Gearing Questions

[jimconte]

OP. Reflecting on your recent posts, and after googling your bike -

Do not change your crankset. You have a 50/34 which is perfectly adequate and is the de facto standard for road bikes now because unless you race, most dudes lack to power or passion to drive a standard 53/39 crank. It's not a huge difference anyways. Half a gear in the harder gears on the cassette. But very expensive to change

Your cassette is easy IMO. Get yourself a 12-23. This gets you a TON of gears in the 25-35kmh speed at 80-100rpm cadence. If you run out of gears charging down a hill, consider it good practice to spin up to 150rpm.

I personally had a BIG jump in my cycling when I went from 12-27 to 12-23 (and lately 11-23). It forces you to toughen up on some of the shorter climbs (because you can climb a lot of 100-200m pinch climbs in the big ring) and you are able to pick a good gear when you're spinning away with your mates on the flat. You'll appreciate the 16 and 18 cogs a lot, and those are the ones you miss first as the cassette gets wider. I found I was wimping out to the 24 and 27 a lot, instead of standing up and pushing through it with the 21 or 23. Also, the gaps between the 21-24-28 aren't very friendly for convincing you to get pushing hard. You have to "reset" your cadence and it's hard to get the rhythm flowing again when you're already struggling. You will struggle, for sure. But you'll get stronger, and you'll stop needing those bottom gears as much. Then you'll be FASTER.

Make no mistake - the 28 cog with a compact is only necessary for seriously crazy climbs or bailing you out. I was riding a 28 last weekend on the verge of cramping badly; the easy gear gave me some breathing space to get the water in and survive the climb. But you shouldn't be that silly. You are unlikely to be trying climbs after pushing 80kms quite hard for a while. It took me a couple years to get this far. This advice might not be conventional wisdom, but you do need to force yourself to improve and a 12-23 is a great way to do that.

12-23 climbing as a beginner or even a long time novice latic acid up big time and you will be searching for another gear that is not there we have all done it

[jimconte]

Suggest you look at a gear speed calculator like http://www.machars.net/bikecalc.htm

You can use the cassette ratios I mention below to put into the calculator. I mostly look at the variation between cadence (speed you spin the pedals at) & speed on the 'speed' tab. As a guide, on flat rides I aim for a cadence of 100. For hill climbs, I want to spin as close to 100 as possible but for anything over about 5% gradient, with a 34 on the front and 28 at the back, I can't sustain it and I need to slow my cadence. For any climb longer than 1-2km, I would always aim to keep my cadence above 60 otherwise I'll be cooked!

I've ridden a shimano 105, 50-34 (compact) chain ring since I started cycling 3-4 years ago. I originally rode a 11-25 cassette, but switched to a 11-28 to make steep and long climbs easier (able to spin at higher cadence for the same speed). For reference, I race crits in C/D grade and also ride hills/mountains around VIC. I'm fairly hefty at over 90kg (heavier makes climbing harder!).


Speed / Cadence
A compact chainring (50-34) is all you need and what I'd recommend. In the big ring (50) and the smallest ring on the cassette (11) at a cadence of 100, you are doing 56.9kph. Getting your cadence up to 110 will get you over 60kph - enough to win sprints in races up to B grade.

To illustrate the difference between the different cassettes for climbing, I've based the cadence at 60 for a tough long climb in the little ring (34):

With a 23 you'll be doing 11.1kph
With a 25 you'll be doing 10.2kph
With a 28 you'll be doing 9.1kph

Of course, you want to go as fast as possible, but going uphill with a 23 will mean that if you want to go slower than 11.1kph, then you have to push a slower cadence than 60, which hurts your legs more and isn't sustainable for as long period of time. i.e. Riding up a sustained 10% gradient, I know that I can't really ride faster than 11kph for any period of time. Now, I could do this in the 23 at a cadence of 60, or I could use a 28 with a more comfortable and easier cadence of 70. It also means that if the hill gets steeper, I can still drop my speed down to 9kph and maintain a cadence of 60.


Gear spacing
Gears for an 11-23 cassette go: 11-12-13-14-15-16-17-19-21-23
Gears for an 11-25 cassette go: 11-12-13-14-15-17-19-21-23-25
Gears for an 11-28 cassette go: 11-12-13-14-15-17-19-21-24-28

Apart from the different top end of the range (higher number is easier for going uphills), the only difference is the 'gaps' in the gearing. 11-23 having smaller transitions between gears than 11-28 (numbers go up by 1 instead of 2 or 3), which makes it easier to ride a particular cadence and speed. This can be a key factor if you only do flat riding or bunch riding where there is very little speed differences over the course of the ride and/or you want to maintain the same cadence throughout. As a new rider, I doubt this will bother you and it'd therefore be better to choose a cassette with a larger range of gearing which can take you anywhere.

