Singlespeed & Fixed Gear - Improving Response without losing top end

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fordfasterr
12-27-05, 09:10 AM
It was suggested to me recently that I should reduce my gear ratio because its too high.
I am currently using a 52x 15 gear. I was looking at some of the websites with gear ratio calculators and such .. so far this gearing is 93.6. ( http://home.i1.net/~dwolfe/gerz/ )
I average 13 - 16 mph but I don't know what my rpms are (I know this can be calculated) but I don't know exactly how, but I know that they are generally quite low.
I was told that reducing the gear ratio and increasing my rpms will help me to build my leg strength and cadence as well as my coordination and such...
I basically ride 100% flat surfaces and average 2 or 3 over-passes on each ride, mostly easy slopes that I currently have no trouble getting over...
I was thinking that I should only reduce the ratio by a little bit to see if i like the higher rpms... switching to a 17t rear cog will set my ratio to: 82.6 thats almost 10% lower than with the 15t ...
Is this a reasonable change, otherwise, what gear ratio should I shoot for ?
SamHouston
12-27-05, 09:35 AM
13-16 mph is not very fast for a gear capable of 3x that. You could definately use a step downward from that if you aren't spinning. For instance a 48x16 will provide an average speed of 18mph at a reasonable cadence It'll be easier to control at such speed as well.
And it'll save your knees.
I run 39x15, which gives about 69 gear inches. I average between 16-20mph. I am definitely a spinner, so 39x15 might be too spin-happy for you, but I would still recommend you try a lower gear. Either with the 17 like you said, or maybe try 42x15 if you happen to have a 42 tooth laying around. That gives you 75 gear inches, which would be a drastic change from what you have, and require some getting used to, but might work out well.
noumena9
12-27-05, 09:44 AM
if you feel like you are riding as fast as you can on that gear then lowering your gear will increase your top speed. I ride an 86" gear and I can pretty easy hold 20-22mph on the flats, spinning out at 37 on the downhills. I can average the same speeds with a 75" gear, too, but I spin out at 33 or so. You're way the hell up there in gearing.... I don't think that I could push that gear effectively at the velodrome, even. my intuition is that you would find a new enjoyment in biking with something like a 77".
Lower your gearing and your legs will thank you. It will take practice, but you shouldn't lose top end at all.
Lunigma
12-27-05, 10:09 AM
I am currently using a 52x 15 gear. I was looking at some of the websites with gear ratio calculators and such .. so far this gearing is 93.6.
JESUS CHRIST! that's big, why did you choose such a high gear or how did you come about picking that gear? i think people reserve that kinda gear for the track were they can draft and it's flat. if your pushing 93 right now at 15 mph i would go down to the 70s that's killer on anyones knees, your not going fast enough.
fordfasterr
12-27-05, 10:11 AM
Ok, I'm gonna shoot for an 18t cog and see how that works out for me.
(or if the LBS does not have an 18t, i'll get a 14t and switch to the small 40t front chainring on my sugino vp crank).
=)
That will set my gear to: 78.0
Thanks for all the advice folks !!!!!
taras0000
12-27-05, 10:43 AM
Ok, I'm gonna shoot for an 18t cog and see how that works out for me.
(or if the LBS does not have an 18t, i'll get a 14t and switch to the small 40t front chainring on my sugino vp crank).
=)
That will set my gear to: 78.0
Thanks for all the advice folks !!!!!
A 50x17 should do you nicely for now. it's not that far off of the 48x16 mentioned earlier and that's a nice all around gear.
fordfasterr
12-27-05, 11:17 AM
I think the best I can do for now is 40 x 14 from my LBS.
If i want the specific stuff, i'll have to order it... which I might just do.
Thanks for the help.
I can hear you knees smiling from here.
fordfasterr
12-27-05, 11:27 AM
I can hear you knees smiling from here.
I hear them smiling 2...
anyway... a 40x14 will yield a 77.1 ratio...
I think that might be in the ballpark...... we'll see how it goes.
fordfasterr
12-27-05, 07:32 PM
OK.. update:
All done with the gear swap... I switched the ring gear to the 40t and then installed a 14t cog...
I took a few links out of the chain and adjusted the tension and tested it out....
so far so good !!!!!!
=)
helvetica
12-27-05, 07:36 PM
steroids
fordfasterr
12-29-05, 06:33 AM
Ok, I rode to work today ( day off on Wed due to family visiting), and it felt quite different. I was winded a little earlier in the ride than usual. I think its because I'm just not used to the higher rpms all the time. I made it to work in 20 minutes as usual, so I did not lose any speed however I did not stop as much as usual either, so I think I may have actually gone a little slower. My legs feel different as well, they don't feel as " pumped " as they did with the 52x15 gears... They feel a little more tired than usual... Anyway, Hopefully I'll get used to it soon... =)
So, in regards to this topic, the response has improved. I can blast out of a full stop much quicker than before, and the bike seems to reach my cruising speed much sooner than before. =)
ok, here are the updated pics:
http://www.nitrousworld.com/images/bicycle_pics/Schwinn/40x14_update/MVC-001F.JPG
http://www.nitrousworld.com/images/bicycle_pics/Schwinn/40x14_update/MVC-002F.JPG
http://www.nitrousworld.com/images/bicycle_pics/Schwinn/40x14_update/MVC-003F.JPG
http://www.nitrousworld.com/images/bicycle_pics/Schwinn/40x14_update/MVC-004F.JPG
BTW: the lockring on my bike was taken out off of a new bianchi pista from the LBS... the original LBS was late with the shipment of the lockring, so I went to another bike shop and they didn't have one either, but the mechanic just opened up a box with a chrome pista and removed the stock lockring and sold it to me for $ 5.
lol =) .. I have a bianchi part on my $37. schwinn...
