Gearing question

PaulKK

Hi all,

Currently have a 30-39-50 triple with an 11-25 cassette (10 speed tiagra).

I'm finding tackling some of the steeper hills around tough going.

I've had the bike a year and managed about 1200 km on it, tending to do 40-50km or so spins at a time but ive done an 80 as my longest.

Most of the guys I cycle with seem to find the hills a lot easier than me, although it may be that I'm not as fit as them.

I was thinking about changing the rear cassette to a 12-28 or 12-30. Would this be a good idea?

Was eyeing up this: http://www.chainreactioncycles.com/mobile/ie/en/shimano-tiagra-4600-10-speed-road-cassette/rp-prod67228

Any advice?

AstraMonti

A 12/27 will work, I think you need to have a long cage to make the 12-30 fit. But with a 30/27 you should be able to climb walls with no trouble. You might just need more time on the bike to get used to the hills. Obviously the more your weight the harder the hills are.

PaulKK

Cheers, so would the 12-27 be worth a shot then? I presume I'll gain maybe one or two lower gears than I have now?

07Lapierre

An 11-25 with a triple should be more than enough for irish hills.

Brian?

Not trying to be a prick, but a 30-25 should be as low as you ever need in Ireland.

Hills are supposed to be hard.

Seaneh

AstraMonti wrote: »

A 12/27 will work, I think you need to have a long cage to make the 12-30 fit. But with a 30/27 you should be able to climb walls with no trouble. You might just need more time on the bike to get used to the hills. Obviously the more your weight the harder the hills are.

medium cage shimano will take 30t cassettes (31 max).

Seaneh

Brian? wrote: »

Not trying to be a prick, but a 30-25 should be as low as you ever need in Ireland.

Hills are supposed to be hard.

Ah, for some people, you need the reassurance of the granny gears (28/30) even if you will rarely use them, its good to know they are there sometimes.

I'm a big lad and I'd use them the odd time on very steep hills, comming out of moycullen headed to Spiddle I'd have used them about half the tines I did the route.

Brian?

Seaneh wrote: »

Ah, for some people, you need the reassurance of the granny gears (28/30) even if you will rarely use them, its good to know they are there sometimes.

I'm a big lad and I'd use them the odd time on very steep hills, comming out of moycullen headed to Spiddle I'd have used them about half the tines I did the route.

I understand why people want them, that's grand. But you shouldn't really need them once you've been cycling a wee bit.

I'm just over 100kg and I've a compact with an 11-25. I rarely use the 25. I bought a standard crankset I'm going to switch to and may use a 12-28 with that for a while.

Last year I used a standard with an 11-25 and did some serious climbing. The 25 got plenty of use but that was it.

Basically what I'm saying is, hills are supposed to be hard. Get better legs. Get better lungs. Embrace the suffering.

quozl

Would you do most of your more serious climbing standing, Brian? If you're standing you'll push quite a bit higher gear than someone who prefers to sit and spin.

I would consider 30/25 a pretty low gear but if the OP would like to try a 27 then why not.

Brian?

quozl wrote: »

Would you do most of your more serious climbing standing, Brian? If you're standing you'll push quite a bit higher gear than someone who prefers to sit and spin.

I would consider 30/25 a pretty low gear but if the OP would like to try a 27 then why not.

I rarely stand climbing.

Nothing stopping the OP trying any gear he wants. I'm just saying it won't benefit him the way trying harder will .

Wishbone Ash

Brian? wrote: »

I'm just over 100kg and I've a compact with an 11-25. I rarely use the 25. .

That pretty impressive. I'm 22kgs lighter than you and at times I'm under pressure on a 34/28 - e.g. going westwards over the Wicklow Gap into a headwind.

(Perhaps you're a good bit younger? )

AstraMonti

Seaneh wrote: »

medium cage shimano will take 30t cassettes (31 max).

Well, looking at the shimano tech docs there isn't actually a tiagra medium cage, only a short or long. The 9speed version can take up to 27t, the 10speed up to 30.

http://techdocs.shimano.com/techdocs/blevel.jsp;jsessionid=QlRQSKHXVnKLHlYzx0zy1JyTGjbKZlnxZRKbGYJB5qXmT23sMdJr!1217596882?ASSORTMENT%3C%3East_id=1408474395181679&FOLDER%3C%3Efolder_id=2534374302051921&bmUID=k3YlDyG

Brian?

Wishbone Ash wrote: »

That pretty impressive. I'm 22kgs lighter than you and at times I'm under pressure on a 34/28 - e.g. going westwards over the Wicklow Gap into a headwind.

(Perhaps you're a good bit younger? )

I struggle. Big time.

Wishbone Ash

Brian? wrote: »

I struggle. Big time.

I was in the Alps in August with a group and some of the lads who were heavier than me were using 53/39 with 25/12 and climbing half way down the block while I was grinding on the 34/28. To make matters worse, most of them only cycle now and again.

smacl

Brian? wrote: »

I struggle. Big time.

