Changing rings...

[robpearson]

I'm currently riding a trek 1.2 with 50/34 fsa vero Chainset, and as a committed MTB rider I'm really struggling with spinning my legs really fast. My comfortable pedalling speed of about 70-80rpm means I struggle at higher speeds (usually pointing down hill).
My question is, can I replace my 50 with a 52 or 53 tooth chain ring? If I do, am I going to have to change the 34 up to a 39 to make up for the large gap in the ratios?

For reference, my smallest ring at the back is a 12t

Any advice gratefully accepted. (apart from references to rule 5)

[Roman]

robpearson said:

I'm currently riding a trek 1.2 with 50/34 fsa vero Chainset, and as a committed MTB rider I'm really struggling with spinning my legs really fast. My comfortable pedalling speed of about 70-80rpm means I struggle at higher speeds (usually pointing down hill).
My question is, can I replace my 50 with a 52 or 53 tooth chain ring? If I do, am I going to have to change the 34 up to a 39 to make up for the large gap in the ratios?

For reference, my smallest ring at the back is a 12t

Any advice gratefully accepted. (apart from references to rule 5)

Easier to change your cassette (which is a consumable anyway) to one with an 11t top sprocket instead of a 12. This would give you a slightly higher top gear than fitting a 54t chainring with a 12 and no issues with lengthening your chain, or moving your front mech either.

You should do some practice pedalling at 90-100rpm though - it will help your endurance and efficiency by smoothing out your pedal stroke and power delivery.

[Oscar the Grouch]

Changing the 50 chainring to a 52 or 53 would require a complete new crankset as the bolt pattern is different (110 vs 130 bcd).

Changing to an 11-25 or 11-27 rear cassette would be easy to do.

I do agree with last reply - 90-95rpm is easy to ride at with some practise

Edited by Oscar the Grouch on Tuesday 22 March 05:31

[zasker]

I mainly mountian bike and my cadence has always been on the low side (70 - 75) and have really struggled in the past to increase it but I've done some session on the turbo trainer and concentrated on keeping my cadence up when out on my bike and over a matter of 3 - 4 weeks have so far got it upto around 85. Agree with the others though that the easiest way would be to change your cassette but also try and concentrate on upping your cadence.

[itsnotarace]

Posted this the other week in that 35mph on a hybrid thread, it's worth a read.

http://cyclingskills.blogspot.com/2009/05/speed-le...