There's a hill near my house where I used to regularly hit 70kph. There's a super-sketchy cross street right at the bottom of that hill with motorists always trying to white-knuckle gun it into traffic, so I've stopped doing that.
For all of my crashes I was going at or under 15kph. Which is probably why I'm still here to tell you all about it.
70 kph definitely sounds like helmet speed to me. Though I admit as a kid I was sometimes clocked (by someone with a speedometer) at 40-50 kph on my city bike on slight downward slopes, and I never wore a helmet. But those were only brief bits under fairly optimal circumstances. The last couple of times I fell (less than a handful over the past 30 years) were all extremely icy road conditions. Almost all, because I just remember one where a car brutally cut me off turning into a side street while I was barreling down the road at pretty extreme speed. I avoided a collision by making an extremely tight turn into the same side street. That was a street that really should have had a separate bike path.
(I think it was here [0], though I don't remember crossing that raised sidewalk; maybe they changed that since then, or I misremember.)
There's a hill near my house where I used to regularly hit 70kph. There's a super-sketchy cross street right at the bottom of that hill with motorists always trying to white-knuckle gun it into traffic, so I've stopped doing that.
For all of my crashes I was going at or under 15kph. Which is probably why I'm still here to tell you all about it.