Does Crank Length Matter? | How Short Is Too Short?

[Music] I've always favored long cranks on my bike but have I been stubbornly wrong about this five Dev sent me these incredible looking titanium cranks in a load of different sizes ask around and it appears that shorter cranks are the way forward both in terms of comfort and performance so will using these change my mind let's find out oh Ando get we try these tiny little things very bizarre [Music] this where did I get my hands on such outrageously bling cranks then well these are made by Californian component manufacturer 5 Dev these are super premium CNC machined titanium cranks fully made in house their San Diego HQ five Dev have applied what they've learned Machining titanium Aerospace and medical parts to the bike world creting titanium componentry for when you want to take your bike set up let's say the big extra mile these are nuts I mean they also look absolutely banging they're pretty cool aren't they I do think though crank size in general it's one of those aspects of a bike fit that we often kind of stick with what we know and we don't bother changing it because it can be quite a big overall to go changing your cranks on all your bikes if you do own multiple bikes um and I'm the same in that regard so I stick with 175 Ms on all the bikes I use here at gcn it's just kind of easier because it's a standard offering it's easy to get with the build that comes with your bike you don't have to put too much extra work in changing things so I stick with it but when I was racing I did opt for longer cranks I went with 177 and a half and I found it to be a really beneficial change I felt like I could accelerate better at lower speeds and I could also manage lower cadences better um which is really important in certain racing scenarios I'm also over 2 m tall so surely bigger is better when it comes to length the science is a different story however while as longer cranks allow you to increase your torque at the bottom bracket torque equals distance Time Force the actual power that you put down will depend on your Cadence longer cranks have a longer distance to complete one full pedal Revolution so Cadence will decrease the long long you go plus out on the road our bikes have gears we can use different gear ratios instead to ride at different speeds and On Any Given terrain a longer crank is essentially a lower gear ratio if you delve into the research on this conclusions are similar changing your crank length won't directly change your power but big butt Comfort is a factor and that is related to your power recently I caught up with Phil Bert who's arguably one of the sports best bike Fitters and has worked as head of physiotherapy for British cycling for over 12 years and he explained why this could be the case when I finished at Bri cycle in team Sky my main job was to make unbelievably aggressive eror positions work from so you can improve the flexibility of the person you know or you can change the parameters of the fit to allow someone to be you know incredibly low at the front the problem with c and that's partly why my old mucker in the in the xro den at British I Dr Paul Barrett one of the smartest men I've ever worked with his PhD in 2012 was based upon with uh out with Jim Martin you probably read some of the research did lots of research on crank length they were the first ones to uncoupled crank length being important an important factor in power so given that knowledge given that we had people like Bradley Wiggins chewing their kneecaps their F coming up into their chest they can't breathe because they can't descend their diaphragm when they F when they pop dead center they hit that Clos that they can't Engage The glute the biggest strongest muscle in the body so these positions were very Arrow but we were getting dead spots in the in the power production uncomfortable shifting around in the saddle therefore not being arrow in the arrow footprint the optimal a foot all these things that why we started manipulate crank and we're great things so you know in Rio we W men rode 165 and the women rode 160 you know generally that's where it was at um Bradley three weeks to four is our record heard basically this chat we're having now and when you can nice to drop that now there's a man he was riding 177 half went straight to 170 against advice I have to admit one go and he dropped 30 mil out his front end and dropped his CDA by over 3% on the track now that's a man who won the Tour of France and Olympic gold medal inour in t you wouldn't say you had a bad AOW position would you smaller cranks then part of the argument goes they allow you to ride in a more aerodynamic position what aggressive position at the front because on the up cycle of your pedal cycle your hips aren't as closed because the cranks aren't as long they're not bringing that knee and your leg as high into your body so you can ride lower at the front getting into that aerodynamic position bit more aggressive also they can help eliminate knee back and hip pain for that same reason and I think Phil summed up the reasoning behind this pretty well but if I say to you right now Conor you can jump on this one M High Gym box 100 times yeah or this 4 in Step either way I'll give you1 which one would you choose so yeah I would choose the smaller box and I think on paper in theory I'm really starting to see the logic of why shorter cranks would work for me even with my big feet my big body and my long legs but right now I've got a load of short cranks in front of me I got the open road and my bike let's see how these go in the real world let's give them a world yeah right so fitted to my bike already I've got 170 mil cranks that's 5 mil lower than my usual 175 straight away you notice the difference on your pedaling it just feels like you're PED in smaller circles I've adapted my position a bit so my saddle has had to has had to come up a bit as the cranks are shorter so I'm reaching less to the pedals First Impressions though actually pretty good I was kind of expecting as soon as I went shorter to feel like it was just it was just wrong but actually feel quite smooth of course I'm just riding super easy now I need to put these to the test and the way I've decided to try and gauge my effort with these I picked out a loop Here Local Loop we've done it plenty of times on GCM before I recently