Big ring - how does that work

secretsam

Have started using the big ring on my Sirrus more and more, having been a total middle ring junky before.

Am now flying at over 5mph, even on a clear road - but it takes apparently no more effort than using the middle ring - how does that work?!?!?!?!?!?!?

prawny

TBF 5mph isn't that fast 8)

UndercoverElephant

Tip: Combine it with a slightly smaller ring on the back and you might break the 6mph barrier.

monkeysm8

@5mph damn you fast!!!!

Kieran_Burns

being serious - it'll be because cadence is King.

Greg T

Doubling your speed to 10 MPH is a big step - given the mechanical advantage that the change in gearing gives you probably turn the pedals at the same pace as you did before.

The pace old people shag at

Very slowly and extremely infrequently.

I put myself in that group.

Kieran_Burns

Oh yeah and you'll find a fair overlap on the gearing between the smaller and bigger rings.

On my Tricross the highest 3 gears using the middle ring are the same (ish) as the middle 3 when using the big ring.

Eau Rouge

Kieran_Burns wrote:

Oh yeah and you'll find a fair overlap on the gearing between the smaller and bigger rings.

On my Tricross the highest 3 gears using the middle ring are the same (ish) as the middle 3 when using the big ring.

+1 The big ring isn't a whole new set of gears, and your bike doesn't actually have 27 (or 30) gears.

Put your details in http://www.sheldonbrown.com/gears/ and you'll see the overlaps

Aidy

Eau Rouge wrote:

+1 The big ring isn't a whole new set of gears, and your bike doesn't actually have 27 (or 30) gears.

Of course it still has 27 gears.
The fact that ranges overlap, and that some combinations may be equivalent, doesn't actually stop there from being 27 distinct gear combinations.

That's like saying that if you have 10 £1 coins, you don't actually have £10.

Eau Rouge

Aidy wrote:

Eau Rouge wrote:

+1 The big ring isn't a whole new set of gears, and your bike doesn't actually have 27 (or 30) gears.

Of course it still has 27 gears.
The fact that ranges overlap, and that some combinations may be equivalent, doesn't actually stop there from being 27 distinct gear combinations.

That's like saying that if you have 10 £1 coins, you don't actually have £10.

That depneds what you call a "gear". It has 27 (or 30) combinations of the front and back sprockets. I was using the term 'gear' to mean the gear ratio created by a combination of the front and back sprocket the chain is running on, and there will be less than 27 of them.

You may have £10, but you only have 1 coin type. If the pool table needs 50p pieces you're still out of luck.

DonDaddyD

Have started using the big ring on my Sirrus more and more, having been a total middle ring junky before.

Am now flying at over 5mph, even on a clear road

Damn hybrids.

If you had drop handle bars and did the same thing you'd reach escape velocity and fly out into orbit. FACT!

roger_merriman

yup even with wide spaced chainrings you don't tend to get more than a 3 gears extra lower or higher.

derailers are not elegent bits of kit really.

Headhuunter

Sorry but 5mph? That's walking/gentle jog pace! What speed were you travelling at before? You must've been almost wobbling off your bike! I'm not sure I could cycle at less than 5mph for any length of time if I tried.

Sorry if this is serious, but it sounds like a joke post or you've got your bike computer set up wrong....

prawny

Headhuunter wrote:

Sorry but 5mph? That's walking/gentle jog pace! What speed were you travelling at before? You must've been almost wobbling off your bike! I'm not sure I could cycle at less than 5mph for any length of time if I tried.

Sorry if this is serious, but it sounds like a joke post or you've got your bike computer set up wrong....

I'm thinking typo. I bet he missed a 2. I doubt it was a 3 or I'm getting a sirrus :shock:

CiB

Aidy wrote:

Eau Rouge wrote:

+1 The big ring isn't a whole new set of gears, and your bike doesn't actually have 27 (or 30) gears.

