I’ve got 50 and 53 now, depending on the season.
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Besides, if you buy the bike in a shop, I reckon you can change your cranks (length, chain rings) at no extra cost — especially when you pay five digits for a bike.
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Since the link is down now, this is basically the interesting bit:
Maybe it is a mistake, like the 1kg weight, maybe it isn’t …
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Just to give some context as to why people go for larger chain rings, it’s not necessarily for the top gear ratio, its to have larger gears while staying out of the 11t cog. The two main mechanical ideas behind this are that larger gears bend the chain less (less friction) and AFAIK the big ring is better aligned with the second or third cog on the cassette thus giving a better chain line.
In track cycling it is common to see riders using a 15t cog rather than a 13t, which is the smallest commonly available, pared with a larger chainring. I’m not sure if its just my imagination but I think I can feel the difference between a 50t and 53t chainring when they are setup with a very similar gear ratio.
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How? The difference is sub 1 Watts at 300 Watts according to several sources. No PM on the market can reliably measure that, and you think you can feel that?
Just to quote (Friction Facts: free speed from proper shifting - BikeRadar)
- A 53-15t combination, for example, yields almost the exact same gear ratio as a 39-11t but the latter requires an extra 1.5w to maintain the same speed – and that’s in a lab setting where the chainline can be perfectly aligned
Massive gains right there for a 14 tooth chainring difference, and 4 tooth cog difference.
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@Aeroiseverything As I said, I’m not sure if its just my imagination, but bigger chainrings have always felt better/smoother (easier to pedal, accelerate, maintain speed) to me, especially on the track.
It may not be huge, but right now the trend in pursuit and sprints is to use chainrings between 58-62t pared with 14-16t cogs. The average pursuit rider will be putting out 400+ watts and at the world cup level its closer to 600w so that marginal gain may not be so marginal anymore.
Back down to earth (road cycling), I still see no reason to shift towards smaller chainrings and 10t cogs on the cassette. Even if it doesn’t make a huge difference its still going against the mechanical principals and IMO makes no sense.
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I completely agree - I have no idea why anyone would think a 10t cog was a sensible engineering decision.
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That’s true, 11-32 cassettes have become very common in the pro peloton for that reason. Although I’d say we amateurs spend most of our time in smaller gears anyway. I wouldn’t optimize for the largest gear, but the one I use the most when going fast.
It makes a ton of sense, the reason is gear range. The 10-36 cassette that’ll be on my new bike will have roughly the same range as a 11-40 cassette. Rotor’s 10-39 cassette has the same range as a 50/34 coupled to a 11-30 cassette.
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I don’t know where you all live and how you all ride like.
The smaller chain rings of SRAM all offer a wider range and much better gearing at the top end of the cassette. I have a 50/37 10-33 and a 48/35 10-36, where I can swap out cassettes with 10-28.
That means on my race bike I have a 37/33 (1.12) compared to a 39/32 (1.22) on the equivalent Shimano.
That means you need to pedal at 9 percent more power on a steep climb. For me, a rather trained and light rider, this is a relevant benefit.
The potential loss of 1W at threshold and 3 watts at max sprint is rather pointless.
Still interesting how everyone agrees on the importance of drive train efficiency, when we are talking sub 0.5% of power loss.
I don’t think everyone in here has everything else maxed out (waxed chain, fastest tires, latex tubes, fastest helmet etc) to make this somehow a relevant consideration.
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If it is less than 1W at 300W, it is less than 2W at 600W… still very marginal.
Plus, it makes 1x an option for more people. My next bike has a 1x SRAM drive train, I’ll have a 42-tooth chainring with a 10-36 cassette in the rear. I’ll have an easier gear than 34:28 and I lose one gear at the top (my 50:11). I reckon for races I could try a 44- or a 46-tooth chainring, too. But since we have quite a few proper mountains, I’d rather err on the side of having climbing gears rather than having/not having a downhill gear. I’ve been paying attention to what gears I use, and I am rarely in my 50:11. Even on the flats, I am not in my 50:12 very often, it is usually the 50:13.
Shimano not allowing for proper, officially supported 1x road bike drivetrains is a big minus in my book.
That’s SRAM’s amazing “leapfrogging” of the bicycle industry 
I have a 10t on the MTB, but chainring sizes are a limiter there. Road, I don’t see a purpose, just seems like a way for SRAM to try and create a new standard that likely won’t stick
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Yassssss. Time to trade mine in
Wider gear range over fractions of a watt of efficiency gains. That’s the thought process…
Since we are all world tour level here, we don’t Need wider range, I get it.
There is things to criticize sram for, certainly. But their cassette is certainly the best I have ever ridden.
All the people I ride with are very envious of my gearing, when they need to ride out of the saddle for several minutes up steeper climbs, while I can stay planted on everything that is not Mortirolo, Zoncolan or Angliru. All of them are very fit and ambitious, but you can only ride at 320W at 80 cadence for so long…
From here on:
if you want to discuss the efficiency of drivetrains and ring sizes further, please create a thread for that!
Back to Shimano 2021 please.
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I heard it will be Disc only
That’d surprise me. Shimano is a very conservative company.
I’ve been assured rim brakes will be offered…if nothing else Ineos will need them
Nope, pretty much confirmed to be rim and disc.
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