Road bike gearing…

Following on from my last “what am I doing wrong” thread, where seemingly I’m not quite as slow as I thought I was, or I am and there’s just loads of other slow people on here too, I have a question about gearing…

My bike has a Tiagra setup with 34/50 compact, and a 12-25 9spd cassette, as from the factory, which I understand is pretty much the norm these days at the price point. Given this gearing is lower than the STD chainsets on more expsnive bikes, with 39/53 setups and 11-25 cassettes seemingly, why do I still struggle to find the “right” gear? I’m either too far down the cassette in the 34T ring all the time, or too high up it in the 50T.

I’m not the fastest or the fittest (you don’t say!) rider, but on a mountain bike I can hold my own well. In fact, I run a 1×10 setup on my hardtail and don’t struggle with that anywhere (except occasionally wanting taller gears on long descents), but it seems to me I need lower gears still on my road bike… What’s the reasoning behind the 34/50 compact then? Cos it’s an annoyingly big gap, seems like a 46T outer would make a lot more sense with only a tiny drop in top speed…

If you want a 46 tooth outer, Ive got a lightly used one you can have for £10.

Yup, compacts are not for every.one. Even 39-52 is too big a gap for me

Train more and get your legs used to turning over the 50 tooth. You really shouldnt need to be using the 34 that much at all unless its really steep where you live? The gap between rings is a bit annoying, but if you get used to riding in the big(ish) ring all the time you’ll not need to change down at the front so often….

Uh…what about his cadence?

Uh…what about his cadence?

What about it? Very high or low? Spinning is good, but its really not the be all and end all. And is it really that bad to use the small end of the cassette and small ring?

Putting a 46 on would give you CX type gearing? Go for it if you want, but I wouldnt bother, you’ll miss the top end if you start riding chain gangs.

dt, some details/pics please if you would, might be interested in that.

You really shouldnt need to be using the 34 that much at all unless its really steep where you live?

I don’t really use the inner unless I’m climbing, but as a result, I find I spend too much time in the 2nd/3rd cogs on the cassette whilst on the 50T, more so than I’d like. Obviously if I then drop to the 34T to compensate, I’m straight down to about 6th cog on the back to compensate for the massive jump between gears on the front. I’ve only really found one hill that I couldn’t quite manage on the 34-25 bottom gear, but it was steeper than 1 in 4 at the top so hardly surprising really, and I almost made it, but the gap between rings makes for a right faff I find.

How long have you had the bike btw? I did find the jump on the compact annoying at first, but now I find I shift down/up almost at the same time and it doesnt annoy me at all now, but everyone is differnt.

I’ve only really found one hill that I couldn’t quite manage on the 34-25 bottom gear, but it was steeper than 1 in 4 at the top so hardly surprising really, and I almost made it, but the gap between rings makes for a right faff I find.

Yup, thats steep. No shame in struggling up/ not making it when its that steep!

Why not get an 11-28 or 12-27 cassette and spend most of your time in the 50t ring? I’ve got a 52/34 compact on my road bike and I’ve used the 34t on only 2 occasions since last July. It took me a few months of perseverence to get used to pushing the 52t everywhere, but the old saying ‘no pain, no gain’ was never truer. Living in the Pennines, most of my longer rides (60-80miles) include around 6-8,000ft of ascent (according to Endomondo) and I average around the 16mph mark too.

what massive jump on the front?

42-52 is another comparison…doesn’t suit your aim tho!

what massive jump on the front?

That 47.1% jump between the 34 and the 50… Durrr! 😕

Knocked up a quick spreadsheet last night based on the calculations in the old hub gear spreadsheet I created a while back (if anyone wants a copy of either). Generally shifting up from the 34 to the 50 on the front is like shifting 4 gears on the back at the same time. Too much IMO.

How long have you had the bike btw? I did find the jump on the compact annoying at first, but now I find I shift down/up almost at the same time and it doesnt annoy me at all now, but everyone is differnt.

