Chainset/crankset

[jtothec101]

Hi there,

Massively new to biking, and am undertaking a massive 1000 mile charity bike ride in the summer.

I have myself a lovely new road bike, and have managed to damage the crank arm and chain ring, looking to replace them all.

I currently have a Truvativ Iso Flow 39/52, not looking to spend too much money, but one something as good if not better for around £50.

I have found RaceFace Cadence Road Chainset 39/53 - is this too big? i don't understand about the ratio's at all!

If you have any suggestions of better, or more suitable chainsets, please let me know. Really want to get back on the bike and training as soon as possible.

Thank you,

Jack

[bobtravers]

Well, you will go to a higher speed with a 53 teeth chainring, but you will have to put much more effort...

If you were happy with a 52/39, why not stick to a new one??? Another thing to check, is will the length of your chain will fit a 53 teeth chainring, and also is your rear and front derailleur will take a new difference of gearing?

[1FJEF]

I didn't know that 1 tooth would make that much difference on a chain ring.

[DaveM]

(03-28-2012, 04:25 AM)1FJEF Wrote:  I didn't know that 1 tooth would make that much difference on a chain ring.

Adding 1 tooth to a 52 tooth chainring ups the gear ratio by less than 2%. So at the same cadence you would go less than 2% faster and probably have to put out around 2% more effort (due to higher wind resistance). So "more effort"? yes. "much more"? maybe not.

[1FJEF]

I wonder if you would feel it? I guess so, as I can feel a one tooth difference on a rear cog as I shift up.

[DaveM]

Probably, 2%'s not nothin. But one tooth in the back usually means a much bigger jump. Going from a 20 tooth to a 21 tooth is a 5% change. It's the percentage increase/decrease in size you feel, not the specific number of teeth added.

[bobtravers]

Euh, running a 52 or a 50 makes a lot of difference for climbing as an example... That why they introduced compact design crankset a couple years ago...

[Joe_W]

Well, if you climb on the big chain ring you are a stronger person than I... the compact design is so that you can look like a pro (only two chain rings) but can actually ride uphill instead of pushing the bike. The difference there is 34 in contrast to 39 (or 45 for my old Peugeot), a difference of 12% (or 29%).