Advice on gearing for hills

[Sethis01]

Hi, all. I need advice on my gearing setup for climbing hills. Im currently running 53-39T up front and 11-28T on the cassette (Shimano 105).  

My issue is that I struggle on inclines in comparison to flats. On flats I'm passing a lot of people in races and on the climbs I drop cadence a lot and lose momentum. 

I feel that I need to change my setup to be more hill friendly.  However,  I worry that if I change too much that I would overspin on declines and flats?

Can I simply change the cassette to 32 or 34T? Or should I make changes at the front?

I understand there is a training aspect but im looking for mechanical advice.

I appreciate your guidance!

Edited October 18, 2025 by Sethis01

[David Marshall]

We need a little more info to give good advice. 

Exactly which model105 groupset you have and the cage length of the rear derailleur.  The model number will be printed on the shifters under the rubber hood and on the body of the rear derailleur.

The derailleur cage length is a bit tricky to establish but rule of thumb is if you can freely pass a third pulley wheel through the cage between the two pulleys it is a medium cage and if not it is a short cage.

From your chainring sizes I assume that you have a 10 speed 105 and a short cage RD (because that was the most common).  11 speed tend to be compact (50/34) or mid-compact (52/36).

Your easiest fix for the 10 speed scenario is to replace the RD with a 9 speed Shimano MTB RD - or Shimano MTB compatible RD.   

The simplest to get hold of is the Sunrace M90 at around R400.  This would allow for a 34/11 cassette giving you an 18% improvement over the current 28T climbing gear.

If this does not cover your set up let us know what you have.

Edited October 18, 2025 by David Marshall

[Ncayi]

As Mr Marshal said, you will receive a lot more feedback if you provide more technical information about you current setup. 

I moved from an 50-34 and 11-28 setup to a 52-36 and 11-28 when I lived in the south of JHB, it's mostly flat. When I moved north I had to change to an 11-32  at the back and kept the front the same.  Then I realised I was spinning on on steep descents so I moved to a 53-36 setup.

I was using a shimano 105 R7000 crankset and an Ultegra R8000 GS (medium cage) rear derailleur. So if your derailleur allows, I would say get a bigger cassette. It doesn't take long to adjust to the new jumps in gears. And if the pocket allows, perhaps also move to a semi compact 52-36 in the front.

A big gear is great only if you can spin it.

 

[NotSoBigBen]

8 hours ago, Ncayi said:

As Mr Marshal said, you will receive a lot more feedback if you provide more technical information about you current setup. 

I moved from an 50-34 and 11-28 setup to a 52-36 and 11-28 when I lived in the south of JHB, it's mostly flat. When I moved north I had to change to an 11-32  at the back and kept the front the same.  Then I realised I was spinning on on steep descents so I moved to a 53-36 setup.

I was using a shimano 105 R7000 crankset and an Ultegra R8000 GS (medium cage) rear derailleur. So if your derailleur allows, I would say get a bigger cassette. It doesn't take long to adjust to the new jumps in gears. And if the pocket allows, perhaps also move to a semi compact 52-36 in the front.

A big gear is great only if you can spin it.

 

That last sentence is gold my friend!

[love2fly]

Without being too intrusive, what is your ballpark weight? I ride a 10 speed Ultegra groupset with exactly that gearing and other than the most serious hills inagineable I seldom use my granny gear.

Until Feb this year I weighed in at around 115kg but am now down to 90kg which has made a huge difference. I've never bought into compact and sub compact and never will and still run out of gears on descents but that's a random sample of one...🤘

[Baracuda]

Reading through this, one is unsure of the problem - are you running out of gears? i.e. is your lowest gear too hard on regional hills?

Hard to advise without knowing where you stay, the hills and your weight. e.g. if you stay in Prince Albert and plan to ride up the Swartberg pass often, one would recommend mtb gearing or 105 compact with the largest cluster your rear derailleur can take. 

[Eugene]

Sometimes all we need is to train more on hills. 

[NotSoBigBen]

37 minutes ago, Eugene said:

Sometimes all we need is to train more on hills. 

🤯 no surely not ... jeez I heard you buy an e-motorbike before you take such a drastic step 🤪

[Sethis01]

Thank you all so much for your input! 

