crank and bb for an older bike

[cloudhead]

Hi, I have a Trek from 1985 and need to get a new crank and bottom bracket. It's a realm I am not too familiar with. Its a touring bike, so I am looking at triple cranksets.

I had the rear of the frame spread to 130mm so I can fit a modern wheelset, not sure if that affects the decision of the bottom bracket width.

Thanks in advance for any tips.

-Court

 

[dabac]

At that age, I'm assuming it's square taper.
Despite all the new designs available, there really isn't much wrong with square taper, and parts are still readily available. Measure the width of your BB shell (68/73 mm), your axle length, and figure out which threading you have(Sheldon Brown-Bicycle Technical Information will tell you how), then go buy whatever fits and catches your fancy.

 

[Peter@vecchios]

Hi, I have a Trek from 1985 and need to get a new crank and bottom bracket. It's a realm I am not too familiar with. Its a touring bike, so I am looking at triple cranksets.

I had the rear of the frame spread to 130mm so I can fit a modern wheelset, not sure if that affects the decision of the bottom bracket width.

Thanks in advance for any tips.

-Court

Any modern triple crank will work just fine on that frame. shimano 105 version is nice, has fairly low gearing(50/39/30) and swapping the 30 for a 26 is no big deal since the big ring is a 50t.

 

[cloudhead]

Thanks for the tips.

The BB on my road bike from this year looks quite a bit more engineered than what I am used to. I have a 105 (double) crank on my road bike, so maybe i'll try tinkering with it before I yet-again purchase something that doesn't fit. Also found a pretty cool Sugino, which is what the original crank was.

So if I am reading correctly, most modern cranks will fit a square taper? Is there a way to find out what kind of threading my BB has? I read that there are differences between french, british and italian styles.

Thanks again,

COurt

 

[alienator]

So if I am reading correctly, most modern cranks will fit a square taper? Is there a way to find out what kind of threading my BB has? I read that there are differences between french, british and italian styles.

No. Peter meant that most any triple crankset will work. A crankset includes the crank arms and the bottom bracket assembly. Square tape cranks only work on square taper bottom brackets.

 

[cloudhead]

No. Peter meant that most any triple crankset will work. A crankset includes the crank arms and the bottom bracket assembly. Square tape cranks only work on square taper bottom brackets.

Thanks for the clarification.