did an effort on it and I manage a time of 30 minutes and 30 seconds around 9 and 1/2 km I'm going to repeat that today see how I get on and I'm going to keep on going smaller terms of crank size that is 170 mil cranks 3 2 1 we're [Music] off I think I'm going relatively fast feels much smoother best way to describe it less movement around my hips in my lower back definitely able to hold a lower position more and be more [Music] comfortable the lungs still hurt [Applause] though really hard to tell at the moment I do just feel like I'm lacking bit leverage then once I found my rhythm I do feel like I'm going relatively [Music] well hard eff like [Music] this first run done then on the 170 mil cranks wait till the end I'm going to reveal the time got a few more runs to go before I kind of draw any conclusions for myself and one of the advantages of these cranks is they come as part of kind of threepiece setup meaning they can be run with different length axles and bottom brackets so what I said to start this video that you know changing your crank length is maybe a little bit of an overhaul of all your bikes these can actually be swapped between bikes relatively easily which is a bit of an advantage making making my life well not really my life cuz I'm not actually the one change them at the moment thanks Adam making Adam's life easier anyway I've decided to switch things up again now I'm taking bit more of a drastic change I'm going to 155 mil length really short not the sort of length that comes as standard let's see how things will feel when they go to extremes [Music] right then 155 mil cranks are fitted and are good to go they felt pretty outrageous when I first started riding on them but after a bit of tweaking little bit of riding they were they're feeling surprisingly natural actually they're doing a Max effort is a different story and there's only one way to find out how that will feel speaking of which let's do it 3 two one we're off right oh jeus bad [Music] start this is strange this feels really weird feel like I'm kind of doing like half a pedal stroke going up to halfway think I'm about a Sim of time actually maybe a t slower [Music] not suffering as much as I thought I would [Music] though it's very hard to kind of get myself up to speed but then once I'm there does feel a bit easier 2K to go [Music] pretty buckled that one was actually quite hard there's a time in the beginning and I thought it was going to be faster and I was kind of getting on top of my pace and able to settle in and it actually felt pretty cruy but I'm pretty sure I think it was slower I'm going to look at the Times all at the end not going to touch them until then I think what let me down was just that change of pace so when you hit a drag hit a bit of an incline and changing gear and getting onp top of that gear was just really hard to do cuz you're just pedaling such small little circles anyway we're not done yet because next up we're going even smaller 145 I'm slightly worried I'm about to ped the bike think we take it to too too much of an extreme but it's all a bit of fun it's all a bit of fun yeah the SE is going to go have to go even higher so that's another slight worry that kind of pushing things to above where the seat POS should be I think this is just this is going a bit too small but I'm going to ride it anyway and you're going to see what happens right then nothing else for it let the small cranks see the road three two one we're off oh where's the pedal there is look like a massive kit but it's not a massive kit it's so hard to get going I feel ridiculous I don't know why I'm not pedaling through the corners cuz the crank's never going to touch the ground I'm not sure this is something I hav be to get used to I think you would in away it's just so hard to Pedal it feels just feels like by the time your muscles are getting engaged and having to relax again [Music] this is where this is where I really struggle I just can't accelerate I'm trying as hard as I can I'm literally trying as hard as I can you just don't have that that leverage to accelerate and knock up through the gears I think we've taken it beyond the point of extremes here worth noting as well this is such a small crank so we could only fit a 34 tooth chain ring on the front I'm not undergeared cuz as you do swap to a smaller crank it's almost as if you're going to a bigger gear the way the mechanics works out I feel like I'm walking by putting my foot directly in front of the other one but like tow to heel tow to heel on a big gorilla Big Skinny gorilla on like my son's bike nearly there though 2K to go right then results time I'm pretty battered after a day of experimentation but let's go through the time so on the 170s I managed to complete the route in 14 minutes so actually only 30 seconds slower than my best recent time around here so I'm quite happy with but then things they didn't hold up okay so when I went to the 155s it's quite a bit slower 40 seconds slower than the 170s I went to 40 minutes and 40 seconds then on the 145s I was really slow 17 minutes so pretty much 3 minutes slower than the 170s I dropped off a metaphorical Cliff um so I think I show we we did take things to extremes that's obvious isn't it and I think the really small cranks for me me just didn't quite work it went past the point of being optimal way past the point of being optimal but the 170s they felt really comfy I really enjoyed riding those and I can see how that would be valuable actually to kind of take that to the rest of my riding so for me I'm willing to swap to the 170s carry on ride them see how I get on and I'll let you all know in the comment section down below how I get on with that but also let me know if you've ever tried experimenting with your crank size big thanks to five of course for allowing us to go go mad on this part of our bike fit of my bike fit it's been really interesting actually and I'll be interested to hear your thoughts as well so let me know what you think if you found this video useful please give it a big thumbs up and we'll see you on the next one time to get these back on my bike they they look pretty cool as well oh yeah Cru into the cafe in style

Channel: Global Cycling Network

Views: 108,909

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Id: k4zcAUv9sfo

Length: 15min 52sec (952 seconds)

Published: Fri Jun 14 2024