The best replacement for spd pedals is speedplay.

The best alternatives to spd pedals are rated as following:
★★★★★  speedplay
★★★★★  look
★★  look pedals
★★  egg beater
★  spd sl pedals

Your alternative for spd pedals is not listed? Suggest!
Speaking about spd pedals, one probably shouldn't forget about normal shoes.

Other search terms related to spd pedals and their ratings are:
★★★★★ normal shoes
You have in mind a companion for spd pedals and it is not yet here? Propose!



Google Trends

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spd pedals
speedplay
look