Shorter Cranks: Higher FTP!

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A Free FTP Boost! Surely the Holy Grail of cycling performance hacks?
I'm 192 cm tall (6 foot 4 inches) and have swapped out my 175 mm cranks for 160 mm cranks. Sounds CRAZY right?
Well I've already found that this has helped my hip pain, reduced my heart rate on sub FTP effort rides, INCREASED my power output on uphill max power tests and now I'm checking out whether 15mm smaller cranks will also help to increase my Functional Threshold Power.
The more I explore the benefits of going to shorter cranks, the more I wonder why it is not more prevalent amongst professionals and amateurs alike. So far I really haven't seen any downside.
Contents
0:00 Intro
1:14 Shorter Cranks Win
1:21 Today's FTP Test
2:29 Test Protocol
3:15 HTFU
4:03 Disappointing
4:50 FTP Evaluation
5:48 6 BPM Heart Rate Differential
6:07 10 Watts Benefit?
7:12 The Ultimate FTP Comparison
7:50 Would You Change For 10 Free Watts?
My Previous Videos On The Benefits Of Shorter Cranks!
• Why You Need Shorter C... (Why You Need Shorter Cranks)
• How much will 15 mm sh... (Bike Fit And Biomechanics of Shorter Cranks)
• Does riding with short... (Shorter Cranks Lower Heart Rate)
• Want More Power? Crank... (Shorter Cranks More Power)

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Опубликовано:

15 июл 2024

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Комментарии : 56

@pukkagoblin 5 месяцев назад

Good luck mate. Keen to see results. Got some 165mm’s sitting in my basket, similar curiosity. Can relate with the 4dp test!

@podiumphysio657 5 месяцев назад

Thank you! So of course I've come down with man flu now and will need to put that testing back a few days so I dont die...

@ilovephotography1254 4 месяца назад

The bike industry is all about geometry. Bar widths, stem lengths, head and seat angles, top tube and chain stay lengths and wheel sizes. Frame are sold in from extra small to extra large. Some manufactures might have a few mm difference, some might not. I say to the bike industry it's time to pay attention to crank sizes. My inseam is 28inches. My bike came equipped with 170mm crank arms. I switched to 155mm. Immediately I noticed a more natural pedal motion. There are shorter cranks on the market, but for now I'll stick with these.

@podiumphysio657 4 месяца назад

i think in summary the issue is that the bike industry is all about component uniformity. And this is understandable to a degree to try to manage costs which are spiralling. I've just ordered a new XXL bike, and it comes standard with 175mm crankS. I've had to order a separate SRAM 160 mm crank set for an extra $250,, and will be left with the original 175s that are of no use to me at present. Bit of a waste really. It would be lovely if the person with the credit card could have some input into how the bike is specced straight from the factory or distributor.

@ilovephotography1254 4 месяца назад

Some bikes manufactures offer bikes without pedals. Why not sell bikes without crank arms and do this at a reduced price. It would have be nice if you could have purchased you 160mm at half of what you paid. If one company does this and it's successful, other will follow. Extra short and extra tall ridders would benefit and less crank arms being used as paperweights.@@podiumphysio657

@ronfeldman4386 4 месяца назад

What I do trhe 4DP test every 12 weeks. Going from 175mm cranks to 160mm cranks is extreme. There are so many variables for each cyclist. Muscular endurance is a huge variable, If your quads, hamstrings and glutes can't produce high amounts of power, Then your rpm/cadence might make up for your shortcomings. That's when shorter cranks will help. If you are a power monster, 175mm cranks will allow you to spin at 100 to 150 cadence with a much higher power output.

@podiumphysio657 4 месяца назад

Hey Ron. First and foremost I have dropped down to 160mm cranks to look after my hips. I have very poor hip flexibility due to osteoarthritis so shorter cranks allow me to keep a more open hip angle at top dead centre. Also, I produce more power at slower cadences, which is why I am a strong climber out of the saddle but only an average sprinter/ flat lander. I cant image ever spinning at 150 RPM! You might see from watching some of the other videos I did in this "Shorter Cranks" series that my slow cadence/ out of saddle climbing power is up over 1200w, but on the flat with a faster cadence I struggle to get into the 900w range.

@SIvers-or2ke 5 месяцев назад

Mate. I totally agree with you on the effects of Covid on our abilities. I noticed the same thing. So you’re not alone. Thanks for another great video. Appreciate you doing these. Would you be better served by doing the 4D test on the same day in two weeks ? ie : a Monday, then same test after a weekend on the next Monday. To eliminate any variables that may present themselves by doing it in the same week. Just a thought

@podiumphysio657 5 месяцев назад

Yeah COVID itself, for the week I felt affected wasn't so bad at the time, but I definitely feel like I've had the top 5% shaved off my performances since then.

