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Part 1: Fit­ting the Driv­e­train into the Mod­i­fied FXR Frame

What be­gan with two guys, a 1993 H-D FXRP with a blown mo­tor, and a bot­tle of Tul­lam­ore Dew has turned into a bike build that has never been at­tempted be­fore. Like most mon­u­men­tal bike builds, this one started with a large amount of hopes and dreams. Then we added a boat­load of skill and am­ple amount of pa­tience to the mix. The idea was drunk­enly dreamed up by me and Danny Wil­son, aka Mo­tor Witch. The mat­ing of a 2018 Harley-david­son Mil­wau­kee-eight driv­e­line into the ven­er­a­ble FXR chas­sis was the game plan. We orig­i­nally wanted to find a crashed 2018 Road King and jack it for its driv­e­train and wiring har­ness, but we de­cided to just ask the fine folks at Harley-david­son to part­ner with us on the build and to sup­ply us with the parts to make this bike a re­al­ity. And they did! Speak­ing of part­ners, Danny and I both knew we fall short in the met­al­work­ing depart­ment and that this bike was go­ing to need a lot of it. That is why we called in fab­ri­ca­tor ex­traor­di­naire Justin Cole­man, from Torch In­dus­tries. We also rang up Big Chris, from FXR Di­vi­sion, who knows the ins and outs of the chas­sis and has done many funky and fresh FXR builds with all sorts of mo­tors and trans­mis­sions. Af­ter a meet­ing over some hot­ter-than-hell Thai food, a deal was made, the team was formed, and we were all ready to get to work on the M8FXR.

The terms next level, ground­break­ing, and game changer have been thrown around so many times in the realm of cus­tom bikes that when a build such as this comes to be there are re­ally no ad­jec­tives left with which to de­scribe it. This is no Twin Cam swap where you just cut out a cross-mem­ber, jam the thing in the frame, and throw a car­bu­re­tor on it. This was go­ing to be fab work done by a team of guys who, com­bined, have more than 100 years of real-deal mo­tor­cy­cle-build­ing and met­al­work­ing skills. We knew go­ing into it that it wasn’t go­ing to be easy be­cause the mo­tor is very dif­fer­ent from the H-D Evo­lu­tion that came in the bike. Plus, we wanted to use a stock 2018 H-D wiring har­ness with CAN bus elec­tron­ics so the bike could take ad­van­tage of a big elec­tron­i­cally con­trolled throt­tle body and ac­cu­rately be per­for­mance tuned on the Dyno when com­pleted. And so, we started the build with much wide-eyed op­ti­mism.

Know­ing that we had no guide­lines to go on and that the M-8 en­gine and trans­mis­sion were go­ing to be in and out of the FXR frame more than a few times, Danny dis­as­sem­bled the brand-new fac­tory Harley-david­son en­gine and re­moved rolling assem­bly and trans­mis­sion guts to make it lighter and eas­ier to move around. The empty en­gine and driv­e­line were brought from Buddy Stubbs H-D in Cave Creek, Ari­zona, where the bike is be­ing put to­gether, to FXR Di­vi­sion in Phoenix. Justin, Chris, and Danny then got busy fig­ur­ing out what

needed to be done to get the M-8 to ac­tu­ally fit into the FXR frame. We all agreed that we wanted the M8FXR to look as if Harley-david­son built this bike from the fac­tory. Danny first placed the mo­tor into the frame with­out the top end on it so Justin could bet­ter as­sess what needed to be done on the bot­tom frame rails. Once that was done, a set of Chop­per Hauss front mo­tor mounts “bor­rowed” from Ram­jet Rac­ing was dras­ti­cally mod­i­fied to work with both the frame rails and the Mil­wau­kee-eight bot­tom end. Af­ter many more mea­sure­ments were made to both the frame and the en­gine, it was de­cided that the bot­tom of the frame’s back­bone needed to be se­ri­ously sec­tioned so the Mil­wau­kee-eight’s “bub­ble head” top end and oil­ing sys­tem would prop­erly fit.

Due to the in­crease in horse­power with the new mo­tor, Justin also had to make a se­ries of braces and gus­sets on both front and rear for the frame, as well as turn the orig­i­nal lower cross-mem­ber brace into a mount for an H-D Dyna jiffy stand. Once the frame was deemed straight, Justin fin­ish-welded it to mimic the stock welds. Justin also smoothed the hy­dro­formed back­bone so it had the same look as it did from the fac­tory. Once all torch­work was done, the frame was sent off to be chem­i­cally stripped of all the orig­i­nal fac­tory paint. Though this fea­ture makes it look like the job of get­ting the Mil­wau­kee-eight into the FXRP frame was rather easy, we can as­sure you that it took al­most three months of trimming, cut­ting, weld­ing, and metal-fin­ish­ing the frame to make it look as if it rolled off the Harley-david­son fac­tory floor.


1 1. Justin Cole­man, of Torch In­dus­tries, took a large amount of ma­te­rial out of the back­bone of the FXR to make room for the Mil­wau­kee-eight en­gine.

22. Justin and Danny “Mo­tor Witch” Wil­son in­stalled the H-D M-8 mo­tor into the bike for what seemed like the 50th time to get all the clear­ances and fab­ri­ca­tion points cor­rect.

3. The FXR frame was all cleaned up and stripped of its old paint, so you can bet­ter see what was re­ally done to it. 3

4.The down­tubes have two brac­ing tubes welded onto them, as well as mod­i­fied Twin Cam mo­tor mounts from Chop­per Hauss. 4

5.The en­gine cross-mem­ber has been re­placed with a cus­tom jiffy stand mount, while an­other brace was made at the rear of the frame, where the 2018 six-speed bag­ger trans­mis­sion will re­side. 5

6.Danny in­stalls the Mil­wau­kee-eight en­gine for fi­nal mock-up. 6

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