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Discussion Starter · #1 ·
Anyone know the weight of the Surly Mr Whirly crankset components? I finally ordered a 180mm 2x9 set up with Middleburn 20 and 30 tooth rings, and am curious of the weight.
I understand the Middleburns are lighter, and I wonder if going with the Surly's for the external bottom bracket bearings are worth the weight penalty over the Middleburn isis setup.
 

· Witty McWitterson
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The Surly's are certainly on the stout end of things. Very stiff, but they won't win any wieght wienie contests. If you want to save wieght, stay with the middleburn's.

//I love my Mr. Whirly's though.
 

· Always Learning
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TONYACCURSO said:
Anyone know the weight of the Surly Mr Whirly crankset components? I finally ordered a 180mm 2x9 set up with Middleburn 20 and 30 tooth rings, and am curious of the weight.
I understand the Middleburns are lighter, and I wonder if going with the Surly's for the external bottom bracket bearings are worth the weight penalty over the Middleburn isis setup.
You can run your weights for the Middleburn set here using the pull down menu to get a pretty good close approximation:

http://www.middleburn.co.uk/tech_crankweights.php
 

· Jam Econo
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TONYACCURSO said:
Thanks for the info. I think my XT cranks weigh around 760, so the difference isnt too terrible.

CB2, does that include chainrings, and if so , how many?.
That includes a 33t stainless steel ring.

My XT Hollowtech II's w/ bashguard and 32t ring complete w/ bb cups weigh 870 grams, so essentially they weigh the same. With 32t alloy ring they actually do weigh the same.
 

· Recovering couch patato
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Crank weight is SO utterly insignificant when you though changing crank lengths in the mix.
All your power is transmitted by cranks. The way and amount they flex effects end speed more that multiple kgs of crank weight ever could.
 

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Discussion Starter · #10 ·
The Surly cranks are compatible with Shimano and Race Face bottom bracket cups, according to the web site.

Compact spiders are on backorder. Looks like I will have to hunt them down...
 

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Cloxxki said:
Crank weight is SO utterly insignificant when you though changing crank lengths in the mix.
All your power is transmitted by cranks. The way and amount they flex effects end speed more that multiple kgs of crank weight ever could.
Sorry, but that's simply not correct.

If your cranks/rings are flexing badly enough that you throw your chain, yes, that's bad. But the energy lost through crankarm flex (tenths of a watt) is so minimal that it's not even worth thinking about.
 

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Cloxxki said:
Crank weight is SO utterly insignificant when you though changing crank lengths in the mix.
All your power is transmitted by cranks. The way and amount they flex effects end speed more that multiple kgs of crank weight ever could.
Your posts are silly. Just stop.
 

· Recovering couch patato
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duke of kent said:
Sorry, but that's simply not correct.

If your cranks/rings are flexing badly enough that you throw your chain, yes, that's bad. But the energy lost through crankarm flex (tenths of a watt) is so minimal that it's not even worth thinking about.
A factor, whether you like it or not, is the way the arms flex, and in which way they come back into their original position. Shoudl cranks deform a lot, sucking up part of your effort, and take half a rotation to bounce back, that's bad.

But most important of course it to get the right crank length, and to get used to riding with it. Most riders are NOT using their ideal cranklength. S riders all used too long ones (when turning the world standard of 175mm), XL riders are always cutting themselves short. In THAT resect, crank weight is pretty much irrelevant. How would I climb with 500g 170mm cranks versus 3000g 200mm ones? If the 200's fit me better, the weight is of secundary importance.

That all said, I will probably not complete my Superfly build until I've found some lightweight custom length cranks for it. High Sierra's are just so cumbersome, impossible to get a normal BB long enough for those.
 

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Cloxxki said:
A factor, whether you like it or not, is the way the arms flex, and in which way they come back into their original position. Shoudl cranks deform a lot, sucking up part of your effort, and take half a rotation to bounce back, that's bad.

But most important of course it to get the right crank length, and to get used to riding with it. Most riders are NOT using their ideal cranklength. S riders all used too long ones (when turning the world standard of 175mm), XL riders are always cutting themselves short. In THAT resect, crank weight is pretty much irrelevant. How would I climb with 500g 170mm cranks versus 3000g 200mm ones? If the 200's fit me better, the weight is of secundary importance.

That all said, I will probably not complete my Superfly build until I've found some lightweight custom length cranks for it. High Sierra's are just so cumbersome, impossible to get a normal BB long enough for those.
Modern aluminum crankarms are deflecting millimeters at most. And if this flex was significant, there would be either a) lots of broken crankarms out there or b) lots of heat being lost due to this flex.

That said, I agree with you on your second point. Getting fit to the proper crank length is very important. I'm currently trying to decide what my next set of cranks will be, and don't want to buy Middleburn RS8s because they only come in 175mm, which is too long for someone of my femur length.

Have you measured your Superfly frame to determine just how long of a crankset you can get away with? It would be a shame to order some 200mm custom cranks and not be able to use them because they come in contact with your chainstays.
 

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A great leap sideways

Irrespective of weight, unless you're hucking, or jumping stuff, and are really hard on crank spindles, the Middleburns are the better choice. This is a total "No Brainer" to me:
In relation to the "Mr Whirlys, the Middleburn's will offer a better chainline: all the outboard bearing design triples have dismal chain lines compared to square taper and Isis BB's. Important? Just wait for that first big, long, muddy ride......hello chain suck.
Then there's the weather sealing issue: the outboard BB's don't have a great track record @ this either. Add drag from the larger seals and this is only partially addressed with ceramic bearing on the outboard designs, in relation to the Sq. tapers/Isis BB's.
Now, the BB30 designs, etc.are trying to address the Q-factor issues of the outboards by modifying the existing BB dimensions, to solve a problem that doesn't really exist in great measure previously.
Basically, as much as I'd like all the latest iterations of BB/crank design, they're all a great leap sideways at best compared to the nearly completely forgotten Sq. tapers.
I could go on, but, I've got things to do. Short answer - get the Middleburns.
 

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Quote But most important of course it to get the right crank length, and to get used to riding with it. Most riders are NOT using their ideal cranklength. "

There is simply no, or very little science to support that.
With Sosonka (sp?) caught for doping, his world hour record on 190 mm's is placed in a different light too.
I am close to 6'5" and have road and mountain 175's and 180's. I prefer the 175's. If there was an advantage I would feel it, do I?
I too doubt that crank stiffness will make a big difference. With all the SRM's and powertaps in use nowdays, any significant findings should be common knowledge by now. I ride a cheap- light carbon road crank on the MTB, and don't feel I would be faster on a stiffer setup.
 
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