@GoustiFruit 5 месяцев назад

Covid, or vaXX ? I didn't get the second, I probably got the first at least twice : each time, one day feeling very bad. The next day I was OK. The next week I was training as usual.

@podiumphysio657 5 месяцев назад

@@GoustiFruit I generally had no problem with the Vaxx in the short term, but COVID was almost as bad as influenza for me. # very uncomfortable days and probably 2 weeks to get back to feeling maybe 90%

@GoustiFruit 5 месяцев назад

@@podiumphysio657Did you get it AFTER the vaXX ?

@podiumphysio657 5 месяцев назад

@@GoustiFruit Yes I think it was after 2nd Vaxx

@swites 26 дней назад

Super interesting. I have an inseam of around 88.5cm which is quite long, so have run 175mm cranks ever since 2010. But at 6ft4 your inseam would be substantially longer than mine so I probably should try 170mm cranks at least and compare! I do have a bit of trouble in aero position etc.

@podiumphysio657 25 дней назад

This is one case in life when less is more !

@GoustiFruit 5 месяцев назад

Well, changing my cranks "could" give me 10W more, but it *will* take me at least extra $300. I would need to change my powermeter. But I've been thinking about it.

@podiumphysio657 5 месяцев назад

I know a lot of riders that would pay $300 for 10 free watts😅

@igvabe 5 месяцев назад

I have 2 TT bikes, both with 165mm cranks and a racebike with 170mm cranks. I definitely feel a difference in comfort, especially in the low TT position, but don't feel any difference in power output. From a pure mechanical/physics point of view, it shouldn't matter much so I'm thinking it's more bio-mechanical related: Is it possible that the power/ftp differences you record are caused by your hip arthritis- which would 'block' you when using the longer cranks?

@podiumphysio657 5 месяцев назад

Look it is possible that there is some "inhibition" of my output with longer cranks, however I would doubt it as that is what I have used for 10 years so I would suggest my body has adapted as best it can to that length. I really think the performace boost is due to all the factors discussed in the first video. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE--3sCebN63rI.html

@WillPower46 5 месяцев назад

I wonder how much natural cadence ability plays a factor. For example we know that power is torque x RPM. So if the shorter cranks enables you to ride at your natural cadence of say 95 (as I saw yours was around that number) then shorter cranks are of benefit in power production. Still for someone like myself whose natural cadence is around 75-80, I feel more comfortable bushing a bigger gear at a lower cadence, then perhaps the extra torque that I can produce with the longer lever say 175's, would allow me to produce more power than I otherwise could at a higher cadence with shorter cranks and a smaller gear?

@podiumphysio657 5 месяцев назад

Hey. So there is a broader discussion about HOW the shorter cranks are beneficial in an earlier video I did (ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE--3sCebN63rI.html) . Really the concept is predicated on self selecting gearing and cadence. I actually dont normally regard myself as a spinner on training rides with my buddies, however if I am working at a high power output, particularly indoors, i tend to lift my cadence quite a bit because it just feels more sustainable that way. If you prefer a slower cadence, you might actually be better off with shorter cranks because at any given RPM, the foot would move slower around a smaller circle (160s), than it would around a larger circle (175)s, as Jim Martin says in that video. I've done 4 different types of performance testing with these shorter cranks so far (see my Shorter Cranks playlist) and every time my results have been superior. I've also done some max power 5 s sprints on my trainer in ergo mode which is not yet ready to publish, which show about a 8-10% power improvement with shorter cranks. Have not found any downside yet...

@bobbrian6526 5 месяцев назад

interesting, im wondering if shorter cranks means less reliance on hamstring muscles. Also, you could try setting the power at around 360w on erg mode and seeing how long you can hand on, from your numbers Id guess it would be around 10 mins

@podiumphysio657 5 месяцев назад

Theoretically with shorter cranks, and the seat moved up, there would be reduced knee bend so the hamstrings would be at a relative mechanical disadvantage. So perhaps this could place more emphasis on the glutes? Interesting idea... I've done many training session in the past where I've set the erg mode to 400 and hold on for dear life (but only with 175mm cranks as part of my normal training). There are any number of combinations and permutations of tests that could be tried here. I'm working first on the ones I think the majority of people would find most interesting. I must admit though I am absolutely fascinated by the power increase I had with my uphill climb on the 160s. It was more than a 10% improvement!