LóFarkas
12-29-05, 06:49 AM
Hopefully they'll remember to put a new one on that Pista...
kurremkarm
12-29-05, 10:47 AM
This thread reminded me that i need to clean my chain.
Oh and if you mean average speed, like on a cyclo puter was 13-16 that can actually be some fairly fast riding when you throw in stops and such.
humancongereel
12-29-05, 02:04 PM
good move to gear down. you'll spin, get a better pedal cadence, stronger legs, throw on a higher gear in a bit, and you'll be capable of going faster, etc...start small, then work up. wasn't my first impulse either, but it's true.
baxtefer
12-29-05, 02:10 PM
13-16 Mph with a 52x15? that's a cadence of around 50rpm, which is ridiculously slow.
gear down so you can learn to spin at least 80 rpm.
fordfasterr
12-29-05, 04:35 PM
13-16 Mph with a 52x15? that's a cadence of around 50rpm, which is ridiculously slow.
gear down so you can learn to spin at least 80 rpm.
I am working on it.
So far it is a little more work for me based on what I'm used to but I like it.
I am able to get up to speed much quicker and still reach comfortably high speeds with relative ease.
pinkrobe
12-29-05, 05:54 PM
OK.. update:
All done with the gear swap... I switched the ring gear to the 40t and then installed a 14t cog...
I took a few links out of the chain and adjusted the tension and tested it out....
so far so good !!!!!!
=)
I like the 40x14 myself. It's easy to get away from lights, and I top out at around 40 km/h [25mph]. 52x15 - I'd never make it home!
gally99
12-29-05, 06:11 PM
i rode about 94 inches, before an unrelated knee injury, and i loved it...
a quick spin isn't for everyone... i think cadence is a very personal thing...
and personally, i had no problem with quick starts, just occasionally the front wheel would come up for a couple of feet...
i also had 200+ pounds to drop on the pedals...
fordfasterr
01-01-06, 09:13 PM
well, the 14t cog didn't work out... it was cut too thin and the blades were at an agle like if the cog was made for a multi-gear setup ...
I had to remove it because the chain would pop off now and then even after It was on real tight...
SO I re-installed the original 15t cog that I had with the 52t chainring... so now i'm running a 72 inch gear....
it will take some getting used to, but I like the spinning thing.. I got used to the 77 gear inch with the 14t cog real quick and I liked it... so now I'll get to spin a little bit more and hopefully the chain won't fall off anymore.....
woot ! =)
LóFarkas
01-02-06, 03:39 AM
Sounds like your gear calculations are way off. Lemme check: Supposing 175 cranks and 700*23 wheels 52/15 gives a 91.1 inch gear (93.6 if you have a 27 inch rear, courtesy of Sheldon "gain ratio" Brown). Too high, even if you don't notice it right now.
fordfasterr
01-02-06, 05:35 AM
i have 27 1/4 size tires.
so my current ratio is 72 (40x15).
Aeroplane
01-02-06, 07:04 AM
i have 27 1/4 size tires.
so my current ratio is 72 (40x15).
For clarity's sake: You are running at 72 gear inches, your ratio is 2.66 (40/15).
As far as choices, I'm glad you decided to drop from that ridiculous 52/15 thing. Sure, tall and slow is good for some folks, but it's usually pretty hard to do anything useful with it. I started with a 52/16 and I thought it was awesome. Then again, I only had two lights on my commute.
Once I moved down to a 48-16 everything got a LOT easier. I learned to skid and skip. I could hit top speed sooner, and didn't lose much top end. Trackstanding still isn't easy, but it's easier. I recommend that you save up, and in a couple months order a 17t or 18t cog (a good one) and try it out with your 52t ring. That way you have a full range of gearings to choose from. Choices are good.
LóFarkas
01-02-06, 07:36 AM
Oh, sorry. I misread your post. Now we return to our scheduled programme.
fordfasterr
01-02-06, 05:18 PM
I took the day off and rode practically the entire day... mostly on the beach in hollywood (FL).
I gave this new gearing (40x15) a good test ride and I like it alot. A few comments about it:
1. it is much easier to pedal than the old gearing.
2. it is easier to get out of the hole and reach top speed than before.
3. it is SCARY to go down overpasses !!!!!!! LOL >>> RPM !!! <<<
4. Never lost the chain. (due to 15t cog being made specifically for FG).
now all I have to do is figure out how to get all the salty beach sand off of my chain !
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