CRF 450x trike

[socs28]

Updates, I'll get pictures as I take it apart and put it back together. We ended up shaving 1/4" off the front brake support to center the front wheel, still have to trim the spacers to finish the front up. Waiting on my bar risers so I can run the forks a little high through the triples. I'm going to try to hookup the quad switches this weekend. We finished the subframe today by grafting the front of the crf subframe into the rear of the trx subframe. I think it came out really well. I ride sand so we will be doing a no airbox kit. I am now struggling with the exhaust. It seems with fitting the quad seat where looks right on the crf tank, it shortens the overall length and it looks like I need to cut about 3 inches out of the pipe. I'm not liking that idea. Also, the space to fit the pipe between the spring and the frame is very tight and is limiting my options. Did people that have done this with a yfz spring or the crf spring use an 06 up pipe or the 04-05? I also still need to mount the front fender. I am going to put everything together with the stock crf pipe this weekend so I can test ride it. Honestly, I am a little concerned about my rake angle. It feels a little stretched.

[socs28]

Update, it is pretty much together, the exhaust turned out to be way more of a pain than I had expected. I haven't seen anyone mention anything about it, but an aftermarket trx pipe, just does not fit without modification, so modify we did. I also went to a fox yfz shock with remote reservoir, that helped a lot. It needs a refill, which I should be getting done today. I think I'll be moving to an R frame instead of the X to steepen the rake angle a bit.

[socs28]

Uploading a couple photos. I am going to restart a thread as a build thread and go in as much detail as I can. Probably next week. When I move to the R frame this winter, I'll post pictures of modified parts. I had to go back to the crf shock because the yfz spring was too soft so especially with the X frame it was too raked out.

[Poco Loco]

Nice to see people making custom builds...What are your plans for the kick starter? You gonna cut out the rear fender or make the plastics hinge up and back? Would be cool to install a TRX 450 motor into the frame and have it kick forward. The gearing would be much better for a trike too. Just courious over here.

[Matt85'350x]

Uploading a couple photos. I am going to restart a thread as a build thread and go in as much detail as I can. Probably next week. When I move to the R frame this winter, I'll post pictures of modified parts. I had to go back to the crf shock because the yfz spring was too soft so especially with the X frame it was too raked out.

Anxiously waiting the more detailed pics.

[socs28]

I'm sorry I haven't gotten more pics out yet...life, you know. They will come. Poco Loco, on the kick start I was really excited about having it as a backup, and if I turned my foot just right it actually cleared. My plan was to cut it and rebend like another member had done. However, at some point putting things together I had loaded the bike into the truck and couldn't get it out of first gear. Come to find out, one of the nubs inside the case that the inside parts of the kick start screw into had broken off and lodged under the shift lever. So, at this point, it has no kick start. My understanding is the trx motor is wider and won't fit in this frame, but the X gearing works well anyway. 1st gear is the same as the quad and then it slowly widens out from there. At this point my only complaint would be the motor doesn't quite have enough to pull the top of 5th hard going into a stiff wind or on soft sand, so all that means is more power right? I plan on putting the R valves/Cam in it and see where it is then. If that's enough I'll probably leave it there. It already has a DASA pipe and air box eliminated. If I still need more than I'll have it ported.

[socs28]

OK, going to do my best to line out what went into the build. I'll start with the swingarm, I had Tyson Racing build it. He used the diameter of the yfz for the front tube, but I sent him these dimensions to set it up. Sprocket side tube is 49.85mm, 94.85mm gap in the middle, and 50.75mm tube on the side opposite the sprocket. These were with my digital micrometer, I'm guessing it's really supposed to be 50, 95, and 51, but what I used worked. I also had him make the gap for the knuckle attachment be 42mm to match the crf knuckle. If I use the yfz knuckle then it will need to be shimmed. I did end up using the YFZ dogbone part of the linkage because the offset wasn't right for the CRF. It bolted right on, but I am shimming (for now with washers) between it and the back knuckle mount.



He then did the main part of the swingarm with +2 yfz dimensions, then used the trx bearing carrier housing. I got the chain guide mounted locally and had to move the brake stay nub forward a bit. He got the sprocket alignment right on. For the bearings, I ended up getting a blaster/banshee kit, including the bolt, because the yfz dust covers on the end are too big for the chromalloy tubing. I lathed down the collars to the proper length, this was done through the guess and check method after getting as close a measurement as I could. Make sure you get a thin dirt bike chain, a standard chain will rub on your case. We also ended up with a banshee front chain rub that we had to dremel out to fit around the swingarm, it's just a doughnut. Lastly on the bolt, we ground a washer to fit the CRF frame and welded it to the end of the bolt because you can't get a socket in to hold it in to tighten it down. It's meant to use the frame as the stop. I believe that's it for the swingarm.

The triples are VTX, we had to move the steering stem over from the CRF, then used the CRF bearings. The bottom fork holes has to be bored 1mm and the top has to be shimmed. I used 3 wraps of .5mm aluminum It should only have to go 1mm, but that is what worked. We had to grind off the VTX steering stop and put our own on.

The front hub is 86 250R, we ground off the nub for the odometer. We used the 250R axle and then had a spacer made to fit around the threaded end to fit the hole in the CRF fork. The stock atc spacers on the axle were lathed to the proper length and we found a nut that fit the threading to lock it on. We ended up having to take a 1/4" off the mount for the front brake caliper to fit with the centered wheel and then welded the ATC front brake disk to the CRF disk to make that work. We used the original ATC front tire/wheel dimensions, which are an 11 x 8 inch wheel. This made fitting very tight. going with the new quad 10x7 would give much better clearance, but I wanted the size of the ATC for riding reasons. You can see in the last picture that the tire rubs slightly on the fork when you bottom out, centering is very important.



I used the trx front brake lever/reservoir, because the crf won't fit around a thumb throttle. I have setup the quad start button/kill/light switches, which was a challenge, because the wiring is quite different. I can detail that later if anyone wants it.

All my welding was done by John's Custom Fabrication in Coos Bay, Oregon. I mention it here because the most involved part was the subframe, they did a great job. We ended up measuring the height of a trx and working for that. We took the TRX and CRF subframes and grafted them together. I'm not sure this would be durable enough for dirt, but we ride sand all the time and I believe it will be OK. I'm attaching pictures to try to show this as best as we can. The most difficult part was clearing the shock reservoir. If/When I get a stiffer spring for the YFZ remote reservoir shock, this wouldn't be a problem.



The pipe was a problem, I don't know if an 04/05 would fit better. Maybe using a CRF header with a trx muffler, I don't know, but it was a problem, so we ended up cutting, bending and rewelding the header. With the CRF shock reservoir it is actually touching, but it does make it through. I will be wrapping it, but haven't gotten to that yet.



For pegs, we merged the CRF plate to a YFZ blingstar peg. I like them quite well so far. I wanted to maintain the breakaway feature of the CRF/ATC.



I have added the trailtech fan because it didn't like the treeshots too well without it, it's done fine since. I am waiting on an IMS 3.2 gallon tank, but I'm concerned it's not going to fit with the fan.

Hopefully that helps some people as there was a good amount of trial and error, I am sure I could have saved well over $500 if I had known some of these things up front, as now I have a number of useless parts lying around, but I guess that's the way it goes.

[socs28]

Updated pic, the only think I've done since this is switch to the IMS 3.2Gal tank which fits...just barely with the TT fan and just bumps on the left side fork, but I think once I switch the R frame the rake change may fix it.

[Dirtcrasher]

I'm sure you said it before, but what are those forks made for?? Just the dirt bike??

[socs28]

Yes, the forks are off the dirt bike.