kosmo886

I am looking to replace my current chainring which is a 48/32 with a new ones given I find myself looking for a lower gear going down hills. The rear is not changing and is 11-34. I am pretty much deciding between 52/36 and 53/39. Any reason to choose one over the other? I am leaning toward the 53/39 given right now I rarely go down to the small chain ring at all and spend most time on the middle to lower end of the cog on the big chainring.

Any versatility issue I should consider? What kind of climbs am I really going to need the advantage of 36 vs. 39 or even the current 32 on the front? Any thoughts would be great. Thanks!

shelbyfv

Given your strength and potential, go with the grown man's 53/39. You don't need that 34 in back either, you might want to start a separate thread about that.

Iride01 

Lower gear to go down hills?

Lower to me, and I think most is a lower ratio which is an easier gear. IE, the big cogs with lots of teeth on the rear cassette.

Going from a 48/32 to a 52/36 or 53/39 might be a big change for you. I've been riding a 52/36 for the last 5 years and am thinking of going to a 53/39. I used to run a 7 speed 14-28 rear with a 53/39 and found it easy enough for all but one very long hill in my area that suddenly steepened to over 10 percent grade shortly before the top.

So it really depends on your terrain for your ride and your fitness level. Take a look at the lowest ratio gear combination you routinely use to keep you from walking your bike up the hills you ride. If that will still be an available ratio when you put one of those cranksets on your bike then you'll probably be good. Also take a look and make sure the ratios you normally ride cruising won't be on the 1st, 2nd or 3rd cogs of your cassette (the low gear ratios) for those cranksets. I usually look to keep my cruising cogs on the 5th or 6th thru 8th or 9th cog of an eleven speed rear.

rubiksoval

I usually ride a 53/39, 11-28.

My other bike has a 52/36, 11-28.

The 36 is nicer for longer climbs (3 km+ with extended sections over 10%) or for easier paces up grades of 15% plus. 39x28 is fine for me for anything else. But neither is particularly significant where I live, and I could do alright with each.

kosmo886

Ok, so maybe my terminology is a bit off. I’ve only been on a few rides so far, but on multiple occasions have tried to shift and found to be at the end of the gearing. Ie. Wanting a tougher gear. This means (in my mind) that I should change my gearing. Good news is if I screw it up I can always switch back and the chainrings are only $150 bucks so not a big deal experiment since the bike is new and I can get the same rings with different teeth for an easy switch. I guess it seems to me that the difference between 52 and 53 is very minor. Any reason to not just go for the 53?

kosmo886

That’s helpful. In that example with my 11-34 on the rear, a 39-34 would be an easier climbing gear than. Your 36-28, so sounds like for you at least, the 53/39 has more applicability.

Iride01 

It's especially a non issue if you are going to keep the old rings or crankset. I have a 50/34 crankset I bought just for times I might be in areas that have much more climbing than I'm used to. So far, they are unused.

And since it sounds like you can DIY them, then it's a quick change if you have the parts on your shelf. So yes try out one of the bigger rings. You might find that buying the entire crankset new and selling the bare crank on ebay a better deal than buying just the rings.

HTupolev

Insufficient low-end gearing becomes tangibly detrimental to performance long before it actually forces you to get off and walk. Look at the lowest ratio gear combination that you routinely use to keep from feeling bottomed-out.

kosmo886

To be clear, I’ve never changed a crankset, but doesn’t look too challenging given that parts should be plug and play! Famous last words I suppose.

I will plan to keep my existing rings, so no issue there. Interesting thought about buying the whole set. Didn’t see any comparable cranks for sale on EBay. The rings alone are $160 and full crankset is $325. These are the Praxis Zaynate Carbons. Any idea what some carbon cranks are worth “used”?

tomato coupe

You started a thread 3 days ago where you stated you had only done 2 outdoor rides ... ever. Why are you in such a hurry to change your gearing?

kosmo886

Because If I am a few rides in and already being limited in gearing it probably means I should make a change. It’s also a pretty darn easy and relatively speaking cheap fix, so why not?

CAT7RDR

This sounds like a case for: https://www.sheldonbrown.com/gear-calc.html

Play with the calculator to your heart's content and get a better idea with the type riding you do, cadence, speed and the terrain what would work for you?

shelbyfv

Sock rides are like dog years

Dean V

Can you even get 53/39 chainrings that will fit your existing crankset?
Also 48-11 should be a big enough gear.
Learn to pedal faster.

tomato coupe

Are you sure?

shelbyfv

That's a good idea. OP should start a cadence thread.

znomit

Are you riding up these hills that you can't pedal fast enough down?

BluFalconActual

Just a reminder, you’ll probably have to change the chain as well to get the right size if going from 48 to 53 teeth

ZHVelo

Do the math - 52/11 vs. 53/11 is a 0.09 difference as is 39/34 vs. 36/34

However, one of them represents 2%, the other 8%.

Going for the 53 gives you a biggest gear 2% bigger than the 52, but your lowest gear is 8% bigger. Which do you think will benefit you more, 2% on a flat/downhill or 8% on a climb?

Personally I climb a lot, so I will be going for gearing that gives me a lower gear.

DaveSSS 

A shimano 11-34 has poor sprocket spacing. On a road bike, I'd hate 11-13-15-17...

I use a 48/32 with Campy 12 11-34, but I'm 67 years old and ride in the foothills and mountains of Colorado. On more moderate terrain a young fit person would probably use a 53/39 crank and 11-25 cassette.

AdkMtnMonster

I was thinking about asking the OP if he is rapping out a cadence of 120+ for his descents. If not, then, well... you guys know what I’m talkin about.

waters60

Don’t assume swapping chainrings over is easy. With my Campy stuff it was but other cranks require removal of a crankarm😳

genejockey 

I guess if you're really spinning out with 48x11, you're descending hills that probably require the 36x34 to get up. You might spin out the 48x11 at about 38 mph.

DaveSSS 

That's what I do. Spin up to 38, then tuck down and coast on up to 50-54 mph.

genejockey 

I don't have the kind of long descents that let me get up to that kind of speed, so mostly I just see how fast I can coast up to then start pedalling when speed stops increasing. I should see how fast I can go if I work more on the downhills......