Crank length
 

[Closed] Crank length

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Inadvertently got some 170mm cranks instead of usual 175mm

Will I notice difference?

Thanks

 
Posted : 03/02/2017 7:54 am
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See Sheldon Brown.

 
Posted : 03/02/2017 7:59 am
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Unlikely.
They may be better than 175 for the knees.
Do a search on here, there is loads of info.

Edit,
Forgot to ask, if they are a different colour, this may be an issue

 
Posted : 03/02/2017 7:59 am
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I suspect you won't notice any difference. I can't.

 
Posted : 03/02/2017 7:59 am
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I've not noticed any difference, just slightly less pedal strikes, I'll probably go 165 next time...

 
Posted : 03/02/2017 8:18 am
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Most folk either find it better or don't notice. I'm not sure I've even seen comment from someone who said 175 to 170 was worse.

 
Posted : 03/02/2017 9:19 am
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I got some 155mm cranks once (deliberately). That was a bad plan. 🙂

 
Posted : 03/02/2017 9:21 am
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For some, 2.5mmm can be life changing.

I don't notice 5mm.

 
Posted : 03/02/2017 9:25 am
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it's not a massive difference.

my 38yo knees prefer 165's to 175's, and i've got really long legs.

 
Posted : 03/02/2017 9:30 am
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I'm one of the ones that can notice a 2.5mm difference, but only on a road bike, and because I've got finicky knees.

 
Posted : 03/02/2017 9:33 am
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In 1995 Marco Pantani went from 170mm to 172.5mm in search of more power, but, instead he regained his old pelvic problems.

 
Posted : 03/02/2017 9:35 am
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When I go from 165 to 170 I don't notice anything but if I then ride 170 for a while I do notice going back to 165 for the first 5 minutes or so. Off road 175 are ok but not if it's riding where I'm in the saddle all the time. Out of choice I think I'd go with 165 on everything.

 
Posted : 03/02/2017 9:54 am
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Don't forget to take a tape measure to the garage and rise your saddle by 5mm, unless you end up exposing the safe limit marker. 😉

As someone with short legs (I typically buy 30" inside legs trousers) and a long torso for ~5'10", I do wonder if really I should be using shorter cranks on my bikes.

The Wazoo, like many fatbikes, comes with 175mm cranks. I'm sure encourages me to push the limits on raising the saddle height so as to try and get my knees relatively lower compared to my hips at the top of the stroke, to reduce pressure on my knees.

Even on previous bikes that had 172.5mm cranks, I've always been a "spinner" rather than a "grinder" as regards gear selection, to try and protect my knees.

 
Posted : 03/02/2017 9:57 am
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I think i prefer 170, but can't really notice that much differnece. I really really notice changes to q factor though.

 
Posted : 03/02/2017 10:00 am
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I'm convinced I can feel the sorter cranks on my CX bike, sufficiently that it first made me check (I didn't know when I bought the bike they were 170's) and this morning, I placed an order for a new crankset - anyone want a 200 mile old 170mm race face cx crankset?

 
Posted : 03/02/2017 10:02 am
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There are lots of opinions on crank length, and only you will know the answer to your question.

Geoff Apps says
https://crosscountrycycle.wordpress.com/2014/11/13/crank-length/

Chris Boardman says
“I don’t think anybody’s really messed around with crank length yet because we’re constrained by history. I’d like to see a lot of people using 150mm cranks. All of the physiology data I’ve ever seen says that for an endurance athlete crank length actually doesn’t make any difference. But shorter cranks mean you’re more aerodynamic – if you’re trying to get into a tuck you can get lower because your knees aren’t coming up. So shorter cranks could produce a really big net gain but it’s a fashion thing.”
https://roadcyclinguk.com/gear/chris-boardmans-seven-tech-trends-2016.html

Phil Burt says
There is no “correct” crank length, as there is no appreciable difference in power output between 150 – 180mm cranks
http://velocitysportscycling.com/cycling-myth-busting-from-team-sky/
https://books.google.co.uk/books?id=VB_kAwAAQBAJ&pg=PA176&lpg=PA176&dq=phil+burt+crank+length&source=bl&ots=Q2XvCwwzt-&sig=j0Vd4xRD_E5z7Ua8Nr9bTQcNi1s&hl=en&sa=X&ved=0ahUKEwjxidHK5vPRAhXrC8AKHZRwCToQ6AEIQzAG#v=onepage&q=phil%20burt%20crank%20length&f=false

GCN say
https://www.youtube.com/watch?v=eMAxH_Ud8YE

https://www.youtube.com/watch?v=vUygkHlcVMQ

and
http://www.recumbents.com/wisil/MartinDocs/Determinants%20of%20Maximal%20Cycling%20Power.pdf

https://www.ncbi.nlm.nih.gov/pubmed/11417428

http://www.bhpc.org.uk/short-and-sweet-a-discussion-on-crank-length-by-mike-burrows.aspx

 
Posted : 03/02/2017 11:25 am
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road and mtb are either 172.5 or 175 and I don't notice any difference.

Track bike is 165 and I do feel them noticeably different

 
Posted : 03/02/2017 11:39 am
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I'd never thought too much about it until I had a set of Race Face CX cranks fitted to my commuting hybrid. Everything had been 175mm until then, except for some 180mm BMX back-in-day. The first 10 minutes on 170mm felt different. The next day didn't notice.

It's only when I ride my MTB and hybrid back to back that I notice. Then there's so much going on with body position, components, big squashy tyres, and lack of gears on my MTB that it's soon forgotten.

I had a try of a mates SS with 185mm cranks on. It felt like I was pedalling in slow motion. Easier for grinding up hills though.

 
Posted : 03/02/2017 12:01 pm
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If you don't notice the difference, try putting different lengths in each side.

 
Posted : 03/02/2017 12:52 pm