Dual suspension bike gears upgrade.?

hi i was wondering if its possible to upgrade my bike from 18 gears up to 21 or even 24. how much would something like this cost in a bike shop or is it easy to do myself?

this is a pic of what it looks like. great deal.

http://www.argos.co.uk/wcsstore/argos/im...

It would (probably) be quite easy to change to a 21 speed set up. I am assuming that the rear gears are a freewheel system and that there is a six speed indexed right hand gear shifter.

Items needed; 7 speed freewheel and a seven speed shifter.

Other items than might be needed; freewheel remover, rear derailleur, rear gear cable and possibly new grips and perhaps a new chain.

The cost could be around 拢40 to 拢50 and probably a similar price if a bike shop did it for you.

To change to 24 speed will mean a new rear wheel as screw on freewheels normally only go up to 7 cogs. For 8 speeds and above, a free hub cassette set up is needed together with a rear derailleur and chain. You also might need a different chain set.

I think that the best thing to do would be to use the bike as it is and save some money in order to buy the bike you WANT.

There are often 'last years' bikes to be bought from large dealers at lower prices than yo would think. You might go for 24, 27 or even a 30 speed machine with a decent frame and quality wheels.

I agree with the other answers. From experience I know they are right.

Maybe you can solve your gearing problem by changing the size of some of the rear gears.
I do not know what you need, but lets say you want a easier pace for climbing. Then probably changing your largest rear gear to one with one or two more more could do the trick.
The solution is easy and not to expensive. Probably some cable tension adjustment might be needed.
Ask at a good bike shop for an alternative like this, for a good percentage difference between rear gears is advisable to have comfortable and feasible rear gearing.

Raleigh T_BOLT. you would have to change the rear sprocket, the rear changer, the chain, and the gear shifters, cost about 拢70 in parts plus fitting,and would end up only with more gears, not better gearing, not really any advantage .
It is much more cost effiecient to buy the bike with the gearing you want than to try to change it later.

Sorry, several problems to overcome. The stopper is the upgrade would cost more than you paid for the bike.