Gearing Advice

[Gibbo9]

Hi All,
I hope you are all well and are coping with the pandemic as best you can. It has been quite some time since I last posted on here, although I do pop in now and again to see what is going on.

I am back seeking advice on gearing as the topic and subsequent explanations confuse me greatly.

For reference...I have recently moved to Taiwan for work and, to my delight, have discovered that this country is just made for cycling, it is massive here and all cyclists are catered for. The only problem is the terrain, which is extremely hilly, mountainous even. Now I struggle at the best of times with most ascents, I tend to just select as low a gear as possible and grind it out. However, I am finding that I can't make some ascents in even my lowest gear. I have been advised that I can change my groupset to give me greater options for climbing without losing anything at the top end.

Can any of you super folk lend any advice please, in laymans terms would be great.

Thanks in advance.

Oh forgot to add that I am currently riding a Kuota Kobalt (3 years old) although I am upgrading shortly to a Colnago (part of the reason I am asking as I can get it built to my own spec).

 

[Tigerbiten]

Top gear is easy ........
Are you happy starting to freewheel at around 25 mph/40 kmph, in which case your chainring wants to be 4x bigger than the smallest sprocket.
Or do you want pedal madly downhill at 35 mph/55 kmph, in which case you may want to go 4.5x chainring/small sprocket.

First gear is more tricky
As you're trying to cope with steep hills then your back wheel wants to do more than one revolution for one turn of the pedals.
A good starting point is the the largest sprocket is 4 teeth bigger than the chainring.
You can lower but you do start to run into the question of "at what speed do you lose your balance" with very low first gears.

Range:-
A long cage rear derailleur can cope with a maximum of roughly 48 teeth.
How you split them front/back depends on the number of chainrings.
1x is all at the back, 2x is roughly 33%/66% or 16t/32t front back, 3x is roughly 50%/50% or 24t/24t.
These are maximum numbers and you don't need to use the full range.
For a 2x setup it helps if you don't go the standard compact double.
So 48/32 and 11-36 for high speeds downhill runs or 44/28 and 11-32 for freewheeling speeds.
A 48/36/26 triple and the same 11-32 block give you both high speeds downhill and easy hill climbing.
For a 1x setup then a 44t chainring and an 11-46 block comes close.

Now it's just a case of playing on a gear calculator to fine tune the settings.

Luck .............

 

[Gibbo9]

Top gear is easy ........
Are you happy starting to freewheel at around 25 mph/40 kmph, in which case your chainring wants to be 4x bigger than the smallest sprocket.
Or do you want pedal madly downhill at 35 mph/55 kmph, in which case you may want to go 4.5x chainring/small sprocket.

First gear is more tricky
As you're trying to cope with steep hills then your back wheel wants to do more than one revolution for one turn of the pedals.
A good starting point is the the largest sprocket is 4 teeth bigger than the chainring.
You can lower but you do start to run into the question of "at what speed do you lose your balance" with very low first gears.

Range:-
A long cage rear derailleur can cope with a maximum of roughly 48 teeth.
How you split them front/back depends on the number of chainrings.
1x is all at the back, 2x is roughly 33%/66% or 16t/32t front back, 3x is roughly 50%/50% or 24t/24t.
These are maximum numbers and you don't need to use the full range.
For a 2x setup it helps if you don't go the standard compact double.
So 48/32 and 11-36 for high speeds downhill runs or 44/28 and 11-32 for freewheeling speeds.
A 48/36/26 triple and the same 11-32 block give you both high speeds downhill and easy hill climbing.
For a 1x setup then a 44t chainring and an 11-46 block comes close.

Now it's just a case of playing on a gear calculator to fine tune the settings.

Luck .............

Thanks for this, it makes sense even to me. I am more of a freewheeler down the hills, I tend to hang on the brakes if I am honest and don't like to go over 50kph if I can help it. I am finding that with my current set up, when I am cruising on the flat, I am almost in my top gear, something I would rarely have used even a few months ago.

It sometimes feels as if I am stuck between gears, current gear feels like I am spinning too fast but if I go one up then I feel it's too hard to maintain cadence and my thighs fade quickly.

A cyclist friend of mine recommended a 36/50 compact set up which he says makes climbing easier whilst still retaining the top end?

Hope this makes sense, it has been playing on my mind for a while and is important for me to get the correct set up for the new bike.

 

[DCBassman]

On my old Scott, there's a 52-42-30 triple, so plenty of top end. But on the back is a 9-speed 12-36 Alivio mtb setup. Good for anything! But I doubt Colnago would want to fit a triple!

Lots of options, anyhow.

 

[Tigerbiten]

It sometimes feels as if I am stuck between gears, current gear feels like I am spinning too fast but if I go one up then I feel it's too hard to maintain cadence and my thighs fade quickly.

