compact 50/34 vs standard 53/39

[colinw]

Got my eye on a machine which comes fitted with a compact crank 50/34. My current ride is a 53/39.

Which is better and whats the real difference ?

 

C

[singletrackmind]

53 is faster, only ladies(sorry guys) use a 50

[SeanMort]

Compact cranks are easier on the legs for hilly rides, but if you want some speed on flatter rides then it gets more difficult using them. Depends on the rider and the ride. Just search on the Hub, there is a thread on compact cranks and a gear ratio chart somewhere.

[Ox_Wagon]

If you want to sprint for the 500th position a 53 is definitively the way to go.

 

Check the tech treads, as it has been discussed to death.

Ox_Wagon2008-08-28 10:58:17

[GIRR]

Just stick with the 53, we don't have the hills in this country to warrant a 50.

 

Here a link https://www.bikehub.co.za/forum_posts.asp?TID=24219&KW=compact+crank

[mbaymike]

you can come and try a 50 here in mosselbay...we have a few hills here that may warrant a 50. 

[SwissVan]

 

Below is a link to the Full speed ahead website that has a pdf leaflet on compacts.

Long story short... they give you better low gears for hills without loosing to much on the top end...kind of like having a triple on the front but with only 2 chain rings.

They used to have a nice gear comparison chart on their website but dont seem to be able to find it now...

 

http://road.fullspeedahead.com/fly.aspx?layout=tech&taxid=74

Select ROAD and then Cranksets and click on compact revolution from the list

 

 

[daggavis]

Will also depend on the rear cassette you're running..i.e. a 50/11 combination has a higher ratio than 53/12.

 

 

[Red Zone]

You loose cred if you pull up with a compact, rathern slap on a 56 blade, blow your knees out and look like a man! Go Cancelara!

[mbaymike]

this may be a dof question....why not put a 53 big blade on...keep the small chainring for the climbs.

[Gman1834]

This is from http://sheldonbrown.com/gears/

 

Gear chart using KPH @ 100 RPM

For 700 X 23 / 23-622 tire with 175 mm cranks

With Custom Sizes Cassette

	36	8.3 %	39
23	19.7		21.3
8.7 %
25	18.1		19.6

 

Gear chart using KPH @ 100 RPM

For 700 X 23 / 23-622 tire with 175 mm cranks

With Custom Sizes Cassette

	50	6.0 %	53
11	57.2		60.6
9.1 %
12	52.4		55.6

 

You can see that running a 53/12 is just as fast as a 50/11

And in the low gear 36/23 and 39/25 gives you the same climbing speed.

 

[Minion]

The compact starts looking more favorable if you use a 34 tooth small chainring:

Gear chart using KPH @ 100 RPM

For 700 X 23 / 23-622 tire with 175 mm cranks

With Custom Sizes Cassette

	34	14.7 %	39
23	18.6		21.3
8.7 %
25	17.1		19.6

Gear chart using KPH @ 100 RPM

For 700 X 23 / 23-622 tire with 175 mm cranks

With Custom Sizes Cassette

	50	6.0 %	53
11	57.2		60.6
9.1 %
12	52.4		55.6

It gives a slightly higher top speed than 53-12 and better climbing than 39-25...if you're adapted to spinning a really high cadence.

 

[jabbathemutt007]

 

 

Below is a link to the Full speed ahead website that has a pdf leaflet on compacts.

Long story short... they give you better low gears for hills without loosing to much on the top end...kind of like having a triple on the front but with only 2 chain rings.

They used to have a nice gear comparison chart on their website but dont seem to be able to find it now...

 

http://road.fullspeedahead.com/fly.aspx?layout=tech&taxid=74

Select ROAD and then Cranksets and click on compact revolution from the list

 

 

To get gear inch chart to see gear equivalences try:

http://www.analyticcycling.com/GearChart_Page.html

A 50x11 is actually a bigger gear than a 53x12. Also power is a function of both cadence and gear size and some people turn out more power at a higher cadence especially when climbing.

 

 

 

[NotSoBigBen]

If I have to tell you all one more time that compact is for .............

[jabbathemutt007]

 

If I have to tell you all one more time that compact is for .............

 

Must be tough when the girls drop you on a climb.

 

[NotSoBigBen]

If I have to tell you all one more time that compact is for .............

Must be tough when the girls drop you on a climb.

 

It's OK I nail them on the down with my 53/11 ...........