The information in these books (Dialed and F6) is great. I do have one question. I am planning on upgrading from a 2008 Med S-works Epic to a 2021 Epic Pro. The geometry has changed drastically especially with the release of the 2021 bike. Based on your charts in the Dialed In book, you recommend a reach of 410mm for my height (5’ 8”). Based on the radically different geometry this puts me on a small frame. As you are very familiar with Specialized can you give me any insight into going longer with the new geo on the med frame (possibly shorter stem depending on SHO) vs. holding back and riding a small frame? I live in the SE USA and the most technical riding is done during my Xterra races at Oak Mountain (way less technical than out west).
1) Use the code in Dialed to sign up at www.llbmtb.com. You can use the Rider and Bike Calculator to model the fit of both sizes.
2) If you can, test ride both sizes.
3) I too am 5’8″. I recently rode the 2021 Epic EVO Pro in size medium. With a 35mm stem and SQlab 30X bars, it fit well. Here’s my review.
I hope this helps,