Hmm, I think the upper pulley isn't technically an "idler". An idler usually transmits no force, but that one kind of does: the seat stay is pulled down by chain tension via the upper pulley. The bottom is truly an idler: only guides the chain. This applies to most all iTrack type designs where the idler is not fixed relative to the cranks. Perhaps a better, more technically accurate name could help some folks intuit how the idler effects the suspension...
Sept. 7, 2023, 3:11 p.m. - Justin White
Hmm, I think the upper pulley isn't technically an "idler". An idler usually transmits no force, but that one kind of does: the seat stay is pulled down by chain tension via the upper pulley. The bottom is truly an idler: only guides the chain. This applies to most all iTrack type designs where the idler is not fixed relative to the cranks. Perhaps a better, more technically accurate name could help some folks intuit how the idler effects the suspension...