Year and a bit, though riding has been sporadic on it truth be told. Rode it loads when I first got it, then not for a few months, now gonna get back into it a bit more as I can’t really afford the fuel to go MTBing so much these days (no trails within 15 miles of where I live really). Maybe I’ll just get used to it too, but I can understand the desire for a triple in a lot of cases, less so for the spread of gears, more so just to stop massive ratio jumps when changing chainrings.

Why not get an 11-28 or 12-27 cassette and spend most of your time in the 50t ring?

Initially thought about this. BUT… The 12-27 only changes the top 2 sprockets. The ratios are thus…

27, 24, 21, 19, 17, 15, 14, 13, 12

For the 12-25 I have now it’s…

25, 23, 21, 19, 17, 15, 14, 13, 12

The only 2 ratios that are changed, are the ones I rarely/never use on the 50T chainring. And though I’d perhaps like a 27T bailout for climbing on really steep stuff, it might also defeat the point a little.

Hence my reasoning on a 46T outer maybe, as it would drop the overall ratio, and mean I’d use the 17 (and maybe the 15) more on my current cassette?

That 47.1% jump between the 34 and the 50… Durrr!

sorry i thought you meant there was a big gap in your gearing when using either 50 or 34. when in fact they overlap a fair bit.

personally i don’t have a problem as i instinctively shift the rear the corresponding 3 cogs the same time as the front so i’m in the correct ‘next gear’, i do it without thinking with just a slight reduction in pressure on the pedals, never had an issue with crunching gears/mis-shifts/dropped chains but then my gears are set up properly and i keep the drivetrain clean.

Personally I just treat my set-up as 1 x 9, with the bonus of a ‘get out of jail free card’ 34t inner as an absolute last resort. From your original post (I only read the first page though) it seems to me that you need to increase your strength and dropping onto the 34t at the first sign of a slope is counter-productive to your aims. Rather than go down to a 46t outer I reckon you should get a 52t instead, swap your cassette as suggested and teach yourself to mash out the miles. It’ll take a while to get used to it, but you’ll feel the benefit down the line.

My gear setup is faultless, can’t complain at all about that, the Tiagra makes the equivalent MTB level Deore feel agricultural IMO. Never a missed shift, everything as it should be etc. Just seems I either need to get used to the ratios, or change them for something more favourable. Cos on a mountain bike, I’ve never had to shift more than one cog on the back to make up for changing up/down a chainring on the front, so to have to go up 3 cogs on the back at the same time as shifting from 34 to 50 up front, to be in the equivalent next ratio up still (or shift 4 on the back to stay in the same ratio) feels VERY odd to me.

get some aero wheels and fast tyres. then you’ll be in smaller sprockets (higher gears) when your on the 50t ring on the flatter sections. depending how good your current stuff is. and……ride harder.

My set up’s a 50/34 11-28, I spend most time on the 34 on hilly rides and keep a cadence around 90. Use the 50 on descents.

You can ride all day on the 39 from a standard 53/39.
The problem with compact is that have to use the 50, the 34 just isn’t a riding gear if that makes sense?
And I know there is overlap between the two types, but I find the drop when you’re ‘suddenly’ on a climb too big.
In hilly or undulating terrain I keep it in 39 and flick between three gears. I find it keeps fatigue at bay and my cadence remains reasonable.
39 is also useful in strong headwinds.
A few blokes bung a 27 on the back of their training bikes.

but I find the drop when you’re ‘suddenly’ on a climb too big.

I always think the chains come off!

You’re not on your own.

I’ve been having the same thoughts for quite a while.
I find that I’m at the bottom of the cassette on the smaller ring and the top on the big ring.

I’ve got used to changing 3 gears for a chain ring change and I’m trying to ride the bigger ring more but it doesn’t feel right.
Compared to a mountain bike, road gears have far less difference between them – My reading of this was so you can find just the right gear but the massive difference in chain rings seems to be counter to this.

My current thinking is that I need to man up and ride in the big ring more.

I hate compacts on road bikes as well. 50 seems just a fraction too high sometimes but 34 is way too low. 39/53 is perfect for me.

