Replacing shimano 600 crankset with 105.

Hi Guys,
am wondering if its OK to replace a shimano 600 crankset and bottom bracket with a 105 crankset and bottom bracket (octalink)?

Yes, as long as you get the correct BB for your frame.

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+1. I've done it and it works. You might need to adjust your derailer mounting a little if you are going to use chainrings with different tooth counts than what you originally had.

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FWIW. Depending on the situation where you are (specifically, eBay), it might be slightly better (more economical in the long run) to look for an Ultegra crankset because:

• the Ultegra chainrings are better (i.e., nickel-plated == longer wearing)
• the Ultegra crank comes with self-extracting bolts

In North America, the price difference (new OR used) isn't very large (or, not as large as the cost differential for the rings & bolts ... way-back-when, when NEW, the difference was only about $20US [the cost of the self-extracting bolts, alone] & the chainrings probably cost 50% more) -- so, the 105 Octalink crankset is is one of the 105 components which isn't the bargain one might presume or hope for.

I've got an unused 105 Octalink BB as a spare in my toolbox, so I cannot tell you if it is signifcantly better-or-worse than the Ultegra/DA bottom brackets, but my reckoning is that the difference is mostly cosmetic (and, cost).

I actually prefer the 112.5mm XTR Octalink because it means I can readily move between a double & a triple crankset (a discovery made through laziness) whereby I only need to adjust the front derailleur's inner stop (after switching cranks, that is). The XT & LX Octalinks have a different spline pattern, in case you were wondering.

Good point! I cannot really feel any difference between an Ultegra BB and a 105 BB, however, according to our buddy steelem, you will be able to go 20 MPH faster if you use a DA BB instead of a 105 BB .

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I only managed to get about 15,000km (in fact, it was catching a little at about 8,000km, not so you'd notice when riding) out of a 105 Octalink BB, a figure that looks poor in comparison with a cheaper square taper BB, and probably reflects the much smaller bearings that I imagine are able to fit with the fat axle. I'm not sure whether Ultegra is any better, but I'm in the process of finding out.
If you don't already own the BB/crankset, you should prefer a Hollowtech II set.

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