Nick Bain

I am still rocking a 53 tooth Chainring, many local riders are compact 50. This would seem to be a great advantage in efficiency in the 20-30mph pace range. Under 20mph I am Still in the 39 ring which I feel is a small advantage since they go to the 50 right away at about 16-18 mph.

Your thoughts?

Trsnrtr

Everybody chooses their own weapon to bring to a ride. Some have Aero wheels and some don't. Some have 15# bikes and some don't. You get the point. Fairness doesn't enter in to it.

Besides, some people spin 110 rpm and some trudge at 80.

Choose wisely and whatever works.

rpenmanparker 

Efficiency with regard to chainring size? Huh? Please explain.

datlas 

You are at a disadvantage because you are probably grinding away at too high a gear.

HTupolev

Impossible to say much of anything without although knowing the cassettes being used, and the typical speeds of riders, their preferred cadences in various circumstances, how willing they are to multi-shift to work around ratio gaps, etc. And even if you did know those things, it's hard to characterize the relevance of various efficiency differences, partly because it mostly just isn't significant as long as the bike provides the ratios you need.

stockae92

I don't really get the issue, maybe somebody can explain that to me if its the otherwise.

Its about the gear ratio, not just if your crank ring

e.g

front 50 x rear 18 = 2.78
front 39 x rear 14 = 2.79

Their ratio is close enough that with the same effort and cadence, the speed should be real close.

BikeCalc.com - Bicycle Gear Ratio Chart

So I don't see how having just 50 vs 39 front would be any advantage? Maybe except the 50x34 crank would be slightly light than 53x39 in the crank setup?

Nick Bain

The closer ratios of a 50 would mean better tolerance to minute speed changes where a 53er would be more likely to be between gears assuming a standard of 90 rpm.

hermanchauw

More teeth = less chain curvature = smoother.

kbarch

OK, but note that most of the time, OP is still on the 39 when his riding mates have shifted to the 50 - how does that play into things? Better or worse?

Nick Bain

Not most of the time, I don't know where you got that from. That is during the start of the ride before it gets to be an assault. Most of the time is 20-25.

Spoonrobot 

Unfair advantage for what? You get your name in the paper for winning the city limit sprint?

Gonna start complaining about people with low crr tires? Aero frames?

kbarch

I got that from your comment that the folks you ride with shift to the 50 at 16+ whereas you don't shift to the 53 until 20+, i.e., most of the time when they shift to the big ring, you're still on the little, and it takes a considerable increase in speed before you move up to the big ring, too. You didn't mention traveling at 20-25 most of the time before. Besides, I've found that rides where that's the cruising speed typically wind up averaging 16-18 overall. While many (often rightly) loudly proclaim that average speed is meaningless, when looking at what chain ring people are on most of the time, I think it could mean a lot. I guess it doesn't if you're only concerned with your advantage at 20+, after you're both on the big ring, but then I wonder why you brought up the issue of when the front shift is made.
I'm not good at math, but I find it interesting, so I hope I don't sound argumentative here - I'm genuinely curious. Meanwhile, I think that when it "gets to be an assault," having a bigger big ring would definitely be an advantage - a no-brainer, but not unfair. Nothing is stopping the other guys from riding a standard.

jamesdak 

?? You mean people actually use the smaller chain ring when not climbing???? WHAT!!!!

Nick Bain

ok call it a fair advantage then.

redlude97

Chain line is more important to efficiency than A 3 tooth difference

MinnMan

Though I think that the overall gist of this thread is pretty silly, yes, on my bike with a 53/39 (and a 12-27 in back, fwiw), I can ride quite happily in the flats on my 39, unless the pace is, say, above 22 mph. Admittedly, I am more often in the big ring, but when you don't have a compact, the small chain ring is more than just for climbing.

f4rrest

So, is 20-25 before or during the "assault"?

79pmooney

Larger chainrings and cogs are slightly more efficient. Slightly. Having the right gear ratios for the speed, effort and your legs is really important. Nothing about either the 50 tooth or the 53 have anything special there except the best cassettes for each (for any particular rider) will be slightly different. This was a concern 30 years ago when the smallest cog was a 13. Now with 11, hardly.

Ben

B. Carfree

You're getting old. Thirty years ago we had 12 tooth cogs. Now forty years ago...

HTupolev

I'm curious about that timeline. I know that Fuji had a bike with the 7-speed SunTour New Winner 12T cog at least as early as 1979, but I'm not sure when they released that or what may have come before.

Masque

War never changes.

I remember back in WW2 when all our boys were equipped with triples, and even then the supply of good chainrings was dry before we even got to the shores of France.

I'm glad to hear that you are better equipped for your local group ride. May you have the best luck with your assault. May you claim victory in this mighty conflict. Mighty hero, you carry our hopes on your back.

I wish only that we could one day sue for peace, and with light hearts and bandaged wounds... just go ride bikes together.

But go out there and slay those who oppose you, mighty standard-pedaler! I will await you, fresh paraffin in hand, when you return victorious.

Dan333SP

I get what you're saying with this. Cassettes typically have bigger gaps as you shift from one gear to the next at the wide end. A SRAM 11-28 11s will go up 1 tooth at a time until you get to the 17, then it jumps to the 19, 22, 25, and 28.

If you're pedaling 90 rpm with a compact 50t big ring, you'd have your final 2-tooth jump as you accelerate and shift up from 18.5mph to 20.7mph, while with a 53t you'd hit it between 19.7mph and 22mph. Above that and it's all single tooth differences as you go into smaller cogs on most road cassettes so there isn't any real difference there until you get to speeds where you are spinning out the 50t.

Still, most people don't pedal at a completely fixed rpm and are just fine spinning up a bit before shifting, so I don't think there is any real advantage here.

rubiksoval

Rode a 50/34 for half a season. 34 was almost useless and spent most time in the 50. Annoyed the crap out of me. That and having to ride in the 50 and on the end of the cassette any time it got fast was irritating.

rpenmanparker 

Post du jour. Chapeau!

jamesdak 

Lol,I was sorta kidding although I really don't bother with the smaller chain ring for most rides. Even on the old Antares rocking it's 52/42 setup. Maybe in a crazy strong headwind I might need it but otherwise no. I have no issue with varying my cadence, I prefer that for sure.