Hi all,
This may come off as a newbie question. If it has been discussed at length before I apologize, I have searched several related terms and not come up with anything relavent. My desire is to build a fat tire ebike using a mid-drive conversion kit, the Bafang BBSHD (aka M615) being, at the moment, my ideal motor as far as specifications. I have done some thorough research and feel that a mid-drive is superior to a hub drive for my application. The problem I am confronting is this: All of the fat tire bikes that I wish to use for this project have, by nature, exceptionally wide bottom brackets, the Giant Yukon 2 with its 137mm bottom bracket being a prime example. Other bikes on my desired list being the Surly Wednesday, Kona Wo, and Salsa Mukluk all have, as far as I know, bottom brackets well in excess of 130mm. Why is this a problem? According to the spec sheet, the BBSHD only allows for bottom brackets up to 120mm. My question to the brain trust is: What are my options? Are there any ready-made solutions to this? Is there any way to adapt the BBSHD to bottom brackets over 120mm? (I know an excellent machinist) Are there any other mid-drive conversion kit brands of similar specification which do accept 135-140mm bottom brackets which I can look at? Are there any bicycle models which take a 26x4 or larger tire that have a bottom bracket under 120mm? (unlikely, I know) I appreciate any advice. I am mechanically inclined, but not extremely well-versed in ebike systems (yet... which is why I am here).
This may come off as a newbie question. If it has been discussed at length before I apologize, I have searched several related terms and not come up with anything relavent. My desire is to build a fat tire ebike using a mid-drive conversion kit, the Bafang BBSHD (aka M615) being, at the moment, my ideal motor as far as specifications. I have done some thorough research and feel that a mid-drive is superior to a hub drive for my application. The problem I am confronting is this: All of the fat tire bikes that I wish to use for this project have, by nature, exceptionally wide bottom brackets, the Giant Yukon 2 with its 137mm bottom bracket being a prime example. Other bikes on my desired list being the Surly Wednesday, Kona Wo, and Salsa Mukluk all have, as far as I know, bottom brackets well in excess of 130mm. Why is this a problem? According to the spec sheet, the BBSHD only allows for bottom brackets up to 120mm. My question to the brain trust is: What are my options? Are there any ready-made solutions to this? Is there any way to adapt the BBSHD to bottom brackets over 120mm? (I know an excellent machinist) Are there any other mid-drive conversion kit brands of similar specification which do accept 135-140mm bottom brackets which I can look at? Are there any bicycle models which take a 26x4 or larger tire that have a bottom bracket under 120mm? (unlikely, I know) I appreciate any advice. I am mechanically inclined, but not extremely well-versed in ebike systems (yet... which is why I am here).
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