Sunday, July 19, 2015

Difference between Ultegra 6800 and Ultegra 6700 Crankset

Now that I have both the new Ultegra 6800 11 speed crankset and the previous Ultegra 6700 10 speed crankset, I can do a detailed comparison of these two cranksets! It will be interesting to see how similar or different these cranksets are between these two generations of Ultegra cranksets.

Let's start with a weight comparison! However, it must be noted that this weight comparison is not that accurate, as the Ultegra 6800 11 speed crankset is a compact 50/34T crankset, while the Ultegra 6700 10 speed crankset is a standard 53/39T crankset. Both have 170mm crank arms.

Ultegra 6800 complete crankset, 677 grams.

Ultegra 6700 complete crankset, exactly 700 grams.

Left crank of Ultegra 6800, 197 grams.

Left crank of Ultegra 6700, 201 grams. Just a tiny bit heavier.

Right crank + chain rings of Ultegra 6800, 480 grams.

Right crank + chain rings of Ultegra 6700, 499 grams. The weight difference is probably due to the larger chainrings.

It can be seen that the Ultegra 6700 crankset is about 23 grams heavier than the Ultegra 6800 crankset. This is a relatively small difference, and is probably due to the larger chainrings on the Ultegra 6700 crankset.

Now, let's take a closer look at the left crank arm. As shown below, the Ultegra logo direction has been changed between Ultegra 6700 and 6800. On the Ultegra 6700 left crank arm, the Ultegra logo is right side up when the crank arm points backwards. However, for Ultegra 6800, the logo direction has been changed such that the logo is right side up when the crank arm points forward. The new Ultegra logo is also larger.

Difference in logo direction between the Ultegra 6700 left crankarm on top and the new Ultegra 6800 crank arm at the bottom.

The new 6800 crank arm on the right is generally wider than the previous 6700 crank arm, and yet is more lightweight.

New 6800 crank arm on the right is manufactured by bonding 2 halves of the crank arm together, as can be seen from the seam on the crank arm. Previous 6700 crank arm was forged in one piece.

Ultegra 6700 crankset on the left, new Ultegra 6800 crankset on the right. Visible difference in chain ring sizes. The Ultegra 6700 right crank arm is 5 arm and forged in one piece, while the Ultegra 6800 right crank arm is bonded with 2 pieces and is a 4 arm design.


Overall view of the 2 Ultegra cranksets. Quite different appearance, as the previous 5 arm design has been replaced by the new generation of 4 arm crank design.

Main differences:
1) Previous 5 arm design vs new 4 arm design
2) 2 piece forged + bonded construction for the new 6800 crankset, vs 1 piece forged construction for the previous 6700 crankset
3) Logo direction on the left crank arm is different

Main similarities:
1) Similar glossy grey colour and surface finishing
2) Hollowglide outer chainring
3) Similar weight (accounting for the different chain ring sizes)
4) Same hollow spindle and crank arm fixing method

The main difference would have to be the appearance, from the 5 arm design to the 4 arm design. Otherwise, the construction and the surface finishing are quite similar.

12 comments:

  1. Newer one looks nice & aggressive while the older one looks like a octopus.

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  2. Hi, wonderful review and comparison. Can I ask if I can use Ultegra 6800 or with my Tern Link D8? If can, what do I need to change beside the BB and chain. Or I should use Ultra 6700 instead. Thanks

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    Replies
    1. First of all, you will need to change the rear wheel to be 11 speed compatible. Then all the components will need to be changed to 11 speed. Shifter, Rd, fd, crankset, cassette, bb, chain.

      If using Ultegra 6700 which is 10 speed, you can use your current wheelset. But all the components will still need to be changed to 10 speed.

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  3. Thanks for prompt reply bro. Just a bit more question, since I'm new in biking. May u help to clarify more about if I go for ULTEGRA 6700 crankset and use only the 53 T drivetrain (remove the 39T drivetrain) what do I need to change?. From what I understand if I change only the crankset I still can use the original cassette, DR and so on? Thank you

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    Replies
    1. You can use the original components, just change crankset and bb. But not much use. You will also experience chain drop as there is no FD to prevent chain drop. The original crankset has chain guards to prevent chain drop.

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  4. Is there any difference in Q factor or pedal position i.e via angle differences

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  5. Hi, have you measured if the chainrings thickness and chainring gap (distance between 2 chainrings) are the same or different between the 6700 and 6800. I'm thinking to upgrade my 10 speeds 105 front single to front double and don't know if I can use the 6800 with the current 105 10 speeds chain and cassette or not.

    Thank you.

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    Replies
    1. The chainring thickness is the same, while the gap between the chain rings differ by less than 1mm. Can use without issue.

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    2. Thank you very much

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  6. I found the front shifting on the ultegra 6800 crank to be worse than that of my DA7800 crank that has 6700 rings on it. Fewer shift gates and pins are to blame. Oh, and I tried it with 6870 di2. Still worse than the 6700 with 7800FD under power. If you're going 11 speed, the 9000 crank's rings have 10 gates compared to the 6800's paltry 4.

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  7. 6700 rings are better, with far more ramps, gates, and pins than the 6800. In fact, I found 6870 di2 to have worse front shifting than my 7800 gruppo with 6700 chainrings. The rings just don't pick up the chain that well under power. The 9000 rings are far better (as are the 6700 for those still running 10 speed).

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