CHAIN EFFICIENCY TEST, Part 1

Transcription

1 CHAIN EFFICIENCY TEST, Part 1 5 HIGH-END MODELS, FACTORY LUBE SUMMARY OF RESULTS- 5 high-end chains models were tested for efficiency using both the Full Load Test Method (FLT) and Full Tension Test Method (FTT). 25 samples were tested with each test method, 5 samples of each of the 5 models. Of the five models tested, the Shimano CN-7901 (Dura Ace) is the most efficient chain out-of-thebox. The Dura Ace consumed an average of W (97.22% efficiency). The results show the SRAM PC-1091R to be the least efficient chain out-of-the-box, consuming an average of W (96.05% efficiency). A difference of 3.12 watts (1.17% efficiency difference) is seen between most efficient and least efficient models. The variance found within a given model (i.e., the efficiencies of the same models compared to each other) was lowest (favorable) at 0.45 watts found on the Wipperman Connex 10S1, while the KMC X10SL Gold demonstrated the highest variance within the model at 0.72 watts. The average variance among all 25 samples is 0.58 watts.

2 Graph 1: Final results showing average chain friction of each model

3 COMPLETE RESULTS- FULL LOAD TEST METHOD Graph 2: Individual sample results. Full Load Test Method. (chain friction; Chain Group 1 Group 2 Group 3 Group 4 Group 5 Avg Std Dev Shimano CN Campagnolo Ultra Narrow KMC X10SL Gold Wipperman Connex 10SL SRAM PC1091R Table 1: Individual Results. Full Load Test Method.

4 COMPLETE RESULTS- FULL TENSION TEST METHOD Graph 3: Individual sample results. Full Tension Test Method. (chain friction; Chain Group 1 Group 2 Group 3 Group 4 Group 5 Avg Std Dev Shimano CN Campagnolo UN KMC X10SL Gold Wipperman Connex 10S SRAM PC1091R Table 2: Individual Results. Full Tension Test Method. (watts@250w)

5 TEST DETAILS Goal- The goal of the test was to determine the most efficient high-end 10sp chain. The chain with the highest efficiency will contribute to a faster top speed at a given rider output. Products- Five 10-speed chain models were tested. Each model chosen is the top-of-the-line chain from the respective manufacturer. A total sample size of 25 chains was tested, five chains of each model. Chains were purchased through typical bicycle component retailers. To ensure randomness between samples and to minimize the possibility of receiving two or more chains from the same production run, no more than one chain of a particular model-type was purchased from a single retailer. Test Method- This test utilized both the Full Load Test Method (FLT) and the Full Tension Test Method (FTT). Final results from both test methods were averaged to achieve the overall efficiency ratings seen in Graph 1. This combination of equipment simulates an equivalent force scenario as seen on an actual bike drivetrain (FLT method), plus highly accurate friction measurements to 1/50 th of a watt (FTT method). Additional details of each piece of equipment can be found here: - Chains were tested using a rotating torque loading of 250 watts for the FLT. FTT tension approximated 250 watts. - 95RPM front ring cadence was used. - The 25 samples were divided into five sample sets. A single sample set consists of five chains; one sample of each model chain. - To minimize bias based on the test order of the samples within a sample set, the testing order of the chains of each of the five samples sets was rotated by one position for each subsequent sample group test. I.e., each chain was ultimately tested at each place in line, first through fifth. - Each chain was tested with the FLT for 30 minutes, and the FTT for 10 minutes. The 30 minute timeframe for the FLT test allowed for an initial run-in period for each chain. - Data was captured at the end of each sample run; at 30 minutes for FLT, at 10 minutes for FTT. - Data was averaged at 1-minute intervals. Sampling rate was 25 samples/second. - A brand new cog and ring was used for this test. To ensure consistency, the same cog and ring were used on both the FLT and FTT portions of this test. The ring is an FSA 10sp 53T. The cog is a SRAM 11T removed from a PG speed cassette. - The accuracy of the FLT is +/ watts. - The accuracy of the FTT is +/ watts. - Equipment system losses (the losses from the ceramic bearings used in the test equipment) are inherently present. For the Results graphs and tables at the beginning of this report, the

6 bearing system losses were removed from the raw data. The Results data is pure chain friction. - The variance found within a given model data is based on the measurements from the FTT, due to its higher accuracy. A final note: This test was performed with the ring and cog in a purely coplanar manner, with new chains, in a controlled environment. The test does not account for chain offset, lube variations, friction from wear, dirty conditions, etc. Future tests are scheduled to address these variables. This specific test, while not absolute, and considering the other variables a chain may encounter, nevertheless provides valuable insight to baseline performance of the friction losses and efficiencies of the chains tested.