Why no multishift?

[roilev]

Why does SRAM forbid multishift on EMTBs?
When I can change multiple gears with multiple clicks so much faster?
Multishift on my analog bike is so slow - I would assume it is much better for the components on EMTB too.

 

[RustyIron]

Back in the old days when everyone was rollin' Amish Style, people would sometimes break chains by shifting under heavy load. Doing multiple shifts under heavy load exacerbated the problem.

Nowadays the same problem still exists, except we have the added power of the motor, PLUS the overrun. Beginners might be tempted to run through the whole cassette, with the chain lagging behind, while under power. A broken chain will be the result. That's why SRAM recommends one gear per click of the shifter.

Personally, I always ran my AXS shifters in multi-shift, but I'm very aware of how fast I'm shifting and how fast the chain is jumping cogs. I never broke a chain on my AXS bikes.

Nowadays we have the tranny derailleurs and flattop chains. While I still try to shift smoothly when conditions allow, I'm not averse to just slamming it gear to gear.

So if you're hyper-aware of the quality of your shifting, go ahead and set it to multi shift. If you're the sort of rider whose shifting sounds like a rock crusher, set it up to shift one gear at a time.

 

[Mr 'P']

Chains aren't designed to take much if any side load. Pushing chains from one sprocket to another, changing gear, puts the chain under side load. Pushing the chain across multiple sprockets at the same time increases that side load considerably. Even without the extra load provided by the eMTB motor many of us have experienced a broken chain caused by the side load imposed by the derailleur pushing the chain sideways while chaining gear especially if we are pushing the pedals hard at the time. Its not a good idea to change gear 'under load', you can hear the result. Changing multiple gears at once is worse because the side load is so much more and with the considerable load provided by the motor increases the likelihood of a broken chain.

 

[sethimus]

because most ebikers need to be saved from themselves

 

[roilev]

You can still shift manually. That's not prohibited for E-MBTbs. And, indeed, much faster than multishift. Which totally negates the "save the chain" idea ?!?