A pair of tensioner system from ACE were being installed on a 6 speed BWR hub’s Brompton earlier today. They were very simple, light weight and nicely budgeted. The installations were very straight forward too.
A routine test was performed after the simple installations and found there was some clicking sound whenever the rear wheels is spinning at the 1st ,3rd and 5th gears. We went down for a look at the tensioner wheels, it wasn’t hard to spot the tensioner wheels were in contact with the spokes, these contacts created the clicking sound.
When the tensioner wheels were removed to compare with the others, It was found it had an extra 4mm of stack height. These extra 4mm were clearly the cause of the concern. The ACE tensioner wheels were nicely crafted with the dust cap integrated as part of the metal parts. Having been clarified with the manufacturer, the extra stack height was created for the extra travel distance that are friendly for the external 3 & 4 speed system. They will be improving the design accordingly.
We tested the wheels on a few 2 speed wheels set and they were working fine.