The Basics of Road Bike Gearing
- Posted on
- By Nick Runtsch
- Posted in earing
This post examines the effects caused by the size of a bike's cassette and chainrings, as well as the number of gears on the bike.
Recently, a lot of customers have been asking about changing the gearing on their road bikes. There are a few reasons to change gearing, but most customers want to make it easier to pedal up hills in relative comfort (i.e. without pedal mashing in a low cadence). With hilly events like the Wicklow 200 and the Ring of Kerry, easier gearing is a great way to save your legs and not wear yourself out too fast.
This post will describe the advantages and limitations of different gearing setups including the maximum possible range for Shimano equipment. It will also discuss the effect of the number of gears on a bike. For ease of understanding, the units for a particular gear will be in km/h at 90rpm cadence on a 700x28 tyre rather than gear ratio or gear inches.
Currently, the most common gearing setup on new road bikes is a 50/34 chainset with an 11-28 cassette. This means that the big and small chainring have 50 and 34 teeth, respectively, and the cassette’s smallest cog has 11 teeth and its largest cog has 28 teeth. This setup has a good range in which the shortest (easiest) gear combination, 34-28, has a speed of 14.1 km/h at a cadence of 90 rpm and the tallest (hardest) combination, 50-11, has a speed of 52.8 km/h.
However, what if you can’t sustain 14.1 km/h while climbing and you don’t want to drop your cadence too much? In that case, the easiest change to make is to swap your cassette to one with larger cogs. Switching the cassette to an 11-30 decreases the speed from 14.1 to 13.2 km/h and switching to an 11-34 decreases it to 11.6 km/h. These cassettes have the same 11 tooth small cog, so maximum speed is not affected.
The chart below shows the speeds of each gear combination using Shimano 11-28, 11-30, and 11-34 cassette with a 50-34 chainset.
As shown, the maximum speed is the same with the 11 tooth cog and the 11-28 and 11-30 cassettes share the same gearing combinations until the largest three cogs. However, the 11-34 cassette has easier gearing in every combination except while in the 11 tooth cog.
The largest cassette your bike can handle depends on your rear derailleur cage length. Shimano road bike rear derailleurs have two possible derailleur cage lengths: short cage (SS) or long cage (GS). Current 11 speed SS derailleurs can handle up to a 30t cog, while GS derailleurs can handle up to a 34t cog. Older systems generally have lower capacities and it’s best to check with us if you’re not sure what your derailleur can handle. You may need to change your derailleur to get the range you want.
Another factor to consider is the size of your chainrings. Shimano chainsets currently come in three chainring configurations: 50/34 (compact), 52/36 (mid compact), or 53/39 (standard). All of these sizes are compatible with the same cassette and derailleur combinations. So, for example, if your bike has a 53/39 chainset and a 11-30 cassette, your easiest gear, 39-30, has a speed of 15.0 km/h at 90 rpm compared to a speed of 13.2 km/h with a compact chainset and the same cassette.
The chart below compares two gearing setups using 53/39 and 50/34 chainsets with the same 11-28 cassette.
As shown, chainring size has a large effect on speed. For most people, a chainset with compact 50/34 chainrings provides a gear range that suits all their needs.
Most new endurance and entry level road bikes are specced with 50/34 chainsets, racing bikes with 52/36, and time trial bikes with 53/39. This is good news for most riders as the gearing corresponds to the type of riding for which the bike is intended. However, this wasn’t always the case. The compact 50/34 chainring combination only gained popularity about 10 years ago as an alternative to triple chainring chainsets and the mid compact 52/36 has only been around a few years. This means that if you have an older bike or a racing style bike that you use to train in the mountains you may have bigger chainrings than you’d like.
Depending on your chainset it can be easy or impossible to switch chainring sizes. Shimano 11 speed chainsets feature fully interchangeable chainrings. A few other newer chainsets have this feature, but with most other chainsets it’s not possible to change chainring sizes. In these cases the entire chainset has to be changed if different chainring sizes are desired. This is due to the mounting of the chainrings on the crank arm spider.
Number of Gears
The effect of the number of gears on a bike is commonly misconstrued. Depending on the spec, new road bikes will have cassettes with between 8 and 12 cogs and usually 2 chainrings. Although the number of gears differs between an 8 speed bike and an 11 speed bike, the range of gears is generally similar or the same.
The chart below shows gearing combinations with three cassettes, a 9-, a 10-, and an 11-speed, all with the same 11-28 range.
As can be seen, the range of all three cassettes is exactly the same. What differs between the three is the size of the step between each gear. A 9 speed cassette has larger steps between gears than an 11 speed, which means that you may need to pedal at a faster or slower cadence to maintain your speed or pedal a bit harder or softer to maintain your cadence than you would with an 11 speed cassette.
