Sooner or later I needed to use the day bike again as that's the bike set up to take the trailer. By this time the ping had developed into something that was akin to a submarine sonar searching for oncoming traffic. I determined that the ping was created on the down stroke of the left crank. The pedals were good quality Velo Orange which left the bottom bracket as the suspect which was confirmed as the culprit when I changed the pedals and the same noise persisted.
One Chain Reaction purchase later provided a replacement Shimano UN55. When I took the existing Truvative sealed unit Bottom Bracket out I found that the sealed bearing assembly had come apart from the rest of the housing. The rather cheap construction method employed by Truvative is a disappointment since its almost bound to go wrong. The unit had only been in place for about 2 years and I can only assume that the load of pulling a trailer was too great. The Shimano construction is much better since the bearings are an integral part of the housing and not a 'bolt on'.
|You can see that the Truvative uses a separate baring whereas the Shimano baring is integral|