What cog combination is ideal for a road bike?

[Ming the Merciless]

I find it easier to think about gear inches than cog combinations; there are many duplicate and overlapping ratios on a bike.
Pro riders use gear ratios suitable for professional athletes. Many amatuers copy these ratios without the power plant to turn them.

I don’t think they choose them knowingly. It’s just the bike they buy comes with them.

 

[Dogtrousers]

Pro riders use gear ratios suitable for professional athletes. Many amatuers copy these ratios without the power plant to turn them.

I don’t think they choose them knowingly. It’s just the bike they buy comes with them.

I don't think pros run a bottom gear of 34/32 except maybe if it's a stage like the Anglirou. But I could be wrong - I don't actually find out and note down what ratios they are using - that would be weird. I have a suspicion they don't use 50T big rings as a matter of course either, but I don't know.

I doubt that amateurs copy the ratios the pros use because no one except the nerdiest weirdo actually has any idea what ratios the pros use.

I also don't think the bikes on sale ape the ratios used by the pros - for reasons above. It's too arcane a subject. Sure, bikes ape the look and style of pro bikes but details like gear ratios? Honestly, I doubt it.

But I do agree that the top end of a standard(ish) road bike top gear of 50/11 is too high to be of regular use by your average Joe(sephine) cyclist other than on downhill stretches.

But bikes aren't just for the average and I'm sure there are a fair few riders out there who zoom along at 21-28mph on the flat (60-80rpm on a 120" gear) so maybe the manufacturers are trying to include these riders in their target. I was passed by a guy pedalling hard on a long slight downhill (about 1% down) yesterday, he must have been doing 40-50kmh (about 30mph). I'll bet he was making full use of his 11T sprocket.

Whenever my next drivetrain revamp comes due I think I'll consider a subcompact chainset. That 11T sprocket is always so clean. There's one stretch of road where I regularly use it (a long gentle downhill that comes at the end of my rides - and I'm pedalling ludicrously slowly) but that's it.

 

[Ming the Merciless]

On my recumbent my big front cog is 44. When that wears out. I’ll likely swap that to the 46t spare I have. But I doubt I’ll ever fit anything much bigger.

 

[CXRAndy]

Different setups for different uses.

56x11 TT bike

General do it all Tripster
Triple crankset with range 50/36/26 11-40 cass

Ebike 40x11

 

[TheDoctor]

I'm currently riding a 34T chainset to a 13-32 8 speed cassette. My next build will be 34T again to an 11-36 9 speed.
There's no right answer. You want a low gear that'll get you up your local steep hill, maybe another below that, and a high gear for when the wind's behind you, and some in between.

 

[Eurostar]

I find the guide on page 48 of this pdf quite useful. The author is pro-Rohloff but try to ignore that. http://www.sjscycles.com/thornpdf/thorn_mega_brochure.pdf

For calculating ratios there's Sheldon Brown's famous calculator https://www.sheldonbrown.com/gear-calc.html

 

[All uphill]

I find the guide on page 48 of this pdf quite useful. The author is pro-Rohloff but try to ignore that. http://www.sjscycles.com/thornpdf/thorn_mega_brochure.pdf

For calculating ratios there's Sheldon Brown's famous calculator https://www.sheldonbrown.com/gear-calc.html

That St John St book (Bible!) is a very interesting read. Thanks!

 

[Eurostar]

That St John St book (Bible!) is a very interesting read. Thanks!

You're welcome! There's a lot in it, isn't there?

 

[freiston]

My favourite online gear calculator has sliders and label changers so that you can see speeds attained at certain cadences in particular gears. I like to spin at a cadence no slower than 60 rpm (often 90+) rather than grind and I'm slow - so I use low gears a lot. My bike has 26/36/48 on the front and 9 speed 11-34 on the back. I would hazard a guess that most of my riding is done on the middle seven sprockets of the cassette and the 36T chainring but I will use all three chainrings on most rides though I only use the 48T chainring on good fast descents.

Here's a link to the aforementioned gear calculator showing my gearing (bottom) and my nephew's gearing (top) on his bike (CAAD 12 I think):

https://www.gear-calculator.com/?GR...36,48&RZ2=11,13,15,17,20,23,26,30,34&UF2=2170

 

[Punkawallah]

Ooooh. My Galaxy came with 48/36 front, and 14-24 rear. Found that there was no ‘purchase’ on even slight downgrades, so swapped the front for 52/40. Much better, but that hill down the road was a pain. So, swapped out the rear for 14-28 (14-32 has no removal tool available at a reasonable price atm).

When the Galaxy went to a ’touring’/winter’ bike, replaced the front with a 48/34.

So, gearing changes to suit your requirements. Ymmv, T&CA apply.

 

[T4tomo]

So, swapped out the rear for 14-28 (14-32 has no removal tool available at a reasonable price atm).

that's quite an odd statement cassette removal tools are common to the freehub on the bike and don't vary with size of rear cog, unless you have some unique situation somewhat irrelevant to the OP? hmm 14-X maybe you are on an old freewheel set up, again somewhat irrelevant to the OP.


as a guide to the OP, macho gearing is going a bit out of fashion. standard starter road bikes were being supplied 50-34 & 11-25 about 10 years ago, that move to 11-28 and a lot now with 11-34. it really depend where you ride and how hill it is. if you are riding out from North London to Hertfordshire hills, then whilst 36-27 as your lowest gear is manageable, you might want to see if you can get hold a 11-30 or 12-30 cassette to make life a bit easier. if your bike as detachable chainrings that is also the route you could go, buy getting a 50 & 34 T rings of a the correct size (BCD) to fit (53to 34 will be quite a big drop for your FD to cope with, and you would need to adjust the height position of the FD anyway.. You don't say whether its Shimano stuff or Campag gears, but replace like with like

 

[Blue Hills]

as a guide to the OP, macho gearing is going a bit out of fashion. standard starter road bikes were being supplied 50-34 & 11-25 about 10 years ago, that move to 11-28 and a lot now with 11-34.

