Short Duration Chain Break-In

Goal:

To determine chain efficiency vs initial run time (the effects of a short break-in period).

Chains:

Three brand new models of high-end 10sp chains were tested.  A single sample of each of the following models:  Chain A- Campagnolo Ultra Narrow 10 (Record), Chain B- Shimano CN-7901 (Dura Ace), Chain C- SRAM PC-1091R (Red).

Results:

All three chains exhibited decreasing friction losses (increased efficiency) as run time increased.  The average increase in efficiency after 8 hours of run time is 0.45 watts.  The graph below shows friction losses of the three chains from t=0 to t=8 hours.

Graph 1: Chain Friction Losses at given run times

Test Details:

• New chains were used for this test, with factory lube.
• A new 53T-11T FSA ring/SRAM cog combination was used.
• 95RPM cadence
• For the run time, the chains were run with the Full Load Test Method at 250W actual rotational load. Subsequently, for data collection at the specific time intervals, the chains were then tested using the FTT method.  Though this method of swapping between FLT for run time and FTT for data collection took an increased effort, the FTT yields more accurate results.
• The accuracy of the FTT is +/- 0.02 watts
• Equipment system losses (the losses from the ceramic bearings used in the test equipment) are inherently present in the raw data.For the ‘Results’ graph above and table below in this report, the bearing system losses were removed from the chain friction results.

Data Table:

Table1: chain losses in watts at given run time