shimano/sram 53-34 chainset..... possible??

vectra0

Hi all
quick question: is it possible to make a chainset from the rings using 53 big ring and 34 small ring....?
Thinks SRAM force or shimano? Running 12\25 on the back FYI
Thanks all :-)

imposter2.0

The 19t jump from 34 to 53 is probably too great for most FDs to handle effectively. You might need to reduce on the 53, or increase on the 34..

vectra0

52-36? Better?

t4tomo

Or how about 50-34?

How many time have you actually spun out 50-12 or 50-11? And did free wheeling for a while really matter?

I'm guessing the answers are not very often and no.

vectra0

Its for time trialling..... Particularly hilly time trials, in which I often spin out 50-11
The main problem is the 16 cog on the rear is what I'm missing to shift up the block nicely and I often feel i'm missing this gear This only comes in a 12-25/27
the issue here is I ride with very high cadence hence the 52 wanted on the front so I dont spin out the 12.... A bit complicated really :-)

cycleclinic

Spinning out 50-11 thats a taller ratio than 53-12! I know I can't spin out on 53-12 even when doing 35mph in a race pack. I hit 42.7 mph in yesterdays race (downhill) and was not spinning out so your defination of spinning out is not mine. I mean I only hit 127 cadence at 43mph and that is sustainable for a while if you train for it (the 127 cadence not the 43 mph bit I need gravity for that).

50-11 will have you doing 124 cadence at 44 mph you can sustain that cadence! if you are doing that sort of speed alot when TT you won't be on this forum you will be in a professional team and have a coach to answer the questions and give advise.

52-36t is a much better combination but if you use that ditch the stupid 11T start cassette and go with a 12T start cassette. Only people who can sustain silly watts can justify an 11T start cassette the rest of us a 12T or even a 13T start cassette is fine. Personally I find 53-15T fine at 30 mph (109 rpm).

Train for cadence and once you can spin at 100 rpm the entire TT then fine tune you gear ratio selection. I suspect that if you are saying you are spinning out 50-11T you are not averaging 100 rpm for your cadence.

banditvic

53 34 is possible the mechs cope with it, the problem lies with when on the front 34 you won't want to go in your 3 highest gears on the cassette due to chain rubbing on the 53 ring and picking up chain. I ran it for a while you soon get used to it.

vectra0

Ok so maybe not spinning out, but it certainly feels there is a lot less to push at 35mph downhill with 50-11 :-)
I agree that the 12 is the way to go.
So for 52-36 you have to get separate chain rings? (Not standard sizing)

vectra0

I'm running SRAM force 10sp. Looking at chainrings, it seems 52 is 4mm and 36 is 3mm will this work?
Cheers guys

cycleclinic

what do you mean by 4mm and 3mm. Just get 110 BCD sized rings. As I said 50-11 is a taller ratio than I have and I have to hit 45mph before the spinning out begins but really I have spun up to 160+ (and that would be a daft speed in 53-12T) and at that cadance your legs feel like flying off but you can't stop spinning either so your legs fly off.

Try some cadance training for a few weeks so 130 rpm becomes something you can handle. A 34 inner ring on a TT bike is just wrong. a 34T inner ring is for very hilly routes and on those you maybe just as fast on a standard road bike.

lawrences

t4tomo wrote:

Or how about 50-34?

How many time have you actually spun out 50-12 or 50-11? And did free wheeling for a while really matter?

I'm guessing the answers are not very often and no.

A few times on a 52-11 and yes because I could have gone faster and that's the aim of the game.

vectra0

Thanks cycle clinic. I'll check out the 110 BCD :-) and do some cadence work ;-)

jibberjim

t4tomo wrote:

Or how about 50-34?

How many time have you actually spun out 50-12 or 50-11? And did free wheeling for a while really matter?

I'm guessing the answers are not very often and no.

The reason to want a 53 or 52 is nothing to do with spinning out the 11 or 12, it's about having close ratios in the important place for your normal cruising speeds. The difference between the 11 and 12 gears is over 9%, the difference between the 14 and 15 only 7%, the jump is bigger the lower down the cassette you're forced.

Gearing is not about optimising for the extremes.

racingcondor

Not the cheapest option but these play nicely with Force and are very stiff rings indeed. 52/36 is on the options list -

http://www.sigmasport.co.uk/item/Praxis-Works/Compact-110BCD-Chainrings/2HVY?gclid=CJ3mk9Owx78CFcbJtAodcAwAAg

Grill

racingcondor wrote:

Not the cheapest option but these play nicely with Force and are very stiff rings indeed. 52/36 is on the options list -

http://www.sigmasport.co.uk/item/Praxis-Works/Compact-110BCD-Chainrings/2HVY?gclid=CJ3mk9Owx78CFcbJtAodcAwAAg

I use these on my Wyndy. Only rings I've used that are as smooth as DA.

vectra0

They look perfect!

springtide9

I have a mid-compact on my N2A which is compact size 110BCD but with 36/52 chainrings.. so guessing a 52T chainrings are available on their own for compact chainsets. It's an FSA SL-K Light if interested.