The Effect of Shoe Bending Stiffness on Predictors of Sprint Performance

Author(s):  
N Hopkinson ◽  
M Caine ◽  
D Toon
2020 ◽  
Author(s):  
James Warren Hurt ◽  
Rodger Kram

Most competitive and recreational road cyclists use stiff-soled shoes designed for cycling and “clipless” pedals that firmly attach to the shoes. There are many unsubstantiated claims by cyclists and industry professionals about the advantages of cycling shoes and clipless pedals. Scientific research has shown that cycling shoes and clipless pedals have no significant effects on the metabolic cost of cycling during submaximal, steady-state efforts. However, a recent study demonstrated that, compared to running shoes, cycling shoes and clipless pedals do provide performance benefits relevant to sprint cycling. Here, we investigated if there was a positive relationship between longitudinal bending stiffness of cycling shoe soles and sprint performance. We measured the mechanical power outputs, velocities, and cadences of 19 healthy male recreational/competitive cyclists during maximal sprint cycling. Participants rode outdoors on a paved asphalt road with a steady, uphill grade of 4.9%. Each subject completed nine 50 m cycling sprints in three (single-blinded) shoe conditions: identical shoe uppers with injection moulded nylon soles, carbon fibre-fibreglass blend soles, and full carbon fibre soles. The same clipless pedals were used throughout all tests. No significant differences were detected between the three shoe soles for: 50 m average and peak 1-second power, average change and peak change in velocity, average and peak cadence, maximal sprint velocity, peak acceleration, and peak crank torque (all p > 0.31). Greater longitudinal bending stiffness of cycling shoe soles had no effect on sprint performance during short uphill sprints.


2017 ◽  
Vol 5 (2) ◽  
pp. 17-21
Author(s):  
M K Tambe ◽  
◽  
A V Turankar ◽  
S Lingawar ◽  
N B Dhokane ◽  
...  

2020 ◽  
Vol 2020 (9) ◽  
pp. 35-46
Author(s):  
Aleksandr Skachkov ◽  
Viktor Vasilevskiy ◽  
Aleksey Yuhnevskiy

The consideration of existing methods for a modal analysis has shown a possibility for the lowest frequency definition of bending vibrations in a coach car body in a vertical plane based on an indirect method reduced to the assessment of the bending stiffness of the one-dimensional model as a Bernoulli-Euler beam with fragment-constant parameters. The assessment mentioned can be obtained by means of the comparison of model deflections (rated) and a prototype (measured experimentally upon a natural body) with the use of the least-squares method that results in the necessity of the solution of the multi-dimensional problem with the reverse coefficient. The introduction of the hypothesis on ratability of real bending stiffness of the prototype and easily calculated geometrical stiffness of a model reduces a multi-dimensional problem incorrect according to Adamar to the simplest search of the extremum of one variable function. The procedure offered for the indirect assessment of bending stiffness was checked through the solution of model problems. The values obtained are offered to use for the assessment of the lowest frequency of bending vibrations with the aid of Ritz and Grammel methods. In case of rigid poles it results in formulae for frequencies into which there are included directly the experimental values of deflections.


Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 923
Author(s):  
Kun Huang ◽  
Ji Yao

The potential application field of single-walled carbon nanotubes (SWCNTs) is immense, due to their remarkable mechanical and electrical properties. However, their mechanical properties under combined physical fields have not attracted researchers’ attention. For the first time, the present paper proposes beam theory to model SWCNTs’ mechanical properties under combined temperature and electrostatic fields. Unlike the classical Bernoulli–Euler beam model, this new model has independent extensional stiffness and bending stiffness. Static bending, buckling, and nonlinear vibrations are investigated through the classical beam model and the new model. The results show that the classical beam model significantly underestimates the influence of temperature and electrostatic fields on the mechanical properties of SWCNTs because the model overestimates the bending stiffness. The results also suggest that it may be necessary to re-examine the accuracy of the classical beam model of SWCNTs.


Author(s):  
Sadegh Dastorani ◽  
Reza Hasanzadeh Ghasemi ◽  
Reza Soheilifard

Author(s):  
Peter Krustrup ◽  
Magni Mohr ◽  
Lars Nybo ◽  
Dimitrios Draganidis ◽  
Morten B. Randers ◽  
...  

1999 ◽  
Vol 65 (636) ◽  
pp. 3368-3374
Author(s):  
Hiroshi IIZUKA ◽  
Hideo TAKAHASHI ◽  
Toshio TETSUKA

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