Cheap Vs Expensive

[Peter Armstrong]

A compact is fine! 50:11 is plenty tall enough, I barely ever touch that ratio. I am a bit of a spinner though, but still even on descent's you would probably bottle it before you felt the gears were limiting you. Once you are descending at those speeds you will most likely freewheel and try to get nice and aero.

Narr, Ive maxed at 47mph, I just run out of gears, anything 40+ any its just too high rpm, I'm looking for higher gears. I NEVER BOTTLE IT ARRRRRRRRRRR!!

 

[Rob3rt]

The input from the pedal's will have a minimal impact on speed at those speeds vs taking on a nice aero position.

 

[Peter Armstrong]

I can get a nice areo posistion and pedal, so does anyone know if your looking for higher gear is somthing you have to buy addtional or can you buy it striaght on the bike from new?

 

[Rob3rt]

Getting bigger gears for the descent, which is a short period of time vs the ascent, will cripple your climbing unless you end up with a very wide range cassette to accommodate both. In which case your gear spacing will be wide and a pain on the flat.

 

[Peter Armstrong]

Getting bigger gears for the descent, which is a short period of time vs the ascent, will cripple your climbing unless you end up with a very wide range cassette to accommodate both. In which case your gear spacing will be wide and a pain on the flat.

So maybe work on my cadance speed instead of worring about the high end gears?

 

[Rob3rt]

Just get into a good position and hold it, work on minimising speed losses in your cornering and you will get faster on descents, no point spinning like a madman, you wont be able to keep on top of it.

Just for interest, many pro's use compact's and big cassette's on the climb's, which means they are also running compacts on the descents!

 

[Peter Armstrong]

But I like being a madman, thats how I have loads of KOM sprints and decents

 

[rb58]

Looking at some bikes £800-£100 and most have compact 50/34, is this the norm? I want somthing that has 52+ for some serious decent speed.

Would you have to alter the gears yourself?

This is normal. Most road bikes these days will have a compact double, which is probably the best compromise for mere humans. But, many will also offer the option of a regular double, which will be something like 52/39. Or if hills are a challenge for you, then a triple could offer you 52/39/30. Search the forum if you want to know the pros and cons of each, as it is discussed at length quite frequently..... Also, before you jump for a large chainring, read up about the efficiency of pedalling a higher cadence which might influence your choice.

 

[Rob3rt]

If you want big gear's get them, by all means! Sound like you have made your mind up anyway.

 

[Globalti]

Rob3rt: Eek! Really sorry mate, one false apostrophe is bad but four in a row is too painful....!

"pros use compacts and big cassettes on the climbs".

... carry on!

 

[GrasB]

Assuming a high power cadence range of 95-135rpm in the nice tight range of an 11-23 cassette, 13-17t sprockets, we get the following speeds:
50t = 21.8-40.5mph
53t = 23.1-42.9mph
56t = 24.4-45.4mph
59t = 25.7-47.8mph

You should be able to high the high 140rpm for short perods but 135rpm is about what most people top out at for sustained periods. That's 47.9mph on 50/11, 53/11 50.7mph, 56/11 53.6mph & 59/11 is 56.5mph, from about 50mph looking to need about 600-800w to beat the aerodynamic disadvantage of peddling v's being in an aero position that you physically can't pedal in.

 

[Peter Armstrong]

Assuming a high power cadence range of 95-135rpm in the nice tight range of an 11-23 cassette, 13-17t sprockets, we get the following speeds:
50t = 21.8-40.5mph
53t = 23.1-42.9mph
56t = 24.4-45.4mph
59t = 25.7-47.8mph

You should be able to high the high 140rpm for short perods but 135rpm is about what most people top out at for sustained periods. That's 47.9mph on 50/11, 53/11 50.7mph, 56/11 53.6mph & 59/11 is 56.5mph, from about 50mph looking to need about 600-800w to beat the aerodynamic disadvantage of peddling v's being in an aero position that you physically can't pedal in.

Thankx, interesting stuff!

 

[Peter Armstrong]

My current rust bucket has 52t and was wanting maybe a little higher of a gear thats all

 

[Peter Armstrong]

Been looking at this http://www.evanscycles.com/products/cannondale/caad8-6-tia-2012-compact-road-bike-ec031475

 

[Rob3rt]

Looking at your data from another thread, if you are interested in increasing your average speed (I see that you are averaging like 15-16mph) you would be better off investing time into getting better at going up hills quicker (or money into easier gearing to get up them faster, exactly as a compact would offer) and on your sustainable flat speed than it would brief periods of high speed down a hill or a couple of hundred metre flat out sprint a few times per ride.