What cog combination is ideal for a road bike?

[Chap sur le velo]

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?

 

[Ming the Merciless]

There no ideal ratio. Depends on your weight, fitness, whether you stand on most hills. If you don’t have many steep hills or steep ones are very short (like section on Swaines) then higher gearing is fine. For lower gearing bigger largest cog on back or smaller chain rings at front.

 

[cougie uk]

As Ming says - you need what works for you.

I doubt many people have gears low enough to spin up a 1 in 5 hill.

 

[ColinJ]

I doubt many people have gears low enough to spin up a 1 in 5 hill.

The ones who don't are either very fit, don't ride up 20% hills, or slowly grovel!

I prefer a ratio of 1 : 1 or lower for any extended ramps of 20+%.

I used to have a bottom gear of 39/29 (1.34 : 1) on my CAAD5 but I found that too much like hard work on 15+%, and there is a lot of that round here. I put a triple chainset on the bike and a slightly bigger cassette. I now have a bottom gear of 28/30 (0.93 : 1), which I find okay for 20% and doable for short stretches of 25%.

 

[Cycleops]

If you want to get up Swains Lane a bit easier swap the cassette out for something like a 12-36. The RD might not be able to handle it so a wolf tooth extender will be needed. You might need a longer chain too.
If you want a gear for everything put a triple on the front.

 

[CXRAndy]

As Ming says - you need what works for you.

I doubt many people have gears low enough to spin up a 1 in 5 hill.

I do .

I can spin up 30+ % on my Tripster ATR

 

[HLaB]

I like a 52/36 with an 11-28 rear as that suits me and the terrain I come across. But as said there is no ideal: If it was pancake flat always and/or I was really strong I might prefer a larger chain ring (something like a 53/39 or bigger) with a more tightly spaced cassette (say an 11-23). If I regularly rode up long hills I do the exact opposite smaller chain rings (say 50/34) and 14-30.
Another variable that determines the gearing which is ideal for an individual is what type of riding they do. A rider of a on road bike might prefer higher gears, whereas a user of a off road bike will generally have lower gears.

 

[Alex321]

As everybody else has said, it depends on the rider and the terrain they are likely to meet.

Personally, riding in the Vale of Glamorgan, with a fair amount of smallish hills, I ride with a 105 groupset with 50/34 and 11-32. I quite often find myself spinning in the bottom gear on the longer hills, even if they are only 8-10%. But I can get up the few 15-20% hills round here (all of which are pretty short) by standing on the pedals.

Until a couple of weeks ago, I was riding a hybrid with SRAM X5 48/36/26 and 11-34, but I hardly ever used the smallest chainring.

I suspect those living in places like the Peak district or Yorkshire dales wouldn't consider it hilly round here at all, and probably think I'm a bit of a wimp needing gears that low for what I face.

 

[rogerzilla]

I like 50/39 and 13-21. This will not suit many people

 

[CharleyFarley]

You asked about a guide. You can calculate gear/inches for any combination of cogs. It might seem a bit technical but it's really quite easy. On this chart you will be able to calculate the gear/inches for any of the combination of cogs you already have. Then from what you learn about those, you can decide what you might want to achieve.

Divide chain ring teeth by rear cog teeth. Multiply by tire diameter.
Example:
38 chain ring teeth, divide by 28 sprocket teeth X 26. = 35 gear inches. That's the distance in inches traveled by the bike for each revolution of the pedals. That's just for one combination of cogs, so you calculate it for each combination.

I bought a new cruiser from a bike shop and it came with a Megarange freewheel (set of rear sprockets). It was horrible, okay for a mountain bike but not a cruiser. So I put a regular 14-28 freewheel on it. The lowest gear then wasn't low enough, so using the gear/inches chart I could calculate what size chain ring would work. It pretty much takes the guesswork out of buying another chain ring.

https://www.bikecalc.com/gear_inches

 

[Kajjal]

It’s really personal preference but be realistic about where you ride and how you want to ride. I use my gravel bike on and off road it has 48/32 and 11-34 rear cassette. The lower gearing is especially useful off road but also any steep hill on road. In comparison my mountain bike has even lower gearing and the only real issue going up steep hills is maintaining traction and keeping the front wheel down.

 

[ColinJ]

It’s really personal preference but be realistic about where you ride and how you want to ride. I use my gravel bike on and off road it has 48/32 and 11-34 rear cassette. The lower gearing is especially useful off road but also any steep hill on road. In comparison my mountain bike has even lower gearing and the only real issue going up steep hills is maintaining traction and keeping the front wheel down.

When I bought my CAADX it had 46/36 chainrings and (I think?) a 12-28 cassette. I tackled a few tough local climbs on it, such as this one...

I managed to get up that in 36/28 but it was hard work so I altered the gears on the bike. It now has 46/34 rings and a 12-36 cassette. It is MUCH nicer doing steep climbs in a 34/36 gear than 36/28!

 

[MichaelW2]

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.

 

[Dogtrousers]

36/27 is about a 35" gear

That would be way too high as a bottom gear for me, but I'm not a very athletic specimen. If you can get up the steepest hills you come across on it then fine. If you feel you could do with something lower then get something lower.

In the UK we often measure gears in inches. It goes back to penny farthing days. It's the diameter a direct-drive wheel with equivalent gearing. So a penny farthing with a 28" (say) wheel would have lower gearing than one with a 100" wheel (and you'd need very long legs to be able to ride it).

On the continent they prefer développement in metres, which is the distance the bike goes forward for one turn of the pedals. That's a bit easier to envision but it's not used much here. a 35" gear would have a développement of about 2.8m

Most (or many) off the peg road bikes these days come with 50/34 and 11-32 (or 34) so a range of about 28" (or 26") to 119"

btw, I have ridden up Swains lane - only once and it was a while ago - it was steep but I don't think it was as steep as 20% Sorry to sound a note of scepticism.

 

[Arrowfoot]

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?

Looks like you are fit to do 36(front) and 27(back).

Since circa 2010, industry has popularised front at 50/34 compact. To spin you need to get 11/30 or 11/32 at the back. They are now common in newer bikes as people are keen to do hills as part of their routine. 11/32 is in short supply, better get 11/30 if you can.

So you are looking at 34(front) and 30 or 32(rear). If you into hill and steep gradient in a big way than 34 at the back.

If you get 11/32 you need a new RD with a medium cage and you a new chain.