A cyclist friend of mine recommended a 36/50 compact set up which he says makes climbing easier whilst still retaining the top end?

Hope this makes sense, it has been playing on my mind for a while and is important for me to get the correct set up for the new bike.

Sounds fairly normal if you have a cassette with a wide range but few sprockets.
Ideally you want your top gears to have around a 12% step.
If it's bigger than this then it's hard to spin a gear fast enough to get in the power band of the next gear.
Hence getting stuck between gears.
This is where more sprockets help as you can add a sprocket to fill a large gear step.
Look at the difference between a 11-12-13-14-15-17-19-21-24-28-32 11-speed cassette and a 11-12-14-16-18-21-24-28-32 9-speed cassette.
Both have the same range, but the first has only one step of 16.7% between the 24-28 sprockets, while the second has 3, 12-14, 18-21, 24-28.
Or even a 11-12-13-14-15-17-19-22-25-28-32 11-speed, same range and sprocket count as the first but 2 sprockets that are 1 tooth bigger.
It may make a difference if the bigger step (19-22 vs 19-21) is in a part of the cassette you most commonly use.
This is the reason why some people start with 2 less than ideal cassettes, split them down to individual sprockets and rebuild one to give them their ideal cassette plus a lot of spare parts ........
So it not only the number of sprockets that is important but their size as well.

As for a 50/36 compact double, it's to big as your not interested in speed.
I'd be more inclined to go for chainring 10% smaller, something like an 44/28 Alpine double will make hill climbing SO much easier.

Hope that helps ............

 

[CXRAndy]

Hi All,
I hope you are all well and are coping with the pandemic as best you can. It has been quite some time since I last posted on here, although I do pop in now and again to see what is going on.

I am back seeking advice on gearing as the topic and subsequent explanations confuse me greatly.

For reference...I have recently moved to Taiwan for work and, to my delight, have discovered that this country is just made for cycling, it is massive here and all cyclists are catered for. The only problem is the terrain, which is extremely hilly, mountainous even. Now I struggle at the best of times with most ascents, I tend to just select as low a gear as possible and grind it out. However, I am finding that I can't make some ascents in even my lowest gear. I have been advised that I can change my groupset to give me greater options for climbing without losing anything at the top end.

Can any of you super folk lend any advice please, in laymans terms would be great.

Thanks in advance.

Oh forgot to add that I am currently riding a Kuota Kobalt (3 years old) although I am upgrading shortly to a Colnago (part of the reason I am asking as I can get it built to my own spec).

I love messing with gearing. I run a triple di2 setup with 50/36/26 and a 11-40 cass for mountains. I can stay seated a spin up 25% gradients.

Compact cranks are usually 50/34, sub compact/adventure cranks 48/32 or 46/30. Shimano do a 46/31 GRX crankset. Mated to a 11-36 SRAM cassette will significantly help you to stay seated and spin up steep hills.

I use bikecalc.com to work out gearing, the cadence I want to achieve at a certain speed. I know 4 mph is the lowest speed I would climb at, and would like to maintain 80rpm. Once you know these numbers selecting the gears becomes much easier

 

[HLaB]

Hi All,
I hope you are all well and are coping with the pandemic as best you can. It has been quite some time since I last posted on here, although I do pop in now and again to see what is going on.

I am back seeking advice on gearing as the topic and subsequent explanations confuse me greatly.

For reference...I have recently moved to Taiwan for work and, to my delight, have discovered that this country is just made for cycling, it is massive here and all cyclists are catered for. The only problem is the terrain, which is extremely hilly, mountainous even. Now I struggle at the best of times with most ascents, I tend to just select as low a gear as possible and grind it out. However, I am finding that I can't make some ascents in even my lowest gear. I have been advised that I can change my groupset to give me greater options for climbing without losing anything at the top end.

Can any of you super folk lend any advice please, in laymans terms would be great.

Thanks in advance.

Oh forgot to add that I am currently riding a Kuota Kobalt (3 years old) although I am upgrading shortly to a Colnago (part of the reason I am asking as I can get it built to my own spec).

If you want to spin uphills (especially long ones) its easiest (not necessarily easy) with gears positioned so that the chain is on the smallest ring at the front and the largest cog at the wheel. The smaller (front), the larger (rear) are theoretically the more spinnier it'll be. Id suggest that rather than a 50/36 the traditional compact 50/34 would be better (perhaps even a sub compact but you'll lose a little speed downhill) and the largest cassette you can get on the back an 11-28 cassette is a safe bet but you may be able or can mod the bike for something larger like an 12-32 or 34. Good luck

 

[Milkfloat]

What have you got at the moment? Count the teeth on the smallest front ring and the largest rear, when can then help a little more. Even better can you see any model numbers on your front and rear mech?

