When Do You Shift Chainring?

[SoloCyclist]

I've been riding a Compact setup for around 5yrs. This has resulted in me rarely needing to use the smaller chainring except for the really steeper climbs. I took my new bike for a spin today and this has a standard 53/39 and 12-25 at the back.

This has me thinking that I probably have never learned exactly how to use the gears to best effect. Just now I will stay in the 53 till I run out of power then shift down. But, going from 53-23, assuming I don't use the 25 while in the largest chainring, means I have to shift up the cogs or I will be in too low a gear. This kills momentum.

So if I'm approaching a climb I know well and won't be able to stay in the 53 should I down shift onto the 39 at the bottom and then I can come down the gears as and when I need to?

What if I'm in an area that I don't know so well. Say I encounter an unexpected sharp increase in gradient. I'm in 53/23 should I drop to the 39 then adjust to a cog that suits, or is there a better way? Is it advisable to double shift using both shifters at once?

 

[HLaB]

'When Do You Shift Chainring?'
Probably not often enough I prefer a bigger cassette (I run an 11-26) and do most of my riding on my compact 52/38's big ring (avoiding big/big) and only drop down when I need to My summer bike is also an 53/39 with a 12-25 I also run a similar style but I do tend to spend more time in the upper an lower chain ring but I try not to shoot to often between them and incur the possible chain derailment. I do find when I do change a quick double shift is smoothest. Occasionally I do plan ahead and shift to the small before a climb but not often

 

[guitarpete247]

I drop down when I'm just past the middle of my rear cogs. Then I shift down on front and up one at the back. I do this on MTB triple as well, though on the middle chainring I think I have more leeway at the back. This is the way I've always ridden.
I used to have a mate who fitted a double on the front of his 5 speed years ago. He never got a dérailleur as he he felt he could just lean down and lift the chain when he wanted to change. This was in the flatlands of South Yorkshire so no hills to down shift for only the occasional railway bridge.

 

[HLaB]

I used to have a mate who fitted a double on the front of his 5 speed years ago. He never got a dérailleur as he he felt he could just lean down and lift the chain when he wanted to change. This was in the flatlands of South Yorkshire so no hills to down shift for only the occasional railway bridge.

And he didn't have any fingers, well not ones of flesh and bone anyway

 

[Moss]

Horses for courses! Best option for regular riding is : While in the outer ring C/set 50/53, try riding as much as possible in the centre cog on the cassette, and let you legs become accustomed to riding that gear, on the approach to a climb, leave it in that gear until the road inclines and after riding on the hill drop to the 34/39, then use the cassette cogs as needed on the climb. This is just basic advise, because there are many situations that will require other variations to conquer that hill.

 

[aberal]

You only have to shift when you have to, to maintain cadence. So if you are spinning at (say) 90 rpm and you hit a hill then you shift down to keep spinning at that rate. Whether this involves dropping down to the larger cogs at the rear or dropping down to the small chainring depends on the circumstance.

 

[guitarpete247]

And he didn't have any fingers, well not ones of flesh and bone anyway

I thought he was a prat. But he managed by stopping pedalling, bending over as he freewheeled and lifting the chain either up or down. He did end up with oily fingers.

 

[deanE]

As a newbie, living in Cornwall, I find that I am on the small chainwheel of a compact most of the time. However, I have found that there is a position along the cassette where changing rear or front cog makes little distance. I find that this is the change point for me, usually going one down/one up simultaneously.

 

[fenlandpsychocyclist]

I try to keep my legs churning at around 80rpm all the time whilst being slightly out of breath.
I change up and down to suit those two criteria.

 

[SoloCyclist]

'When Do You Shift Chainring?'
Probably not often enough I prefer a bigger cassette (I run an 11-26) and do most of my riding on my compact 52/38's big ring (avoiding big/big) and only drop down when I need to My summer bike is also an 53/39 with a 12-25 I also run a similar style but I do tend to spend more time in the upper an lower chain ring but I try not to shoot to often between them and incur the possible chain derailment. I do find when I do change a quick double shift is smoothest. Occasionally I do plan ahead and shift to the small before a climb but not often

Thanks for the replies lads,

I do understand the need to try and keep the cadence and resistance constant. What I am trying to get at is if there is a recognised 'most efficient' of getting over to the small chainring when it's required without killing my momentum. HLaB's first reply above seems to best grasp what I'm getting at (Apart from not shitting between changes ) I was hesitant to try doubleshifting incase I was putting excess strain on anything, or cause a chain off.

So what I was doing was changing from 53 to 39 whilst in the 23 cog. This removes almost all resistance like your chain has come off, loses your momentum and you need to quickly shift the cogs at the back to get in the right gear (resistance) but it definetly kills your forward motion. So if HLaB is right and on occasion when it can't be planned I can double shift (Change Chainring and Cogs at same time)

Does everyone agree.

 

[totallyfixed]

When I was nowt but a lad and dad was a racing cyclist I always remember him asking me what gears were for, "to help me get up hills", "to go faster down hills", all the usual replies and each got a shake of the head, after running out of ideas he said, "to keep your legs spinning at the same rate" [cadence was too big a word in Lancashire in those days].
By the time I was 11 or 12 I could probably fettle most things on a bike including gears, what did dad race? Fixed. What goes around comes around.

 

[gaz]

Before I need to

 

[gbs]

and on occasion when it can't be planned I can double shift (Change Chainring and Cogs at same time)

Does everyone agree.

I asked the qn on the forum about 18 months ago and was told that double shifting increased the probability of de-chaining. No explanation was forthcoming.

My own experience refutes the assertion but nonetheless I try to avoid doubleshifting. If the episode is unplanned then probably a lot of power is going through the system and so double shifting may not be the best option.

 

[Steve H]

Double shifting is fine in my experience. Just ease off the power slightly when shifting.

 

[Bicycle]

If I'm on a geared bike on roads I know, shifting becomes part of the rhythm of the ride. Former commuting runs spring to mind.

There are short, sharp inclines where I'd be out of the saddle if feeling fine and knocking back the gears if feeling slightly tired.

I think of the chainring shift as just 'two-ish shifts at once' and move rings mostly on the basis of what the next bit of road looks like. My geared bike is 39/53, so I have a lot of 'common ground' between the two rings.

Cogging up to the top of top as I start a big descent is just an imperious feeling. Intoxicating. In a slightly more hurty way, nestling it back into the little ring for a bastard of a climb is nice too.

In my experience, double shifts are fine. There are places where I always use them. I can hear myself saying to the kids on a ride "Try both thumbs together". It should be fine if things are mechanically happy.

Like many, I have a cadence that is a sort of 'happy zone' when I'm on a geared bike and I shift to stay in it. It is around 90-105.