12-30 cassette - wiil it work?

arlowood

Just considering the possibility of buying some new stiffer wheels to use on hillier sportives. At the same time I was thinking of equipping them with the new Tiagra 12-30 cassette so that i could just swap them over before the events.

My current set-up is fine for the normal fitness/recreational riding I do around my local area but I would like some extra gearing for those killer hills that feature on some sportives.

Current set up is Dura Ace compact chainset (50/34) with a Dura Ace rear mech and Ultegra 11-28 cassette. I'm presuming that the rear mech has a medium cage fitted to cope with the 28 tooth lower gear.

Any idea if I can just pop the 12-30 kitted wheelset on to that set-up without any major headaches?

napoleond

I'm pretty sure the rear mech would not cope. To be blunt, if you can't get up UK hills on a 34-28 then you need to train better!

ugo.santalucia

I have to agree with NapD... a stiffer wheelset, as you say, won't make you go up hills you can't normally do and a 30 sprocket will still see you struggling up those hills you can't do with a 28.
On tarmac, it's not the gear that gets you up a hill, but the power/weight ratio... that's what you need to improve, either by losing weight or by increasing power, normally training achieves both at the same time.

In MTB is different, as the crazy gradients on dirt mean you have to sit on the saddle the all time and you do need very small gears for that... that also explains why most MTBikers are quite chubby...

ginsterdrz

There shouldn't be any issues with 12-30 if the rear mech cage is medium. You may need to wind your 'b' adjustment screw out to allow the mech to cope with the extra 2 teeth. I've read that you can go to 32 with care.
Try a general Google search and you'll find lots of American articles on the matter. They seem very knowledgeable on the subject and adventurous enough to actually try all the possible combinations.
Shimano official recommendations are only for litigation defence!
I went down the SRAM Apex route to run 11-32 and glad I did for some of the North Wales Sportives in 2011 and Apex was put together for Contador if I remember rightly!

rajMAN

Ride more hills with what you have! adventurous or not, if your struggling on that 28 then 30 is not going to open up a whole new world. :shock:

keef66

I had a business trip yesterday to Kirkbymoorside, so I threw the bike in the car so I could explore Rosedale on the way back. The weather was beautiful, the roads dry, and the sheep quite considerate. Despite the perfect conditions and a lowest gear of 30 x 25 I failed to make it up either the chimney or the one on the opposite side of the valley without resting / walking a bit.

I'm resisting the urge to buy a bigger cassette; instead I've concluded I need to do some training if I'm ever to get up hills like that. Trouble is there's nothing remotely that steep round here.
Considering the steepest hill I can find and riding it repeatedly in too high a gear and with a rucsack full of bricks.

And I don't think I'll be entering the Fred Whitton any time soon....

ugo.santalucia

keef66 wrote:

I had a business trip yesterday to Kirkbymoorside, so I threw the bike in the car so I could explore Rosedale on the way back. The weather was beautiful, the roads dry, and the sheep quite considerate. Despite the perfect conditions and a lowest gear of 30 x 25 I failed to make it up either the chimney or the one on the opposite side of the valley without resting / walking a bit.

I'm resisting the urge to buy a bigger cassette; instead I've concluded I need to do some training if I'm ever to get up hills like that. Trouble is there's nothing remotely that steep round here.
Considering the steepest hill I can find and riding it repeatedly in too high a gear and with a rucsack full of bricks.

And I don't think I'll be entering the Fred Whitton any time soon....

Either that or you can conclude that a 1:4 is simply bad engineering and not worth the hassle to go up... surely there is another way to get to the other side...
Some climbs are just stupid

rajMAN

I would agree with you there Ugo. some climbs are just stupid!! :shock:

andy_nD

I rode 12-30 on an Ultegra 6700 GS (short cage) rear mech last year without any problems. I had to tighten the b screw in all the way to keep the mech clear of the cassette, and had to keep well clear of dodgy gear combos (big ring/big sprocket), but didn't have any serious problems. While the setup worked okay, I did find that shifting wasn't as smooth as it was harder to get the indexing right.

I'm inclined to agree with other posters that a more conventional 11-28 should be enough to get you up most hills, but I did find that the 34-30 gear at least gave me the option to keep a higher cadence, which is a more comfortable way to ride for me.

