How should I upgrade my hard-tail mountain bike?

I have a Giant XTC-850 Disc and would like to burn a little money on it. The chain got kind of rusted, so was thinking about replacing that of course. Other than that, the other parts work pretty well. I ride mostly on concrete trails with some light off-road riding. I'd like it to go faster on straight concrete runs. Any suggestions? Crank shaft assembly change make any difference? Thanks to all!

Replacing the chain may or may not be helpful. Exterior rust on a chain is not a big problem. Just cleaning the chain and applying lube will usually take care of superficial rust.

A chain actually wears from the inside. As long as the internal surfaces have not rusted and worn, you are OK. Chains needs to be replaced before they have worn. If the chain is old and worn, your cassette and chainriings will be worn, as well. Putting a new chain on a bike with worn chainrings and cassette will cause lots of shifting problems.

Your bikeshop can measure the chain to see if it is worn. If it has, your best expenditure will be to replace the chain, chainrngs and cassette. Be forewarned, this is an expensive operation.

Unless you need to replace your chainrings, and you can get a deal on a complete crankset, I'd recommend you forget about a new crankset. A crankset is an expensive component and will do nearly nothing to improve your performance.

The best investments in improved performance come from reducing the rotational mass of your bike. To go faster, your single best exenditure will be lightweight tires. To go the fastest on concrete, you may want to consider slicks. Slicks will both reduce weight, and rolling resistance on pavement. Unfortunately cornering performance of slicks on dirt is not good. Thus, depending on how fast you want to go when off-road, you may want to compromise with a semi-slick design with knobs toward the sides of the tread for cornering on dirt.

Hope this helps.

Replace the rusted chain IMMEDIATELY ( www.pricepoint.com) Ask any bike mechanic the specific size of your crankset (175 or 170 mm are most likely). The best yet reasonable crankset prices are at Blue Sky Cycling (www.blueskycycling.com) ---Shimano LX or XT are fine or go for the Race Face if its your choice. Buy some lube too for the new chains.

hey. replace the chain before you do any damage to your bike.
Bikes to look at for what your doing would be Giant again. There good bikes
hope that helped

new chain for sure.....25-60 bucks.
maybe a new rear cassette (sprockets - around $80-150) - the racing ones have higher gearing to go faster. (remember it;s a mountain bike so the gears are lower than a road bike. if you don't need the low gears for climbing steep hills - you could look into putting road cranks on it.
good new cranks will cost over $150 new (road or mountain ones) - but they can make things smoother and faster - cranks can come with new bottom bracket assembly and berigns - look for ones with external berings - ceramic begins are way faster but way expensive. In my opinion unless you are having problems this (new cranks and botom bracket and berrings) is too expensive for your purposes.

Tires for concrete (instead of dirt - around $60 bucks) will absolutely make you faster and in my opinion would give you the best bang for your buck- since you ride on concrete.
You could buy rims with hubs and cassete and tires -(maybe 150 on ebay) and have a 2nd set of wheels to switch off between dirt riding and concrete riding.

Ergon grips are really great if you ride allot. http://www.ergon-bike.com/

in my opinion if you are going to spend more than $150 or $200 on a mountain bike for the purpose of riding on concrete - just buy a cheap hybrid or road bike instead - you will be much happier & the higher gearing will make you go faster and farther on concrete.

http://www.bikesdirect.com/
http://www.performancebike.com/ (they have stores in allot of cities)