OP: It might be worth experimenting with the cassette a bit? Try changing to one with closer ratios, 11-23 or 11-25., it might help offset the big jump between the chainrings and make it easier to find that “just right” gear.

I wouldn’t worry about cadence or bigger gears.
If this sounds patronising then I’m sorry, but a good few riders that join us tend to spin furiously on the hills on their compacts. They don’t seem to be getting anywhere and look knackered. I also think you have poor control when you are over spinning.
My advice (no pro coach here) is to ease off, relax, drop a gear and let the bike do the work and make smooth progress.
Of course having the bike and shoes properly set up is essential.

Edit; Also don’t charge at the hills in an effort to get up em quick, settle in and wind it up.

i have to say having recently got a bike with tiagra compact setup i agree both about the quality of the shifting action and how disconcerting the switch between rings is. i’m now used to simultaneously changing ring and shifting two or three at the back to ease the difference a bit.

I’m either too far down the cassette in the 34T ring all the time, or too high up it in the 50T

I had the same problem with compact. That and spinning out on descents. I hated it, so I went with triple.

It makes sense if you live anywhere near any kind of hill. Better shifting, better gear spread, better everything, and for a tiny increase in weight.

39:53 is perfect I think. Very rare that the 39 gets used unless it’s a steep climb. using either a 12:28 or 11:25 depending on wheels.

Having said that i have a 54 outer now as 53’s were out of stock 😆

I went with a compact for the Pyrenees. Don’t like the big drop to a 34 here though and swapped it for a 36 I had in the shed. Nicer, but probably equally go back to regular chainset.

The gear ratios on compacts are horrible imo, made even worse on anything bigger than a 11-25 cassette.

Changed my double to a compact some time ago and used to run a 11-27 but couldn’t get on with it. Changed to a 11-25 which was a little better but in the end decided to go back to a double and I am a lot happier. I think changing to a 11-23 will get the ratios exactly where I want them.

I live in a reasonably hilly area too but don’t find the lack of the 34 to much of a problem although some hills require my finest gear munching to get up the hill.

I don’t like the jump on my compact, either. Is swapping the inner ring to a 36T likely to make much difference?

39:53 here. Shift at the front with 2 at the back, what’s the problem?

My set up’s a 50/34 11-28

Same here on one of my bikes. Changing to the 11-28 from an 11-25 was very noticeable.

My other road bike wears a MTB long-cage mech and has 50/34 and 11-32.

sram comact is 36-50. don’t find it a big gap at all. only car park test rides on a std so not much to compare to though.

what’s the problem?

For me it was because on easier rides I was constantly shifting between rings, it was a right pain. Less overlap means more ring shifting I reckon.

Im running a 39/50 with a 12/23 (old 8 speed).

I find the 53 too big so thinking about a 39/50 now.

I cant understand why anyone would need less than a 39 up front. Im not fast at the mo and with a 39 and 23 as my lowest gear i can get up anything. (checks knees for expolding cartilage)

I cant understand why anyone would need less than a 39 up front

‘Cause God invented these things called hills and I’m old and unfit.

I use to do hill climbs on a 42 and im not fit. But then im only 11 stone.

Because some of us want/need to spin, rather than heave on the pedals. If I am out for a base training ride then hammering for 30 mins out of a Welsh Valley isn’t what I want to be doing.

I cant understand why anyone would need less than a 39 up front.

Go on then. So they can ride up Hardknott pass after 100 miles in the rain this Sunday. I bet no one doing the FW is running a 39/23.

most of the above is why I stick with a triple chainset, especially good for the chilterns & what with me being a self confessed lover of granny rings too, oh & paying just £67.50 for an ultegra chainset from merlin helped 🙂

was very glad of my compact in sierra nevada mountains last week, my mate on a standard struggled to keep his effort low enough to climb for 1.5-2hours without blowing up. I did have to make a bit of a consious effort not to just dawdle though!

Also i dont find the jump between the front rings a problem, I tend to just put a double (ie front and back)shift in at the same time and its a very clean change with quite a small effort jump