Chainset/Gear ratios/I don`t understand!!

[Sunny Portrush]

Hi,

I was thinking of entering a sportive but looking at some of the blurb, it says that they a bottom gear of 39 x 25-28 minimum is recommended.

I have a compact chainset (50/34) and the cassette is 11/30. I take it that means my bottom gear is 34x30.

Does that mean that my bottom gearing is easier when climbing than say 39x28?

FWIW, I quite like going uphill, i`m just not very fast at doing it!

 

[Mo1959]

Hi,

I was thinking of entering a sportive but looking at some of the blurb, it says that they a bottom gear of 39 x 25-28 minimum is recommended.

I have a compact chainset (50/34) and the cassette is 11/30. I take it that means my bottom gear is 34x30.

Does that mean that my bottom gearing is easier when climbing than say 39x28?

FWIW, I quite like going uphill, i`m just not very fast at doing it!

Yes, quite a bit easier so you should be fine. My lowest is 34/28 and I can get up most hills around here even although I'm getting on a bit! Lol

 

[Sunny Portrush]

Yes, quite a bit easier so you should be fine. My lowest is 34/28 and I can get up most hills around here even although I'm getting on a bit! Lol

Cheers, although I`m not sure it`s what I want to hear - I was looking for an excuse as to why i`m useless at climbing lol

 

[Sailorsi]

Sheldon explains all regarding gear ratios should you wish to do some more reading. It gets a little technical but good for comparing different bikes. Here's the link to his calculator:
http://www.sheldonbrown.com/gears/
Good luck on your Sportive, I have yet to attempt one but keep coming up with excuses.....

 

[Dogtrousers]

Cheers, although I`m not sure it`s what I want to hear - I was looking for an excuse as to why i`m useless at climbing lol

"My brakes were rubbing and I didn't realise"

 

[Racing roadkill]

It's complicated, you need to think in terms of 'gear inches' or ratios, rather than discreet 'gears' you'll find there is a fair bit of overlap in the combinations between chain rings and sprockets. Then you have to factor in the actual physical size of the chain rings ( thinking in gear inches addresses this to an extent). So you may find that a granny ring and given sprocket, will have the same ratio as a big ring and different sprocket, but the gear inch calculation will give the reason it doesn't feel the same. I have triple chainsets on 2 bikes, a compact on 1, and a semi compact on another. I have an 8 speed cassette (11-25), on one of the tripled hybrids, a 9 speed 12-27 cassette on the tripled road bike, a 10 speed 11-32 on the compacted hybrid, and an 11-28 10 speed on the semi compacted road bike. I can do all the hills I encounter regularly, on my travels on any of the bikes, but if I know I'm going to be going up a 25% gradient, I'll use the triple 12-27, because I've got more choice, and less gap, between ratios.

 

[Sunny Portrush]

"My brakes were rubbing and I didn't realise"

lol - no-one told me the hill went up-the-ways!

 

[Sunny Portrush]

[QUOTE 3909632, member: 9609"]your 34>30 will be about 23% easier than a 39<28
if you have a sprocket with 24t, then try your bike in 34>24 this will be very similar to 39>28[/QUOTE]

Well, that`s made my night - 23% easier, if I went any slower uphill, I`d be going backwards lol

 

[cyberknight]

I go slower up hills twiddling a low gear than standing and pushing a bigger one , my legs just dont like to spin away .