Upgrade Shimano Ultegra 6800 crankset for something lighter?

Discuss light weight issues concerning road bikes & parts.
dwmark2
Posts: 11
Joined: Wed Oct 02, 2013 5:31 pm

by dwmark2

Can anyone help me out with a crankset upgrade decision?

I just bought a full Shimano Ultegra 6800 groupset, but was considering swapping out the crankset for something lighter. The 2014 6800 compact crankset (52/36t 172.5mm w/o BB) weighs 700g on my scale and the 6800 BB weighs 77g. I was considering swapping this for either the FSA K-force light compact or the FSA SL-K light compact because they (according to FSA’s website) are supposed to weigh ~556g w/o BB. I would pair those cranks with the FSA BB386evo bottom bracket (87g) and hopefully end up saving some weight.

The problem is I can’t seem to actually find any cranks that are anywhere near the claimed weight from the FSA website (maybe all the cranks on ebay are older models and weigh more?). Can someone help me out with either finding an appropriate crankset/BB combo weighing less than 777g (ideally for less than $300) or convince me that I shouldn’t switch away from the Ultegra 6800 crankset.

Note: the Shimano 6800 crankset is 11spd and the FSA cranksets are 10 spd, but many other forum posts have lead me to believe it would be fine to use a 10 spd crankset with an 11spd system.

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btompkins0112
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by btompkins0112

FSA website weights are horribly inaccurate and probably are closer to the crankset weight w/o rings. Better off sticking with the 6800s than using any FSA garbage cranks. The shifting on the 6800s is going to be so much better it is worth any weight penalty over the FSAs (assuming there truly is any in a real weight to weight comparison).

What kind of bike you have would be a good thing to know in order to give better options.

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Ivan
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by Ivan

Having used ultegra 6500 and 6700 as well as DA7800 cranksets. They all brought me durability, great shifting and easy/cheap maintenance with only one broken BB bolt (on octalink BB) in about 10 years of heavy use. I am a big fan of Shimano cranksets.
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dwmark2
Posts: 11
Joined: Wed Oct 02, 2013 5:31 pm

by dwmark2

Thanks, that is what I was leaning towards after spending too many hours scouring the web for acurate weights and messaging clueless ebay sellers.

btompkins,
I am building up a chinese carbon bike. Love them or hate them, I figured I'd give it a try. Its the fm098 (Venge look-alike). My current weight is ~6395g (I dont have my excel sheet with weights in front of me) and I was hoping to get to below 6350 (14lbs). Right now Im also trying to find a good deal on an Easton EC90 SLX fork (285g) to replace the stock 385g chinese carbon fork.

Ivan,

I too have used Shimano for years and love their stuff. I guess I just got a little too caught up in the weights. Thanks for the insight.

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btompkins0112
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Location: Mississippi

by btompkins0112

There is a fork for sale in the classifieds....just what you are looking for.

Look into some S-Works cranks as another option.

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Rick
Posts: 2032
Joined: Sat Aug 29, 2009 4:30 pm

by Rick

I just got a 6800 compact, and mine was 680 gms (big savings!)

I think you could save ~90 gms by going to SRAM Red, and then maybe a little more by switching out the exogram chainrings. But given the excellent quality of the Shimano, it doesn't seem worth it.

If the frame is BB30, then you could save another ~100 grams with SRAM Red.

dwmark2
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by dwmark2

I really want to contact Prendrefeu, but I cant send any PMs. Am I missing the button or do I need a certain number of posts to enable that feature? Help! :(

pdlpsher1
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by pdlpsher1

I'm a big fan of carbon cranks specifically the Sram red. When I went from an alloy Shimano crank to the new Red I could feel the drop in rotational weight. The crank also has a velvety feel to it most likely due to the vibration absorption properties of carbon. And they are super stiff. As an added bonus the Sram BB has less drag than the Shimano equivalent BB. Currently I'm running Di2 9770 with the Sram Red and Sram 11-speed chain rings. Shifting is superb and the 'feel' of the crank is wonderful. I never thought a crank would make that big of a difference. GL.

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btompkins0112
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by btompkins0112

Let me pull my Wellies on real quick :smartass:

lannes
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Joined: Sat Nov 10, 2007 9:51 pm

by lannes

btompkins0112 wrote:FSA website weights are horribly inaccurate and probably are closer to the crankset weight w/o rings. Better off sticking with the 6800s than using any FSA garbage cranks. The shifting on the 6800s is going to be so much better it is worth any weight penalty over the FSAs (assuming there truly is any in a real weight to weight comparison).

What kind of bike you have would be a good thing to know in order to give better options.


+1 the FSA website weights are crank only add about 120gms for the chainrings depending on the combination.

the best of both worlds would be Dura Ace 9000 crankset, shimano stiffness and shift quality with a slighty lower weight of 632gms (depending on the chainring combination).
I think the compact version may be also a tiny bit lighter.

http://www.bikerumor.com/2012/12/13/unb ... eed-group/

Denavelo
Posts: 379
Joined: Wed Apr 08, 2009 8:01 pm

by Denavelo

I just scored a 6800 group as well.
I opted for Rotor 3D cranks with Praxis works rings.
11 speed compliant and some of the best shifting out there.
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stormur
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by stormur

6800 crank is extremely easy to scratch. Rotor crank extremely difficult. Shifting difference between Rotor 36-52 and 6800 34-50 ( same t difference ) : NONE.

Weight difference between rotor and 6800 : NONE.

Major difference is BB : Rotor is WAY smoother and lasts longer.

Place where I really noticed difference .... -Wrong : didn't noticed, I was schocked - was between ANY 36-46 chainrings and Shimano 36-46 CX70 crankset. THAT is shifting. Even in comparison to Miche which I'm fan of.


All the rest is quiet comparable ( at same chainring sizes ), if you think you'll amazed how brand A chainrings shift in comparison to brand B... it will be rather disappointment.

Exception is FSA 10spd marked chainrings. This is obvious disaster... even throwing chain from 46 to 36 can be a challenge for it.. require special FD adjustment, thn work... acceptable. But never "very good" . Max is OK-ish.
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hjb1000
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Location: Australia

by hjb1000

btompkins0112 wrote:The shifting on the 6800s is going to be so much better it is worth any weight penalty over the FSAs (assuming there truly is any in a real weight to weight comparison).


Agreed.
Regardless of any weight differences, FSA is not what I would consider an 'upgrade' to 6800.

Wookski
Posts: 662
Joined: Tue Feb 23, 2016 5:51 am

by Wookski

Try Rotor 3D+ with Praxis rings for a cheap'ish upgrade or just throw the credit card at a set of THM's and never worry about FOMO again!

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