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1 - is this configuration good, 140 back and 160mm front .
2 - Do you have a seller or brand you recommend on Aliexpress ?
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1) I tried 140/140 for a while, for emergency braking the front is a little short.
Even with my 68kg, a 160mm is a must for me now.
Even with the weight penalty
2) Deckas makes good and colorful floating rotors, I've been using them on my gravel for a year or two.
However they are only ISO( 6 bolts ), and you would need a CL adapter.
Thus adding an interface, with its potential issues.