What components are required to upgrade from a 14 speed to 24 speed?

Question

I made the mistake of buying a 14 speed bike... I live in WA so it's hills everywhere you turn, took it for a spin yesterday and while on flat surfaces it felt great, but taking hills or going down a massive hill, I was totally limited on my gear options.

What components are required to do this upgrade? I'm not looking to go all out, I'm just starting to train for my first sprint tri.

Here are my current components for my Motobecane Mirage S.

These are my specific questions

• Do I need a new chain, or will this chain be compatible with an upgrade to 24 speed
• I need new Cassette/Freewheel, right?
• I need new shifters (I'm assuming 3X8... as its 3x8 is it pretty much compatible with any 24 speed upgrade?)
• I need a new Rear Derailleur? (This should be an 8 speed correct?)
• Do I need a new front derailleur? If so, do the front and rear derailleurs need to be compatible.

I just want to make sure I'm not buying these new components to install and find out it wont work because they are not compatible. I'm pretty new to this so I need some advice. We do all our bike work/upgrades ourselves to save money.

Answer 1

First, make sure your bike is fit properly - with a bad fit, your efficiency is likely lousy.

More sprockets is not necessarily going to make you go faster/easier - changing gear appropriately and becoming more physically fit will (along with better selected sprockets sizes - we went ages before the Gillette razor-blade increase in rear sprockets...). Most of the more sprocket drive trains are driven by hype.

You may need better choices of sprockets, but certainly, with a 2 x 7 setup, you have enough choices that it should be fine (for example, if you were touring, a 11 cog in the rear would be useless - you'd want a range of larger cogs so you could move the stuff you're lugging around). A 24 speed would need a 3 x 8 setup which means new crankset, new front derailleur, possibly new bottom bracket, new cassette and new shifters (these are the real killer if you want brifters; bar ends or downtube or friction shifters somewhere are cheaper) assuming you could get the chainline and what not right (the RD will be fine if you stay shimano). At this point, with a cheap bike like the Mirage S (400 dollars), you're better off just replacing the whole bike, since parts and labor will cost more than the bike is worth/costs (you will also need some tools you might not have, like a crank puller and cassette tool and cable cutters and what not).

If you're going for a sprint tri, you should be in decent physical shape, so I'd look at fit or just spend some time getting used to the gearing - whenever I haven't ridden my road bike in a while and I get back on, I feel like its geared way too high, but after a few weeks, I feel fine.

If you want to change something and you're sticking to this bike, your best bet is to just change the cassette to something with a wider range of gearing. This may necessitate a new rear derailleur (go wide range (marketed with a SGS code) from Shimano). I guess a new chain may be needed as well if you're using weird gear combinations. I suggest you go to your LBS and see what they'd recommend for a new cassette if you want something easier, given the terrain you're likely to ride.

TL;DR: Don't do this. Either get used to the gearing, put on a larger rear cassette or get a new bike. More speeds isn't necessarily better, knowing how to use them and picking the right speeds is far more valuable.

Answer 2

Normally to change the gearing you only need to increase and decrease the size of the cogs. The number of gears determines the difference between gear shifts, ot the end gears. No need to upgrade to 24 speed.

I advise caution making too many changes as its a lower end bike and parts are expensive.

Overall the bike looks reasonably geared for a road bike. I suspect you are not cycle fit, hence the problems are more about technique and specific fitness than the bike.

If you want to increase the top speed, you will need to increase the size of the larges front cog or decrease the size of the smallest rear cog. you current have 50x12 respectively. A 50x11 would give you around 10% more speed. Changing the front to 52 would probably not be worth it.

The lowest gear is determined by the small front / large rear cog. In you case you are running 34/28. For road use this is reasonable already, although for hills lower might be better. To lower your lowest gear, either decrease the size of the front cog or increase the rear. Unfortunately the rear derailleur is only rated for 28 tooth max, so you will need to replace this. A 30 front chain ring would help - are you chain rings bolted or riveted to the crankest? If bolted they can be changed individually - but increasing the difference may require a new rear derailleur.

I would suggest that if you decide to go ahead and spend money, upgrade the derailleur and look for a cassette (rear cogs) in the range 11/13/15/18/21/24/30 or 32. Likely you will also need a new chain as the larger rear cog will probably mean the existing one will not be long enough.

As always, Sheldon Brown has excellent information.