[Closed] Roady question...

What is the mech?

Worst case, a 9 speed MTB mech will enable you to fit an 11-36 if you were so inclined.

Depends how old.Newer versions will take a 30.You can push the capacity a bit with a longer (or screw it in from the back) B-tension screw but you will have to be careful with chain length.

If the rear mech is a relatively recent model an 11-30 casette should be fine. You may need a longer chain though. I got up Holme Moss with a 11-30 set up on my steel cycclocross bike so you should be fine.

Won't his rear mech have a model number on the back of the body?
From that you can tell if it's short or long cage. If it's short you'll be limited to 27/28 tooth cassette.
If it's long then err bigger, but I don't know about long cage.

Pretty sure if it's 10 speed, it's either short SS or long GS.

12-30 will be fine assuming you have the same 105 mech tht I got with my original 12-27 set up. Suspect a 32 tooth might be pushing it so would probably look for an MTB rear mech if I was going that low.

You might be surprised at how low 34x30 feels on a road bike. I definitely noticed a big difference going from 34x27 to 34x28

I've just built a bike with a short cage 105 (5700) and a 12-30 cassette, works fine but I wouldn't stretch it to 32.

If it's 5700 105, then a short cage will cope with up to a 30T cog largest, and a medium cage (long cage is MTB stuff only really) will allow up to a 32T on a compact/double or up to a 30T on a triple.

If it's 5600 105 technically you're limited to a 27T largest cog on the back, though have heard a number of people running 28's fine.

I quite like the 12-30 cassette as it happens, you get the 12-15 ratios straight through which is useful, before it starts jumping up 2 teeth at a time. There's no real big gaps anywhere in the block, and you get a very useful spread of ratios. Much more useful than an 11-32 anyway, which has 2T jumps from the 12 up to the 22, rendering it a total PITA if you like to keep a constant cadence when in a chain gang or the like, and the 32T lowest gear isn't usefully lower than the 30 anyway...

Won't his rear mech have a model number on the back of the body?

Yes. Hence asking what the mech is, although I admit it could have been clearer!

Why ? are you that unfit?
50/34 with an 11-28 its fine for the Dales although there are massive gaps in gearing.

You mean it's fine for you. What if the OP is doing 200 mile touring rides, with 20kg of luggage? Does he need your permission to change his gearing?

I find a standard 53/39 fine, are you really that unfit you need a compact [i]and[/i] a 28t cassette? 🙄

Dales_rider - Member

Why ? are you that unfit?
50/34 with an 11-28 its fine for the Dales although there are massive gaps in gearing.

God this frustrates me...

Some people obviously climb better or worse than others.

I recently had all this when swapping to a 32 for Streatley hill, no I'm not THAT unfit... but it's a bloody long steep hill... I just bloody needed it...

Meh, I had an mtb 11-36 with a 53/39 on my road bike as it was on a budget & those were parts I already had. A girl rider I know pointed and laughed at my "dinner plate" cassette with an mtb rear mech but it worked fine for the 6 months until it wore out & I could afford to replace it.

Some people are just snobs

Btw, now running a 30t with 50/34 with 105rm with no problems

I find a standard 53/39 fine, are you really that unfit you need a compact and a 28t cassette?

Pah! A 28? A 25? I'll see your 25 and lower you a 21 straight block on a 46/56 - I climb like a scolded whippet#, of course 😉

To the OP, a 12-30T Ultegra cassette will be fine without adjustment, and should get you up the hills at a steady pace. A 32 will work, but you will have bigger gaps lower down, which you may dislike more.

#Actually, I like a compact, and even though I like climbing on 34/25, I quite like the option of the 28T after 100 miles and 3000m of hilly stuff.

Beware - some manufacturers spec a longer derailleur hanger with a long-cage derailleur so as to get the dimensions right.

Specialized Roubaix hanger from a Comp with 11-27 and from a Sport with 11-30 and long-cage:

[img] [/img]

[s]To the OP, a 12-30T Ultegra cassette will be fine without adjustment, and should get you up the hills at a steady pace. A 32 will work, but you will have bigger gaps lower down, which you may dislike more.
[/s]

Not if it's 5600 105, a 28t will just work, 30 will need a longer b-screw.

I did wonder how long it would take for a certain persons overinflated ego would appear on this thread 😮

Just changed bikes and gone from a 34-28 bottom gear to a 34-30. Feels like you can spin up anything*, but only very slowly.

When I say "anything", the Riber hill climb appears to still be beyond me, but I suspect the problem is with my head and/or my wibbly belly, rather than it being a gearing issue.

May I recommend a triple chainset if sir can afford it? It's vastly superior because you get closer ratios at the back, less of a jump at the front and wider gears still.

Of course, you do need a triple shifter at the front but you may already have one - my bike came with a standard chainset and still had a triple shifter. But not a triple mech - they are different.

njee20 - Member

I find a standard 53/39 fine, are you really that unfit you need a compact and a 28t cassette?

