I have a 12-year-old Giant Rincon mountain/hybrid bike (not exactly sure what you'd call it, but it has a horizontal top tube) that I want to convert to singlespeed. It needs a new crankset, however, so I was hoping for suggestions on what type you would go with, or what the important considerations are, if it's going to be specifically for singlespeed. Thanks.

When I built up my singlespeed, I used an inexpensive Dimension cyclo-cross crankset and narrow chainring bolts. It's made for two rings, but looks, and works, fine with just one.

I'm not sure what you want in a crankset. If you want something with more zoot, you can look at something like this.

Whatever crankset you choose, you will almost certainly need a new bottom bracket with shorter spindles. That gives you the opportunity to go with a splined interface, if you want. Or, you can go cheaper and stay with a square spindle bottom bracket.

Another thought: you could replace the outer chainring with a bashguard, eliminate the middle ring, and, if you have enough frame clearance, mount your single speed ring to the granny spider. That way you use the same crankset and bottom bracket, and leave no empty spider arms. I considered doing this, but just didn't like the look.

Whatever you do, use a chainring with no shift pins and ramps. Ditto the cog...use a BMX cog. Those shifting aids make your chain want to shift. On a singlespeed this is not good.

Thanks for the helpful advice - that should get me started on the right track. I hadn't thought about those little shift ramps.

??? Why ??? I've built quite a few single speed/fixed gear bikes and have never had to shorten the BB spindle. Use the middle chainring position of the crank and you'll be fine. On a geared bike the BB and crank are spec-ed to provide a straight chainline w/ the middle ring.

Agree that this is the best course, but you can make do with ramped cogs and chainrings though as long as your chainline is nice and straight and your chain tension is good. Let's you use existing spare parts to test out gear combos until you find the right one.

Ramps, pins + grinder = smooth chainring!

L8R

Why? Jonny T. was talking about using a single speed crankset, that's why. If he is swapping out a triple for a double or single, he'll probably want a shorter spindle.

I read it as he was looking for recommendations for a crankset that will be on a bike that will specifically be for single speeding, not necessarily an SS specific crank. Regardless, it probably won't be necessary for a different BB which ever way he goes. Especially if he's converting an old cassette wheel for SS duty. Plenty of chainine adjustment back there. Just don't want to see anyone droping extra cash when they don't need to when converting a 12 year old bike.

Point taken. There is indeed a lot of room for chainline adjustment.

Then again, how many 12 yr old bikes do you come across that couldn't use a new bottom bracket?

True, unless the thing has barely been used.

I'm curious about the cranks though - Why do you need a new pair Jonny? Bent? Stripped? Just complete Junk to begin with? Might only need a spiffy new Spot Single Speed Chainring.

It's a mess - bent, and pedal threads of the arms are stripped.