Opening up a conversation:
I've been doing bike fits since late 90's. Dan's FIST clinic definitely updated my classic Serotta training in 2009. I've fit several thousand folks and more recently, while being all-in on getting Wove's saddle business going, pro's largely reach out to me for on-going bike fit help. What I'm seeing (and I'm sure everyone here on ST is seeing) are pro's having their saddles close to all of the way forward, and extender plates/mounts under their aerobars to get very far forward and ahead of what the bike's stock pad reach allows for. It seems Dan's original 80deg seattube angle should make a come back, beyond the use of saddle clamp sliders allowing for effective 80deg sta's. I’d suggest 82deg sta’s. And, tri bikes should come with greater pad reach/x (and slacker hta's). I’d suggest 3-6cm greater pad reach/x across size ranges XS-XL for most brands.
Which current tri bikes have the greatest pad reach/x?
Second, a lot of pro's share that their bodies are telling them to place more of their mass over the pedals, but then their quads feel fried, so they or their bike fitter scoot their saddles far back to keep their posterior chain/glutes engaged.
While I've done and published research in biomechanics and human evolutionary biology at harvard and in ithaca, I jumped over to organizational behavior for my doctoral work, but if I had continued in that area, I would propose and then test the following hypothesis, which I have not seen in the published research literature:
H: Quad vs glute engagement is a function of the horizontal distance x from the rider's contact point on the saddle to the pedal spindle when the crank is forward and parallel to the ground (3 o'clock position). image below.
- Shorter distance x = more quad engagement.
- Longer distance x = more glute engagement.
There is published evidence that when performing weighted squats, bringing one’s knees in more towards the toes = more quad muscle fiber recruitment, and more behind the toes = more glutes. applicable to cycling? If not, why are top fitters sharing with pros that the reason the fitter is placing the pro further rearward is to engage the posterior chain? It seems to me the fitters are focusing on saddle nose to bb distance but not the distance x in the hypothesis above as the culprit for glute vs quad engagement. see images and observations a) - h) below.
Edits so that information is in one place:
a) the rider wants to keep their center of mass far ahead of the bb
b) they want to keep their glutes engaged
c) the hypothesis above is that longer distance x allows for the glutes to be engaged
d) if the rider goes to shorter cranks, the rider and often their bike fitter perceive that there is a need to move the rider rearward towards the bb to keep the glutes engaged. I'm hypothesizing that this perception is due to a need to keep distance x the same as it was when they had longer cranks. The fact is, moving the saddle rearward re-closes the hip angle despite using shorter cranks.
e) Moving the saddle rearward will also lead to the rider inching forward during a race to accomplish a) (center of mass over the pedals) and they will experience quad fatigue due to distance x now being shorter.
f) the rider will scoot back to re-engage the glutes but then inch forward to accomplish a). Rinse and repeat. inch, scoot, inch, scoot, inch...
g) a solution is to set the rider up to accomplish a) and use longer cranks to accomplish c).
h) longer pad reach/x will be required to accomplish g) so that the rider is not scrunched up on the bike.
- also see: crank length effect on gearing via mechanical advantage
- pro’s training by power while monitoring cadence simply shift gears to maintain power/cadence, which in effect controls for crank length effect on gain ratio, making the effect of crank length to the rider primarily biomechanical.
- changing to shorter crank length makes gearing harder; changing to longer crank length makes gearing easier. Change gear range appropriately so not maxed out too easy/hard so that cadence can be maintained. see gain ratio link above.
- pedal/angular velocity increases with longer cranks if cadence is maintained, and there are some biomechanical and metabolic changes related to changing crank length in addition to % muscle recruitment (quad vs glute engagement).
- If a rider is sliding forward on a saddle with a slick cover material, that can definitely fatigue quads. The Wove V8 saddle has a grippy cover for that reason, to hold the rider in place.