Clearly, bicycle gearing is not a simple topic and there are many considerations to make before you make changes to your gearing. However, hopefully this post has given you a better understanding of the effects different gearing can have on your ride.
Hi 360cycles.ie admin, Thanks for the post!
Any thoughts on 52/36 with 11-34 vs 50/34 with 11-32 for mountains (iong step accending and corresponsdig decends)?
Hi what a brilliant article thank you.
Our son rides an old bike (Pinarello FP5 about 13 years old) 10 speed. 12-25 cassette. Struggles on hills. Recent bike fit found he needs a longer crank. So I am thinking of replacing crankset and cassette to fix a number of problems in one go.
Would it be right to go for a 50/34 crankset and 11-34 cassette? I will need to check if it will fit ok.
He does 50-60 mile training rides and races weekly but he is only 16 yo so am trying to get balance right.
Thank you in advance.
I have a 52/36 crank with 12/25 cassette (10 speed) I ride a combo of flats and moderate hills (2000ft) tops. Is this a good combo or should I go with some other combination?
Thank you for your advise.
I have 52/36 crankset and 11-28 cassette and plan on riding Pikes peak, 14,000 ft. Climb. Will this group set work?
360 Cycles Support:
It will work but will not be efficient. We would recommend 50/34 chainset and 30t cassette or bigger.
Hi! i have a 53/39 shimano 105 crankset and 11/28 8 speed cassette do you think its possible to install the crankset?t
360 Cycles answer:
It is possible to install them, however, they are not fully compatible. It may work but gear skipping, rubbing noise and mis-shifting is expected. If you have no other option and you need the bike to get from A to B and you are ok with restricted number of gears, it will work.
I have a 50/34 with 11-34. I find it a bit too low geared. Would you suggest going all the way to 53/39? And what cassette would pair up nicely? I almost never use the small chainring today.
hello! is it suitable to use a 39-53T chainset with 11-32T cassette? lately, Its become harder to find a compact chainset like 34-50T in market. Can you suggest the best option for me? appreciate your help.
If the charts are made for a 11 speed cassette why when on the big front ring it goes from 11 to 2 and on the small front ring it goes from 10 to 1?
I don't understand that. Are you just purely avoiding cross-chaining?
Hi, I have an Ultegra 10 speed 53/39 and 12/25 combination on my old Giant TCR. I have moved to a very hilly area and need advice on changing my gears. My thoughts were to go to 11-28 cassette, but I think a change to 50/34 might also be needed. Can you advise on chain length also?
i have 39/53 x 11-32 10 speed with tiagra midcage Rd.
im considering changing my cogs to 11-34
should i stick to my current setup or upgrade with bigger cogs?
They're not cogs they are sprockets. Cogs drive other cogs in gears, sprockets drive chains.
I just acquired a wilier Izoard with campagnolo record 53/39 and 11/25. My fitlrst thoughts were what a bike. Now after this article ( just got the bike today), I am wondering if I didn't make a mistake. I am not a racer and I will only be doing long rides, with maybe a few I terval training ones. Should I consider changing the 10 spread gears at the back? Would it be a mistake?
Hi, what size chain do I need, ie links for 50-34 and 11-32 ( Colnago CLX )
Hey, I'm considering to change my 11-34 cassette to a 11-30 (Shimano 105 R7000 with 50-34 crank) since I don't have too many climbs around here and therefore don't need those high gears. Do I need to change my chain / cage as well, or is it going to fit?
I am on 52/36 with 11-30 cassette. I can thinking of changing to 50/34 Chain Ring to aid my personal fitness weakness in attacking slopes.
Good article, thanks.
Is there much of a difference between a 52/36 11/28 cassette and 48/35 10/28 speed cassette.
I'm a bit confused which is better for road racing a Sram e tap 48/10T or Shimano ultegra di2 53/11T cassette.
I am going to upgrade from 53/39 crank and 11-25 cassette with shimano 105 short cage to 12-30 cassette with same crank.
Would you think my short cage compatible with new set up by adjusting B screw , do I need to use longer chain?
