The insane power loss and drag on IGH when cruising at low 50W pedal power, now I know why my Belt Drive IGH bike feels soooo hard to pedal for 9 miles compared to my regular chain bike (The dark blue line is Rohloff with crazy good efficiency)
by Coven_Evelynn_LoL
8 Comments
I mean, the worst offender there is only 5 watts different from a chain at low power. That’s nothing
Do you have the exact same tires on those 2 bikes?
It’s not just the IGH; it’s also the belt. Belts have greater power loss, even more so if they are not installed correctly.
I’m happy with my P1.18 and can feel the difference when I switch (as well as the difference in weight). But I really like the fact that I just need to wash the belt with a hose, spray some silicone on it, and that’s it, every 500 km when it starts squeaking. (If its not squeaking I dont do anything)
When I’m without gearbox or IGH: I’m too stupid to look ahead and change gears in time. It’s OK while unloaded, but with full panniers it sucks.
Edit: I’m too stupid to shift with derailleur
I am yet again reminded that I made the right decision coughing up the extra money to get a Rohloff in my cargo bike
This is not an “insane power loss”. The actual difference is a few percent.
At worst you have bias, already thinking it’s bad and therefore concluding it’s bad.
95 vs 91 percent efficiency is not that crazy. Or frankly noticeable.
And no I am not reading the graph wrong
Would be interesting to see Enviolo on that chart, by reputation at least it’s the worst IGH for efficiency.
I truly wonder what kind of efficiency my chain full of sludge, grit and rust gets.
Efficiency at speed is not the only factor here.
I commute about 25 miles/day with a Specialized Turbo Vado 5.0 model that has a regular chain and SRAM derailleur. My commute runs diagonally across a suburban metro area and has about 30 stop lights and stop signs. So I’m always braking suddenly at red lights.
I would replace the SRAM derailleur with an IGH in an instant because half the time I stop quickly for a red light I find myself in the wrong gear. And starting back up from a dead stop in too high of a gear is very inefficient and tiring and your bike goes CLUNK CLUNK when you try to downshift while accelerating from a stop. An IGH lets you downshift when you are stopped. A derailleur and chain doesn’t allow this. Yes, you can train yourself to downshift at every stop but often in urban riding you brake fast and don’t have the time.
Downshifting is a bigger issue with e-bikes because you ride at a higher top speed and thus tend to cruise in higher gears and so need to do more downshifting at every stop.
But looking at this chart it is clear I want a Rohloff for my next e-bike if I ever get another one.