Changing crank length
I want change my crank length. I have a 2014 Boardman CX team With an FSA Gossamer Compact PF30 (BB30) chain-set. What are my options? Do I need to change the whole crank AND cogs? What questions should I be asking?
Later, I might want to fit power meter cranks ( I don't think that there is a pedal option for MTB clips). Obviously if there is a power meter left/right set that does the same job, it would be worth considering. There's no point in changing a crank just to change it again later. What questions should I be asking?
Later, I might want to fit power meter cranks ( I don't think that there is a pedal option for MTB clips). Obviously if there is a power meter left/right set that does the same job, it would be worth considering. There's no point in changing a crank just to change it again later. What questions should I be asking?
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Buy new crank arms and put your old chainrings from your Gossamer onto them (assuming they're still in good nick). FSA chainrings fit Shimano, Sram cranks etc as long as the BCD is the same. i.e. 110 or 130 and they have the same number of chainring bolts.0
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That narrows it down. Thanks .. its a 5 bolt 110bcd.0
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Main question you should ask is why are you changing the crank length. From what to what ?0
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Naturally, Whenever someone posts a technical question, Someone will always say "don't do it" or "why bother". The answers are:
from 175 to 165mm
Because at my height and build I believe it will suit me better. There is some data to suggest that even shorter would be even better, but I'm not going to extremes.0 -
Suit you in what way? What is your height? If you do make such a change you will have to adjust your saddle as well.0
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Sutton Rider wrote:If you do make such a change you will have to adjust your saddle as well.
Nooooooooooo ! Not adjust the saddle ... don't do it mate, it's not worth the effort. If you don't have a qr saddle you are going to have to break the Allen Key out.
Seriously why do you think mtb'rs spend hundreds on dropper posts
You might be better off buying a new bike with shorter cranks and the saddle already adjusted.
Mind you I had a bike fit once ... they charged me £300 to alter the saddle so that's a cheaper option than a new bike
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pbassred wrote:( I don't think that there is a pedal option for MTB clips).
What do you mean by this? It reads as if you don't think you can get a power meter that can take MTB pedals (which, of course, you can). But I've probably misunderstood you.ROAD < Scott Foil HMX Di2, Volagi Liscio Di2, Jamis Renegade Elite Di2, Cube Reaction Race > ROUGH0 -
I think he means a pedal based system like Garmin Vector rather than a crank to which you can mount a standard threaded pedal0
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Man Of Lard wrote:I think he means a pedal based system like Garmin Vector rather than a crank to which you can mount a standard threaded pedal
Ah - that makes sense....ROAD < Scott Foil HMX Di2, Volagi Liscio Di2, Jamis Renegade Elite Di2, Cube Reaction Race > ROUGH0 -
Actually I'm quite flush right now so maybe I could buy a couple of bikes with different length cranks and see what works best. Possibly a couple more for stem lengths.
Obviously as a time-served Toolmaker with 30 years experience in manufacturing I might struggle with an allen key so I need to leave that to the spotty first jobber at halfords.
I did apply a decal once...
Spot on, Snr LardI think he means a pedal based system like Garmin Vector rather than a crank to which you can mount a standard threaded pedal
Anyway. none of this is helping, so I'll pop down to my LBS. Wiggle didn't respond (to the same question) either. Have a pleasant day every one. Peace.
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pbassred wrote:Naturally, Whenever someone posts a technical question, Someone will always say "don't do it" or "why bother". The answers are:
from 175 to 165mm
Because at my height and build I believe it will suit me better. There is some data to suggest that even shorter would be even better, but I'm not going to extremes.
What is your height/inseam and why do you think it'll suit you better?0 -
A few years back everyone was trying longer cranks - 177.5mm0
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pbassred wrote:Naturally, Whenever someone posts a technical question, Someone will always say "don't do it" or "why bother". The answers are:
from 175 to 165mm
Because at my height and build I believe it will suit me better. There is some data to suggest that even shorter would be even better, but I'm not going to extremes.
I use 165mm crank arms and find it makes for a much more comfortable ride using a higher cadence easier. Smaller turning circle = shorter distance to complete. Raising the seat post is required to allow for the reduced height at the bottom of the pedal stroke, but I hardly see it as a chore like some are making out. The increased seat height will also give you increased clearance at the top of the pedal stroke to enable you to get on the power stroke easier.
To be honest, the subject has been done to death on these web pages and the nay sayers will continue to pooh pooh the very notion of it having any benefit. Only you can be the judge of that. It works for me, so could work for you.I ride a bike. Doesn't make me green or a tree hugger. I drive a car too.0 -
Chris Boardman is reported as saying
“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-bo ... i4cFvUQ.970 -
rpaton wrote:Chris Boardman is reported as saying
“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-bo ... i4cFvUQ.97
Short crank arms are also a physical thing. If you like a high cadence, the shorter crank arm makes it easier to do with a lesser circumference length. The increased seat height also creates more room at the top of the pedal stroke.I ride a bike. Doesn't make me green or a tree hugger. I drive a car too.0 -
This might explain a bit more about crank length options
https://www.youtube.com/watch?v=vUygkHlcVMQ0 -
I'm a big supporter of shorter cranks; the list of advantages is long, and disadvantages very short.
Many videos on Youtube about this (including our own!) so won't go into details here, but suffice to say I'm looking for a (very hard to find) set of Sworks cranks in 165 or 167.5 (from my current 170's). I'm 5'7", or 1.74m0 -
bernithebiker wrote:I'm a big supporter of shorter cranks; the list of advantages is long, and disadvantages very short.
Many videos on Youtube about this (including our own!) so won't go into details here, but suffice to say I'm looking for a (very hard to find) set of Sworks cranks in 165 or 167.5 (from my current 170's). I'm 5'7", or 1.74m
5.7 is 170 cm - stop kidding yourself ;-)0 -
thegreatdivide wrote:bernithebiker wrote:I'm a big supporter of shorter cranks; the list of advantages is long, and disadvantages very short.
Many videos on Youtube about this (including our own!) so won't go into details here, but suffice to say I'm looking for a (very hard to find) set of Sworks cranks in 165 or 167.5 (from my current 170's). I'm 5'7", or 1.74m
5.7 is 170 cm - stop kidding yourself ;-)
1.74m sounds better than 5'7" !!
Anyway, on a good day, I'm 1.75m!0 -
bernithebiker wrote:
1.74m sounds better than 5'7" !!
Anyway, on a good day, I'm 1.75m!
It sounds better for a reason: 1.74m is 5'8½" 1.70m is 5'7" - which are you? - you can't be both...0 -
Man Of Lard wrote:bernithebiker wrote:
1.74m sounds better than 5'7" !!
Anyway, on a good day, I'm 1.75m!
It sounds better for a reason: 1.74m is 5'8½" 1.70m is 5'7" - which are you? - you can't be both...
Ah, silly me, I converted 1.74m and got 5.70 feet, which I didn't look at too closely and assumed 5'7" which it's not.
So it's the 1.74m that's right!0