Hey! I have a grx 810 di2 which gets me a 48/31 on an 11 speed. The current cassette is a 11-34 and I’m looking to get a cassette for my road wheel setup. What cassette do you recommend? I’d like to have closer gears like an 11-32 or 11-30 But not sure if the di2 system will need to be re programmed or not each time I switch a wheel set. A quick brake alignment is fine. Just not sure how it’ll be with the di2 software. Thus planning on sticking to the same 11-34 on both sets but not sure if there are significant advantages on an 11-32 or 11-30 with my front crank being 48/31 keeping in mind adjustments on the di2 I am unsure if there’s any or how complicated or not. Would love you help! Thanks
I’m purchasing a new bike. I currently run 50/34-11/28 with a 172.5 crank. I had a fit done and on my new bike I’m going down to a 165 crank so I went with a 52/36-11/30 combo. I’m wondering if it will be similar to my current setup or if I should have stayed with a 50/34? I’m happy with what I have now and don’t want to really go any lower. Can you tell me the differences in those two setups? Thanks
Hi. I ride a Ventum One with Di2 and a 53/39 and 11-speed 11/25 rear cassette. This setup has worked well for flat races such as Ironmans Maryland and Florida. My next two races, Ironmans Lake Placid and Hawaii, have much more climbing. Question: Is this setup adequate or should I consider swapping the cassette (maybe an 11/32?), crankset, both? Thanks much!
"I have 53/39 crank and 11/28 rear derailleur is this a good combination?" - Christian
Hi Christian. Yes this combination is great. This would very common amongst pro riders. If you put a bigger cassette on, you will need a longer chain. This would result in slack in the chain in the small ring and harder gears at the back. This can rattle around on bad roads and be quite annoying.
I have 53/39 crank and 11/28 rear derailleur is this a good combination?
"Hi, I just bought a new groupset and I picked cassette of 10/33 and crankset of 46/33... I love to climb hills and with this new setup? Will it give me hard time? I haven't receive the groupset yet but just wanted to make sure I did not screw up on my gear ratio"
Absolutely not. This ratio will be very good for climbing. You will have a nice high cadence with this setup. You may run out of gears on the descent, but climbing should be a pleasure.
Hi, I just bought a new groupset and I picked cassette of 10/33 and crankset of 46/33... I love to climb hills and with this new setup? Will it give me hard time? I haven't receive the groupset yet but just wanted to make sure I did not screw up on my gear ratio
"Question for you on this one. I have a bike from when I was younger and able to ride it that had 53/39 to 11-23. I have changed out the cassette to 12-27 and was wondering can I get away with just changing the front chain ring to a 34 making it 53/34 or is that too big of a step, to make going up the hills easier. It is on an old 90's KHS with Shimano Ultegra FC 6800 crankset, thanks!!!"
It's not recommended as when you drop the chain from the big ring to the small, 8 times out of ten it will always come off the chainring. If you are going to a 34t you will need a 50t. And if you choose 36t then a 52t is recommended.
Question for you on this one. I have a bike from when I was younger and able to ride it that had 53/39 to 11-23. I have changed out the cassette to 12-27 and was wondering can I get away with just changing the front chain ring to a 34 making it 53/34 or is that too big of a step, to make going up the hills easier. It is on an old 90's KHS with Shimano Ultegra FC 6800 crankset, thanks!!!
"Hi, I have 2 bikes - one 10 speed with an Tiagra11-28 (my winter bike) and one with 11 speed Ultegra11-32 - looking at the above I should be able to get the same speed out etc. although I appreciate the jumps between gears is wider - is that correct? If so I'll stick with the 11-28 and just work harder up the hills! :-)
Yes there will be wider jumps in the gears towards the lower climbing gears. 28t is more than enough for most rides especially if there is compact chainset on. 32t cassettes are great for longer sportive or very hilly long routes. So, yes I'd recommend leaving the 28t to keep you working harder and keep you warmer in the winter.
Hi, I have 2 bikes - one 10 speed with an Tiagra11-28 (my winter bike) and one with 11 speed Ultegra11-32 - looking at the above I should be able to get the same speed out etc. although I appreciate the jumps between gears is wider - is that correct? If so I'll stick with the 11-28 and just work harder up the hills! :-)
"I have SRAM Force 22 with a 53/39 an 11/26 in the back, is this a little extreme for a novice?"
Hi Daniel. It's certainly on the tougher end of gear ratios. This would be a common gear ratio used for road racing. But if you're slim and stronger than the average cyclist then you may be well able to push those gears. If you wanted to climb a bit more comfortably then I'd recommend going 52/36 and maybe an 11/28 on the back. This is what I ride and I think it's a nice balance of lower gears to spin on the climb but not too low with the 52t so I can still push hard on the flat roads.
I have SRAM Force 22 with a 53/39 an 11/26 in the back, is this a little extreme for a novice?
"I find it difficult to climb hills, like most people. So with a new bike I was thinking of specifying a 34/50 (172.5 dia crank) chain set and 11/34 cassette (Shimano 105 gear set). Question is should I also look increasing the crank diameter as well i.e. getting a 175dia crank with 34/50 or would 172.5 dia crank with 36/52 be easier or maybe with 39/53? Or am I wasting my time with these last 3 options."
