Biggest problem with shorter cranks is climbing. On hills you will notice that yes you need the more rpms and faster cadence but on hills that means shifting down a gear or two to allow you to have that cadence while climbing… but this effectively takes away two gears from your lower range which means the % grades you can tackle goes down. And this is really noticeable too. So a bike set up with 172.5 cranks and an 11-34 cassette can effectively go up steeper hills than the same bike equipped with 165 cranks and the same cassette…. I love shorter cranks for racing triathelon and flat stuff but for mountain road racing and for anything steeper the shorter cranks just don’t work…. Unless you run a mountain bike rear mech and a 42 cassette….the effect is even noticeable on hills with just 8% and the steeper you go the more pronounced
This is true, but the effect is only equivalent to 1 or 2 teeth on the cassette (depending how much you shorten the cranks). I run a 52/36 with an 11-30 cassette. When I changed to 167.5 (from 170) I felt no difference in climbing severe grades. If (and when) I go to 165, the steepest hills here in Mallorca (short 12-13%) may be slightly tougher, but I'm sure I will manage. If you are a rider that is already on the limit climbing with a 50/34 and 11-34 cassette, then yes, changing from 172.5 to 165 may cause an issue.
@ yea that happened to me on my tri bike (Cervelo P5) when I jumped to 160 cranks. I love them but climbing was way harder it felt like I lost a total of two complete gears from the bottom range and even on 6/7% grades it was very noticeable. I think this affect is exponential and not linear in terms of how %grade and the X amount of shorter mm cranks together creat an exponential affect. For example I think the jump you have made is not too bad but at 160 you will note it 10X going from 165 to 160 Vs 175 to 170 even though both represent 5 mm changes if that makes sense and the exponentiality of the change is even more pronounced the steeper you go. I’m coming over from Ironman racing to road biking and have a new s works sl8 being built and I’m having to learn a lot so thanks for the help
@@thepatternforms859 interesting - I'm not sure if it's exponential or not to be honest. but in any case, exponentials vary considerably.....my feeling is that's it's linear, or very close to, but not sure how to prove that...! Depends a lot on the riding you do - mountains or flats and how much wiggle room you have with your current gears. I would think that a drop from 170 to 165 is easily compensated for by reducing small ring to 34, or getting a 34-11 cassette.
Downsides: higher center of gravity from the saddle height increase (though tbf could theoretically be fine with lower bb), which at 188cm and going from 175mm to 165mm I really noticed. And for the same bar drop you would need to add spacers. Also, MA decreases so you need a larger cassette to get the same low gearing
Good points. For me, it's just 2.5mm we're talking about so any differences are small. Extra saddle to bar drop is a good thing to have aerowise. True, re. the MA, but I didn't notice any difference with my 2.5mm, and my lowest gear is still low enough.
By opening up the hip angles you're able to rotate the hips forward to flatten your back. By going shorter I found that my bar setup needed to go lower, not higher, which is very counterintuitive. The aero benefits are huge and one of the most underrated benefits of going shorter.
You nailed it! That's also been my experience. It's easier to push on the pedals with shorter cranks. I'm 170cm tall with a 80cm inseam. I'm running 155s (down from 170).
being 188cm tall (6'2." roughly) I started with 177.5 cranks and reduced to 175 over time, but honestly wouldn't go smaller than this already. My inseam is just very slightly north of mean measurement for my height.
Hey! What about comparacing with Ostro V1? I have one and I love it. But found it a little bit heavy for climbing. Now I think about buying the new O2 VAM to have 2 bikes. Then I found you videos about SL8 and think that probably I should just switch from Ostro to this "one bike to rule them all". What do you think? What do you like most against ostro? Do you feel the huge gap between them?
Honestly, no. Imagineyou wanted to spin your back wheel on a wet slope. Not enough torque? Change up a gear (easier) on the cassette. Now you can spin. Just to show how you can increase your torque in a number of ways, your cassette being one of them. Also, with shorter cranks, the portion of the revolution where you can apply high torque increases, because the pedal is less far away from your centre.
I recently changed my cranks from the original 172.5mm to the cybrei 165mm. I’m 5’10 (178cm) with relative shorter legs. I haven’t have the chance to try it in mountains roads, just fast group rides in flats roads. They perform superb. My only negative I found so far is that is harder to do short burst of acceleration, when the group do a change of rythm or someone attacks and you want to answer that attack. That’s why I suspect that it could be a problem in the steepers ramps and I can’t make my mind yet
@@martinabadesame height as you with 81cm inseam. I went to 165mm cranks, it felt ok but lost that surging top end needed for fast bunch rides. Went back to 172.5 and felt great again. Maybe 170mm is the sweet spot
Biggest problem with shorter cranks is climbing. On hills you will notice that yes you need the more rpms and faster cadence but on hills that means shifting down a gear or two to allow you to have that cadence while climbing… but this effectively takes away two gears from your lower range which means the % grades you can tackle goes down. And this is really noticeable too. So a bike set up with 172.5 cranks and an 11-34 cassette can effectively go up steeper hills than the same bike equipped with 165 cranks and the same cassette…. I love shorter cranks for racing triathelon and flat stuff but for mountain road racing and for anything steeper the shorter cranks just don’t work…. Unless you run a mountain bike rear mech and a 42 cassette….the effect is even noticeable on hills with just 8% and the steeper you go the more pronounced
This is true, but the effect is only equivalent to 1 or 2 teeth on the cassette (depending how much you shorten the cranks). I run a 52/36 with an 11-30 cassette. When I changed to 167.5 (from 170) I felt no difference in climbing severe grades. If (and when) I go to 165, the steepest hills here in Mallorca (short 12-13%) may be slightly tougher, but I'm sure I will manage.
