New answers tagged

2

Since the front derailleur moves up when shifting out and the outer ring is smaller, the chain will most likely fall off. And shifting inwards will wear the bigger chainring since it is not made for changing gears from the bottom right. The bigger chainring has small pins that will make changing gears smoother but the other side doesn't, so you're basically ...


1

Chainline could be an issue. Cross-chaining, i.e. big ring and big cog or small-small, is bad because it increases chain wear and drivetrain friction. With the large chainring on the outside as it normally is, it’s positioned to have good chainline with the middle and smaller cogs, i.e. your highest gears. If the big ring was on the inside, then when you ...


2

I've done the chain-setting by hand for a couple days when I was waiting for a replacement front mech to arrive. It worked, but without a FD cage the chain could bounce around and fall off at bumps, like coasting through gravel. Also, setting the chain while riding was awful-risky because you're bent right down to reach your chain. It gets old fast, and ...


3

For road bikes the subcompact cranks have a bolt circle of 110 mm diameter. The smallest chainring that fits is 34 teeth. There are cranks with smaller bolt circles and small chain rings available, but the selection is limited. Your proposed 42/26 is available in mountain bike cranks, but matching that with road cassettes is a challenge. The chainlines ...


10

There is a limit to the amount of tension a given chain should be put under. Smaller chainrings increase that force - the pedal arm and chainring form a lever, and the smaller the chainring (and longer the pedal arm) the more force will be applied to the chain given a fixed force on the pedal. What you might be gaining in terms of chainring and cassette ...


14

Gear ratio range. If you decrease the chainring sizes you decrease the highest ratios available. It's not possible to make the gap between the chainrings much bigger and get decent front shifting so the large ring has to shrink with the small one. It's easier for manufacturers to make a wide ratio cassette that retains an 11 tooth sprocket and shifts ...


11

You mostly answered your own question: the racing market drives the industry, sometimes to the detriment of the availability of real-world gearing. A major compounding factor is that there are a lot of hoops a person has to jump through to get smaller rings on their road bike, starting with buying new, weird, mostly old or retro cranks. Making things work ...


3

For completeness, I ended up replacing the bolted-on brazeon mount with a band-on braze-on mount. This allowed me to raise the derailleur by those critical last few millimetres. If the bike had a brazed-on braze-on mount then I might have had to cut it off and file the seat tube to a round finish, but fortunately this Cannondale frame had a small bracket ...


Top 50 recent answers are included