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| *Vultures Knob>>>Road Bike |
Is a 52/18 fixie gear ratio very fast? |
I recently bought a fixed gear road bike used that is set up 52/18 with 27" tires. Since I live in Denver I haven't been able to ride it yet because of the ice. I checked some of the gear ratio calculators and got conflicing answers. Is this gear ratio really stiff? I want to train on this bike on 20 to 30-mile rides that are fairly flat with a few hills (Central and South Denver). What is a 52/18 ratio most appropriate for? If I need to back off on the chainring size, I would like to do it soon while the weather is still bad. Gear Development is the distance your bike will travel with one pedal revolution. It is also the key to finding the answer to your question. To find your gear development, use this formula: (GD in feet)=(# chainring teeth)/(# cog teeth) X 27inches X 3.14 / 12 To find your speed in Miles Per Hour, use this formula: MPH=GD X RPM X .0114 (where RPM is your cadence) So with your bike set up.the GD would be 20.41 feet, and your MPH at say, a 90 RPM cadence would be 20.94 MPH. That is a pretty reasonable speed for a solo ride. In a typical ride, you might range from 70 RPM up to 115 RPM. That would give you a comfortable speed range of 16 to 27 MPH. If your terrain (and legs) support that, then you are good to go! If not, then you can use the formulas above to figure out the perfect setup for you. Hope this helps! Source(s): US Cycling Federation Sport Coach Manual for Competitive Cycling, 1996 that's a pretty decent gear for flats...you'll have to plan your hills out by resting before you get to a hill and then hitting it with a good steady run....I once rode a whole winter on a 40x13 which is close to a 53x17...you should be able to ride 20mph on the flats I used to drink Capt Morgans Spiced rum in Aurora I got on Colfax Ave Yo Thats a pretty high gear... about 2.9:1 ratio. It is definitely a good gear for flats and slight inclines but those classified as "climbs" will be out of the question for most people. You might want to go with long crank arms... perhaps 175 or 180mm if you keep those rings so you have a little more torque. I would personally try to get the ratio to about 2.3:1... 42 to 44 tooth chainring w/18T rear. As mentioned before you'll need to time your hills with a good head start but be careful you don't pull a muscle. Your going to need to try a few different combinations out, fixed is just like that. I know i swapped out the gears on mine a few times looking for that perfect balance of speed and efficiency, It's going to depend allot on the terrain where you live and your strength. Speaking of pulling muscles mirage may have pulled the one between his ears so careful of dudes answers........ 15 years as a bike mechanic and too many to list riding...... |
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