Compact crank advice.......
 

Hi all,

I am currently running a 52*39 14*25 setup on my bike an I am in need of lower gears. (Its fine for where I live in CT but when I went up to race in VT last summer I was constantly grinding my lowest gear a lot.) I'm probably going to switch the low end of my cassette to have a 27 or 28 tooth cog but I also would want a smaller inner chainring on the crank. (currently a [Shimano 105] double) I am a junior, so if I switch to a normal compact crank (34*50) I will lose some of my top end gear, which I can't do because it is low enough as it is and when I race in non-junior races I am put at a disadvantage, so I would like to keep my top end. I have been researching about a compact 34*52 setup. I read about someone using a 53*33 compact crank so I assume it is possible. I know that FSA sells a 110 BCD 52 outer chainring but they say it can only be used with FSA cranks. Is this really true? I would not like to go with a FSA crank as I have read bad reviews about them and would like to stick with either a Shimano R700 compact crank or an Ultegra SL compact. Does any one know if the FSA chainring would work with the Shimano crank? If not, can anyone point me towards another solution?

Thanks for any advice.

just realized I kinda sorta copied another thread.......sorry

dude. a 50x12 gear is going to be almost 11% taller than your current 52x14.

52*14 is the limit for juniors though.......

14tooth is the limit in junior races right?
52/34 is a big jump for the front dr, probably it'd work but i'm not sure how smooth the shifting would be.
52/36 would probably be better

ahh ok, i didnt know that.

never heard of paragraphs?

i'll assume you're asking about FSA vs Shimano. I suggest you get yourself Shimano.

... noticed at the end of that brick of text you were asking if fsa chainrings would work with a shimano crank. answer is yes.

i don't really mind how smooth it shifts, just as long as it does without problems. I would rather have the lower gear. Does anyone know if the FSA chainring would by compatable with the Shimano crank?

sorry bout that......

Thanks!

Is the junior limit calculated on the minimum number of teeth they can have in the back, gear inches or roll out?

If it's either of the last two, you could run 50/34 (or 50/36) then 13-25 or 13-26. the 50/13 combination should give you 81 gear inches which is the same as 52/14. so you lose nothing in the bottom.

I personally race on FSA K-Force (both 50/36 and 53/39) and have never had an issue with them. I've used the 36 ring (FSA) on a set of Shimano R700's that I have also with no issues.

--brett

I would recommend against FSA too. I had some on my Felt and the left one broke where it bolts on to the BB spindle plus they are heavy, I saved 150g swapping to 105 compact cranks and Tiagra BB.

My first compact was a Ritchey Logic. It had the 110mm spider but came with a 53/38. When I lived in Michigan, I put on a 42. When I moved to Utah, the 38 left me huffing on the big long steep climbs so I put some FSA 50/34s on and it worked fine.

I think that your solution will be to be swapping chainrings and or cassettes based on the riding scenario that you will be faced with. Not a big deal, I use to swap cassettes all the time in less time than it takes to change a tire. I would suggest that you stick with a medium to longish cage on your rear derailure to accommodate chain wrap for the variable range that you are talking about.

I've read this thread with great interest and, not wishing to usurp the OP, I have a question of my own.

I just bought an new, full carbon, '06 105 compact 50-36 & 13-25 for my daughter - price, size and fit were right. The purpose of the purchase is so that she can accompany me on long, easy rides. The dominant features of the surrounding landscape are flat and rural and she's new to cycling. After reading the preceding posts, I'm wondering if I was a bit too hasty on the purchase.

Question: Is the gear ratio as described more oriented to hills or flats given that she's new to the sport?

I've attempted to understand the gear ratios in all of this to better understand what I've got. On the easiest, ie 36/25 she'll be pulling 1.44. That, in my estimation, should be easier than my own 39/25 at 1.56. If she wishes to pull hard, then her 50/13 at 3.84 is somewhat less aggressive than a standard compact, ie 53/12 at 4.41, hence it should be less effort on her part.

A lot of the preceding discussion on compacts refers to an inner ring with 34T. Overall should we be okay or have I purchased something unsuitable for a 12 year old?

Thx.

The needs for your 12 year olds should be fine with what you mentioned. Yes, you are probably right there are some low gears (hill) that she won't be using, but I think there will be some high gears she won't be using for now also.

Should be just fine.

If she's having troubles on any hills that might be encountered, a cassette with a 27t cog is easy to find and swap in, of course. And as noted, a 34 could easily be put on the cranks as well with few troubles.

The best way to find out is, of course, to get her out on the road and see how she does! :)

The gear limit is by rollout, so you can go to a 50x34 compact crank. Also, I have never seen someone cranking down a VT hill that is faster than a nose off the front wheel, balls-to-the-wall tuck.

I remember when age 15 and under the limit was 52-15. Which at the time was amazing how they stipulated that since it took me forever to find a shop who could remove cogs off a Shimano 600 6-speed freewheel and reconfigure with a 15t cog. I still have that freewheel somewhere. Then of course not once did anyones bike ever get checked. I was one of the very few stupid fools who actually complied with that rule, well actually I never found any other rider who had complied.