gearing giant boulder

You will already have a 28/38/48 crankset, the best way to do is a 8 speed 11-24 cassette from Sunrace. Changing to a road crankset requires many $$, more than the bike is worth, a CRX4 will be cheaper.

I did an Upland recently: http://www.cyclingforums.com/t363004.html

For speed a chart feed the options into here: http://sheldonbrown.com/gears/

i think it came std with a 11-28 cassette what i want is a better top end

thanks

bigkev said:

I think it came std with a 11-28 cassette what I want is a better top end

We have a city wide speed limit of 50kph here in Perth. With gearing of 48:11 and 1.5" slicks, a cadence of 90 gives 47kph! You want more? :eek:

but main roads are 100km and in sydney a lot of roads are 60kph .

gclark8 said:

We have a city wide speed limit of 50kph here in Perth. With gearing of 48:11 and 1.5" slicks, a cadence of 90 gives 47kph! You want more? :eek:

Don't waste your money on a new cassette or crankset. I'd get a road bike instead of a boulder regardless of what tires you have on it. It will come geared for you to get in shape and to kick your butt. It will probably be about 5 pounds lighter than your boulder too. It is well worth your money, trust me.

I'd try to get a second hand road triple chainset and matching BB on e-bay, for <$50. I'd keep your existing FD and shifter, as they'd work adequately (you'd need to lift the FD a little up your seat tube).
Given the small improvement in gearing, and the value of your bike, spending any more simply isn't worth it.
You may also need to work on getting your cadence higher - 48/11 should be adequate for all but relatively steep downhills in Sydney.