Spd v spd-sl for indoor use

I would have guessed this had been discussed a million times but the search function found basically nothing.

Any opinions on the better pedal for Zwift use? Especially once the walking outside and clipping in issues of spd-sl are super minimized inside? Assuming a good fit and a stiff shoe, would there be any difference in power transfer?

I have both, and it’s a noticeable difference if you switch back and forth. However, if you’re sticking with one pair of shoes all the time, indoors and out - you’ll get used to whichever system you choose.

The larger SPD-SL cleat has more contact surface with its matching pedal. This provides a bigger platform, which results in a more firmly-planted feeling on your pedals. IMO, this is magnified on an indoor trainer vs. riding outdoors.

There’s also a practical question of how much walking you’ll do in these shoes. If they’ll be used outdoors, and you plan on walking a lot (especially on unpaved surfaces) - the SPD’s have a clear advantage.


There may be little difference in power transfer. Some people subjectively feel that the SPD-SL platform is a bit more secure than the SPD platform. I mean, the SPD-SL pedal is objectively wider, whereas the SPD platform does rely a bit on the lugs in your shoe contacting the cleat (I believe). I think the SPD platform should have a slightly higher stack height than SPD-SL (assuming similar price point). In my case, I like the SPD-SL platform better, and I think I feel like it’s more stable, but I’d be hard pressed to swear that my power transfer is materially worse. I actually use two bikes on my trainer, one with SPD and one with SPD-SL. I think this should be down to personal preference. For that matter, if you actually ride on the road, it should still be a matter of personal preference even though most people use SPD-SLs or other road pedals.

1 Like

Thanks guys

I got some road pedals.

Appreciate the advice