Ultegra Gearing - Can you Customize?



seehunt

New Member
Jan 20, 2006
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Just picked up a new bike and the bike shop put a standard ultegra double on it, 39/53 with a 12-25, instead of the triple I ordered. I ride in the hilly county north of NYC, and although I managed ok on the hills last weekend, I still think I could use lower gearing on the worst of them. The shop is willing to do anything I want, go to the triple that I ordered, go compact, etc.
Point is, I like the reduced weight of the double, so I am thinking of trying the compact double, 34/50, along with a 12-27 cogset since this would go much of the way toward the 30 tooth chainring and 25 tooth rear gear on the triple. I just don't like the loss of top end (1.5mph less at 80rpm) with this setup and was wondering if anyone had experience with replacing the 12 tooth cog with an 11 tooth one (would cut the 80 rpm difference to .5mph).
I realize that the shifting would not be as smooth to this cog, but it is usually not the type of gearing I would change in an emergency.
Any suggestions?
 
I guess you have to ask yourself how much you use a 53x12 in the first place. I'm currently speccing out a new bike for my wife and we'll be going with the 50/34 compact double and 12-27 cassette. Won't know how it'll turn out until she rides it, but I suspect she'll prefer it over her current triple because she refuses to use the 30t gear she has up front (out of pride, I think).

In her case, she woudn't miss the top end loss, because she rarely goes past a 52x15. Having a 50 up front just means she'd use more of the cassette.
 
Have a friend who did this, but he used the top half of a 12-25 cassette and the bottom half of an 11-23 cassette so there is a 2 tooth gap at the 16 or 17 but he says it's barely noticeable. you could probably do this with your setup to get an 11-27 but shifting won't be the best.
 
I thought about other options, but I would rather have the rough shift at the high end where I probably wont use it a lot, mostly on long downhills or on long flat runs with the wind to my back. (or a really good day!:p ).

I thought I read somewhere that you could switch in the outer cog the easiest, at least on older models. My Ultegra is brand new, so I am not sure if you can still do this.
 
You don't mention what type of rider you are, nor your objectives... The decision should be based (in great part) on those issues. Obviously top speed is important to you for whatever reason you want it. Whether it is racing, or a faster commute... or something else.

As a casual rider, I only use 52x12 (I have no 53) on a descent... And could probably get just as much speed by getting up to speed with the 50x12 and then coasting in a nice aero position...

Your needs and capabilities are probably different than mine, but that is my $0.02

I hope you are happy with whatever option(s) you pick.
 
I think you are on the right path with the compact 50/34 and the 12/27. You could start out with the 12/27 and if you need additional speed I would ask your LBS about the upcoming SRAM 11-26 cassette later this year. A 50/11 gives you a larger road gear than a 53/12 so that should meet your additional speed needs should they appear.
 
I am a long time mtn. bike rider, who has been using my mtn bike to ride with the C riders in my local club. (I may also be doing some B rides with the new road bike eventually) I may be oversensitive, but while the hills on the mtn. bike were never an issue, keeping up on the downhills and even some flats has been, due to the lack of higher gears. Because of this I am reluctant to give too much up in this area, but to be honest, I haven't even tried it yet.

My first switch will be to leave on the standard double and just go from a 12-25 to a 12-27 cogset. This may be enough for all but the steepest hills, since I did not have problems last week on a hilly 35 mile route. (my road bike is 17 lbs vs my mtn. bike's 30 lbs./fat tires).

If I feel I need more low end, I would then have them switch to the compact crankset.
Only then will I be able to evaluate whether I really need an 11 vs the 12.
Having been a motorcyclist, I do love the speed on the downhills, not for racing, just for the fun of it.:D
 
seehunt said:
Having been a motorcyclist, I do love the speed on the downhills, not for racing, just for the fun of it.:D
I have never been a motorcyclist, but I recently saw somewhere someone describe a "superman" position for maximum downhill speed... The position name is obvious for a position where you ride with your gut on the seat and your legs extended behind you... Very aero and fast, but apparently very difficult to get back into a normal position.

Back in the dark ages (about 1980) I rode a bike down a particular hill regularly and I loved the speed. I would slide back off the seat and get to where my sternum was almost back to the seat, and my nose was just behind the stem... the bulk of my weight was on my legs since I left my feet in the pedals, so I was able to slide back up into a normal position when I had to at the bottom of the hill. As an almost 50 year old man I would not do that now, but as a youngster it was a blast!
 
dgregory57 said:
I have never been a motorcyclist, but I recently saw somewhere someone describe a "superman" position for maximum downhill speed... The position name is obvious for a position where you ride with your gut on the seat and your legs extended behind you... Very aero and fast, but apparently very difficult to get back into a normal position.

Back in the dark ages (about 1980) I rode a bike down a particular hill regularly and I loved the speed. I would slide back off the seat and get to where my sternum was almost back to the seat, and my nose was just behind the stem... the bulk of my weight was on my legs since I left my feet in the pedals, so I was able to slide back up into a normal position when I had to at the bottom of the hill. As an almost 50 year old man I would not do that now, but as a youngster it was a blast!

AT LAST! Someone who understands!!! :cool:
P.S. - I am 52, but never want to grow up!
 
It's funny to me that this comes up now... I just had the post about ordering a new tarmac... and the thing is, it comes in a 53x39 double w/ a 12-25 cassette, and doesn't come in a triple. I wanted to go with a compact, but I can't afford it right now. So, it looks like I'll be making the "trudge" up hills with the normal double. I've never even ridden a double, and my current triple is a 52x42x30, which gets me up anything.

I've done some gear inch calculations and speed conversions, and found that I'll be cruising around in the 53x17 and 53x19 most of the time. Is there any crossover in these gears? What I mean by "crossover" is that the chain doesn't make a straight line from the chainring to the cassette. Is there a cool cruising zone with the double? Like, from 21-23 mph at about 80-100 rpm?
Also, how hard is it lugging up hills with the double? Since the small chainring on a double is smaller than the middle chainring on a triple, I don't know hard it will be to push the gears on a big hill, since these two chainrings don't compare.

So, let me know what you think. You know anybody looking to buy an ultegra double crankset?
By the way, check out this webpage (Shimano's Ultegra cassette variations):
http://bike.shimano.com/catalog/cycle/products/component.jsp?PRODUCT%3C%3Eprd_id=845524441770452&FOLDER%3C%3Efolder_id=2534374302040144&ASSORTMENT%3C%3East_id=1408474395181419&bmUID=1144898208195
 

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