In the end I ditched it because of the less-than-ideal shifting, and because having a stupidly easy gear in the back pocket was making me slow and lazy..

keef66

But I WANT to get up it!!! The sheep don't seem to find it difficult.

Gary D

keef66 wrote:

But I WANT to get up it!!! The sheep don't seem to find it difficult.

They're not riding bikes though .............. unless you have very gifted sheep up your way

I'm pretty good at walking up hills - especially when pushing my bike!! :oops: :oops:

Gary.

derek48

I've just fitted a tiagra 12-30 cassette to replace a 12- 27, with an ultegra sl medium cage mech. It worked perfectly from the word go without having to adjust anything.

hodge68

went from 12-25 to 12-28 as my power to weight ratio aint what it should be, it made all the difference. Have to say its not so much i end up on the 28 that much, but just knowing its there makes me feel a lot better.

mamba80

The guy wants it for some sportives etc and coming across a 25% climb after 80 or 90 miles is not the same as encountering the same climb on a sunday morning after 20 miles.
as to the RD i doubt the DA mech is medium (the 7900 std mech was set up for the new 11 28 cassettes) but fit the new cassette and try it first, with your current set-up i'm sure you can afford a new RD if needed

arlowood

Thanks for all the input. I do take the point that if i can't get up the hills currently on a 34/28 combo then 34/30 isn't going to help a great deal.

I think it's partly a psychological thing but i am training hard with my current set-up with my first registered sportive at the end of April. I just need to find some killer hills locally to test my fitness after riding different distances.

Regarding the 30 tooth compatibility issue, I think i may have found the answer in the Q&A section on p193 of the current Cycling Plus. Some guy asked about needing a long cage mech when switching from a 12-25 to a 12-27 or 11-28 cassette. The answer is that :- "Actually, with the current crop of short cage Shimano derailleurs, there is no need to switch to a long cage rear mech when swapping to a 12-27 or 11-28 cassette. Although not recommended by the manufacturers, we've tested up to a 30-tooth sprocket and Di2 and cable-actuated short and standard length cage derailleurs can handle it quite happily (Campag and Shimano)"

Since I never resort to big/big or small/small combos when riding, i think i will be OK with a 12-30 on my current set up without the need to fiddle with the B-screw or chain length.

John.T

Don't forget that the max cassette size of both Shimano short cage road mechs (SS) and long cage (GS) is the same. 27 tooth (28 on the latest ones) which can be pushed a bit depending on the length of your mech hanger. The longer cage is only to take the extra chain for a triple.
We should stop calling them short and long (medium) and use the correct designations. SS and GS.

Luke2642

I realise this is an old thread, but I really fancied chiming in

I completely disagree with the "To be blunt, if you can't get up UK hills on a 34-28 then you need to train better!" idea.

For decades, gears on racing bikes have been too big. It's now normal to be able to spin at 100rpm for an extended period of time. At 50km/h this means you only need a 44T x 11T at the top end. A 46T x 11T top gear covers most people, most of the time.

At the bottom end, if you're in Yorkshire, the Lakes, Wales, Scotland, to mention but a few places, you will regularly meet 10% hills, most rides will have a 15% hill, and occasionally you'll meet 20% or more. If you want to sit and spin at 70rpm, rather than grind away at 30rpm out of the saddle, something like a 1:1 bottom gear is ideal.

If you're on a 12% hill, you weigh 65kg and you want to spin at 70rpm, a 1:1 gear will still mean you have put out 200W. That's not exactly taking it easy.

So what's the solution? Everyone knows triples suck. I really don't know. At least mtb derailleurs can take bigger cassettes, up to 11-42T... but then you have a huge jump between gears, and mixing and matching MTB and Road limits your equipment choice.

Another option is to get a triple chainset with a 28T or 30T on the bottom, throw away the two outer rings, and put a 44T or 46T on the middle ring, and an alloy chainguard where the outer ring would be.

Pros:

Excellent gear range, from 28x28 to 44x11
Only two chainrings, so not as much chain crossing
Nice jump between 28T and 44T, not any worse than the jump on a compact between 34T and 50T
Nice spacing on a 11-28T between gears. Jumps aren't too big.

