You'll have to look closely at the bio pace triples on eBay. Most of them, and really most bio pace from the 80's-90's came on Mountain bikes so most of the cranks are 175's, not 170 like most road cranks of the day. I had no problems with whatever when younger but I have found lately even 172.5's cause knee issues for me so look at your existing cranks and what you may bid on to make sure the length is something you can use.