You all are much smarter then I am.
 

After reading this forum for about a year and a half I have come to realize that if I want a real answer to a biking question i should come here. You all trump the Google machine with your real life experiences, and not trying to sell me anything.

That said, I am looking at building a soma double cross. As of right now I commute on my Yuba Mundo, which I bought when i decided to go car free for anything under 6 miles. The bike is a godsend, and I have moved a washer dryer combo with it but I am slowly starting to realize that being able to zip around quickly is pretty nice as well. I can't zip around in a bike that weighs in at 102 pounds with my child seats and bags on it.

I know next to nothing about component sets, i am learning, but there are a TON of acronyms and measurements in metric systems and my brain is still trying to wrap around it.. I found this

http://kpr.craigslist.org/bik/1938171800.html

and was thinking about using it as the parts donor for the Soma build. Everything I have found said that the 105 group is pretty dang good. I plan on buying a different non-carbon fork, but as far as the drivetrain and handlebars and brakes/tires/etc...is this a good deal?

I don't know if this actually belongs here or in the road bike thread so i will post it both places. I don't know if that is taboo or not and I apologize if so, just want to make sure I put it in the right spot.

My commuter has 105 components. They're pretty nice. Every now and then it'll be a bit sluggish when I shift in the front, but I have a double chainring, and my shifters seem to be made for a triple. (?) That's really the only complaint I've had about them.

Does the carbon bike not fit you, or have structural damage? It'd be a little odd to cannibalize one for parts!

The gearing is a bit low on this, though. If you have any significant hills in your neck of the woods, you might wind up buying a new cassette ( which is like $35 for this group ).

No I think it would fit just fine. I have just heard people say that carbon isn't rigid enough for a commuter bike. having never ridden one I have no clue what they are talking about, and just kind of have to agree with them :-)

would it not be a bad commuter bike?

If you're keen on buying it for parts to build into a commuter bike, you should buy it, but use it for a week as your fun bike, and keep using the one you have now to commute. Decide for yourself, after you get some experience with it. My guess is you could get the money back selling it as is if it was horribly wrong, or at least half of it selling the frameset. Probably more, but I wonder why a carbon frame would be selling for so little ... I could be used to a more expensive market in Seattle.

Can you bring your bike indoors, where you commute to? There are two reasons I kept my aluminum bike as a commuter after getting a carbon road bike, and they both come down to no bikes in the building at work. Carbon bikes are expensive, and prone to theft. Also, carbon is stronger than steel, but it doesn't have much impact strength, so if somebody else dropped another bike onto it at the rack, while they were getting ready to lock theirs, that could cause structural damage.

Carbon fiber dampens vibration, which is one reason it's used in tripods. This means that you don't feel as much road buzz when you ride a carbon frame ( notice that this one has a metal fork, though ), and I think that's why a lot of people will tell you it's not very stiff or rigid. Most bikes in high end races these days are carbon, though. I wouldn't discount it on those grounds.

it would be fine unless you want a rack and panniers, plus it might be a thief magnet. You can always take the parts and sell the frame to get back some of what you spent

Looks like the seller is on a smaller bike than was the right size.. from Tall stem stack and seatpost.

but a parts source and a frame resale it certainly fits that description.

You will need to get cantilever brakes for the doublecross , though..

Unless that cf frame is structurally unsound, I'd use the bike as is. You can scavenge it for parts, but keep the frame if it fits in case you want to build it up later. Who knows, you might like riding around on a bike that weighs 1/5 of your current rig.

Thanks for the responses guys/gals

Yeah the weight issue is starting to really get old. I will have to check things out more when i look at it later today. Thanks again

I had a look at this thread in the road forum. What a wildly different set of responses!! Our spell check seems to be broken in the commuter forum.

I didn't realize that the components were very old, but I don't think it makes a huge difference unless they happen to be very worn out - which I think you'd notice on a test ride. I know it's Craigslist, but I've test rode the stuff I've bought there, and let people ride the two bikes I've sold that way. The guy might want you to leave an ID or something so that you don't steal the bike. But I'd be inclined to ride it as-is, if it fits you. If you do test ride it, though, go up some hills.

Careful when trying out that bike, because cassette and chain, and other parts can be worn out way beyond being useful anymore, but you wouldn't know it if the chain, cassette and the rest is worn out the same amount. You would only notice if the chain eventually snaps, and you went to exchange it, only to find that new chain skips in most gears. Or won't even fit up there. It is a risk to buy older components, and without at least a good chain measuring and a lot of experience in checking bikes, you wouldn't probably even know you got taken.

So it is possible to have worn components work quite fine for you (if you have no reference in as how that group should be working when new), only to find out they are worthless too late.

And I really wonder how come no one mentioned this before - it might be that the price is so low, because the frame was crashed at one point in the past, and not repaired properly or at all. They could simply paint it over, blend it in, and you wouldn't have any way to know. But, you would know only eventually when it fails in use, and that is not a good thing. So, all in all, this bike doesn't look like a good purchase, too much room for something to go wrong. Old bike means components might be shot, composite frame at a suspiciously low price might mean hidden damage or something similar that makes it unsafe to ride.

I personally have no desire to have a carbon frame bike. Some folks say I'm not normal