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Below are technical details of 2 folding bike that I am considering.

Friends, can I safely assume that the option 2 with more gear inches would be a good choice. I am a recreational weekend rider. I am gonna ride this for not more than 30 minutes on comparatively flat paved suburban roads with slight hills. I do not fancy fast but yes I would like to tackle some ascend and descend comfortably.

Is there a bigger question technically related to gears that I am missing?

Option 1

  • Gearing 14-28T 6-speed freewheel.
  • Chainwheel 52T steel chainwheel with 170mm alloy crank arms.
  • ChainRing Teeth : 52
  • Rear Sprocket Teeth: 14,16,18,21,24,28
  • Gear inches 69, 60, 54, 46, 40, 35
  • 6 Speed Shimano drivetrain

Option 2

  • 48T steel chainwheel with 170mm alloy crank arms.
  • ChainRing Teeth : 48
  • Rear Sprocket Teeth : 14,16,18,20,22,24,34
  • Gear inches 64, 56, 49.8, 44.8, 40.8, 37.4, 26.4
  • 7 Speed Shimano drivetrain

Thanks

  • The go-to converter for all the measurements is sheldonbrown.com/gears – Criggie Aug 13 '16 at 12:56
  • Technical question - can you find out if they are cassette-based or freewheel based? 6 speed will probably be a freewheel, whereas 7 speed could be either. You can get a lot more ranges in 7 speed cassettes and freewheels, whereas 6 speed is limited to 14-28 tooth. – Criggie Aug 13 '16 at 13:08
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"Gear inches" is a way to define how "difficult" a given gear is. A larger value means that the gear is more "difficult" and will take more leg muscle to move the bike forward. A smaller value means that the gear is "easier" and hence you'll be able to climb steeper hills.

We can't tell you what range of values is right for you. Your option 2 above has 7 different combos, vs 6 for option 1, and the "smallest" gear is smaller (in gear inches), meaning it will be "easier" than the "smallest" gear for option 1. The "largest" gear for option 2 is also smaller than the "largest" for option 1, meaning that you will not be able to go as fast on flat land or going downhill.

But none of this really has anything to do with the bike being a folder, other than the fact that folders typically have a more limited gear range.

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Like you I have a folder, with 46 tooth single chainring and 14-28 6 speed. That's 60 to 30 gear inches.

On that combination I can easily run out of gears at the top while riding on the flat. So a gear combination of 46/14 can't really pedal faster than 35-40 km/h because at that speed your cadence is 135 RPM.

On the flat I start in 4th gear, cos if I start in lower gears the bike tends to rotate rather than roll forward.

On the other end, riding a steep grade is hard work in 46/28, and anything above 10% grade is a challenge.

Answer Depends on your environment.

Given the same cadence, 52/14 will reach a higher top speed than 48/14.

Suggestion take both bikes for a test ride up the steepest incline you're likely to ride. Compare their low gearing on the way up, and their high gearing on the way back down.

  • Thanks Criggie for all the explanation. The point you made about the suggestion - wish I could do that. But these folders are sold online hence I cannot ride. – Accidental_Everything Aug 13 '16 at 14:20
  • @Accidental_Everything And there's the massive downside of buying on line. My folder was $50 used, even though I bought it sight-unseen it was a good risk. I suggest you get the one with a cassette instead of a freewheel, will give you many more options later, if it doesn't work out right. – Criggie Aug 13 '16 at 23:34

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