Summary
I'd recommend selecting components that get the best flexibility out of your setup - a compact 50-34 chainring and an 11-28 cassette.

A 50-34 (compact) chainring still gives you good top end speed for sprinting (over 60kph at 110 cadence), but is easier for going uphill than a standard 'double' chainring.

The 11-28 cassette would be the best as it has the same 11 gear for going fast on the flat as the 11-23 or 11-25, but it has the larger 28 gear to help you be more comfortable with climbing.

The 11-25 cassette would be fine for flats, rolling hills and many climbs, but will really hurt you once you start pushing sustained (30mins+) and/or difficult (7%+ gradient) climbs.

The 11-23 is a waste of time unless you only ride flats or you like to ride up every hill out of the saddle with your legs burning. Even if you want to do this, you can still do it with an 11-25 by changing down a gear!

cerb wins the best advice prize. Re-read the above.

Just one thing to add - I always laugh at the number of people who think they can push a 53-11, or even a 50-11. I can accept (begrudgingly) that an 11 tooth cog may be used on the odd occasion with compact cranks, but for recreational cyclists to think they 'need 53-11 is kinda laughable. Even Greipel can only push that with a tailwind for 200 metres max.
Ok so there may be the rare occasion where you are on a long downhill with a huge tailwind and you may actually get the chain onto that shiny silver 11 for a couple of moments, but then for the rest of the ride you are alternating between your 15 (too hard) and 17 (too easy) because you sacrificed a 16 tooth cog so you could have the 11.
For me, on standard cranks, I'll take a 16 and an 18 in the middle of my cassette rather than a 11 and 12 any day. I would have 13, 14, 15, 16, 17, 18, 19, 21, 23, 25. No gaps / 1 tooth jumps = smooth and perfect cadence all day.
For compacts I would recommend 12 -27 or 12-28.
Crank length has been proven to be pretty much irrelevant. Most people think tall guys should have 175, short 170, "average" height 172.5 It probably makes no difference.

sorry still learning

[Xplora]

A 28 or 27 is only one gear lower than the 23, effectively. 23/24 is almost the same. You swap the 28 for an 18, and an 11 for a 16 if you go 12-23. You spend a lot more time in 18 and 16 than in 23. If you're cooking it with a compact, then you need to work on your fitness. They sell a lot of bikes with the compact/11-28 combo because it's an easy copout. If you are healthy you can do a lot of climbing with 39/25 but not a lot of people are prepared to ride that much lol.
That search for the lower gear is precisely why I say go 23. Do you want to get better, or just get by? If you just want to get by, Shimano have 30s stock on Tiagra. But I personally found it really hard to improve my cadence and thus cardio because I struggled to spin well at 25-35kmh, since my cassette gaps were so big Better to optimise your work on the flats, and learn to stand and deliver on the climbs. I struggle to understand why you'd subject yourself to the torture if 34/28 is required as a novice. Riding is more fun when sprinting to the coffee shop than suffering as your friends disappear into the distance.

[Derny Driver]

I struggle to understand why you'd subject yourself to the torture if 34/28 is required as a novice.

Gear choice is dependent on a lot of things, how fit you are, how fat you are lol, the terrain you ride regularly ...
I guess its a matter of finding the gear ratios that work for you. Its a personal thing and everyone is different.
My background is racing cyclists at the highest level. They change cassettes from one race to the next. My son trains on 12-25, races on 12-23, TTs on 11-21, and has a 13-28 he uses for one race each year.
At an international tour I attended recently, my riders all had 28 or 29 tooth clusters for the climbs (yes they were long and steep). These are super strong experienced elite riders. So it depends on many things. If you need an easy gear for a climb then don't be embarrassed to put a dinner plate on the back.
You do not need to stick to the stock Shimano common ratios. You can pretty much get any ratio you want. If Shimano don't make it then ring Hillbrick Racing, they will make you any cog combination you want using Miche cogs. (Shimano compatible). That's where I got my sons 13-28 from. One phonecall, and the price is same as buying stock Shimano stuff.

[hannos]

I struggle to understand why you'd subject yourself to the torture if 34/28 is required as a novice. Riding is more fun when sprinting to the coffee shop than suffering as your friends disappear into the distance.

Riding is more fun when you aren't struggling in a too-hard gear.

[Xplora]

I struggle to understand why you'd subject yourself to the torture if 34/28 is required as a novice. Riding is more fun when sprinting to the coffee shop than suffering as your friends disappear into the distance.

Riding is more fun when you aren't struggling in a too-hard gear.

I agree - but I'd say that trying to spin your way through the 16 and 18 cogs is much harder than losing a gear at the back. 15 minutes of climbing versus 6 hours of flats and rolling hills? I know where I want things to be easier. Riders starting out are not going to tackle climbs where fit people need 28s.

