[ViBiker]

For most builds, or purchases, people should take into consideration the pedal assist capability of the bike.

(RPM - Pedal-crank Revolutions Per Minute - pedal rate)
60 rpm is considered a casual-sustainable rate
90 rpm is, a more, top sustainable rate

Figured - rpm x ratio x wheel size = mph

(rpm x 60min) x (Front T / Rear T) x (Wheel " x 3.14) / (12" x 5280') = mph

Examples, 26-27-700c-29'ers, here - Sprocket PA charts

[Saugus18]

Originally Posted by ViBiker

For most builds, or purchases, people should take into consideration the pedal assist capability of the bike.

(BPM - Beats Per Minute - pedal rate)
60 bpm is considered a casual-sustainable rate
90 bpm is, a more, top sustainable rate

Figured - bpm x ratio x wheel size = mph

(bpm x 60min) x (Front T / Rear T) x (Wheel " x 3.14) / (12" x 5280') = mph

Examples, 26-27-700c-29'ers, here - Sprocket PA charts

Thanks for this info. I'll have to learn a little more about this stuff!

[wild]

There is a gear calculator at this site www.gear-calculator.com and it is a lot of fun to drag the gears around and see what you are getting at the wheel.

[Saugus18]

Originally Posted by wild

There is a gear calculator at this site www.gear-calculator.com and it is a lot of fun to drag the gears around and see what you are getting at the wheel.

Thanks... but I'm doing this all from my phone, our PC is down and don't have adobe flash on this phone. My next phone will have it though! Plus we'll probably be getting a new computer as well in the near future. Until then, I can't view certain things properly but I'll bookmark this for future reference.

[qmsdc15]

If you can't access online calculator, simply put, a low gear ratio of 1:1 (for example 28t chainring/28t cog) and a high gear of 4:1 (48t/12t for example) will be sufficiently wide for most riders' needs. A gear lower than 1:1 maybe desired by some, those who ride in very hilly areas, or off road, or pull heavy loads, etc. A gear higher than 4:1 might be needed by racers and those who measure their fitness by their average speed.

Since you're only spinning out on downhills, I don't think you need to change anything right away. When it comes time to replace your drivetrain or buy a new bike, you can make some adjustments, but it doesn't sound like your somewhat limited top end is really a big problem. Don't worry, enjoy your ride.

[Saugus18]

Originally Posted by qmsdc15

If you can't access online calculator, simply put, a low gear ratio of 1:1 (for example 28t chainring/28t cog) and a high gear of 4:1 (48t/12t for example) will be sufficiently wide for most riders' needs. A gear lower than 1:1 maybe desired by some, those who ride in very hilly areas, or off road, or pull heavy loads, etc. A gear higher than 4:1 might be needed by racers and those who measure their fitness by their average speed.

Since you're only spinning out on downhills, I don't think you need to change anything right away. When it comes time to replace your drivetrain or buy a new bike, you can make some adjustments, but it doesn't sound like your somewhat limited top end is really a big problem. Don't worry, enjoy your ride.

Just wondering... did you see my thread in the hybrid section about the Scott bike I test rode yesterday? Check it out if you haven't, I really like the bike. ;?)