HOW TO MAKE UNICORN HARDWAREBackground: I recently traded my stationary backrest / sissy-bar for a “Unicorn”, the OEM Yamaha quick-release backrest. I prefer the look of the bike without the backrest and since my wife only joins me once a year or so I thought the quick release version would be the way to go. However, my Unicorn did not come with the mounting hardware, and it didn’t seem like too many folks had success attempting to re-create the hardware… so here is my story…Step 1: Buy Some Parts!I took a chance that mama-yamaha would try to use the same size parts across bikes, so I ordered the Eluder XV1900 QR Backrest Mount Docking Kit 2DG-F84U0-V0-00. I found it for $117 with shipping from partspak.com. The kit comes with hardware for both sides, but here is a picture of what it comes with for one side:The Eluder uses a different thread size than the Raider, so it isn’t just a ‘bolt on and go’ situation.I did not use the following items; #1, #4, #8. I also didn’t use the S.S. spacers, items #3, but they are pretty nice so I wouldn’t just toss them out… I’m sure they’ll come in handy in a year or two!Step 2: Make Rear PinsThe stock design of the QR hardware (from what I’ve seen in pictures) was designed to allow the rear pulley to rotate or spin. I assume this makes it a touch easier to attach/detach the backrest. I wanted to retain this feature. The Eluder kit has the correct size bushing to allow the pulley to rotate but it’s machined into the bolt (Item #6). Thankfully, this little bushing section is threaded with the correct thread size for our fender strut bolts! So the next step for me was to cut off the bushing. I used a thin cutting wheel on my angle grinder and it sliced right threw it.I was missing a few parts to get the rear pins finalized so I ordered them from McMaster. Note: I could have gone with S.S. for the spacers, but I wasn’t completely certain the sizes I ordered would work so I bought aluminum. Now that I see the finished product looks fine, I’ll stick with them for a while. Anyway, here is an exploded view of the rear pins ready to be bolted on the bike.Step 3: Make Front PinsWhat I didn’t realize when visually looking at the Eluder hardware was that the front pulley (item #2 in first pic) is not the correct size. The small diameter on the Eluder pulley is 14mm. When I first mounted my Unicorn it was sitting too far back for the rear pulley to engage. Thankfully I received a mechanical drawing from another forum member and discovered my issue; the small diameter on the front pulley for the Raider Unicorn is only supposed to be 12mm.Well, I don’t have a full machine shop, but I figured, “How hard could it be to take off 1mm of material radially?”I first taped the front pulley onto the remaining part of the rear bolt.Then I stuck it in a drill to spin the bolt while holding a file against the small diameter.I ran each side of the file for about 30 seconds and then could feel it getting ‘clogged’ with metal chips so I had to stop and brush the chips out with a metal brush. I used calipers every time I stopped and found that I was taking off about 0.33 to 0.50mm each time. After a few short minutes I was able to get the small diameter down around 12mm. I first tried them around 12.25mm diameters and still found it was impossible to get the rear of the Unicorn to pop on, so I kept going. I think both of mine came in between 11.85 and 12.00mm. I would advise you do a test fit once you get below 12.5mm to make sure you don’t overshoot.Here is an exploded view of the front pins ready to be bolted on the bike. Note the electrical tape on the bolt… The ID of the pulley is too big for our bolts so I used the tape to fill in the space. There isn’t any radial load so I expect the tape to last forever. If it does give out then I’ll grab some ¼” ID tubing and make some spacers.Step 4: Mount the Unicorn!I figured you would like to see a few pics of the final product, so here they are. I might take the aluminum spacers off and polish them, but other than that I’m pretty happy with how it came out.Special thanks to sbarrows67, Fiddles, and SicarioPeponi. They provided some much needed pictures and dimensions to get me moving.An especially big thanks to SicarioPeponi who sent me CAD drawings of the pins. I put them into Solidworks and sent the models out for quote at a prototype machine shop. Unfortunately they were coming in around $85 each, so $340 for all four corners… I had already spent the $117 so I kept going with the method used above. With the additional bolts and spacers I needed I’m around $150.Hopefully this post will be useful to someone in the future.
good job! Looks like great, any rattles when attached?
Quote from: Fiddles on Jun 03, 2020, 07:24:43 pmgood job! Looks like great, any rattles when attached?No rattles from the hardware, but I haven't ridden around with the Unicorn on her yet. It sure feels like a tight fit though.My understanding from OLD posts is that some folks have had the backrest fall off while riding? I honestly don't see how that is possible unless you forgot to remove the key. Once it's on the pins and you remove the key, the frame that locks the rear pins does not open up nearly enough to be able to pull the whole backrest off. Is there something more I should watch out for when I use it? I won't ever ride around with it for more than a day, but I certainly don't want to lose it off the bike! Oh... and I don't want to lose the wife off the back of the bike either...
Quote from: Dirtiegirtie on Jun 04, 2020, 07:25:36 amQuote from: Fiddles on Jun 03, 2020, 07:24:43 pmgood job! Looks like great, any rattles when attached?No rattles from the hardware, but I haven't ridden around with the Unicorn on her yet. It sure feels like a tight fit though.My understanding from OLD posts is that some folks have had the backrest fall off while riding? I honestly don't see how that is possible unless you forgot to remove the key. Once it's on the pins and you remove the key, the frame that locks the rear pins does not open up nearly enough to be able to pull the whole backrest off. Is there something more I should watch out for when I use it? I won't ever ride around with it for more than a day, but I certainly don't want to lose it off the bike! Oh... and I don't want to lose the wife off the back of the bike either... I've known of three instances when the backrest came off the bikes - three different Raiders after hitting bumps in the road - there's a reason Yamaha stopped making them and that might be why. The hardware you made looks good and hope it all works for you.
Never had an issue in the 10 years I had mine, of coming loose. In fact I had to yank it pretty hard to get it off. The only issue i had is if i did not reach underneath and help the mechanism release as I turned the key it wanted to twist the key in the lock.
Just to leave the info here as a warning to anyone who sees it ... I had my brand-new (to me) unicorn backrest fall off on my break-it-in ride because I turned the key all the way to "unlocked" and removed it, instead of all the way to "locked". I didn't know the key could be removed at either end. Learned the extremely hard way. Arrived at my destination with no backrest. Doubled back and found I had lost it just after I hitting a not-repaved-yet-just-repaved ridge of asphalt along the way.