breggurns

Will a 52-34 double work? Or is the jump too much.

velocipedio

there is no front derailleur in the world that can shift 18 teeth. 16 teeth is already pusing the limit.

NZLcyclist

I think you can run down to a 38T small ring without changing to a different BCD on the crank - so if it is a standard crank you would have to get a new crank anyway to run a 34T. Have you thought about getting a long cage rear deraileur, and fitting a 32T low gear or even a 34? coupled with a 38 ring this would be a very low gear..... if you truly wanted a lower gear than 38x32/34 you should be looking at converting the bike to a triple chainring setup.

just my 2cents

Brendon

ed073

^^^

What he said.

53-11_alltheway

Even if you could this combo to work, why would you want to do it? 52/34: we are talking greater than a 50% gear change here.

cryogenic

you'd have huge gaps in gears.. yikes

jitteringjr

I think the question is at least worth asking. A 52/34 is only about a 1/2 gear off from a standard 50/34. The 50/34 has a 47% change and upping the big ring to a 52 only adds 4%.

The Percent change on a 52/36 is less than a 50/34, but I have never seen one standard. I think a better question would be will a 52/36 work? FSA’s website lists a 52t in a 110mm bcd so it would seem possible. Why do we never see 52/36’s?

sydney

It's been done.Tyler Hamilton.

jitteringjr

Stage 16 in the 03 tour? I was assuming it was a 50/36.

So it has been done, but why is it not done more often?

hi565

wait 52 in the front and 34 in the back?

Thats like my biggest chain ring in the front and my granny gear in the back.

darkmother

It will work, but not well. Your chain will not shift smoothly, and you may have issues with derailment. Also, it will rub on the big ring when you are in the 34 and the smaller gears at the back. I would try something more conservative, like 36-50.

jitteringjr

No, we are talking chainrings on the crank, not sprockets in the cassette.

DinoShepherd

What road course are you trying to set-up for?

What rear gears are you running?

-Z

breggurns

For juniors we have to pass a roll out to race. They believe that us juniors should use lower gears so we dont mess up our knees. Basically the largest gear we can use is a 52-14. I have been using a 12-25 cassette but have been forced to lock out my two highest cogs to pass the roll out, and I use a compact crank. I just ordered a 14-25 cassette, so I will be using a 50-14 as my largest gear. I was just worried about being under geared. Do you think I will be ok with a 50-14 rather then getting the 52 and having sloppy shifting.

hi565

oh,

that woudl be crazy, just wouldnt work.

fogrider

what do need a 53 up front? if you need the 34, just go with a compact and set it up with a 50/34. I current am running 50/34 with a 12x25 cassette. I had a 48/34 with a 11x25 cassette and rather like that better. witha 48 chainring I can just keep it in the 48 most of the time...I could even climb some mild hills on the 48.

with a 53x12 you get 119 gear inches, with a 48x11 setup I can get 117, with 50x12 I get 112, with a 50x11 I get 119. For most descents, 112 inches is enough to get me up to speed (40 plus mph) and get into a tuck.

PhatRoadie

Do you need a 34? Why not just run a 52-36? 36x25 is a lot of gear. And in a race i would rather have closer ratios and taller top gear than a bail out gear.

Unless you do a lot of climbs.

jitteringjr

Having a 34 sprocket isn't that rare, I know a lady from one of the group rides around here that rides either a 32 or 34 (from the looks of it) with an XT MTB RD. She said she wanted to keep a double up front instead of a triple and still have some granny gears.

Barnaby

The old triple on my Miyata 1000 is 52/47/34. So, The front can handle it, not sure how it would be without the 47 inbetween however. The crank is an SR. I can't remember if I ever went straight from the 52 to the 34, but I never had the thing derail.

Stubacca

Not going to be the same on a double. With the triple, even if you do shift straight down or up between the 52/34, the chain is able to take get a leg up from (or soften it's landing on) the middle ring. That isn't there with the double.

Maybe a compact specific derailleur would do it? Seems like way too big of a jump to me (and a 50-12 is still a pretty big gear, let alone a 50-11), but if you really want to try it...