 

[Gibbo9]

Thank you all, this is really helpful and I can honestly say it is the first time where gearing has been explained to me in a way I can understand.

I will check out the bike tonight and feedback on gearing that I am currently using by which time you guys will probably be up, being as I am 7 hours ahead.

 

[Gibbo9]

Hi All, so just had a look and I’m running a 50/34 MH. Any ideas?

 

[Tigerbiten]

Ok, last part, Cadence and flat land gears.

At the moment I'm not very fit so my cadence is only around 70 rpm.
I can drop down to under 60 rpm but to do that I need to increase the pressure between my feet and the pedals.
This increases the strain on my knee joints and they start to hurt.
As I get fitter then my cadence will naturally increase to around 80 rpm.
Once I get over 90 rpm then I'm starting to overspin and my efficiency drops off quickly.

On a road bike it's around 15 mph/24 kmph that wind resistance start to ramp up badly.
So while it's fairly easy to tick along at this speed, to go faster you need to work a lot harder.
So if I'm pedalling with a cadence of 70 rpm along a flat road in still air at 15 mph/24 kmph then I'm in a 70" gear.
I've found that around 12% between my gears suits my riding style, I like to keep a very steady cadenc and I'm willing to flick up and down gears as needed.
So if I'm going down a gentle slope or I've a tailwind then I may be in one gear higher or a 78" gear.
If I'm on the down slope with the tailwind then I'll may want to be one more gear up or a 88" gear.
Going the opposite up the slope or into a headwind I may want to be one gear down or a 52" gear.
Same slope with a headwind so one more gear down or a 56" gear.
I know these 5 gears, 56"-62"-70"-78"-88", will cover most of my riding if it's not very lumpy, that's why I call them flatland gears ..........
So if I'm thinking of altering my gears I'll plug the new combo of chainrings and cassette into a gear calculator and see where these 5 gears line up.
Are there any big jumps (+15%) in this 56"-88" range, if there are them I may not like that step.
Around a 44t chainring then the cassette combo 14-15-17-19-21 lines up almost exactly with that gear range.
The 14-15 step is a bit small, but thats so bad with the higher gears as it gets harder to spin a gear up to get into the next one as the gear size increases.
As I get fitter and my cadence increases then I'll either just go faster or I'll drop down one gear to keep my speed roughly the same.
A 13-15 step is a far to big a jump for me and a 19-22 is verging that way.
Just a slight warning that while these 5 flatland gears work for me as they match my riding style, they may not work so well for you.
But you get the idea.

Luck .............

 

[Tigerbiten]

Hi All, so just had a look and I’m running a 50/34 MH. Any ideas?

What are the sprocket sizes on your cassette ??
Your smallest sprocket is probably an 11 as that's the standard size small sprocket.
Which gives you a top gear of 50/11 x wheel size (~27") or ~123".
You could probably drop this by 10%-15% or one gear and not miss it as you don't like high speed descents.
Beyond that ????? without the sprocket sizes.

Luck ............

 

[byegad]

On the point of too low a gear.
I had a recumbent bike witha triple up front, 9 cogs at the back and a hub gear at the back. 3x9x3=81 gears.
Top was a massive 150" gear, only of use down hill, where, it could be spun while travelling at 50mph, not a frequent occurrence even in hilly County Durham.
Bottom, on the other hand was a mere 15". At normal pedalling cadence that equated to around 3mph. Recumbent bikes are harder to balance at low speed than a 'normal' upright bike. So it took me a couple of months before I could use the 15" gear and stay on board. Recumbents are hard to push while walking, especially if you have under seat steering. On a normal bike 15" is so slow you may as well walk up the hill pushing the bike.
If you set a 20" bottom gear as the point where you get off and walk then assuming a 26" rear wheel and a largest rear cog of 34 teeth, there are a load of 11-34 cassettes, then a 28 tooth front ring will be close enough.

 

[HLaB]

Hi All, so just had a look and I’m running a 50/34 MH. Any ideas?

Short term if you can fit the largest cassette you can on the rear an 11-28 is a safe bet to fit most bikes. A local bike shop may be able to fit something bigger like a 12-32 but a new deraileur might be needed. (The bigger the better at the rear). If you are still struggling in the longer term consider changing your 50/34 compact for a sub compact (like a 48/32) or a triple with a 30 tooth ring. (The smaller the better at the front). That'll be more expensive however, and you will probably lose top speed downhill (unless you find a very high cadence subsequently). You may find that the larger cassette plus your development however, negates that

 

[Gibbo9]

Thanks everyone, this has been very helpful indeed. I have spoken to my LBS and they are happy for me to come in and discuss and play about with a few options.

Thanks again