Has any heard of a 79BCD before? I’ve got an old shimano Nexave crank set, where, I want to repurpose the cranks and convert to a 1×8.
I dont have much info on the crankset itself, I just know that it’s probably this: https://si.shimano.com/en/pdfs/ev/FC-T401-1691/EV-FC-T401-1691A.pdf
Some pics attached too!
Could it be reused? Or would it be best to just buy new cranks?
by ch0jii
2 Comments
I think it is the same situation as FC-MC12/14/16, a nonstandard BCD bolt circle with a riveted-together 3x chainring set. Only compatible with its dedicated spare part, so you can’t use it with any aftermarket chainrings.
79? i’m almost positive you have a 74 BCD [https://hostelshoppe.com/pages/chainring-bolt-circle-diameter-measurement?srsltid=AfmBOoosNBowzZW8JFJjAPWulP8EjkbkZwLgAvOaHSVjXMtIy2SQdZan](https://hostelshoppe.com/pages/chainring-bolt-circle-diameter-measurement?srsltid=AfmBOoosNBowzZW8JFJjAPWulP8EjkbkZwLgAvOaHSVjXMtIy2SQdZan)
changing the Nexave cranks to a 1x is a pain, since the rings are riveted and the only BCD on your cranks will result in chainrings made for the granny gearing size. (ie smallest CR)
the cost of a new 1x square taper crank w/ chainring is roughly $20-35, so just replace the cranks so you can choose a decent chainring tooth count for your specific needs