If you are a rider that is already on the limit climbing with a 50/34 and 11-34 cassette, then yes, changing from 172.5 to 165 may cause an issue.
@ yea that happened to me on my tri bike (Cervelo P5) when I jumped to 160 cranks. I love them but climbing was way harder it felt like I lost a total of two complete gears from the bottom range and even on 6/7% grades it was very noticeable. I think this affect is exponential and not linear in terms of how %grade and the X amount of shorter mm cranks together creat an exponential affect. For example I think the jump you have made is not too bad but at 160 you will note it 10X going from 165 to 160 Vs 175 to 170 even though both represent 5 mm changes if that makes sense and the exponentiality of the change is even more pronounced the steeper you go. I’m coming over from Ironman racing to road biking and have a new s works sl8 being built and I’m having to learn a lot so thanks for the help
@@thepatternforms859 interesting - I'm not sure if it's exponential or not to be honest. but in any case, exponentials vary considerably.....my feeling is that's it's linear, or very close to, but not sure how to prove that...!
Depends a lot on the riding you do - mountains or flats and how much wiggle room you have with your current gears.
I would think that a drop from 170 to 165 is easily compensated for by reducing small ring to 34, or getting a 34-11 cassette.
Downsides: higher center of gravity from the saddle height increase (though tbf could theoretically be fine with lower bb), which at 188cm and going from 175mm to 165mm I really noticed. And for the same bar drop you would need to add spacers. Also, MA decreases so you need a larger cassette to get the same low gearing
Good points. For me, it's just 2.5mm we're talking about so any differences are small. Extra saddle to bar drop is a good thing to have aerowise. True, re. the MA, but I didn't notice any difference with my 2.5mm, and my lowest gear is still low enough.
By opening up the hip angles you're able to rotate the hips forward to flatten your back. By going shorter I found that my bar setup needed to go lower, not higher, which is very counterintuitive. The aero benefits are huge and one of the most underrated benefits of going shorter.
You nailed it! That's also been my experience. It's easier to push on the pedals with shorter cranks. I'm 170cm tall with a 80cm inseam. I'm running 155s (down from 170).
A little bit late, but I was wondering where you got the 155s?
being 188cm tall (6'2." roughly) I started with 177.5 cranks and reduced to 175 over time, but honestly wouldn't go smaller than this already. My inseam is just very slightly north of mean measurement for my height.
Hey! What about comparacing with Ostro V1? I have one and I love it. But found it a little bit heavy for climbing. Now I think about buying the new O2 VAM to have 2 bikes. Then I found you videos about SL8 and think that probably I should just switch from Ostro to this "one bike to rule them all". What do you think? What do you like most against ostro? Do you feel the huge gap between them?
The V1 is a great bike, but the SL8 is just a touch better in all departments except aero. But yes, the SL8 is the almost perfect do it all bike.
I definitely see your point and I agree. With shorter cranks you make more revolutions per minute which in turn increases your power output.
It's easier to spin fast (or faster), yes, which is necessary to compensate for the loss of torque (assuming your leg force stays the same).
don't you feel you lost some torque in steep ramps? also made it harder to pedal off the saddle?
Honestly, no. Imagineyou wanted to spin your back wheel on a wet slope. Not enough torque? Change up a gear (easier) on the cassette. Now you can spin. Just to show how you can increase your torque in a number of ways, your cassette being one of them.
Also, with shorter cranks, the portion of the revolution where you can apply high torque increases, because the pedal is less far away from your centre.
I recently changed my cranks from the original 172.5mm to the cybrei 165mm. I’m 5’10 (178cm) with relative shorter legs.
I haven’t have the chance to try it in mountains roads, just fast group rides in flats roads. They perform superb. My only negative I found so far is that is harder to do short burst of acceleration, when the group do a change of rythm or someone attacks and you want to answer that attack.
That’s why I suspect that it could be a problem in the steepers ramps and I can’t make my mind yet
@@martinabadeany update?
@@martinabade so You test 165 on steep climbs?
@@martinabadesame height as you with 81cm inseam.
I went to 165mm cranks, it felt ok but lost that surging top end needed for fast bunch rides. Went back to 172.5 and felt great again.
Maybe 170mm is the sweet spot