Rad Power Bikes Owners Forum

Rad Power Bikes Chat => General Chat => Topic started by: Ryan on September 08, 2021, 08:43:56 AM

Title: Need help thinking through gearing
Post by: Ryan on September 08, 2021, 08:43:56 AM
I am trying to compare the RadMini and Lectric XP 2.0 when it comes to gearing. Particularly when it comes to the high gears.

The RadMini has a 48T crankset up front with an 11-34T freewheel.
The Lectric XP has 52T crankset up front with 14-28T freewheel.

Any experts want to weigh in on which one has higher gearing to be able to continue to pedal at higher speeds? Thanks!

Edit: In doing research these are the gear ratios for the highest gear:
4.36 - RadMini
3.71 - Lectric XP 2.0

Lowest gear:
1.41- RadMini
1.85 - Lectric XP 2.0

So the RadMini has better gearing on the top and low end and is thus more versatile. Let me know if you agree  :)
Title: Re: Need help thinking through gearing
Post by: JimL on September 08, 2021, 01:46:42 PM
The total gear ratio is not a complete answer to "energy in - drive out".  Increasing the crank sprocket tooth count reduces torque fed into the chain (by your legs).  This is simply the age old rule of leverage.

The larger crank sprocket also generates more chain speed, which is increased friction for you to work against.  The little things add up, in a world of compromise.

For example:  Smaller rear sprockets have more cyclic variation of torque into the freewheel, as well as a little more friction drag bending the link angles tighter.  At the speeds we ride, this isn't a big deal....but it's one more example of something simple that is actually complicated.

Fun stuff, ain't it?