Struggling is grand if thats what you're into, but smaller gears will let many people like myself get up the hills with way less stress. I changed from 30/23 lowest gear to 30/28, and use my lowest gear regularly, being much happier spinning a higher cadence than grinding a lower one. I find it really saves my knees, particularly on a longer hilly day like the WW200. Even with low gears, I find some ramps (e.g. the full wall, devils elbow, kippure, grassamucky) to be struggle enough. Fair play doing them in 34/25, I think I'd burst a blood vessel. I did the bottom half of the wall in 42/28 last year (mech failure) and was getting tunnel vision near the cross roads, never again!

I also find I go faster uphill at low gear / high cadence which often surprises me. I could be in a high gear (for me) grinding away, drop a gear to take a breather, and suddenly speed up by a couple of kph. That said, I'm a weak climber.

Wishbone Ash

smacl wrote: »

Struggling is grand if thats what you're into, but smaller gears will let many people like myself get up the hills with way less stress. I changed from 30/23 lowest gear to 30/28, and use my lowest gear regularly, being much happier spinning a higher cadence than grinding a lower one. I find it really saves my knees, particularly on a longer hilly day like the WW200. Even with low gears, I find some ramps (e.g. the full wall, devils elbow, kippure, grassamucky) to be struggle enough

I'd be pretty similar preferring to sit back especially on long climbs. I'd get out of the saddle for shorter ones like the Devil's Elbow but find that after a few minutes my lungs can't keep up with my legs. Glassamucky is strangely deceptive - it doesn't look particularly difficult but is quite a drag especially for a mediocre climber like me.

joxerjohn

The trend with shimano appears to be to offer ever lower gearing options to cater for new road cyclists. The latest Tiagra groupsets cater for a 30t on the rear and on many of the newer bikes I see around the €1k mark this comes as standard with a compact double 50/34 crankset. On the Shimano Claris groupset recently launched and also aimed at budget entry level road bike they offer a smaller 48/34 double crankset to go with the 31/32t on the back.

In the case of the OP you may be limited by the model of rear derailleur you have but I would say that 12-27 should work fine for you but that a 12-30 may not. The only difference between the two cassettes is the number of teeth on the two biggest sprokets, 23,25 versus 24,27 on the 12-27. So there is a bit more gearing choice there for you when climbing.

I would say go for the 12-27 and remember there are no hills that steep that you can't get off the bike and walk to the top ! The important thing is not to be put off, get out there enjoy it and do the best you can.

Wishbone Ash

joxerjohn wrote: »

....and remember there are no hills that steep that you can't get off the bike and walk to the top not be seen ....

:eek: FYP

PaulKK

Thanks all, so it looks like the 28 will work fine then? Is there much difference between that and the 30?

Like others have mentioned I prefer to sit and spin so would rather the lower gears and save my knees!

Thankfully I've never had to walk yet but I'd like to get my pace up a bit.

Wishbone Ash

30x25=1.2
30x27=1.11
30x30=1.0

Basically utilising a 30 with your triple will mean one turn of the pedals = one turn of the wheel.


30x28=1.07 (a 28/11 will give you a bit extra for long descents compared to a 12)

ford2600

PaulKK wrote: »

Thanks all, so it looks like the 27 will work fine then? Is there much difference between that and the 30?

Like others have mentioned I prefer to sit and spin so would rather the lower gears and save my knees!

Thankfully I've never had to walk yet but I'd like to get my pace up a bit.

This slightly off topic, but was talking to endurance Donncha Curtrtiss while I struggled up Partick's Hill with him on Sunday.
This is race across america, race around Ireland cyclist. He has spent all his life doing extreme training of one kind or another.
He reckons it took 10 years to get strong cycling legs. His strong and a normal person's strong are not the same mind!
However if newish to cycling give it time, you will get stronger. If you think you need a triple or 30 on back get it. Just keep pedalling.
Everyone is different. I find 34/28 gets me up anything, saying that I'd of been glad of a 30 on back as the laps mounted on Sunday

PaulKK

Wishbone Ash wrote: »

30x25=1.2
30x27=1.11
30x30=1.0

Basically utilising a 30 with your triple will mean one turn of the pedals = one turn of the wheel.


30x28=1.07 (a 28/11 will give you a bit extra for long descents compared to a 12)

So the 12 will lose me a little top speed?

Would you suggest the 12-28 or 12-30 then in that case? Those two are on chain reaction at the moment in the link in the op.

AstraMonti

Do you know which Tiagra rear derailleur you have? That will decide what cassette you can put on the back.

quozl

Why not compromise and get the 12-28

That'd be a big difference over your current 12-25.

