Chainsaw Repair

"Same reason why new Stihl .404 high tooth has no antivibe "Comfort".  Picture shows even amount below rivets on both heel and toe of cutter."

I understand the physical differences, but not why it is a disadvantage for race chains. Trimmed heel would also be less weight

Philbert

I don't know what you're getting at with a trimmed heel for weight saving relating to a antivibe heel....
A race chain is modified all over to save weight, to increase chip clearance and flow.
But when you have a chain where its cutters have built in "shock absorbers " with a space between the bottom of the heel and bar rail, the cutters don't enter the wood as firm and aggressive as it would when there is no space between the bottom of the heel and bar rails.
Sure for a work chain there is less vibration and you won't notice any change in cutting speed. But the differences in cutting speed with a race chain can be  measured in 100/ths of a second with a stop watch.

Reason why Stihl never put Comfort cutters and side links on their .404 high tooth timbersports chain.