Cyclocross - A couple of questions from a newbie crosser

Hi, I've been racing both road & XC for close to 20 years and after hearing about how much fun this thing called cyclocross is I've finally broke down and purchased a cross frame (2003 Giant TCX)

I am currently building it up using some old parts from the "bin". I have a couple of questions for you.

I am using a Dura-ace 8 spd gruppo with a 12-23 cluster and have a couple of options for the cranks. The original DA 53-39 set up or I could use an FSA gossamer compact w/ 50-34 that I currently use on my roadie. I would prefer to use the D/A and not butcher my road bike, I notice that most stock bikes come with 48>50 X 34>36 or there about. will I be at some sort of disadvantage using the D/A? how about a single 42 tooth chain ring up front? BB compatibility is not an issue as I have quite a few kicking about.

secondly; what air pressure ranges are you guys running? I've bought some Michelin clincher tires with a range up to 80 psi.

lastly;I have a set of Salsa cross brake levers that used to be on my commuter, I took them off because I never used them, are they really necessary for cross racing?

Thanks for any feedback I post some pics when she's built.

'Rasher

lots of questions here and no responses....i'm guessing thats because your questions are not necessarily simple, and also because some of them could have been answered by doing some searching.

nevertheless, i will give you a short version:

1. 48x39 is standard for cross gearing. using the DA as you have it could very well put you at a disadvantage.
2. a single 42 ring is indeed a nice way to go, but setting it up is not always that easy. you will need to consider your chainline, bb, and chain guard(s) and/or a chain watcher to avoid dropping your chain.
3. tyre pressure is a science in itself. the psi you can run in a clincher will be determined by the course conditions, weather, terrain, and your weight. unless you are a clydesdale, 80 psi is almost certainly WAY too high. the key in cross is to run them as low as you can get away with (and for clinchers, this is higher than tubs because of the risk of pinch flatting).
4. as for in-line levers. this is a matter of preference. i happen to like them because i come from a mtb background, so i prefer to be on the tops when things are technical. the salsa's weigh nothing, so having them cant really hurt you.

A 53x39 with a 12x23 is way to big. I would say get the compact and maybe even a 12x25. I really like the single 42 ring set up though this year I am trying a double up front again. I also got tubulars this year so I can ride at 30-35psi. As far as the cross levers go I could not live with out them. I almost exculsivly use the tops.

[QUOTE=islenska]lots of questions here and no responses....i'm guessing thats because your questions are not necessarily simple, and also because some of them could have been answered by doing some searching.

Thanks for responding Islenska, I realize my questions are mostly subjective ie: the air pressure and brake issues . I posted only after searching the forum archives and not really find anything helpful.

I completed the build last night with the 50X34 compact crank, and I have installed the cross levers after figuring, as you say, the added weight is well worth the convenience

I plan on a little training tonight before my first race on Sunday. I'll play with the air pressure a bit and hopefully avoid the dreaded snake bite.

Thanks again for your input.

'Rasher