Shimano Nexus 7 internal hub

[Monkreadusuk]

Does anyone know what this means?

The overall range of the Nexus 7-speed is 245%:


Ratio 0.632 0.741 0.843 0.989 1.145 1.335 1.545
Step 17.3% 13.8% 17.3% 15.8% 16.6% 15.8%


For comparison, your old 3-speed had a range of 178%:



Ratio 0.750 1.000 1.333
Step 33.3% 33.3%

 

[Deleted member 23692]

The ratio is the difference between one rotation of the sprocket and one rotation of the wheel

ie in 1st gear for every full revolution of the sprocket the wheel rotates 0.632 of a full turn
in 7th gear the wheels does 1.545 revolutions for every full turn of the sprocket

The range is the difference in percentage between 1st and 7th gear is 7th gear is 245% higher than 1st

The step is the difference between each gear expressed as a percentage ie 2nd is 17.3% higher than 2nd etc

 

[Pale Rider]

It's giving you the gear spread and ratios of the hubs.

Interpreting the figures can be difficult for someone new to the topic.

The seven speed hub has a much wider range - first is lower, top is higher - than the three speed.

The figures also indicate the gear steps for the seven speed are uneven, but they are evenly spread for the three speed.

That's unlikely to bother most riders.

Have a look at this table.

You will see there is no wider range than the venerable mountain bike triple, although some of the gears are so close together they may as well be duplicates.

 

[mjr]

You will see there is no wider range than the venerable mountain bike triple, although some of the gears are so close together they may as well be duplicates.

...and the bottom end is so low that you can wide up walls if they're not completely vertical. That cassette looks like what we used to call a megarange, though!

IMO 30" to 90" will cover most of the riding that most people do. You can make do with a narrower range, bug a wider range or closer spacing is nice to have... but if everything else about a bike is right, you'll get over it - although maybe not over every mountain without walking

 

[Monkreadusuk]

Thanks for the info, I'll have to try find out the size of my front chainring. It's a bit hard to find on a bike like this though :P

 

[MichaelW2]

Work out the "gear inches " of each of the 7 gears, then you can compare directly to any other system.

 

[hamrack]

http://ritzelrechner.de/
I haven't tried this for mapping the ratios on my Alfine 8, but it's great for touring gears and comparing different set ups.