# Shimano 105 Cranks vs Ultegra`



## hawker12 (Oct 19, 2003)

I am building up a new steel frame and really want to use an all Ultegra group. I plan to use a polished compact crank. However, I just don't like the look of the current Ultegra or Dura-Ace cranks...that hubcap look.

If I were to use a 5650 or 5750 105 crank but use an Ultegra or Dura-ace bottom bracket, would I be giving up much in feel and smoothness? I'm a smaller rider so crank flex isn't that big of a concern to me.

Thanks.


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## T0mi (Mar 2, 2011)

shimano 105 parts works as smoothly as dura-ace and ultegra ones. You will probably only get a slightly heavier crank.

But dismissing a part just because of its look, wow.


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## hawker12 (Oct 19, 2003)

T0mi said:


> shimano 105 parts works as smoothly as dura-ace and ultegra ones. You will probably only get a slightly heavier crank.
> 
> But dismissing a part just because of its look, wow.


Thanks for the response. However, you've never bought or not bought anything cycling related because of how it looked? Really?


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## Ventruck (Mar 9, 2009)

R700 is out of the question? You can probably find it for less than a 5750.


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## hawker12 (Oct 19, 2003)

Still trying to sort out this crank question. Yes, I've done my share of searching but I'm still not sure what the difference is between the 105 5650 or 5750?

If I went with a 105 over an Ultegra, could I gain back a few grams by going with a Dura-Ace bottom bracket?


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## frdfandc (Nov 27, 2007)

The 5650 crank is the last gen 105 stuff. The 5750 is the newest gen 105. Difference is weight. The new 105 components are lighter than the previous gen.

The 5650 crank is around 770 grams without a BB. Add 90 grams for the BB. 

The 105 5750 crank has been scaled to weigh 705 grams without a BB. The 5700 BB is advertised to weigh approx 90 grams. So give or take total weight would be about 800g

The Ultegra 6750 crank has been scaled to weigh 698 grams with a BB. The 6700 BB has been scaled to be 90 grams as well. So total would be 788 grams.

The DA 7900 BB has been scaled to be 90 grams. So there is zero benefit as far as weight goes. The DA BB spins smoother due to a different seal design than the 105/Ultegra BB's.

So there is zero weight advantage by using a DA BB.

However, the Ultegra forged outer chain ring is stiffer than the 105 stamped chain ring. So there is a slight difference in flex.


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## yakobo (Aug 22, 2006)

I've read that the 5700 model incorporates new outer chainring features that have been available on ultegra 6700s making for better/smoother shifting. Is this the case?


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## frdfandc (Nov 27, 2007)

The profiles of the ramps/pins have been improved to work with the new asymmetrical chain, so it maintains Shimano's high quality of shifting (which is one of the best for cranks IMO) throughout the line up.


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## Dajianshan (Jul 15, 2007)

I hear you, and was just griping about the same thing. The new Shimano stuff looks too futurama for my taste. I ended up with Campy Chorus, which looks much better than I thought.


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## Hank Stamper (Sep 9, 2009)

I have a 6700 Ultegra crank on one bike and the prior version of 105 on the other and the Ultegra definitely seems better both shifting and stiffness wise.

However, the Ultegra is a compact and the 105 is standard so the shifting may be because of that difference and the stiffness difference I feel could very well be the difference in frames not cranks that I'm feeling.


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## Love Commander (Aug 20, 2009)

Dajianshan said:


> I hear you, and was just griping about the same thing. The new Shimano stuff looks too futurama for my taste. I ended up with Campy Chorus, which looks much better than I thought.


The new Shimano stuff looks like what a 13 year old kid from 1991 would imagine what bike parts from 2011 would look like.


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## Dajianshan (Jul 15, 2007)

Like a 1989 Sony stack stereo.


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## gnatman (Jan 14, 2009)

Have you considedered the R700? If you like the looks, it would be hard to find anything better shifting for the weight/$$$.


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## Peanya (Jun 12, 2008)

I wasn't a fan of the 6700 looks, but got the compact crank to replace my standard 6600. The looks quickly grew on me, and I like them. Sure, I'd prefer more chrome still, but it still looks good! 
If you still want a very nice crankset, look for a 6650. I'd say the old Ultregra shifts just as nice as the new, from my experience.


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## red elvis (Sep 9, 2010)

i decided to stick with the (5700)105 group for now since my bike already has 105 crankset and front derailleur. i bought the cassette, shifters, chain and rear derailleur. i know there will not be any significant change with the weight but we'll see.


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## MrRogers (Feb 23, 2011)

What about getting away from Shimano and going with a SRAM crank? From what I understand they're compatible. 

MrR


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## terbennett (Apr 1, 2006)

Crank schmank... Have you considered an NOS Dura Ace 7800 crankset? If you like shiny chrome, it's hard to beat that one.


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## Richard (Feb 17, 2006)

I still have to agree with Platy Pius. Shimano cranks look like an octopus that lost a fight with a lawnmower.


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## hawker12 (Oct 19, 2003)

terbennett said:


> Crank schmank... Have you considered an NOS Dura Ace 7800 crankset? If you like shiny chrome, it's hard to beat that one.


Only problem there is that I am looking for a compact...the 7800 is a standard.

I've decided to go with the Ultegra even though I really don't care for the looks. I think the R700 and the new 105 cranks look better but from what I've read the new Ultegra 6750 will probably shift a tad better with the other 10 speed DA components I have. Don't care for the space-age,octopus looks though.

Thanks guys, can't wait to get this Landshark built. Ha! Maybe the "shark" and the octopus belong together?


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## Oasisbill (Jan 15, 2011)

Older Ultegra 2008? Look like conventional cranks before the nuts were covered with futurama moon wheel covers....


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