Cons:

Chain line isn't great in high gears
Q-width is higher with a triple.
You have to buy lots of parts.

964cup

Depends on your rear mech. SRAM now have an 11-36 road cassette (intended for 1x, but so what?). Run that with a cross chainset (46/36) and you have the gear range you're looking for. Needs WiFli (although I reckon an Ultegra GS RD would also cope unless your hanger geometry is super tight). I've found that a 34x32 is good enough, and that's comfortably in Ultegra GS territory (so you can stick with Di2).

Luke2642

964Cup wrote:

Depends on your rear mech. SRAM now have an 11-36 road cassette

Very true, it's a simpler option, if you're changing your shifters and derailleur too.

However, even with 11 sprockets, cadence control is difficult with 11-36T because the jumps are so big. It's always a balance

darkhairedlord

is that? no, it can't be? is it manc33 ??

de_sisti

Luke2642 wrote:

I completely disagree with the "Everyone knows triples suck." idea.

FTFY.

markhewitt1978

I run a 12-30 cassette, and I do tend to struggle still when I run out of gears in the Pennines. However I still have 12kg to lose before I get to my acceptable weight so I might wait and see how that goes before I start swapping out my rear mech to accommodate a bigger cassette.

leeshields

Gotta love resurrected threads!

I'm in the middle of this right now, just bought a new bike with Sram RED 53/39 11-26. Swapped the chainrings for 50/34 and riding the other day I'm having to grind it on long pennine climbs.

I've already got knackered knees and a torn cartilage so I'd rather spin too.

Anyhoo just been in the garage tonight and put the 12-30 ultegra cassette from my cross bike on and it seems completely fine even with the short cage , b screw not fully in, shifts fine and will even take big/big, though I wouldn't want to ride it like that but never knowingly would anyway.

Pondering an 11-28 and trying to man up a bit but my current road bike is on apex 11-32

Money no object (and having not just bought the 50/34 spidering) I'd consider 52/36 and 12-30, bit more top end but still a 34 28 equivalent ratio

Decisions decisions.....

bompington

Being old, fat and now on meds for LVH that keep my max heart rate down to about 120, hills are a struggle for me at the best of times.

But when it was time for a new cassette to replace the 11-32 that came with the PX, and shortly after a desperate struggle up Glenshee into a strong wind, I decided that rule 5 applied, so I replaced it with 11-28.

So far it seems to be working: I've managed to improve my best times up some of the local climbs for the first time since the LVH was diagnosed, and I have literally not used the granny gear since buying the new cassette (about 300 miles). That's because I'm religiously avoiding it so that I've got somewhere to go once I hit the big hills on the 3 Pistes - especially the Lecht, which defeated me last year due to a combination of length, steepness and a gale force headwind. Well, maybe a bit of unfitness too...

The funny thing is, when I first got a road bike (the late lamented Rusty Raleigh) it had, like every classic steel bike should, a double (52-42) with 12-21, making 1st gear nearly twice as high as the PX. I used to be able to do 20mph in it.

TLDR: you can squeeze more or less any cassette on a bike. Just ride up hills a lot.

bikingeveryday

I run a 12-32 on a Madone 7 50-34 compact with a Dura-Ace short cage can cross chain big-big, small-small no problem.

ben@31

John.T wrote:

Don't forget that the max cassette size of both Shimano short cage road mechs (SS) and long cage (GS) is the same. 27 tooth (28 on the latest ones) which can be pushed a bit depending on the length of your mech hanger. The longer cage is only to take the extra chain for a triple.
We should stop calling them short and long (medium) and use the correct designations. SS and GS.

Both Shimano and online shops say 11-32T(GS) and 11-28T(SS)

Model Number RD-6870-GS
Series ULTEGRA
Cassette Compatibility 11-speed
Maximum Sprocket Low: 32T, Top: 12T
Minimum Sprocket Low: 28T, Top: 11T
Maximum Front Difference 16T
Total Capacity 37T
Outer Link Steel/Painted
Inner Link Aluminum/Painted
Link Pin Bushings Flouric Coated 4
Average Weight 260g