Help me understand gears

[Tomba]

I've cross posted this as I only got one response in the Know How section.

I've done a search and i'm still confused. I've also had a look at Sheldons gear calculator thingy but still dont get it.

I'm currently riding a hybrid with a front 48/38/28 and a back 11-32 8 speed.

I'm seriously considering a road bike, this is the confusing part. It looks like a lot of them have a compact double 50/34. One in particular has that front and a 12-30 back.

My concern is the hill climbing. At the moment in the granny gear (28 front, 32 back) I can climb decent hills. So with the compact double lowest gear (34 front, 30 back) would it be a lot harder or nearly the same.
The crank length on my hybrid is 175mm and the road bike is 172.5mm.

I know the road bike is lighter so might negate the harder gearing.

I'd appreciate some lay mans enlightening

 

[VamP]

Take a look at this calculator and if it still does not make sense, come back and we'll try to explain.


And to answer your question, yes it will feel like harder work with the compact.

 

[Tomba]

Thanks for the link to the calculator VamP.

I've input my numbers but still dont really understand them

But I suppose you've answered the real question on whether it will feel harder on the granny gear

 

[Moss]

Well you've both confused me! Compact 34/50 with a 12/30 cassette? 34, front and a 30 tooth on the cassette = climbing mount Everest if there was a road to the top! I have a compact 34/50, with a block of 11/28, I can manage most hills at my own pace; and I'm going on to be 64, years old. Had major heart surgery and have some dodgy knee problems! Stop Whinging and get yourself a compact road bike, you'll not regret it; and you'll get a lot fitter and healthier, Of-course it's JMO

 

[Sleeper]

FYI I work my gear ratios back to the crank/wheel revolutions. E.g. First gear in my block = 25, smallest chainring = 39, therefore 39/25 gives me a ratio of 1 (crank rev) : 1.56 (wheel rev)
Apply this to your combos and considerations to get your yardstick
Hope that clarifies? Ben.

 

[Tomba]

Thanks for the replies so far

FYI I work my gear ratios back to the crank/wheel revolutions. E.g. First gear in my block = 25, smallest chainring = 39, therefore 39/25 gives me a ratio of 1 (crank rev) : 1.56 (wheel rev)
Apply this to your combos and considerations to get your yardstick
Hope that clarifies? Ben.

Ben, that makes it easier for me to understand, cheers

Going on that the compact 50/34 lowest gear gives me a ration of 1:1.1333
The closest I can get to that with my hybrid is 28 front 24 back is 1:1.1666.

I'll give a few hills a go on that gear and see how I get on.

Appreciate you lot being patient with a clueless newbie