@bobbrian6526 5 месяцев назад

@@podiumphysio657 tat hill climb was interesting for sure. You only need three or four time/power data points to get a pretty accurate power curve, so you are most of the way there with what you have done so far. Thinking of some shorter cranks myself now

@podiumphysio657 5 месяцев назад

@@bobbrian6526 Awesome! I'l have a few more videos coming out on the Shorter Cranks theme over the next few months...

@starlitshadows 5 месяцев назад

Do you think there is any point in spacing out the Full Monty by a full week for recovery? That test is super demanding.

@podiumphysio657 5 месяцев назад

Yep for sure. I'm planning to do them a week apart. Sorry if that wasn't clear in the video. This will make the lead up to each ride as similar as possible with the same routine, without too much of a gap (say 1 month), where there might be some actual fitness changes that act as confounders.

@musclelessfitness2045 5 месяцев назад

@@podiumphysio657 : You don't have to go full gaz. You could do 2 efforts @ 200 watts back to back with 10-15 mins rest in between

@starlitshadows 5 месяцев назад

@@podiumphysio657 yeah exactly. Will be looking forward to seeing the results.

@huskytwo9686 5 месяцев назад

Surprising results indeed! Are you intentionally holding a set cadence? If so, I believe the test would be more fair if you let cadence go by feel. I think it is expected that cadence should be lower with longer cranks.

@podiumphysio657 5 месяцев назад

On this test I did not try to control cadence, and just went by feel. In this first video (ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE--3sCebN63rI.html) I discuss how Jim Martin debunks the crank length/ cadence myth.

@huskytwo9686 5 месяцев назад

@@podiumphysio657 Thanks, I watched your video but I don't think you mentioned cadence much. I've briefly looked at a paper by Dr Martin in 2001 and he does talk about optimal cadence and pedal speed, though in the context of max power.

@podiumphysio657 5 месяцев назад

@@huskytwo9686 In a previous 30 minute test (ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-QKnsjx9WSKQ.html) I tried to control for cadence but I felt that this was a bit artificial. On this FTP attempt I didnt try to control for cadence and let my legs do what they wanted. In the 50 min attempt you can see in the strava file at the end of the session my cadence drops, which is the beginning of the end...

@kivriel2660 5 месяцев назад

Power is in principle Torque x RPM. If you increase RPM you´ll go faster. But as always there are biomechanics involved. So every human need an individual solution.

@podiumphysio657 5 месяцев назад

Yes exactly. I may be an outlier but I've done lots of tests comparing the 2 conditions now and shorter cranks win for me on all fronts!

@marianneoelund2940 5 месяцев назад

If you repeat the test, note that you should be pedaling at a lower cadence with the longer cranks, in order to equalize foot velocity. If you have an average cadence of 92 rpm with 160 mm cranks, you should drop down to 84 rpm at most, with the 175 mm cranks.

@podiumphysio657 5 месяцев назад

Yes that maths sounds about right, however I did not try to follow any formula with respect to cadence. I just let my legs do what felt right. Having done a few FTP and high intensity "how long can I hold xxx watts for" indoor rides, I was confident that I would automatically choose the correct cadence for each test.

@steveouwerkerk7719 5 месяцев назад

Interesting results but I’d like to see you repeat it - long cranks first then short cranks. Maybe you were not fully recovered from your first effort or maybe you just had a bad leg day the second day. See if the results still match. Everything I’ve read points to no power improvement with crank changes, maybe just cadence.

@podiumphysio657 5 месяцев назад

Hey Steve. Wondering if you have seen Jim Martin's work that I referenced in my first video here (ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE--3sCebN63rI.html). He is a PhD and his work shows there is some power benefits with shorter cranks. I found the same thing in this test (ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-P0qO6Wza58w.html). I appreciate the need for scrutiny, but I dont have any doubt that I was fully recovered 4 days after the first test. You could also perhaps say I likely got a fitness boost from that first 50 minute effort which should help 4 days later?? As I said I'm planning to do a Wahoo Systm 4DP test, 1 week apart, and I'll probably go with the long cranks first this time. That should be more conclusive.

@ramonl.valentin1446 5 месяцев назад

How fast were you going?Speed /effort

@podiumphysio657 5 месяцев назад

Hey there. So the speed is visible on the Strava graphical data sets when I scroll along them. However the speed on these indoor tests is largely irrelevant. If I'm in a very low gear (small chainring and big cog), I'll be recording a very slow speed, and if I'm in a very high gear (big chain ring and small cog) I'll be recording a very fast speed, but due to ergo mode it will feel exactly the same to me.

@ramonl.valentin1446 5 месяцев назад

@@podiumphysio657 you measure at the pedal up a hill , 165 more watts[effort] verses 175 /speed up the hill.