Hi Cash. Crank length is usually based on the riders height. Nowadays there is a big debate on which length is the correct length. Previously it was though that if you were 6ft or higher you'd choose 175mm. But for example Bradley Wiggins rode a 165mm to a gold medal at the rio olympics and he is 6ft 4. So to summarise, I would highly suggest getting a professional bike fit done before going and changing your crank length.
"Is 11/34 cassette and 53/39 chainset a good combination?
I'm trying to upgrade to Ultegra from Claris, which derailleur cage is best for this combination?"
Hi Tim. It is doable but by having a such a large front chainring and cassette there will be a lot chain slap when in the harder gears at the back and smaller chainring on the front. You will need a longer chain to accommodate a 53t chainring and 24t cassette. By having a big cassette like this, you a cancelling out it's benefit by going for 53t cassette. I would recommend a 52/34 chainring setup with an 11/32t or 11/28t cassette.
"i have just changed my rear cassette from 11/28 to 11/32. The chain ring is 50/34 but i cant get the chain to go on the 50 to 32 rear the chain is so tight is ceases. do i need to go to medium cage derailleur or add links to the chain? or both?"
Hi Christopher. You will need a new chain as your current one is too short after going up by four teeth on the cassette.
"I have an ultegra 53/39 with 11/25 what is the best and max setup for long steep climbs?"
HI David. 53/39 11/25 is a very demanding setup. This is what most racers go with for flaish courses. if you wanted one easier gear then I'd recommend going with an 11/28 cassette. If you wanted a lighter step up then I would suggest changing the chain rings to 52/34.
Is 11/34 cassette and 53/39 chainset a good combination?
I'm trying to upgrade to Ultegra from Claris, which derailleur cage is best for this combination?
i have just changed my rear cassette from 11/28 to 11/32. The chain ring is 50/34 but i cant get the chain to go on the 50 to 32 rear the chain is so tight is ceases. do i need to go to medium cage derailleur or add links to the chain? or both?
I find it difficult to climb hills, like most people. So with a new bike I was thinking of specifying a 34/50 (172.5 dia crank) chain set and 11/34 cassette (Shimano 105 gear set). Question is should I also look increasing the crank diameter as well i.e. getting a 175dia crank with 34/50 or would 172.5 dia crank with 36/52 be easier or maybe with 39/53? Or am I wasting my time with these last 3 options.
I have an ultegra 53/39 with 11/25 what is the best and max setup for long steep climbs?
Hi Mike. Max range Claris can handle is 11-34t. You would need to upgrade the derailleur to be able to use 40t cassette
s short cage will fit with 52/36 and 11/30
Hi there, great article, thanks! I've got a Specialized Diverge E5 with a Sunrace 8sp 11-34t running on Claris. I was looking at boosting that out to a 11-40t Sunrace. How can I work out if I need to change my derailleur before buying the cassette?
Depending on the rear derailleur capacity you may be able to increase the cassette size to 32t. You are welcome to visit our store and we will check it for you (you may also need a new chain if increasing the size of the cassette).
I have a Cannondale Synapse with 9 speed (11-26T) & 53/39T when I go uphill I wanted to make it little more easier to peddle. What do you suggest?
You do not need to change the cassette on the trainer to match your road riding wheel. I find while using zwift that any cassette is fine. If you find it a bit tougher on Zwift with the 28t then you can adjust the difficulty in the settings menu.
52/36 is a semi-compact. So your're probably just over geared. A compact chainset is 50/34t and changing to this would immediately open up some much easier gearing for you. If you are infact already on a 50/34t chainset then your next port of call would be to fit an 11-32 or 11-34 cassette. You will need a long cage Claris 8 speed derailleur if you have a short one. You're welcome to call the shop and we will be able to advise you further.
I'm afraid you seem to be at your maximum in terms of gearing. I would suggest trying to gain some efficiency elsewhere by upgrading your tyres and/or wheels. The Synapse is designed for comfort over performance so they bike will not accelerate or give as much return for your effort like it's CAAD13 or Supersix counterparts. But, if you change to a stiffer wheelset then you will get more return for your applied effort. Here is a great article that explains the benefit of changing your wheelset: https://www.icebike.org/42414-2/
A 52/36 with 11-34 can be used but it is not recommended by Shimano. The chain will need to be longer to accommodate this and will cause a bit of chain slap when using the 36 ring on the front and the higher gears on the rear. In short yes, it will work but will work better with a 32t cassette