sub-hypotheses:
- H(a) as you change distance x, the difference in % quad vs glute muscle engagement will be roughly the same despite changes in pad stack/y, changes in saddle angle, and different pedal velocities when cadence is maintained across different crank lengths. (testing interaction terms)
- H(b) changes in pad stack/y, saddle angle or pedal velocity will have non significant effects on quad vs glute engagement when compared simultaneously to the effect of changes in the distance x on quad/glute engagement. (comparing direct effects)
wovebike.com | Wove on instagram
I've been doing bike fits since late 90's. Dan's FIST clinic definitely updated my classic Serotta training in 2009. I've fit several thousand folks and more recently, while being all-in on getting Wove's saddle business going, pro's largely reach out to me for on-going bike fit help. What I'm seeing (and I'm sure everyone here on ST is seeing) are pro's having their saddles close to all of the way forward, and extender plates/mounts under their aerobars to get very far forward and ahead of what the bike's stock pad reach allows for. It seems Dan's original 80deg seattube angle should make a come back, beyond the use of saddle clamp sliders allowing for effective 80deg sta's. I’d suggest 82deg sta’s. And, tri bikes should come with greater pad reach/x (and slacker hta's). I’d suggest 3-6cm greater pad reach/x across size ranges XS-XL for most brands.
Which current tri bikes have the greatest pad reach/x?
Second, a lot of pro's share that their bodies are telling them to place more of their mass over the pedals, but then their quads feel fried, so they or their bike fitter scoot their saddles far back to keep their posterior chain/glutes engaged.
While I've done and published research in biomechanics and human evolutionary biology at harvard and in ithaca, I jumped over to organizational behavior for my doctoral work, but if I had continued in that area, I would propose and then test the following hypothesis, which I have not seen in the published research literature:
H: Quad vs glute engagement is a function of the horizontal distance x from the rider's contact point on the saddle to the pedal spindle when the crank is forward and parallel to the ground (3 o'clock position). image below.
- Shorter distance x = more quad engagement.
- Longer distance x = more glute engagement.
There is published evidence that when performing weighted squats, bringing one’s knees in more towards the toes = more quad muscle fiber recruitment, and more behind the toes = more glutes. applicable to cycling? If not, why are top fitters sharing with pros that the reason the fitter is placing the pro further rearward is to engage the posterior chain? It seems to me the fitters are focusing on saddle nose to bb distance but not the distance x in the hypothesis above as the culprit for glute vs quad engagement. see images and observations a) - h) below.
Edits so that information is in one place:
a) the rider wants to keep their center of mass far ahead of the bb
b) they want to keep their glutes engaged
c) the hypothesis above is that longer distance x allows for the glutes to be engaged
d) if the rider goes to shorter cranks, the rider and often their bike fitter perceive that there is a need to move the rider rearward towards the bb to keep the glutes engaged. I'm hypothesizing that this perception is due to a need to keep distance x the same as it was when they had longer cranks. The fact is, moving the saddle rearward re-closes the hip angle despite using shorter cranks.
e) Moving the saddle rearward will also lead to the rider inching forward during a race to accomplish a) (center of mass over the pedals) and they will experience quad fatigue due to distance x now being shorter.
f) the rider will scoot back to re-engage the glutes but then inch forward to accomplish a). Rinse and repeat. inch, scoot, inch, scoot, inch...
g) a solution is to set the rider up to accomplish a) and use longer cranks to accomplish c).
h) longer pad reach/x will be required to accomplish g) so that the rider is not scrunched up on the bike.
- also see: crank length effect on gearing via mechanical advantage
- pro’s training by power while monitoring cadence simply shift gears to maintain power/cadence, which in effect controls for crank length effect on gain ratio, making the effect of crank length to the rider primarily biomechanical.
- changing to shorter crank length makes gearing harder; changing to longer crank length makes gearing easier. Change gear range appropriately so not maxed out too easy/hard so that cadence can be maintained. see gain ratio link above.
- pedal/angular velocity increases with longer cranks if cadence is maintained, and there are some biomechanical and metabolic changes related to changing crank length in addition to % muscle recruitment (quad vs glute engagement).
- If a rider is sliding forward on a saddle with a slick cover material, that can definitely fatigue quads. The Wove V8 saddle has a grippy cover for that reason, to hold the rider in place.
sub-hypotheses:
- H(a) as you change distance x, the difference in % quad vs glute muscle engagement will be roughly the same despite changes in pad stack/y, changes in saddle angle, and different pedal velocities when cadence is maintained across different crank lengths. (testing interaction terms)
- H(b) changes in pad stack/y, saddle angle or pedal velocity will have non significant effects on quad vs glute engagement when compared simultaneously to the effect of changes in the distance x on quad/glute engagement. (comparing direct effects)
wovebike.com | Wove on instagram
Last edited by:
milesthedog: Oct 19, 23 12:55