@podiumphysio657 5 месяцев назад

I did make a video about performance in an uphill climb, comparing the 2 crank lengths here...ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-P0qO6Wza58w.html

@ashleyhouse9690 5 месяцев назад

I don't know why you use erg mode for your tests. All that does is force you to hold a certain wattage which may or may not be the right number. Clearly as you couldn't complete either test 300W wasn't the right number so you didn't get a clear result. I've been using shorter cranks for a few years now for similar hip reasons to you. 6' 4" and 165mm cranks on all my bikes. I noticed a big improvement all round as soon as I changed and wouldn't go back.

@podiumphysio657 5 месяцев назад

Yep fair call. If I used "passive" mode then it would be 100% up to my "motivation" on the day to get the best result. One day I might be more compelled to work harder than another. So then you would have 2 different FTP power figures and I guess likely 2 different average heart rates. It still seems a bit variable. Even though I didnt make 60 mins on either test, it is definitely a closer approximation of FTP than the 30 min tests I did a few weeks back at 280w. In the current tests the heart rate differential is quite telling I think. However, as I said in the vid, I am planning to do the Wahoo Systm 4DP test, one week apart on the 2 bikes, so hopefully that algorithm will get it right!

@podiumphysio657 5 месяцев назад

Glad to hear the shorter cranks are working out for you. Were you surprised to see "all round improvements"?

@ashleyhouse9690 5 месяцев назад

@@podiumphysio657 After riding 175mm cranks for over 20 years I had read some research into shorter cranks before I decided to take the plunge. I was pleasantly surprised to have my expectations confirmed as far as helping with hip impingement was concerned but I was also surprised that it just seemed to make pedaling just that bit easier. I know that feeling is very subjective but I have always been a bit of a grinder and it sped up my cadence a bit even though I know changing gear would compensate for that anyway. Even though I have a power meter I haven't bothered to do any sort of comparison test. Even if I found I could produce more power with longer cranks, I doubt if I would go back now.

@ashleyhouse9690 5 месяцев назад

@@podiumphysio657 The 60 minute test is a really tough one and although it is supposedly the most accurate, I prefer to use the 20 minute FTP test. You can pace your effort better and in time, with experience, you can get a very accurate result anyway. I usually find also that from experience, I pretty much know what my "effective" FTP is and what I can train to when doing an interval workout for instance. I think the ability to gauge what effort level you can maintain for an extended period is very useful so doing 2 x 20 minute threshold workouts can be very helpful in that regard. I find using Zwift very helpful as well because if you create a workout to hold a certain wattage, say 300W for 20 minutes, if you don't use erg mode you have leeway either way which is why I don't like erg mode. Zwift will prompt you if you are falling too far below the 300W level or exceeding it by too much, usually about 10% either way or maybe 20W, I'm not sure which. It just makes it much easier to stick to a target power without erg mode getting in the way.

@podiumphysio657 5 месяцев назад

@@ashleyhouse9690 Yes I've seen nothing but benefits so far...

@matthewblue7839 5 месяцев назад

Isn’t this like the joke about coukd you lift 1000 lbs once or 100 lbs 10x? You must have had very different rpm/ cadence, shorter cranks higher, longer cranks lower ? Anyone, would need more power/strength to turn over the longer cranks to the same rpm as the shifter cranks? If you have longer femurs then theoretically you get more leverage from the longer cranks, but if you don’t have the strength and power to turn over the gear with the longer cranks, you will not hit a higher ftp? Maybe after a good warm up, you should simply do a max sprint in erg mode on your trainer same large gear and then document max rpm and watts. Not certain what your fast/slow twitch fibre ratio is but bet you hit higher watts with the shorter cranks, unless you are not a Sprinter ?

@podiumphysio657 5 месяцев назад

I've played around with max sprints on my Wahoo. Doing these in erg mode is fraught with danger. If you set the output too high from a standing or slow start, you will never get the cranks moving at all. If you dont use erg mode, you need to take a stab in the dark for your ultimate gearing plan and "incline setting" to add a little resistance spice. I'd suggest even if you put the erg mode at say 1400w, and I had an assistant next to me who could change the setting quickly from say 300w straight to 1400w, even for that 2 seconds that the cranks and flywheel remain turning before grinding to a halt, it would register the power as 1400w, even if that was well above your actual real output ability. I actually tried some repeated max power 5 second sprint test 2 weeks ago which I havent published yet. I hit the high 900s with my short cranks and only high 800s with my longer cranks. Clearly I'm not a sprinter. I need to play around with the settings I use before I put this data online. It definitely makes a difference whether I try to spin at a certain RPM or just let my legs decide...