Of course it still has 27 gears.
The fact that ranges overlap, and that some combinations may be equivalent, doesn't actually stop there from being 27 distinct gear combinations.

That's like saying that if you have 10 £1 coins, you don't actually have £10.

That's what's wrong with your statement. Distinct means different. Of the 27 (30?) gears available, he probably has around 18-22 distinct ratios.

Answer to OPs original question is precisely because of this fact. Higher gears (ie smaller rings on the cassette) with the chain on the middle front ring roughly equate to middle gears on the cassette matched with the bigger front ring.

Have a go with Sheldon Brown's Gear Inch Calculator - in the generated table notice how the same or v nearly the same figures crop up in different places on the table. Some gears are the same.

Aidy

ChrisInBicester wrote:

That's what's wrong with your statement. Distinct means different. Of the 27 (30?) gears available, he probably has around 18-22 distinct ratios.

Of course, I said distinct combinations. Not ratios.

CiB

Splitting hairs mate. My road bike has about 16 gears to choose from; doesn't matter how you dress it up. 10 x 2 doesn't equal 20 gears.

It's surprising how many riders don't 'get' gears. Go over to the Road forum and the same questions pop up on there. Don't bike shops explain this to the uninitiated?

Aidy

ChrisInBicester wrote:

Splitting hairs mate. My road bike has about 16 gears to choose from; doesn't matter how you dress it up. 10 x 2 doesn't equal 20 gears.

It's surprising how many riders don't 'get' gears. Go over to the Road forum and the same questions pop up on there. Don't bike shops explain this to the uninitiated?

No, it really isn't splitting hairs.
44:22 is a different combination to 22:11. But the same ratio.

It's suprising how many riders don't 'get' the difference between a combination and a ratio.

whyamihere

ChrisInBicester wrote:

Don't bike shops explain this to the uninitiated?

Don't be silly. Imagine the scenario:

Shop worker: You see, this 20 speed bike only actually gives you around 13 distinct ratios
Customer: So why am I paying so much? That bike has 14 gears and is half the price! I'll take that one instead.
Shop worker: No, you see...
Customer: You're just trying to make me spend more for no reason. My mind's made up.

CiB

Aidy wrote:

No, it really isn't splitting hairs.
44:22 is a different combination to 22:11. But the same ratio.

It's suprising how many riders don't 'get' the difference between a combination and a ratio.

:roll:

DonDaddyD

Aidy wrote:

ChrisInBicester wrote:

Splitting hairs mate. My road bike has about 16 gears to choose from; doesn't matter how you dress it up. 10 x 2 doesn't equal 20 gears.

It's surprising how many riders don't 'get' gears. Go over to the Road forum and the same questions pop up on there. Don't bike shops explain this to the uninitiated?

No, it really isn't splitting hairs.
44:22 is a different combination to 22:11. But the same ratio.

I agree with this.

But I think your both right.

There are about 3 gears on my bike I use and the rest are duplicated. But there are still 27 different combinations and several ways achieve the same gear ratio,

I could be wrong.

CiB

It's not a question of thinking that we're both right. We are both right. Ratios & gear combinations are entirely different animals that people get confused over. The OP was asking why the big ring didn't offer any real difference; we've now gone off down a path of an apparent argument over something that Aidy & m'self both know is correct - that a bike can have 30 gear combinations but only 22 ratios. There's no argument. Aidy correctly stated 27 distinct combinations; in my enthusiasm I barged in to make the equally valid point that some ratios overlap. I wish I'd kept out of it now.

vorsprung

SecretSam wrote:

Have started using the big ring on my Sirrus more and more, having been a total middle ring junky before.

Am now flying at over 5mph, even on a clear road - but it takes apparently no more effort than using the middle ring - how does that work?!?!?!?!?!?!?

