Take the 2-minute tour ×
Bicycles Stack Exchange is a question and answer site for people who build and repair bicycles, people who train cycling, or commute on bicycles. It's 100% free, no registration required.

I have three gears in the front and 8 in the back, but I always use the highest gear (I live in a flat place) I might drop down one or two gears occationally but this is only a small fraction of the time.

I want to buy new gears and re-center this distribution around something I find useful, I probably only need the top three ratios from my current setup, and I would like to have maybe 5 more ratios above that. Is this type of modification ever performed?

Sorry I don't know any of the relevant cycling vocabulary. Also, what are power ratios measured in and how do I determine the ratio of my current highest gear?

Where should I buy these parts? Can I make this modification for under $100?

share|improve this question
2  
It sounds like you probably have a hybrid or mountain bike. Could you give any more detail about the bike or the specific components on it? –  amcnabb Jul 27 '12 at 21:06
7  
One thing that's been neglected in the answers so far: you may be over-gearing. If you find your cadence is slower than 80–90rpm, then the solution is to just use your lower gears. Riding in too high a gear is inefficient and bad for your knees. –  Stephen Touset Jul 30 '12 at 2:44
add comment

1 Answer 1

To get higher gearing, you'll need either a chainring (front gear) with more teeth or a sprocket with fewer teeth. Mountain bikes usually have smaller chainrings because off-road speeds are generally slower. For example, a mountain bike with a triple crankset with 24, 34, and 42-teeth chainrings would be limited in its top speed by the largest (42-teeth) chainring. In constrast, the largest chainring on a road bike may have 50 or 53 teeth, giving 19% or 26% higher gearing respectively.

Unfortunately, upgrading probably won't be as cheap or easy as you hope. You can't just replace a single chainring, so you would need to get a whole new crankset (the crank arm plus chainrings) and also a new front derailleur. Depending on how much your bike is worth, it may be better to get a new bike.

share|improve this answer
1  
I'm not sure why you couldn't change a single chainring or the cassette... Can you explain why not? –  Benzo Jul 29 '12 at 23:29
    
Increasing the size of a chain ring may mean a new derailleur, or sometimes a new crankset (depending on the PCD of the existing crank set) and a new crankset may mean a new bottom bracket... It's easy in concept- unbolt this and bolt on that - but it's something a novice bike mechanic is better getting the LBS involved in - at least get there advise for your bike. –  mattnz Jul 30 '12 at 5:04
1  
It's more likely that the OP needs to learn to ride with a higher cadence. There are not many out there that will run out of RPM on the flat on a "normal" 24 speed bike and last more than a 1/2 mile - and most of those would know the answer to the question. –  mattnz Jul 30 '12 at 5:06
    
Additionally, if it is a mountain bike it might not have an 11-tooth sprocket in the back as the smallest one. depending on what is current ratios are he could see greater ratio increases by replacing a cassette with a smaller small sprocket than by replacing the a crank. Just depends on the current set up though. –  Brad Jul 30 '12 at 13:39
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.