Here's the teeth on the tiagra 10 speed cassettes:
12-13-14-15-17-19-21-23-25-28
12-13-14-15-17-19-21-24-27-30

So you can see they're the same until you get to the last 3 gears. The 12-28 would turn your current lowest gear into your new 2nd lowest gear - ie both 25s. The 12-30 would mean that your new 2nd lowest gear is still noticably lower (27 rather than 25) than your current lowest gear. Which do you want? How often do you want a lower gear than your current lowest and would you really want two of your ten gears to be lower than your current lowest or would they just be wasted then?

The 30 is a full 20% easier than your 25, and the 28 is 12%. So if you're currently doing 70 rpm and it's 20% easier then you'd be doing 84 rpm in that gear for the same speed. From messing about with 26, 28, and 32 cassettes recently I've found that it makes a larger difference than the percentage would suggest - I guess because as you get further away from your comfortable cadence it's more of an exponential change than a linear one. IE double your gearing and it's going to subjectively feel much more than twice as hard

That's a bizarre rambling way for me to say, I'd get the 12-28 and not the 12-30. You'll probably find the 28 a pretty big difference already and while you might occassionally use the 30-30 gearing, that would be pretty rare IMO and you'd pay the price by turning two of your precious gears into irregularly used ones.


BTW, I don't see a 12-27 Tiagra. You considering something other than you linked in your first post? You're also going to need a new chain and please post your rear derailleur model so that someone can confirm that it'll take a 28.

quozl

I also wouldn't worry about losing the 11 personally. Losing it helps slightly reduce the gapiness in the cassette and also means that you can take a 1 bigger rear cassette as there is one less chain link to be taken up in slack when in the small-small combination.

I hit 71kph last sunday using 50/12 gearing. Admittedly it wasn't for very long but I'd be physically comfortable maintaining 60 kph on a long descent in that gearing. With my lack of bike skills the limiting factor on my descents isn't the gearing it's the nerve/skill. You'd know yourself how important that top gear is to you. You can easily test by seeing how you descend in your 2nd highest gear. Most 11- cassettes would have a 12 as their 2nd sprocket, I think.

PaulKK

My apologies I ment 12-28 in the op.

I will try and get the model of the deraileur and report back. Its a sensa trentino if that makes any difference.

cdaly_

AstraMonti wrote: »

A 12/27 will work, I think you need to have a long cage to make the 12-30 fit.

PaulKK wrote: »

Thanks all, so it looks like the 27 will work fine then? Is there much difference between that and the 30?

I run a 13-32t cassette with a tiagra medium/long cage rear mech without problems. That gives me a 30x32 low gear which I'm very happy with (even after years of cycling). With a triple, you more than likely already have a long cage rear mech. Go for the 12-30t, you'll be grand...

07Lapierre wrote: »

An 11-25 with a triple should be more than enough for irish hills.

Brian? wrote: »

Not trying to be a prick, but a 30-25 should be as low as you ever need in Ireland.

Hills are supposed to be hard.

Go on outta that with that shite, hills are for pedalling over with whatever gear suits...

full gas

PaulKK wrote: »

Hi all,

Currently have a 30-39-50 triple with an 11-25 cassette (10 speed tiagra).

I'm finding tackling some of the steeper hills around tough going.

I've had the bike a year and managed about 1200 km on it, tending to do 40-50km or so spins at a time but ive done an 80 as my longest.

Most of the guys I cycle with seem to find the hills a lot easier than me, although it may be that I'm not as fit as them.

I was thinking about changing the rear cassette to a 12-28 or 12-30. Would this be a good idea?

Was eyeing up this: http://www.chainreactioncycles.com/mobile/ie/en/shimano-tiagra-4600-10-speed-road-cassette/rp-prod67228

Any advice?

I think you would be wiser just to get out more often on the bike, get the mileage up,1200km in a year isn't a lot, don't think changing the ratio will help you to much, just spend more time on the bike will save you a few quid

Brian?

cdaly_ wrote: »

I run a 13-32t cassette with a tiagra medium/long cage rear mech without problems. That gives me a 30x32 low gear which I'm very happy with (even after years of cycling). With a triple, you more than likely already have a long cage rear mech. Go for the 12-30t, you'll be grand...





Go on outta that with that shite, hills are for pedalling over with whatever gear suits...

Then why not just cycle on the flat?

NeedMoreGears

I've used 34/30 (1.13 ratio) which is only a little bit higher than your suggested 30/28 (1.07 ratio). I found, like SMACL, that it allowed me climb steeper hills faster - I originally had a 26. As I became a bit stronger, I used the 30 less and less but the 28 (the next gear on the cassette) got plenty of service and it was always good to know the 30 was there in case I needed it.

By the way, I suffered pretty much the same on the hills with the 26 or the 30 on the back - it just took me less time to get over them with the 30.

Go for it and enjoy the pain!

smacl

Brian? wrote: »

Then why not just cycle on the flat?

a) Sometimes these hills just come at you out of nowhere when you least expect them.
b) Going downhill on the flat presents problems. Going downhill is fun.

NeedMoreGears

smacl wrote: »

a) .... Going downhill is fun.

So is going uphill*






*if you you have the right gearing;)