Re: Jackshaft Kit U-bolts
As usual you bring up some valid points. We do touch on this subject in the manual and especially caution when using aluminum frames. We do recommend using the stock strap from the engine kit but when it comes to safety you can never be too cautious.
The functional issue here is that when you increase the surface area of the clamps they no longer offer as much clamp force and can allow the engine to slip on the seat tube putting too much pressure on the chain adjuster. It is a fine line there. Typically what I do is increase the support of the lower clamp because it does not have the added support of the seat post but leave the upper clamp unmodified so that enough clamp force can be applied.