To give you some extra details:

Shimano 105 R7000 11 speed

53-38, 11-28

Road bike (roughly 8 kg)

Height and weight: 179cm, 73 - 76kg range

FTP - 270ish (not sure if that helps but just trying to give you as much info as possible)

Intended use - mostly rolling terain with occasional hilly areas. (Ironman 70.3 and 140). TT bike not in the budget,  only upgrades to current road bike

Issue: would like a little extra help with hills but worried if I go down from 53/39 that I am going to overspin on decents and flats. Triathlons dont really have massively hilly courses.

Should I rather just increase the cassette  to a 11-30 or 11-32?

I could replace the entire groupset if you think a whole different setup is better.  

Im not 100% sure of the rear derailed specs other than 105 R7000 11 speed (traveling at the moment so can't check).

I acknowledge that hill training is essential but would just like advice on my initial mechanical setup.

Thank you all so much! 😀

 

[Sethis01]

39, not 38 sorry, typo 

[Sethis01]

I was also reading that amateur athletes are highly unlikely to spin out on 52/39 and that even some pros use 50/39 without spinning out.

When it comes to technical knowledge of gearing im a noob

[Paul Ruinaard]

You are not a big guy nor are you unable to put out power at those weights and FTP,  not sure of your age but i would assume you arent in the older generation but TBH adding a couple of teeth on to the top by buying a bigger cassette will likely help you, Thats the simplest and cheapest way of finding out.

If you are getting dropped on the climbs then a lighter gear may work for you at the top.

What everyone is pointing out is that groupsets have limits or guidelines depending on the length of the cage. However I will tell you these can be pushed. Not always recommended as it can screw up shifting but it can work.  I ran 34 and 36 clusters on a nomral 1 speed DI2 Ultegra derailleur and just was careful about shifting. It was outside of the guidelines wrt the total number of teeeth top to bottom but it worked and i had a bail out gear at the top to spin.  if you want speed and are worried aout spinning out a compact crank is probably not for you as you lose the sheer speed a 53/11 or 12 can offer if if you can grind it. If you are a spinner then compacts can be okay but the cadence will always be high

You also need to listen to the advice on trainng i.e. train your weakness - if you are a big gear masher and can learn to spin then you will be faster overall. remember everyone is loking for a solution thta is easy to achieve - training is. hard, as is losing weight. Nobody likes high cadence workouts i can assure you and if you are a big gear grinder you hate them even more.

You can probably mess around a bit with clusters (which is cheaper)  and alter your trainng to address your weak spot IMO.

[Sethis01]

On 10/27/2025 at 9:09 AM, Paul Ruinaard said:

You are not a big guy nor are you unable to put out power at those weights and FTP,  not sure of your age but i would assume you arent in the older generation but TBH adding a couple of teeth on to the top by buying a bigger cassette will likely help you, Thats the simplest and cheapest way of finding out.

If you are getting dropped on the climbs then a lighter gear may work for you at the top.

What everyone is pointing out is that groupsets have limits or guidelines depending on the length of the cage. However I will tell you these can be pushed. Not always recommended as it can screw up shifting but it can work.  I ran 34 and 36 clusters on a nomral 1 speed DI2 Ultegra derailleur and just was careful about shifting. It was outside of the guidelines wrt the total number of teeeth top to bottom but it worked and i had a bail out gear at the top to spin.  if you want speed and are worried aout spinning out a compact crank is probably not for you as you lose the sheer speed a 53/11 or 12 can offer if if you can grind it. If you are a spinner then compacts can be okay but the cadence will always be high

You also need to listen to the advice on trainng i.e. train your weakness - if you are a big gear masher and can learn to spin then you will be faster overall. remember everyone is loking for a solution thta is easy to achieve - training is. hard, as is losing weight. Nobody likes high cadence workouts i can assure you and if you are a big gear grinder you hate them even more.

You can probably mess around a bit with clusters (which is cheaper)  and alter your trainng to address your weak spot IMO.

Hi, @Paul Ruinaard.

Thank you so much for your response and advice, I really appreciate it.

I absolutely agree that training is essential, I just lack mechanical knowledge so it's also something I need to learn. 

I will take your advice with the cassette. Perhaps a 52/36 might offer me the best of both worlds too, I can only try to find out. 

Thank you again!

Ride safe, all! 

[eddy]

I took out my previous bike for a Suikerbosrand ride on Sunday - 53/39 with the 11-25 'climbing cassette'. 

It should be fun..