Derny, I totally agree with you but a lot of people are too tight to outlay 250-500 bucks on multiple cassettes. If you were just going between cassettes, then go for it. I look forward to jumping between 11-32 and 11-23 11spd in the next couple of years. But I don't think the OP is looking for that solution. My comments are not related to a road racer trying to survive a mountain stage to challenge for the GC, but someone doing some bunch riding with mates and maybe a few hitouts on some small climbs. I've found the 23 marvellous for that, even doing 200-300kms a week building the engine.

[Derny Driver]

Derny, I totally agree with you but a lot of people are too tight to outlay 250-500 bucks on multiple cassettes. ...... I don't think the OP is looking for that solution. .

Oh yes agreed, my point was that specific cassettes can be used for specific situations/events. But for general all purpose riding, it will always be a compromise. Like you, I prefer to compromise a cog at either end of the cassette (11, 12 or 25, 27) and have those 16 and 18 cogs in the middle range which are used more often.

[ldrcycles]

Nothing to stop you getting $30 SunRace cassettes rather than "250-500 bucks", unless you're really desperate to save a few grams .

[warthog1]

28-11 cassette with 53/39 chainrings does everything for me without compromise.
Sram 10 sp = , 11-28: 11-12-13-14-15-17-19-22-25-28
Doesn't have the 4 tooth step of the shimano equivalent.
The bottom 5 cogs are all 1 tooth step. In the big ring as you approach the speed that matches your maximal aerobic output is where you need the close ratio. At lower speeds its easy to ride around the bigger gaps and I don't even notice the larger steps. I can keep my cadence where I want it.

[Derny Driver]

I still like my 16 cog.
Riding at speeds between 25 and 30kph you need a 16.
39x16 = 24.58 at 80rpm, 27.65 at 90 rpm and 30.72 at 100 rpm.

I hate 2 and 3 tooth jumps.
Each to their own, everyone is different.

[cerb]

I still like my 16 cog.
Riding at speeds between 25 and 30kph you need a 16.
39x16 = 24.58 at 80rpm, 27.65 at 90 rpm and 30.72 at 100 rpm.

I hate 2 and 3 tooth jumps.
Each to their own, everyone is different.

As I mentioned in gear spacing - the OP is a new rider. If their cadence isn't constant or specific over a specific range of speeds, it's probably not going to be the end of the world!

Also, 34x14 = 24.4 at 80rpm, 27.5 at 90rpm and 30.6at 100rpm. Basically the same gear as your 39x16, but using the compact + 11-28 I recommended.

[warthog1]

Don't know what you wusses are doing pootling around in the small ring. It's for climbing.
Get onto the big ring
If you are on the flat it makes sense to spread the chain load over a larger number of teeth.

[nickobec]

I happily ride & race a 53/39 11-23 combination on my road bike, I am rarely out the big ring and appreciated the small gap in the ratios

I do use the 11 a few times a year, for racing down descents (though it is on a 11-28 cassette when racing in the hills) and not on roads with cross roads or driveways.

My TT bike is 53/44 11-23 combination. Because on a TT bike, I a low cadence big gear rider and in summer we race 8km into a 30kph headwind before turning and riding back with a 30kph tailwind, I do spend a lot of time in the 53 & 11 at 75rpm or so.

Note the are some short 500m climbs near me, but any decent climbing is 30km away, so I know when to go and play in the hills I swap in an 11-26 or 11-28.

Yes I race, but only a D grader, though for some reason I do climb better than my colleagues. Lots of short climbs on a 53x16 singlespeed.

[singlespeedscott]

Running a 53/39 crankset will reduce your instances of cross chaining. Something that people with compacts do to much of.

[ozdavo]

Running a 53/39 crankset will reduce your instances of cross chaining. Something that people with compacts do to much of.

This, I would think would be highly dependant on the strength of the rider. I would think a weaker rider would do more cross chaining... ie spend more time in the small ring & bottom end of the cassette, and big ring and top end of the cassette...

Anyway, cross chaining, while not ideal, is a lot less of an issue with modern groupsets.

[open roader]

Running a 53/39 crankset will reduce your instances of cross chaining. Something that people with compacts do to much of.

Surely it depends upon what speed and cadence a rider wants to hold. With all due respect, I beg to differ. One of the main reasons I switched to compacts was to avoid excess cross chaining.

[singlespeedscott]

Running a 53/39 crankset will reduce your instances of cross chaining. Something that people with compacts do to much of.

Surely it depends upon what speed and cadence a rider wants to hold. With all due respect, I beg to differ. One of the main reasons I switched to compacts was to avoid excess cross chaining.

Once you go beyond your 53x21 you should be dropping to the inner chainring.

