I have an old "
Shimano SG A-52-42-30" Crank, but I need to replace the
42 with a 36 Chain Ring.
I searched in my city but had no luck.
What measurements should I look for? Or should I replace the whole Crank? (i need to keep the 52 + small budget)
I live near Spain and can buy from its "Decathlon."
https://www.decathlon.es/es/search?N...to%20bicicleta
Thank you