Bike Forums - Double to triple crankset conversion

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Double to triple crankset conversion

I have a Shimano Sora 8 speed triple crankset on a flat-bar road bike and want to change to a Sora double crankset. The one on the bike is square taper but the double is an Octalink. So, does it use the same bottom bracket installation tool as the square taper? (I hope I'll be able to use the same crank puller and bb tool.) Can I still use the same triple front derailleur without adjusting height? And do I need to switch shifters? Mine is a 3x Shimano R440 flat-bar shifter.

It's temporary because I want to know if I want to buy a hybrid bike with double crankset. I had the Sora crankset in a box because I hadn't sold it yet and never used it.

A whole lot easier way to get to almost the same place - screw in your low gear limit screw on the FD until you can no longer shift onto the inner. Instant double. No need to do anything with the shifter. Yes, your chainline will not be perfect. Your gears will just work exactly as before. But you get to see if this is a concept that works for you. (I use to do exactly this to turn my tripled road bike into a race bike before I bought a real race bike.)

Ben

"It's temporary because I want to know if I want to buy a hybrid bike with double crankset."
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I think the best way to determine whether if a double crankset will work for you is to use one of those on line gear inch calculators and plug in the numbers on your bike now, and on a bike you are considering.

Compare the range and Gaps between gears on each ring. Also consider how long you are likely to stay on one chain ring. Some double's will have you constantly switching chain ring's, While the triple's middle ring might be enough for 90% of our riding.

Both should function reasonably well when properly adjusted. I'm guessing a double is more forgiving though. My bike came with a triple, Which I like, But if it came with a double, Like my last 2 bikes, I'm sure I could work with that too.

I'll probably try that trick of just adjusting the FD to use only the first two chainrings (or maybe the last two, who knows).

The hybrid I was considering has a 46/30 crankset which I find is a good idea because most of the time I want to roll real slow to save my energy for my workouts. So I find myself using the 28T chainring most of the time (on my winter bike). Come to think of it, if I adjust to use the 30 and 42 chainrings on my Sora crankset, I might have an idea how it will work.

I'm guessing my shifting on a 46/30 crankset might be like this: use the 30T chainring with the largest cog in the rear until I lose my patience if I'm going slightly downhill, then I could start to shift towards the middle of the cassette then shift to the 46T chainring if I'm really in a rush (before I get the the small cog to avoid the small-small combination which would twist my chain).

EDIT: I just calculated different gear combinations on the Sheldon Brown web site. I only have to use the 4 easiest gears while on the smallest chainring then I can switch to the 2nd chainring on a triple crankset or the largest chainring on a double. So it looks like I might be correct in assuming I'd prefer a double cransket. A triple looks a bit useless to me at this point.