Thesis (M.S.)--University of Wisconsin--Madison, 1983. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 61-62).

Thesis (Ph. D. in Civil and Environmental Engineering)--University of California, Berkeley, 2007. / "Spring 2007." Includes bibliographical references (p. 173-179). Also available online via the ITS Berkeley web site (www.its.berkeley.edu).

The aim of the present project was to quantify and compare differences in impact performance and damping effectiveness among various off-road bicycle suspension systems. Two experiments were conducted to compare suspensions. Fork impact performance was tested by measuring peak antero-posterior braking forces and impulses during impact with bumps of 6- and 10-cm height for five mountain bike suspension systems. These results were compared to a rigid fork condition. Comparisons among suspension systems showed small but significant differences in performance. While only marginal differences in peak force were found for the suspension conditions, more substantial differences in braking impulse were observed. Air-Oil design forks had the lowest braking impulse for the range of speeds and impact characteristics of this experiment. In another setting, an analysis of acceleration signals over a range of frequencies on two surface conditions (gravel and trail) was conducted to assess the damping effectiveness of the five suspension systems. The mountain bike was equipped with accelerometers mounted at the axle and frame. A spectral analysis of the signal was performed for each signal to provide a measure of fork effectiveness. Results showed that accelerations ranged from -33 to +40 g at the axle and from -13 to +13 g at the frame, while spectral analyses of the acceleration signals revealed two distinct frequency regions from 0 to 100 Hz and from 300 to 400 Hz. The various suspension systems were all effective in attenuating vibration over the first region. Vibration amplitudes at the frame were considerably less than at the axle for the suspension conditions while similar axle-frame vibrations were observed with the rigid fork. Lower frequency vibration amplitudes were typically greater on the trail than on gravel. In the frequency region between 300-400 Hz, the signal was attenuated at the frame for all conditions including the rigid fork. The quantification and comparison process of the various suspension forks using impulse provided an objective marker for performance, and allowed differentiation between various suspension conditions. Moreover, the effectiveness analysis through the use of accelerometers provided insight into the range of frequencies dampened by a suspension. The lower frequency range dampening suggested that effectiveness of a suspension fork can be quantified even though the experiment did not conclusively differentiate between the forks. / Graduation date: 2001

Thesis (M.S.)--The University of North Carolina at Greensboro, 2009. / Directed by Patrick Lucas; submitted to the Dept. of Interior Architecture. Title from PDF t.p. (viewed Jul. 29, 2009). Includes bibliographical references (p. 97-101).

Mountain bike suspension forks have been developed to reduce the accelerations transmitted to the rider. However, the effectiveness of suspension forks has not been systematically investigated. It was the goal of this project to quantify the amount of impact acceleration damping afforded by three stiffness settings of suspension forks compared to rigid mountain bike forks. Seven experienced mountain bike riders gave their informed consent to participate in the study. The subjects coasted down a ramp and impacted a bump at 5.4 m/s located about 2.3 m past the ramp end. Accelerometers were placed on the axle and frame of the bicycle which was fitted with either a rigid fork (FR) or suspension forks set on soft (F1), medium (F3), or firm (F6) stiffness. Bumps were either small (B1), medium (B2) or large (B3). Accelerometer data were telemetered to a computer, sampled at 1000 Hz and smoothed with Butterworth filter with 50 Hz cutoff. Peak acceleration during impact (P1) and landing (P2) as well as the slope of the impact acceleration peak (jerk, J) were extracted from the data and analyzed using a 2 x 3 x 4 repeated measures ANOVA for each of the dependent variables (P1, P2, J), and with linear contrasts as follow-up tests. A significance level of p<.01 was chosen. All forks were found to produce similar impact acceleration (P1) at the axle and frame on the small bump (B1). On larger bumps (B2 and B3), softer suspension forks (F1 and F3) significantly reduced acceleration transmitted to the rider during bump impact (P1), while maintaining significantly higher axle acceleration than other forks (p<.001); Jerk was significantly reduced at the frame compared to the axle for each suspension fork with the larger bumps. Landing impacts (P2) were of similar magnitude for most fork conditions at both the axle and frame. It appears from these data that suspension forks with moderate stiffness may provide the best impact acceleration damping for mountain bikes encountering impacts with characteristics similar to the bumps and velocity used in this study. It is unclear how these results generalize to other conditions encountered while riding. / Graduation date: 1997

The purpose of this study is to provide the necessary technical background and data for the development of a suspension system for a recumbent bicycle. For this reason, the customer requirements-design criteria for the development of the suspension system were set, and several static and dynamic tests were conducted on the bicycle's suspension components in order to determine their shock absorption properties. The shock absorption properties of the bicycle's components can be used as means of evaluating the specifications of the suspension system that will satisfy the established design criteria best. In addition, a test machine that can be used for damping coefficient and spring constant measurements was designed to provide further assistance with the analysis of the damping and elastic properties of the recumbent bicycle's suspension components. It was designed so that it can also be used for similar testing of other materials and parts used in the bicycle industry. The subject of this study was BikeE, a recumbent bicycle that was developed by Professor D. G. Ullman and the BikeE Corporation in 1992. / Graduation date: 1995

Thesis (Ph. D.)--Ohio State University, 1983. / Includes bibliographical references (leaves 136-146). Available online via OhioLINK's ETD Center

Thesis (Ph. D.)--University of Michigan, 1975. / Also issued in print.

Thesis (Ph. D.)--University of Michigan, 1975. / eContent provider-neutral record in process. Description based on print version record.

Thesis (Ph. D)--University of California, Davis, 2007. / Text document in PDF format. Title from PDF title page (viewed on August 28, 2009). "Received by ITS-Davis: December 2007"--Publication detail webpage. Includes bibliographical references (p. 132-140).