JReade

If it's only the first few turns, I'd chase it from the backside and hope it works. I saved more than a few cranksets this way at the Co-op.

VaBeachTennis

I know this is an old thread and this may be a silly question, but which way did you have to thread the pedal in from the other side? If it was a right thread (crank side) did you have to turn it right or left to get it to thread the other way? I'm about to buy a bike that has the same problem.

FBinNY 

To be sure we're on the same page, you would still be using the same pedal, or one with the same thread direction, ie. right for right regardless of which way you thread it.

The direction you turn it is still the same with respect to the pedal, but the answer depends on where you're standing. If you have a right pedal and are standing to the right of the bike to attach it normally, you would turn it clockwise and it would move away from you and into he crank. If you switch sides when threading the pedal to the back of the crank the same is true, clockwise it moves away from you and toward the crank. (the reverse is true for left threads).

A sure way to never be confused about which way to turn a part is to remember the right hand rule. Hold the part in your palm with your fingers wrapped, and your thumb out as if hitch-hiking. If you turn the part the way your fingers are pointing it will move in the direction your thumb is. For left threads use your left hand, or use the right, but remember that it's backwards.

VaBeachTennis

Thank you for the answer. The problem is on the crank/sprocket side, so to tighten it the way I would tighten a regular pedal for use is toward the front of the bike. So when I try to chases the threads from the other side of the crank, I have to turn it toward the front of the bike too? I know once I get my hands on the bike, it will be pretty self explanatory, I just didn't want to chase the threads the wrong way and further mess up the threads.

FBinNY 

NO, NO, NO.

If you turn a right pedal to the front of the bike, it moves left (stand there and apply FH rule). So if it's on the outside of the crank (normal side) it moves inward (to the left). But when you put it in backward, you still have to turn it to it's right, which would now be toward the back of the bike.

CliffordK

I always use clockwise and counterclockwise.

So, for the right crank, tighten (pedal goes in) by turning clockwise.
Loosen (pedal goes out) by turning it counterclockwise.

The same will be true with threading from the back side.

You can always thread the pedal with your thumbnail in the groove to see which direction the threads will take you.

FBinNY 

Problem is that the turn direction depends on where you're standing.

Let's say that you're standing on the right side of the bike and fitting a right pedal, then yes, you turn it clockwise. But you now decide to thread it into the back of the crank. If you move to the other side of the bike you'll be facing the other way and still turn it clockwise.

But if you stay put on the right side, and simply reach around the crank and thread it from the back side, now everything is reversed clockwise to the pedal, is coun ter-clockwise to you.

Right/Left, clockwise/counter, or whatever, it's about frame of reference. This is a common issue for people new to working on wheels. Like any right hand nut, you tighten a nipple clockwise --- IF you're looking down on it from outside the rim and using a screw or nut driver. But most of the time you're looking out from the hub side, and using a spoke wrench, and from that point of view, "clockwise" is counter-clockwise.

How about clockwise to move the part away from you.

VaBeachTennis

I want to thank you very much for your advice, it all made sense when I started actually doing the job. The person I bought the bike from really flubbed up the threads in the beginning of the crank (when you first insert the pedal) but the pedal caught on and was/is tight on the last 1/3 of the crank. It enabled me to get a pretty snug fit and I was able to apply some pretty good torque to it to tighten it but not over tighten it. I took it for a five mile ride and was mostly spinning it instead of mashing it but I did put some pretty good torque on it and so far so good.
On a really good note, I found a shop that will repair the threads for 15-20 bucks.