Upgrading drive system on the cheap
 

I have had a Trek 470 racing/training bike for the past year for commuting and general travel, recently though ive become interested in going faster/doing more things on my bike, possibly get into racing. Ive just recently upgraded the front an rear wheels which included shimano 105 hubs from old shimano RSX ones, this has apparently now opened up the option of upgrading my current 7 speed shimano RSX system to full 9 speed.

Unfortunately im a poor student, full upgrades are expensive and ebay isnt a huge ammount cheaper. Basicaly for now, all i want is to go faster (i completely top out on the gears all the time, i need more front teeth really) My current RSX chainset is 36/46 tooth, I want to upgrade to 52-53 tooth chainset.

What is the cheapest and most practical way of upgrading this?
Do i have to upgrade the whole drive system or can i get away with just buying a tiagra/shimano 105/ultegra bottom bracket and chainset.

Thanks in advance.

The cheap way might be bigger chainrings on your 110bcd RSX crankset.Otherwise, buy at least a 105 crankset and matching BB. A new FD would be good with rings over about 48 or 50. I think you are throwing away alot of money on that 470,especailly when considering racing it.

which is another reason why i want to do it as cheaply as possible, i just cant afford a new bike for now. I dont think i would race it... i agree that the frame is just far too heavy. But it would be good for getting used to racing gearing and general use.

Im not sure that i want an upgrade that small in terms of chainrings... the only thing i was worried about in terms of a new bb and crankset is chain size and compatability with the older rsx equipment. Should that be ok?

yeah