52/36 to 53/39 huge difference & chain length

[jamin100]

I’ve just brought a new chainset and realised I’ve brought a 53/39 whereas my bike currently has a 52/36

My cassette is 11-32 and.m not changing.. I’m ok on the hills and only use the 36/32 on the real steep stuff or when I’m dead on the way back after a club run a hit a hill..

Is there much difference between the 36/32 combo vs 39/32 ?

Also, will my chain length be ok going from a 52 chain ring to a 53?

 

[I like Skol]

I would be extremely surprised if it caused a problem going from 52T to 53T. You might find the 39T a bit tall if you occasionally find yourself needing the 36/32, there is a difference!

 

[sleuthey]

Is there much difference between the 36/32 combo vs 39/32 ?

Assuming your cadence remains the same then:

The effort level on a hill in lowest gears will need to increase by 8%.

Your top speed in highest gears will increase by 2%.

 

[13 rider]

My two bikes have different gearing the Defy has 53/39 11/28 and the TCR has 52/36 11/30 .I have always got up everything on the Defy but do fine the TCR easier to spin up the hills . You will notice the harder gears but unless it's super steep you will still get up the hills . Not sure about chain length but I would guess you will be fine

 

[Cycleops]

One tooth extra on the front isn't worth getting a new chain for. Should work fine as is.

 

[jamin100]

That’s very precise, thanks

So a 22% increase in power needed to maintain the same effort level on a 39/32 vs a 36/32

Hmmm - not too sure I like the sound of that
I may have to have a think

I could look at it as making me stronger

 

[I like Skol]

I could look at it as making me stronger

Or less enjoyment?

 

[13 rider]

Ask yourself how often you really need the 36/32 to get up the hills .If you normally have a couple of gears left you will probably be ok with 39/32 . I changed from a 50/28 to a 53/28 and found I still got up the hills I just used bottom gear more often
Editted to now read gears not years !!

 

[Sharky]

That’s very precise, thanks

So a 22% increase in power needed to maintain the same effort level on a 39/32 vs a 36/32

Hmmm - not too sure I like the sound of that
I may have to have a think

I could look at it as making me stronger

Both are pretty low gears. With the same effort, you will just pedal a bit slower on the 39 ring.

 

[sleuthey]

That’s very precise, thanks

So a 22% increase in power needed to maintain the same effort level on a 39/32 vs a 36/32

Hmmm - not too sure I like the sound of that
I may have to have a think

I could look at it as making me stronger

While you were replying I realised I cocked up the maths so have corrected it. See above. Sure someone will come along with figures from a trusted gearing ratio chart/calculator.

 

[Sharky]

Ask yourself how often you really need the 36/32 to get up the hills .If you normally have a couple of years left you will probably be ok with 39/32 . I changed from a 50/28 to a 53/28 and found I still got up the hills I just used bottom gear more often

I hope that I have more than a couple of years left.

 

[13 rider]

Assuming your cadence remains the same then:

The effort level on a hill in lowest gears will need to increase by 8%.

Your top speed in highest gears will increase by 2%.

I thought the original sounded wrong but didn't know how to check your maths

 

[13 rider]

I hope that I have more than a couple of years left.

Bloody auto correct editted now

 

[sleuthey]

I thought the original sounded wrong but didn't know how to check your maths

Here you go:

 

[ColinJ]

So a 22% increase in power needed to maintain the same effort level on a 39/32 vs a 36/32

No - the 'effort level' IS how much power you are putting out!

What will change is your cadence and how hard you have to press down on the pedals. (In a higher gear you will push down harder but pedal more slowly for a given speed on the road.)

I'm about to go from a 46/34 chainset on my CX bike to a 53/39. It isn't because I want higher gears (I actually changed the original 36 small ring to the 34) - it is because my cousin is giving me his old powercranks and the spider doesn't take the small rings. There are some steep local climbs that will feel a bit tough in the 39 but I want to monitor power on some rides to see how my fitness is progressing. I have lower gears on other bikes so I will use those for the hard climbs.