As some of you have gathered from some of my recent posts, I'm in the process of modifying my Trek XO cyclocross bike into a light tourer. I've orded most of the parts I intended to switch. I've ordered a Deore LX rear deruallier and 11-32 cassette, bar end shifters and seperate brake levers.

My dilemma is this... I can't decide if it's worthwhile to replace the Sora crankset with 105. The chainring size is fine for light touring (52/42/32) with the 11-32 cassette and the 105 as the same chainring size. The 105 is weighs a little less and it's better quality, but is it worth it? Performancebike.com has a new 105 triple crank set for about $100, and with a compatible bottom bracket, it would cost about $125. Do you think it's worth it? As anyone had experience with both sora and 105 cranks?

Also, on ebay, someone is selling a 105 crankset with 52/42/22 chainrings. The auction still has about 4 days to go, but it looks like it will go for about $40. I'd still have to get a new bottom bracket, but altogether it would be about $65. It really caught my eye because of the size 22 chainring; not only is this usefull for touring, but it's also nice because of all the monster hills here in Seattle :eek: Any useful input is welcome.

Correction: chainring sizes are 24-39-48

There is nothing horrible about the Sora crankset, I would wait until something wears out myself. You will probably see a bigger performance difference over time upgrading from a Sora to 105 derailleur.

If you are thinking of switching because of the chanring sizes, look to see how much it would cost to get smaller rings for the Sora. It is bound to be cheaper that replacing the whole assembly. I also live in Seattle and I do just fine with 30/42/52 rings and a 11-32 cluster.

For around-town and light touring duty, I doubt you will detect any difference in performance or weight by going to the 105.

Regarding ebay auctions, the final selling price is not determined until the last second of the auction. This is especially true for high interest items. Shimano 105 stuff gets a fair amount of interest so I will just about guarantee you that the buying price will be set in the last minutes or seconds of the auction. The best way to see what items like that go for is to search completed items and see what the range of final prices is.

That sounds like good advice. The front crank is one of the more durable, long-lasting of all the moving components, so I doubt it would be worth it for now to shell out $100+ for a new crankset, deraullier, and bottom bracket. The front cranks aren't going to just give-out suddenly, they'll wore out over time.

Update: I'm also looking at ultegra cranks. It's only an additional $20-30 to move from 105 to ultegra, so it's probably worth the extra bucks. I think I'll probably hold off upgrading the crankset for now. The sora is fine for my intended usage (light touring and commuting).

All good advice. Wear out what you got and replace it as needed. You won't get into any trouble with a SORA

I've been looking at cranks and bottom brackets online for a while. I looked @ the Sora vs 105 and found myself also wondering which way to go. I think for me the bottom bracket is the key decider. The new splined octalink & Isis interface with the cranks...is it the new standard? I want what I can get @ Kmart if necessary.