Hello everyone I am in the process of building a 1x8 road bike out of a cannondale r500 frame. Purchased the bike from a guy before I realized that the majority of the components were in terrible shape. So I count my loss and start building. I am wanting to put the least amount of money in it to ride it. I am wondering if I can use a single speed crank that I have? And also who makes a good budget wheelset? Just looking for some recommendations.

Single speed crank is what you should use. Is the one you have the same style? (square taper, or something else?) If so, use it.

Lots of choices on budget wheels. What's wrong with your present wheels?

Exactly how trashed are which parts?

-Just about any crank can be used for singlespeed, typically you'll be using the middle chainring position on a triple crank or an outer chainring position on a double. But not always.

-Even if the derailers are thrashed, you can probably use the rear as a chain tensioner (tighten both limit screws to position the derailer exactly where you want it, line the chain up with the cog you want it on) and the front can be use to keep the chain from jumping the chainring (bend it flatter with pliers if you have to)- again, just use the limit screws to position the derailer where you want it. Disconnect/remove the shift cables. You may not actually need to spend anything at all.

A lot of budget singlespeed cranks are just doubles with a singlespeed chainring. Chainring and bottom bracket/chainline matters far more than the crankarms.

my understanding is that the narrow/wide chainring is pretty important to the performance of a 1x system. I used to run 1x a couple of decades ago, chain drop is a real issue

Narrow-wide is only important in the context of mountain biking, especially full suspension bikes where the chain is length is doing all sorts of craziness. A narrow-wide ring is best, but you could probably get a decently reliable road build with any single-speed chainring

Eh, I've never used a n/w ring and have never had an issue as long as the ring and chain were in ok shape, and my derailer/tensioner had plenty of spring power. They're pretty cheap on ebay these days, I've considered trying one. Not sure what chains they're built for, though (there are lots of chain widths out there).

Well the present wheels have been worn down pretty bad. The shifters would no longer shift I believe something was broke as they were very lose feeling. The single speed crank that I have uses the same bb cartridge so I believe it will work. I believe I just need wheels and a rear derailleur and a shifter.

same style, or exact same style and length?

edit: noticing some of my posting earlier was wandering into strictly singlespeed talk. Honestly, you already have your 1x bike, just remove the parts you don't want (front derailer and cable- or just leave them on and never touch them) and replace the worn parts (rear wheel, derailer). 1x7/1x8 parts are super cheap, even a new pair of integrated shift levers are dirt cheap on ebay these days.

i've toured and commuted extensively(20-30 thousand miles) on a 1x7 and now ride SS. i've had no problems whatsoever, using a standard road double or even a MTB triple crank with a single road chainring. i set a little slack on my SSs and maintain an excellent chainline. good luck.

You know if I wasn't riding with other guys I would set it up just as a SS I love the simplicity but my only issue is I won't be able to keep up with my friends on roadies.

Make sure that your existing single speed chainring is 3/32" not 1/8", so that your 8-speed chain will mesh properly. Set your chainline carefully, getting as close to the 4-5 intercog space as you can. That should do it. Not an IGH set-up, right? So, get a rear derailleur that has a snappy tension spring, and that can handle the largest cog size that you plan.

To save a little money I disassembled the bottom bracket cleaned it and rebuilt it but it is a 113mm bb. Will I have to use a triple crank to get the right chainring? The crankset was a two ring crank. Should I use the inner chainring position to get the best chain line?

A Triple crank the middle chainring is on a good chainline for a 1 by, outermost chainrings , removed or ignored.

Chainline = a line between the center of the cassette (between 4th and 5th of 8), parallel to the centerline of the bike..

so chain deflects the same angle/distance to 1st and 8th cog)

Ok so will the double crank that I have now work? Or should look for a triple?

IDK, can you buy different length BB spindles to get the Chainline right?

or just have a shop do it for You, if its too complicated.

I think most single cranks that aren't the expensive mtb type are almost all 170 mm with the old school sealed bearings and tapered square locks for the arms.

The bb on it right now is a 68x113 if I use the cranks that are on it now and just a single speed chainring bolted to the outermost spot that should give me a good chain line correct?

I was just making a random comment. it's already been suggested that if you want to run a cassette in the back, then it's best for the chainring to be multispeed compatible too, not a single speed ring, which tend to be thicker in the teeth.

I think using the middle ring on a triple would be best for getting the full range. it would be best for chain flex in either the low or high end of the cassette. that flex will cause a little more wear on your chain, and take away a little more efficiency, but more importantly, it might affect your shifting. I don't know about others, but my shifting sucks when I'm in my 53/28, which is a combo that I try to never use.

Actually I'm considering doing the same thing. Except instead of a cassette, I'll be running a igh. It just hit me that it makes a lot more sense to recycle my worn out triple and get a 1/8 chainring than buy a cheapo square tapered Crankset that are way flexier than modern cranks. And it'll let me keep the bb standards the same between the bikes.

So quick question. Am I better off using the middle ring on my triple for optimal chain alignment with the rear SS cog?