S replace for Shimano Z20 /21 Tourney TZ21:



    Hard to find freewheel with thread type screw on 11T small cog, please make sure your this can be used for your bike, good to speed up your 6 7 speed bike and donot need to replace a new wheel set, there are 7S 8S 9S 10S DNP 11T here in store too, please find them if you need. "

    Apparently I can even go with a higher number of gears, I'm just not sure about any clearance issues.
    There are various models of 8 and 9 gears also.

  21. #21
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    If you really think you're on your way to being able to use the top end from either the freewheel you linked originally or that DNP freewheel, just don't buy anything. Work up to pushing that 44/28.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  22. #22
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    Quote Originally Posted by AndrwSwitch View Post
    If you really think you're on your way to being able to use the top end from either the freewheel you linked originally or that DNP freewheel, just don't buy anything. Work up to pushing that 44/28.
    Hehehe... I understand that would indeed be the most beneficial for my body, but over 40 now

  23. #23
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    So it sounds like you really would like to expand your range in both directions.

    Certainly either of the freewheels you linked would give you more low end and the DNP freewheel would give you more top end if it fits.

    I'm not sure you're going to get enough more low end just fitting a freewheel with a 34t cog. You're still not going to have much. But you could have both more low end and still have more high end if you did the DNP freewheel and also fitted a smaller chainring.

    Going to a double or triple crank could too, again, if it fits.

    The 10-speed freewheel would require you to replace both your shifter and your rear derailleur. The 8-speed, you could keep your rear derailleur. If you kept your 13-28 freewheel and changed your chain ring, you wouldn't have to change anything else.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  24. #24
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    Quote Originally Posted by AndrwSwitch View Post
    So it sounds like you really would like to expand your range in both directions.

    Certainly either of the freewheels you linked would give you more low end and the DNP freewheel would give you more top end if it fits.

    I'm not sure you're going to get enough more low end just fitting a freewheel with a 34t cog. You're still not going to have much. But you could have both more low end and still have more high end if you did the DNP freewheel and also fitted a smaller chainring.

    Going to a double or triple crank could too, again, if it fits.

    The 10-speed freewheel would require you to replace both your shifter and your rear derailleur. The 8-speed, you could keep your rear derailleur. If you kept your 13-28 freewheel and changed your chain ring, you wouldn't have to change anything else.
    I'm almost happy with the 28, so I truly believe that even the 32 will be enough...

  25. #25
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    Thinking about going 50t on the chainring, with either of the previous cogs mentioned... if I do, is the current chain still fit?

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    That 10 speed freewheel would be about 12mm wider than your current freewheel - you have room for that?
    What is your plan for shifters?
    If you are adding 10 teeth your chain will probably not be long enough.
    Your present chain will not work for anything more than 8 speed anyways. You would need a 9 or 10 speed chain.

  27. #27
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    Quote Originally Posted by Slash5 View Post
    That 10 speed freewheel would be about 12mm wider than your current freewheel - you have room for that?
    What is your plan for shifters?
    If you are adding 10 teeth your chain will probably not be long enough.
    Your present chain will not work for anything more than 8 speed anyways. You would need a 9 or 10 speed chain.
    Thank you. I have considered that the chain would need to be changed, just wasn't sure about the correct ratios.
    I will just buy a new shifter, not a big deal...
    About the 10spd, the seller announces that it will fit on the same space as a 6, or 7 spd, but I sent a message requesting that value. Btw, 8spd with a 32 (or 34 if I go 50 in the front) is probably enough for me...

  28. #28
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    Quote Originally Posted by Flugelbinder View Post
    Thinking about going 50t on the chainring, with either of the previous cogs mentioned... if I do, is the current chain still fit?
    A 50t with a 34 cog won't be significantly lower than the 44/28 gear you have now, why go that route? I'd be thinking going down to something like a 40t chainring.
    I brake for stinkbugs

  29. #29
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    Quote Originally Posted by J.B. Weld View Post
    A 50t with a 34 cog won't be significantly lower than the 44/28 gear you have now, why go that route? I'd be thinking going down to something like a 40t chainring.
    And leave everything else as is? It's probably easier...

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    Quote Originally Posted by Flugelbinder View Post
    Fair enough.
    Budget is the main question in my (re)build. I bought it used because I liked the frame format compared to other alternatives (budget was also a big concern here). I've owned it for a tad more than a month and already upgraded a few things as I'm slowly learning about this world - more familiar with motorcycles - and new brakes are already being researched.
    I'm running a 28 and I definitely feel like a 30/32 would really help when climbing...
    You can get an 11-30t DNP 7-speed freewheel off Amazon for $33. You can also try a Shimano 14-34t one but I've heard that one has problems, maybe best to play it safe and try the 11-30t one first. I still have a 13-28t one that's new so I'll tell you how the 11-30t one does in about 1000-2000 miles from now

  31. #31
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    Quote Originally Posted by vanamees View Post
    Freewheels are 5,6,7 speeds.
    Actually there are still several 8-speed freewheels you can still buy out there. Two issues with them: the standard rear axle dimensions on these bikes tend to be 10x135 mm. If there is a quick-release skewer in the axle (as in the axle is hollowed out and thus weakened), it's going to be very weak for supporting an 8-speed freewheel and it could break later. Second, the 8-speed freewheel is about 5mm longer than the 7-speed one, and it will end up taking some of your frame dropout space for connecting the frame with the axle. Then you have to start moving washers, retruing the wheel, and all this other BS most people don't want to deal with.

    Either get one of the two 7-speed freewheels I mentioned below, or simply buy a wheel with an 8/9/10 speed cassette-based hub (make sure it has the correct brake-type mounting!!!). There are still a bunch of freehubs out there that have a rim brake setup, dumb as that sounds for 'technological progress' in cassette-based systems.

    The freehub upgrade seems to be the better long-term solution if you plan on putting several thousand more miles on the bike. You can still keep the 7-speed shifters, tune the derailleur towards the large cogs, and see how far up the cogs (large to small) you can shift smoothly, just use those smooth ones for shifting. If I end up doing this conversion I'll let you guys know how it goes. But in a way it seems pointless because an 8-speed cassette can only go up to 34t, and you can as mentioned below get a 30t or 34t with a 7-speed freewheel anyway. It would be more for longevity of the cassette-based system than any real difference in climbing power.

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