There are two reasons why
1) you have got a little bit fitter/ stronger in the leg
2) you are using a very similar gear but with the big ring at the front and a bigger sprocket at the back

Kieran_Burns

ChrisInBicester wrote:

It's not a question of thinking that we're both right. We are both right. Ratios & gear combinations are entirely different animals that people get confused over. The OP was asking why the big ring didn't offer any real difference; we've now gone off down a path of an apparent argument over something that Aidy & m'self both know is correct - that a bike can have 30 gear combinations but only 22 ratios. There's no argument. Aidy correctly stated 27 distinct combinations; in my enthusiasm I barged in to make the equally valid point that some ratios overlap. I wish I'd kept out of it now.

Yeah. Shurrup.




What they're trying to say is: using the big ring, or small ring may produce the same results depending on what you pump into it.

DonDaddyD

ChrisInBicester wrote:

It's not a question of thinking that we're both right. We are both right. Ratios & gear combinations are entirely different animals that people get confused over. The OP was asking why the big ring didn't offer any real difference; we've now gone off down a path of an apparent argument over something that Aidy & m'self both know is correct - that a bike can have 30 gear combinations but only 22 ratios. There's no argument. Aidy correctly stated 27 distinct combinations; in my enthusiasm I barged in to make the equally valid point that some ratios overlap. I wish I'd kept out of it now.

How does that relate to the theory of energy transference?

No!? Seriously, OK, I understand and agree with you. I'm now backing out of the room slowly and calmly.....

Peace be with you....

Bassjunkieuk

Maybe is psychological, you *think* you should be going faster because your using the big ring up front but aren't paying attention to what cog is in use at the rear and instead relying on your legs to indicate when you should move up or down the cassette? As other posters have stated there are some overlaps in gear ratios so you could find yourself using the same ratio gear that you normally use when in the middle ring?

Sheldon's site is great for checking this as it could produce a table that shows GI and I think it does ratios, I personally prefer the GI one as it lets me relate gears on my bike to those used by the SS/FG riders.

Personally I'm finding that I have a sweet spot of about 5-6 gears that I can use for most situations when on the middle ring up front and on the flatter commutes I think I tend to switch between about 2 or 3 (about 65 - 92 GI, the bottom half of the cassette) It's usually only on the brief downhill sections that I'd need to move up to the big ring as I'm sure I didn't use it the other day and hit 32mph racing a car, which looking back on it now must have meant I was doing some mad spinning :-)

I have tried just sticking it in the big ring and have found myself in it occasionally after a downhill sprint if I get a run of green lights. Can't say it makes much difference I just tend to find I use the upper half of the cassette then.

roger_merriman

the other thing is are you a spinner or grinder, around london etc i don't tend to come out of the big ring.

secretsam

Headhuunter wrote:

Sorry but 5mph? That's walking/gentle jog pace! What speed were you travelling at before? You must've been almost wobbling off your bike! I'm not sure I could cycle at less than 5mph for any length of time if I tried.

Sorry if this is serious, but it sounds like a joke post or you've got your bike computer set up wrong....

I was joking... :roll:

UndercoverElephant

SecretSam wrote:

I was joking... :roll:

Of course you were :roll:

secretsam

Right, some clarification:
1. I was joking about the 5mph bit, though I'm not going to challenge for the Maillot Jaune anytime soon
2. I know about gear overlap between different chainrings
3. I'm riding the same rear sprocket but a whole chainring higher
4. I've lost the will to live and realised once again that it's really hard to be humorous in print
5. Don't diss my Sirrus :evil:

Kieran_Burns

SecretSam wrote:

Right, some clarification:
1. I was joking about the 5mph bit, though I'm not going to challenge for the Maillot Jaune anytime soon
2. I know about gear overlap between different chainrings
3. I'm riding the same rear sprocket but a whole chainring higher
4. I've lost the will to live and realised once again that it's really hard to be humorous in print
5. Don't diss my Sirrus :evil:

Well, I'm glad you're finally decided to come back and clarify your position. Have you SEEN what you've started!!!

I've never seen so many :roll: in one thread.

You barstard.



<---- for the hard of humour