My recent purchase of a belt-driven, internally-geared bicycle has me relearning how to shift. The new Priority Eight from Priority Bicycles is built around a Shimano Nexus internally-geared hub. There are varying opinions on the Internet about how best to shift gears in these hubs. I take a look at the manufacturer recommendations and share my own experience so far.
I learned quickly as a child in the early 1970s that derailleur bike gear changes had to be made while pedaling the bike. One of my early memories is of wrenching the shifter lever on an older neighbor boy's brand new ten-speed only to have him go a bit ballistic on me over the fact that no one was in fact pedaling his bike at that moment. And of course, the gears did not shift.
Derailleur bike gear changes are best done while pedaling slower than the bike is moving. In a pinch it's possible to shift into easier rear cogs under load provided you shift just one gear at a time. If you stop for an intersection in a high gear and forget to downshift before stopping, then you'll be faced with wanting to simultaneously pedal hard to get up to speed and pedal easy so as to downshift in order to accelerate better.
Internally geared bikes such as the Priority Eight solve the intersection problem by enabling you to shift while the bike is stopped. You can shift anytime you're not pedaling, which is convenient for commuting.
You can also shift while pedaling. Specifically, Shimano's dealer documentation says that "you can shift gears while lightly pedaling," and that you should "reduce the force being applied to the pedals" while shifting. The documentation also says to "be sure to shift the shifting lever one gear at a time."
My experience on the bike so far is that ever-so-briefly pausing the pedal stroke lets you shift any number of gears in one go. Pause pedaling, choose a new gear, then resume. The sequence becomes second nature with practice, and it takes less time to do than to read this paragraph describing it.
Avoid shifting while pedaling hard. Especially avoid shifting multiple gears at once while pedaling hard. Think of the hub as analogous to an automobile transmission, and pausing your pedal stroke is analogous to pushing in the clutch.
It's also a good idea to periodically monitor your hub alignment. Do that by rotating your shifter into the Gear 4 position and noting the alignment of the two marks in yellow that you see in the following image. You're looking for at least a 2/3rds overlap, and I prefer better than 2/3rds.
You can correct any misalignment by rotating the adjuster knob where the shifter cable enters your shifter. Rotating the knob moves the inner marker back and forth. Align the marks. Shift into Gear 1 and then up to Gear 4 again to double-check your alignment. Repeat until you have it.
Tip: Rotate the adjuster knob no more than three or four clicks at a time. Double check often by shifting from Gear 1 back into Gear 4. You may not always see the effect of rotating the adjuster knob until after performing the Gear 1 through Gear 4 upshift sequence.
Adjusting hub alignment is cake. If you've ever sweated through derailleur adjustment, you'll be gobsmacked at how easily the Priority Eight's hub-shifting can be brought back to spec.
No matter the bike, it's best never to shift while pedaling hard. Always try and pedal slower than the bike is moving. You can shift the Priority Eight while coasting or stopped, and that's an advantage to anyone who commutes. Pause ever-so-briefly. Rotate the shifter. Resume pedaling. Simple!
I made reference to the Shimano Nexus Dealer's Manual (DM-SG0003-04-ENG) and the Shimano Nexus User's Manual (UM-37G0A-004-00-ENG) while researching this post, as well as to my own experience in riding the Priority Eight. While the Shimano manuals both say to shift "one gear at a time", the User's Manual does make reference to "using the shifting lever to multi-shift....". Thus, Shimano's own documentation is unclear and conflicting with respect to shifting multiple gears at once. However, I've had excellent success in multi-shifting my own bike while pedaling is paused.