Different ratios on Ultegra 6800 (for junior racing)

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skiandbikecmh
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by skiandbikecmh

I am a junior in the United States, which means that I need to run junior gearing in all road races.

I am trying to figure out a way to make ultegra 6800 on my new madone work. Since the 11 speed Cassettes start at no larger than a 12 tooth cog, I would have to run a 44 tooth front chainring. Is there any way I can do this on the 6800 crank? or do I need to get a different Crankset?

Looking at the cyclocross rings, the design looks similar to the xtr trail cranks, with rings, and removable nuts that match, which would mean the potential to run rings other than shimano, without custom forging them, with threads. If this is true, is there anyone who would make a 44 tooth ring in the bolt pattern?

by Weenie


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bm0p700f
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by bm0p700f

Custom miche 11 speed cassette. Special order only but doable then you can have anything you want as miche cassette are sperate sprockets. That way you can keep your chainset the way it is. If you can't find someone in the U.S to do this there is always mail order.

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F45
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by F45

Take off the 12 and 13 tooth cogs, have a spacer machined to replace them, adjust rd limit. Use 50/34 chainset.

vdrey
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by vdrey

Do you think you could run a 1x11? You can get a rd cage from k-edge that allows you to run 11-32 or 36, so you would have a wide range with a single 44 chainring.

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LouisN
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by LouisN

Spécialités TA runs them in 10S : http://www.specialites-ta.com/plateau-zephyr.html
But for standard 110 BCD. I don't think it's on the market for the Shimano 6800 specific.

44T may be hard to adjust with the height of the braze-on FD. With some fiddling, like adding a bracket maybe.

Miche cassettes don't work well with Shimano 10S, from what I heard from many JR users .

Oh! And you'll lose a few inches every pedal stroke.

Losing two sprockets is the easiest way...or...go back to 10S :?

Louis :)

bm0p700f
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by bm0p700f

Miche cassettes work fine. The campag ones are very good and shimano versions well are the same but in different splines and spacer spacing. All I use on my road bikes now are Miche cassettes cheap and they work and I can get what ever ratio I please.

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LouisN
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by LouisN

Are you using the "big" ones ?
Maybe the normal small cogs are ok, but,
the junior gearing Primato cassettes (14-15-16 cogs as starting cogs) have a bad reputation here.

A lot of parents advise to go with the 6600 ones instead.

Louis :)

Colin

by Colin

Not sure if it would help, but Shimano makes a 46t chainring for the 6800 cranks. Maybe a 46x12 with some small tires?
You're best/safest bet is probably to just get a new crank and run a 45t chainring and a 12t cassette. That will give you the max rollout and you won't have to resort to tiny tires.

skiandbikecmh
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by skiandbikecmh

Seems like switching the crank is the best way to do this. I would rather not use a special cassette so that I can use different wheels and still take advantage of 11 speed. Now to decide what crank will look the best with the rest of the 6800 group with 44t chainrings...

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LouisN
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by LouisN

What color/model is the bike ?

You'll have identified 11s cassettes in the following cars and mechanic stands for spare wheels ?

Like I wrote earlier, the braze-on fixing on the bike might not let the FD to get low enough to function well on a 44T chainring, they're pretty small rings. The FD cage might be too far from the big ring.
It happened to a young jr girl who's parents bought a Specialized Amira. The front shifting was pretty "shi.ty", the FD cage was at best at 7-8 mm over the big ring.
Think about this...
...And the fact that you'll lose a few inches every pedal stroke...

Louis :)

skiandbikecmh
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by skiandbikecmh

Good to know. The bike is going to be a Madone 7 series in the matte black blue and yellow.

If I use a 45t ring I can have maximum gear ratio, correct?

44t loses a few inches?

I will try to find a 45t, but there are not many manufacturers, getting 44t ring will be easier.

I will check at the my local shop on one of their madones to see what the fd mounting will be like.

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LouisN
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by LouisN

What's your max gear in meters ? 7,63 or 7,93 meters ?
If 7,93 meters (52 X 14), using a 45 X 12 with 23mm tires will bring you over geared, and with a 44T you'll lose 4 inches per stroke (on paper, depending of course on wheel circumference).

Louis :)

skiandbikecmh
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by skiandbikecmh

7.93 meters. I checked the seven cycles gear calculator, and it seems that 44 x 12 with 25 mm tires is the best option

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LouisN
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by LouisN

I agree, and more comfortable :D .

Prepare to check the possibility of having to add a little bracket to the FD braze-on though.

I'd go FSA, Fulcrum or Sram for crankset. Easy to fit standard 110 mm BCD rings. Adding a touch of blue or yellow to match :) .

Louis :)

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LouisN
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by LouisN

Here's an 11S option. Might be an easy option:

http://bbbcycling.com/bike-parts/cassettes/BCS-11S

Not shure about the reliability and the quality of the shifting though.

Certainly not a WW option, as these cassette weigh about 350g...

Louis :)

by Weenie


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