The colour of FS Drive Belt Tensioner springs that is!
This post is a bit overdue......from those halcyon days when pash put together a bearing renovation kit for knackered FS pivot pins, possibly for nutters like me who actually rode their Buell XBs for more than 2000 miles per year
....or who had the time to do those miles!
I may have been the first to have my pivot pin repaired. Around the same time we were discussing use of a softer spring for the FS unit. I don’t recall how it came to be, but in the event l tried a softer spring to the standard FS yellow item. I fitted a blue spring ‘IND4606217T’ rated as ‘medium’ strength. The yellow spring IND4603217T is rated as ‘extra heavy’ loading. I read somewhere that the blue has a 209N resistance compared to the yellow’s 269N.
In practice the blue spring feels much softer. Pushing the XB around it felt like no belt was fitted. The extra free movement was as much of a jump as comparing the yellow spring FS to the factory fixed idler wheel!
You could flex the belt with only two fingers (or one stiff little finger!
All good it would seem, but after only one lengthy ride l checked the belt tension to find that all free play, or spring in the tensioner had disappeared.
It transpired that the fatigue life of the blue spring had been used up in just one run!
I reinstalled the yellow spring, but when l removed this spring recently to clean the FS unit the yellow spring broke in two. This had also reached the end of the road, but it had endured some 10 years of abuse.
I decided to try the ‘red’ spring IND4601217T rated as ‘heavy’ strength, so somewhere between the blue and the yellow. Odd then that l read that the red spring is rated as 216N or not much higher than blue. Hopefully the red had just enough extra strength to avoid premature failure.
So today l put this to the test with a 73 mile ride around the Cotswolds. Pushing my XB by hand and flexing the upper belt by hand did seem to indicate that the red spring was a happy compromise between the blue and the yellow. On my return home the red spring still seemed to have plenty of life left in it. However this is early days and another longer day in the saddle is needed to show if the red spring is a stayer!