Gearing ratio and different configurations

VinceCable

Hi,

For the last 2 years I've been riding a bike with a gearing of :

44/33/22 - 11/32

and I've just bought a Giant Anthem X1 2011 which has a gearing of:

42/32/24 - 11/36

The Anthem is so much faster on flat and most climbs, and I love the 10 spead cassette, but I find it really hard on a local hill which is 15-20% incline, in fact a lot harder to pedal than the other gear ratio. It feels like the Anthem gear ration does not go low enough for me.

Doing a bit of reading up on this I think I calculated in the granny ring the old bike has a gearing of 52 inches and the Anthem a gearing of 57 inches. This does nto seem like a big difference - can anyone make any comments on this for me or add some info?

I was expecting the Anthem to be much easier to climb on but on this hill it is a lot harder - its lighter and faster but I just dont seem to have the puff - having said that the hill was about 2 inches deep in snow/ice so maybe this was adding to the rolling resistance?

The Rookie

Unless you have different tyre sizes your calculations are out, the Anthem spins the cranks 1.5 times for every turn of the rear wheel (lowest) the old bike 1.45 times, so the Anthem is actually 3% lower geared (your calc says it's 10% higher geared which is a lot) and should climb more easily (assuming your in the very lowest gear), but you shouldn't be in the very lowest gear for a 15-20% incline at all, so the lowest gear available should be irrelevant.

What gear do you climb in?

Simon

VinceCable

Well this was the very first time I rode the bike - my old bike is a slack fork angle/chopper style freeride bike with 6 inches of suspension and no lock out.

The ride was a night ride up a snow/ice covered road that was impassable by cars. I was in the lowest gear on the 20% sections afaik, smallest chainring/largest cassette. The tyres are Bonty Mud X 1.8.

I calcuated the gearing from the advice here: http://www.kenkifer.com/bikepages/touring/gears.htm - i may have made a miscalculation.

I am thinking that the rolling resistance and occaisional loss of traction due to the snow and ice, coupled with the 4 layers of clothing (ideal for where I was going but not for the climb) and the mist affecting my asthma may have made me feel it was a lot harder than it actually was. I did love the speed, riding position and feel of the anthem.

The Rookie

I suspect the clothing and wheelspin was the issue....that or maybe you were just going faster than usual and that was why it felt hard work!

I suspect you dod make a mis calce, 50+ inches is much longer than a lowest gear, read that page, it suggests around 21"!

Simon

njee20

but you shouldn't be in the very lowest gear for a 15-20% incline at all, so the lowest gear available should be irrelevant.

That depends on his fitness, perhaps you don't need your lowest gear, but that's a pretty steep climb!

He's right otherwise though, the Anthem has a significantly lower gear.

supersonic

Given the same wheel {and tyre size} it is just a simple ratio of chainring to sprocket ie:

22/32 vs 24/36

=

0.6875 vs 0.6666

So to confirm the above, the lowest on the Anthem is lower... the rest however in the smallring will be a little larger, depending on the exact comparisons of the sprockets.