27/08/2026
Does 300 g actually matter?
We’ve had a few discussions lately about the VHP X being around 300 g heavier than the V7.
It reminded me of a project our intern Phillip did a few years ago. We were looking into whether a KAVENZ downcountry bike should use a high pivot, and the obvious question was:
How much efficiency do we actually lose through the idler?
So instead of guessing, Phillip calculated it and compared his model with drivetrain test-bench data.
At 25 km/h on flat ground, the model looked like this:
126 W aerodynamic drag
48 W rolling resistance
4.5 W drivetrain losses
~2 W idler loss
Total rider power: around 181 W.
The idler was roughly 1% of the picture.
He also compared different idler sizes. Bigger is more efficient, and his conclusion at the time was that 18T or larger made sense to stay below a 1.5% loss target.
Interestingly, today we use a 16T idler on the VHP X.
Why? Because efficiency isn't the only parameter. Packaging, suspension layout, chain management, weight, clearance and durability all have to work together. The small additional theoretical loss was a compromise we were happy to make.
And that's pretty much how we look at those extra 300 g as well.
For an 80 kg rider on a ~16 kg bike, 300 g changes the total system weight by about 0.3%.
On flat ground at constant speed, it makes essentially no difference.
Even on a 10% climb at 10 km/h, those 300 g require only about 0.8 W extra.
You can measure it.
But can you feel it?
We'd rather put those 300 g into a frame that does what we want it to do than chase a number because it looks better on a spec sheet.
Not everything measurable is noticeable.