Interesting - at this rate only a matter of time maybe before triples return to be sold as the latest new thing.
We've already had a move to fatter tyres.

 

[Paul_Smith SRCC]

I have a S/H Willier road bike and the front hub has smaller 36 and larger 53 cogs. The back 11 speed cassette(?) ranges from 27 to 12.
I've been told that's quite steep but what do I compare it to? I can get up the 20% section of Swain's Lane standing and working very hard, but no way I could just spin up it. Is there a useful guide to check out?

Gear ratios are a personal choice, most modern endurance road bikes will now have a 50/34 with 11/34 cassette; using a 27" wheel traditional gear chart that equates to a comparison of lowest gear of 36" on your bike versus 27".

For sure those two numbers may not mean much to many, 36" is these days quite high but you can get up that 20% section working hard and as long as you are happy with that then that's fine. For years I toured a similar low gear to you @35"; I'm no fabulous racing whippet, but when I rode from 'Lands End to John O'groats, (LEJOG)’ I rode up every climb. In that specification I also toured the High Alps with two full panniers and again rode every climb; just, but I did it.

Although a 35" gear was OK for me on Lejog I realised when I was riding in a group I had to keep the gear turning on the climbs and ride quicker than many of my new friends, who were using lower gear ratios than me and able to ride at a slower more sociable pace, that along with wanting to take in the scenery resulted in a desire to fit a lower gear ratio. These days on my Van Nicholas Yukon, the bike I now use for holidays, that has a low gear of 24", which is in effect walking pace and I don't need to use it that often but like that I have it for the odd occasion I need it. I bought my Yukon in 2007 and achieving that low gear was not easy back then, I am glad to say it is now, if I were building that today I'd use a Gravel bike group with 46/30 rings and 11/34 cassette, which gives as high and as low as I need plus my favourite common used ratios in straight chainline combinations.

In conclusion it's not so much that "you have been told that's quite steep", it when you tell yourself that it is.

 

[Paul_Smith SRCC]

This raises an interesting point, that if you have low gears you will inevitably use them. This will probably slow you down as you will have a longer but more pleasant ascent up the hills. I noticed this when I fitted somewhat lower gearing on my bike that my times up my regular big climbs went up. But it's a price worth paying IMO

For me it was an evolution from one style of cycling to another. In my younger years of club riding I was far more keen to push on, must club runs turned into a burn up and I was racing back then; I thoroughly enjoyed it. As I grew older and definitely slower over time I stopped racing and embraced easing back, taking in the scenery far more and cycling to 'chill out' more than 'work out'. Lejog was a a definitive tour for me, I was first at the campsite for the first few days, but around the dinner table in the evening when others related their day I soon realised I had missed much of what they had seen. My personal conclusion was that it was folly to visit these new places only to miss much of what I was cycling through as I was concentrating on my effort.

For sure it is "horses for courses" as the saying goes, choosing the correct gear ratios for me is as much about 'desire' as it is 'physical' ability, if I only factor in the latter I could cope with higher, but these days I desire lower and I am pleased I have them.

 

[Chap sur le velo]

Gear ratios are a personal choice, most modern endurance road bikes will now have a 50/34 with 11/34 cassette; using a 27" wheel traditional gear chart that equates to a comparison of lowest gear of 36" on your bike versus 27".

For sure those two numbers may not mean much to many, 36" is these days quite high but you can get up that 20% section working hard and as long as you are happy with that then that's fine. For years I toured a similar low gear to you @35"; I'm no fabulous racing whippet, but when I rode from 'Lands End to John O'groats, (LEJOG)’ I rode up every climb. In that specification I also toured the High Alps with two full panniers and again rode every climb; just, but I did it.

Although a 35" gear was OK for me on Lejog I realised when I was riding in a group I had to keep the gear turning on the climbs and ride quicker than many of my new friends, who were using lower gear ratios than me and able to ride at a slower more sociable pace, that along with wanting to take in the scenery resulted in a desire to fit a lower gear ratio. These days on my Van Nicholas Yukon, the bike I now use for holidays, that has a low gear of 24", which is in effect walking pace and I don't need to use it that often but like that I have it for the odd occasion I need it. I bought my Yukon in 2007 and achieving that low gear was not easy back then, I am glad to say it is now, if I were building that today I'd use a Gravel bike group with 46/30 rings and 11/34 cassette, which gives as high and as low as I need plus my favourite common used ratios in straight chainline combinations.

In conclusion it's not so much that "you have been told that's quite steep", it when you tell yourself that it is.

Thanks to all who responded.

After posting this and another thread I started on what bike to buy, I decided to go down the new bike route. A Giant Defy comes with the seemingly ubiquitous 34/50 Chainset and 11/34 Cassette. Before Christmas I'm resolving to do my first ever Swains Lane, twice. Will try and reserve "Highest(?)" cogs for second attempt.

Meanwhile new bike and I are off to Cornwall next week so will get to know more soon.