Which Gearing?

Miles wants to know what gearing he should have on his bike; we discuss which chain sets and cassettes he should use on his “average road bike”.

Question:

Sam…
For the average road bike … What size chain wheels (2) and rear hub gears do you recommend?
…Miles Borden

Hi Miles.
This used to be a tricky question as the standard chain set had a 52 tooth large chain ring and a 42 small chain ring, the rear cassette would be 12 to 23 or 13 to 32 and lots of different combinations as there were only 6, 7, 8 or 9 speed cassettes.

Then chain sets became available with a 39 small chain ring which made things much easier, but the big development was the compact chain set with a 50 tooth outside ring and a 34 or 36 inner, this covered every eventuality, and then with 10 (now 11 also) speed cassettes you didn’t need to change gear ratios for different road conditions.

So to answer your question; for an average bike I would go for a compact chain set, 50 x 34 with a 12 to 21 cassette, with this combination you will be able to climb most hills and ride on the flat with out any problems. The only time you might be put out would be on a fast pedal able descent or sprinting, so if you are considering racing you would need to think about a 52 tooth chain ring.

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5 Responses to “Which Gearing?”

Nigel Schuster August 28, 2009

I recently went from compact 50+34 x 12 – 27 for riding in Spain (the driveway was 16%!) to 52+39 x 12 – 25. Now that I’m back in Ontario the gearing is OK but I do miss the light pedaling on a steep hill at the end of a ride. Shifting from ring to ring has less of a jump in ratios for the 52+39. With the compact set up you have to pre plan shifting rings because of the extreme ratio jump 50 to 34. I believe you can keep the same chain when changing inner rings but you may need a new chain when increasing the size of the biggest sprocket on your cassette. Please get 2nd opinion.

sandy September 1, 2009

hI Nigel Schuster, I’m having a new bike delivered here sept 2nd (2010 model bottecchia carbon fiber rd bike dura-ace for 1695)that has the fsa sl-k light hollow carbon 50×34T crank. Where I live there are tons of hills, and my knees are crunchie. I’m having the bike built on thurs. do you think i should have them add an granny ring if they can even do that to make steep hill climbing easier? thxxxxxx. for all replies.

Lashan September 4, 2009

I use a 53/39 with a 7 speed 11-28 rear cassette. I have thought of running a 50/38 chainring but in two minds if the 50T large wud be sufficiant if I need to sprint.

Greg September 4, 2009

Just got a new bike with a compact crankset, 11-26 cassette, so far this is fine here in Colorado, I have some 16-18 % grades on some of my rides and this seems to work all right so far, I am not a small climber but large guy 6′2″ 180 lbs. and 54 years old. I could do this with my old set with a 39 inner but knees paid the price later since I couldn’t spin as fast as needed on the steepest parts.
There is a big gap when going from the large to small rings, and usually when I do I add one or two to the cassette unless on a steep hill. This seems to help with the gap. I shift alot more but my knees are happier.
Hope this gives you some help.
Greg

Yves September 9, 2009

I ride a Specialized Roubaix Expert with a triple crankset (53-39-30) and a 12-27 10 speed cassette. At 51 years of age, I ride about 6000 km per year and on a 50 km mostly flat ride, I maintain 28 km/h average speed, well below a Tour de France pace but OK for my knees. On steep hills (13% for 5 km – Cabot Trail; 12-19% for 10 km – Smuggler’s Notch; 10-15% for 5 km – Jay Peak; 18% for 0.8 km St-Joseph-de-la-Rive) the 30 front gear is great for my knees and the 53 great for reaching 80 km/h downhill. I use the 39 front gear most of the time unless I ride above 35 km/h or below 15 km/h. I realize that a triple crankset would not be useful for all the powerful racers but I am most happy with it as an amateur “performance” cyclist.