[Xplora]

Until I end up on Campy, that's not happening scott LOL The efficiency gains from remaining in the big ring are too great, especially under the load, when you use Shimano and max out at 3 gears at a time. I agree that you are being nicer to your drive train, etc etc etc but you're talking an additional 1c a kilometre to cross chain the hell out of your bike if you are running 105/Ultegra.

[Percrime]

Heh.. I have a friend who is doing a tour in the alps. Her approach to the climbs is .. lighter bike.. lower gears. Of course a compact. Apparently training is not an option. In spite of 5 years training and weighing maybe 40 kg she is the worst climber on the planet... really prone to just stop pedalling. Except that she says she does you would swear she has no clue about gears. What is for sure is that somehow she thinks lower gears will enable her to keep up with riders pushing bigger gears. Nope.. lower gears at the same cadence is slower and the rest of the bunch rides away from you. She does not get that. She is not going to be popular on her tour.

[Xplora]

^^^ That's pretty much what I didn't realise for ages. Getting to the top doesn't make you any faster in the long run. You can put a 22/42 XX1 gear on the back of your Madone 7 and you'd be able to climb HCs untrained; but you'll almost fall over riding at 3kmh if you aren't popping wheelies every revolution. You can get lower gears, but unless you've got injuries/imbalances you must protect, you aren't doing yourself favours in the longer run. Climbing is a unique opportunity to HTFU because you just can't cheat on the tailwind or letting your mates do the work. If you're on a compact, it will hurt for a while to run a 23, but eventually you'll get quicker. And you will be just as quick as your mates running 28s.

percrime, maybe she's just hoping to catch up on the descents somehow?

[Percrime]

She descends worse than she climbs. Quite prone to brake hard for no apparent reason and has never yet touched 50. On the other hand she is a hell of a wheelsucker. Like I said this is not going to go well

[Xplora]

Sure my wife isn't going on a tour of the Alps?

If I can't get rid of my Ultegra brakes I'm putting them on her bike. Hopefully will give her more confidence to attack the descents more (is there anything that slows you down more than a fear that you won't be able to stop?)

[Percrime]

This person.. who is not married... would just go slower. She keeps insisting her brakes are ineffective and they ain't. She breaks back shift cables monthly.. apparently though constantly trying for a lower gear. I think she has the well known 43 50.. 13-27 combo and remember she is damn light. Her most endearing characteristic tho.. is being right there 10 minutes from a regroup point ... then essentially deciding to quit. (and she is a GOOD wheelsucker) Turns up 20 minutes later.. then tells everyone what an easy ride she is having. Ok thats not really relevant to the topic and I am now being bitchy.. but crikey it annoys me. I do not exaggerate btw... she can lose 20 mins when she was right there 10 minutes ago. I think she cant do more than about 220 watts, never has and because of an extreme aversion to actually hurting never will. Thats relavent to the topic

[Xplora]

Yep - extreme aversion to hurt isn't really going to qualify you for riding a bike at reasonable speed. Some older blokes just can't physically push 10% grades without a 30/28 triple; good on them for digging deep and suffering through the climb. But for the rest of us, dropping a gear isn't going to kill you on a compact. Especially if you've bought a bike weighing less than 8 kiloes.

To the OP; if you are wondering how much of a good idea my advice is, force yourself to stay out of the 27/28 gear for a couple weeks. Perfect way to make the adjustment. I realised that 34/24 was plenty even with the rack and the trunk bag and shoes etc in the back. Go forth, my son, embrace the V, and HTFU.

Once you've had your cement IV drip then come back and discuss standard cranks and 28s and 32s. I'm slamming the 28, but I WILL be going semicompact 52/36 switching between 11-23 and 11-32 for mountain days. Full soft. But I've done my time on the tiny cogs.

[singlespeedscott]

Yep - extreme aversion to hurt isn't really going to qualify you for riding a bike at reasonable speed. Some older blokes just can't physically push 10% grades without a 30/28 triple; good on them for digging deep and suffering through the climb. But for the rest of us, dropping a gear isn't going to kill you on a compact. Especially if you've bought a bike weighing less than 8 kiloes.

To the OP; if you are wondering how much of a good idea my advice is, force yourself to stay out of the 27/28 gear for a couple weeks. Perfect way to make the adjustment. I realised that 34/24 was plenty even with the rack and the trunk bag and shoes etc in the back. Go forth, my son, embrace the V, and HTFU.

Once you've had your cement IV drip then come back and discuss standard cranks and 28s and 32s. I'm slamming the 28, but I WILL be going semicompact 52/36 switching between 11-23 and 11-32 for mountain days. Full soft. But I've done my time on the tiny cogs.

You do know that a 39x32 is the same as a 34x28 and a 39x28 is just shy of a 34x25.