So do I on one of the bikes.

sparkingchains - Member

I've a 10 speed 34/50 chainset with a Shimano 12 - 27 cassette and shimano 105 rear mech. I'm after some help smashing hills

I think was the question, now if it read I want to tow a trailer up Ben Nevis, but to "Smash Hills" going lower geared is not the way.
Should I now add IMHO

My idea of increasing fitness for hills as opposed to spending money for 1, Yes 1 extra gear makes sense.
Now if the OP said I'm running a 53/39 with a 12-25 and want to change gearing I'd reccommend going for a compact 52/36 with a 12-32. Non of this triple nonsense and as lower gears.

Mind he may be an old ****er like me and needing a lower gear, hence the reason I went to a compact and a 12-28 and it was a 60th birthday present.

Oh and another point is Streatly Hill a Hill ?

Thanks everyone, mostly very helpful. It's the 105 5600 shifters and mech I have, from what most folk are saying here it seems I can only go up to a 28 in less I get the new mech as well as cassette.

Dales rider - I'm not super duper fit and I'm not super strong but if you look at the current wisdom of hill climbing it ain't coming from Jan Ullrich's style.

As it goes Froome was testing out triple chainsets recently and you should see just how low the gearing they used for mountain stages in the Giro was.

I went from a 28 to a 30 at the back quite recently and the difference is very noticeable. I'm not the strongest of riders when things get steep, but can now cope with 20% and more hills reasonably well. Didn't need to change my rear mech either.

sparkingchains - Member

Dales rider - I'm not super duper fit and I'm not super strong but if you look at the current wisdom of hill climbing it ain't coming from Jan Ullrich's style.

As it goes Froome was testing out triple chainsets recently and you should see just how low the gearing they used for mountain stages in the Giro was.

Sparkchains,
I'm certainly not super duper fit either, I did run an Ultegra triple with a lowest gear of 30 front 25 rear which gave a gearing of 31.6 inches found it OK for around here [Yorkshire Dales]
An Upgrade to Dura Ace gave me 39f 25r and 41" now whilst the gear jumps were very close, which I liked, there was quite a few hills stopped me. Usually as they approached the 20%.
So I changed to 30 rear giving me 34.2"
While lower than the 25 it was OK but as I get older finding to spin some of the steep hills around here hard so made the descision to go 50/34 with an 11-28 giving 31.9" not much different to the triple and so far its good, I have upped my fitness and climbing ability that said I have been stopped twice on the same hill with a gradient of 25%.
Now I'd love to "smash it" but as I probably only see it once or twice a year changing cassette is not worth the effort.
Now as for comparing Alpine climbs with the UK they are totally different, Pro's do run 27s on the rear but with a 39 front and I doubt very much they will ever use triples.

So -
Option 1 stick with your current set up and try and get fit
or
Option 2 Change to a 12-30 to give a 26.3 inch lowest gear, it does work with a short reach mech, I run it with both my Dura Ace and 105 which is fitted on my cross bike.

I'm running this exact set-up, short cage 105 (5600) with 12-30 Ultegra cassette and it works without any additional parts.
Just need to alter the b-screw and all is well.
When I looked into this the mech had a max rating of 27 because that was the max available at the time.
The 12-30 will work.

Just need to alter the b-screw and all is well.

Alter as in 'screw right in', or as in 'replace'? Not insurmountable either way!

Pro's do run 27s on the rear but with a 39 front

Plenty of examples of using lower ratios - David Millar ran an 11-36 previously, and Contador has used an 11-32.

So -
Option 1 stick with your current set up and try and get fit
or
Option 2 Change to a 12-30 to give a 26.3 inch lowest gear

TBH I don't see the downside to Option 2, He's still got he same top gear (12-50) and basically one more gear for climbing, it's not a bad idea at all, if the steps really don't suit you could always go back to the 12-27...

If I'm honest having only ridden a few miles on a 53/39: 11-28 set-up (and still recovering from the mother of all colds, so things might improve fitness wise), I reckon I need to either fit a 12-30 cassette and/or reduce chainring sizes, I'm actually OK-ish climbing on the 39t but I'm not using the harder gears in the big ring, and I'm managing to find an annoying mid-block step, I basically don't have that one gear I'd be comfortable to spin along on the flat in...

So I'm considering fitting a smaller big ring maybe a 50 or 51t, possibly even dropping to a 38T inner as well, I know it's only 1 tooth and sacrilege I'm sure but I can see these little tweaks making the drivetrain work better for me... TBH a compact probably makes more sense, but there you go...

I guess these parts wouldn't exist if people didn't find they needed them...

Oh and another point is Streatly Hill a Hill ?

it features in "100 Greatest Cycling Climbs" and was used in a Tour of Britain, if that ticks enough boxes?

cookeaa - Member

The answer is maybe to run the 52/36 chainset now available, when I upgrade the new bike its on the list with a 12-32

crashtestmonkey - Member

Oh and another point is Streatly Hill a Hill ?

it features in "100 Greatest Cycling Climbs" and was used in a Tour of Britain, if that ticks enough boxes?

It must be then, mind so is Leith Hill I'd done it 3 times from different directions looking for a climb 😉

David millar ran 36 cos he had osymetric rings who don't do compact and he was saving himself for the time trial. Why do I even know this?