Post Number: 3423
|Posted on Sunday, November 27, 2011 - 07:17 am: |
now this is an interesting study sent to me today per mail and some questions.
Here the abstract:
"Effects of front and dual suspension mountain bike systems on uphill cycling performance
MacRAE, HOLDEN S-H.; HISE, KIMBERLEY J.; ALLEN, PETER J.
MacRAE, H. S-H., K. J. HISE, and P. J. ALLEN. Effects of front and dual suspension mountain bike systems on uphill cycling performance. Med. Sci. Sports Exerc., Vol. 32, No. 7, pp. 1276-1280, 2000.
Purpose: The purpose of this study was to evaluate the effects of front suspension (FS) and dual suspension (DS) mountain bike designs on time-trial performance and physiological responses during uphill cycling on a paved- and off-road course.
Methods: Six trained male cyclists (35.6 ± 9 yr, 76.9 ± 8.8 kg, V̇O2peak 58.4 ± 5.6 mL·kg-1·min-1) were timed using both suspension systems on an uphill paved course (1.62 km, 183-m elevation gain) and an uphill off-road course (1.38 km, 123-m elevation gain). During the field trials, V̇O2 was monitored continuously with a KB1-C portable gas analyzer, and power output with an SRM training system.
Results: On the paved course, total ride time on FS (10.4 ± 0.7 min) and DS (10.4 ± 0.8 min) was not different (P > 0.05). Similarly, total ride time on the off-road course was not significantly different on the FS bike (8.3 ± 0.7 min) versus the DS bike (8.4 ± 1.1 min). For each of the course conditions, there was no significant difference between FS and DS in average minute-by-minute V̇O2, whether expressed in absolute (ABS; L·min-1) or relative (REL; mL·[kg body wt + kg bike wt-1]·min-1 values. Average power output (W) was significantly lower for ABS FS versus DS (266.1 ± 61.6 W vs 341.9 ± 61.1 W, P < 0.001) and REL FS versus DS (2.90 ± 0.55 W·kg-1 vs 3.65 ± 0.53 W·kg-1, P < 0.001) during the off-road trials. Power output on the paved course was also significantly different for ABS FS versus DS (266.6 ± 52 W vs 345.4 ± 53.4 W, P < 0.001) and REL FS versus DS (2.99 ± 0.55 W·kg-1 vs 3.84 ± 0.54 W·kg-1, P < 0.001).
Conclusion: We conclude that despite significant differences in power output between FS and DS mountain bike systems during uphill cycling, these differences do not translate into significant differences in oxygen cost or time to complete either a paved- or off-road course"
Same time and same VO2 but very very different wattages between FS and DS
So they would basically use the same " energy" but are able to push very different wattage.
Hmmm need to do some major thinkng here first and than possibly try that out with our K42B portable system and see, whether we really get the same interesting endresult before starting any theory here and or speculation plus I like to read the full paper first.
Post Number: 55
|Posted on Sunday, November 27, 2011 - 08:28 am: |
I would look at it in a different way:
From the view point of basic physics they can't be using the same energy pushing a higher wattage (power [Watt]= energy/time).
Same speed and higher wattage means they are using more energy to do the same work riding a DS bike.
More energy used, same O2 consumption means the difference must be covered from anaerobic sources.
Looks like a proof that FS bike is more energy efficient (dah). If this theory is correct it SHOULD show on a long course.
Too bad no physio data are included.
The question than is why they would not be able to push the same wattage riding FS and beat the @#$% out of those DS's even on this semi-sprint distance?
How was the wattage measured anyhow? Wasn't it just that the power hub or which ever system they used was designed and calibrated for rigid frames only? (No idea how exactly they work so don't shoot me for this).
Post Number: 3424
|Posted on Monday, November 28, 2011 - 12:59 am: |
Karl, thanks for your ideas.
1. True , this study would shed much more light into the result, if we would have any physiological information. Whether it would be HR, of VO2 or lactate or what ever simple ideas of Bio marker we could get.
2. The question of the wattage testing is a great one as well. But normally in cases like that they use SRM which is a really well designed and great system and very reliable.
3. This study shows, how relative little information we are getting, if we take just one information and in this case wattage to try to make a point.
4. The suggestion of racing the same loop once fully aerobically and in teh second case with some additional "anaerobic" contribution of energy is an interesting one.
One may ask, how an athlete can do that, going all out and try in one loop to get the energy just aerobically mainly and than pushing the same loop time but dig in the anaerobic supply line.
Would we not expect , that in the case of mainly aerobic supply they could have tried to push somewhat harder to add the additional "anaerobic" supply to it and the time should have been somewhat faster?
5. Last but not least we may ask, who would accept from the industry a published work like that without digging in for more precise information, as it may have a direct consequences for either industry for customers paying big money for an interesting but as it looks not very well researched project.
Post Number: 56
|Posted on Monday, November 28, 2011 - 02:01 am: |
The first part of what I wrote was just an attempt to look at the problem from a different angle as I felt the study was somehow suggesting that one can expect to be able of a higher energy output using full-suspension bike comparing to front-suspension one and all that using the same amount of O2.
From that arose the question why the same test subject would be unable to use the same energy sources doing his/her best in a time trial independent on the bike type used. And how come more wattage does not translate into faster time?
To my simple mind it still comes out as a wattage measurement problem.
Post Number: 3425
|Posted on Monday, November 28, 2011 - 02:33 am: |
I only can completely agree with you.
There is really no other decent explanation of this results and as I mentioned above.:
How come they even published a result like that as it is one of many worthless publications adding to the flood of publications just for the sake of it.