There's a pretty good write-up here: https://forums.mtbr.com/general-discussion/carbon-frame-repair-1101743.htmlbooo. interested to see what you're doing for the repair. might try it on my old nomad. post steps?
That's the RFX rear end.Jeez, good luck with this. What frame is that?
Maybe next time go for the cheaper rake.
Looks solid.I literally just spent half the day sanding this thing down. This is the worst part of it, there's no real easy way to do it with the nooks and crannies/angles that have to be sanded. Power tools help a bit, but a lot of it just doesn't lend it'self to those kind of tools. The tape I wrapped with for squeezing the CF down was super annoying too. In retrospect I probably used too much and I probably should have gotten the no-stick wrap tape that they sell at composite shops for this purpose. Not sure if they had it, but again, this is the most time consuming part and anything to help make it go faster is nice.
Starting to resemble a seat-stay:
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Trying to show the difference in seat-stay size. Given the compromised structure, I wanted to build it up pretty big.
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Still quite a bit of sanding to go. You can't see the structural layers that were wrapped in the helix patterns, they are too far down.
I got a little bit of tape overlap at the edges, where I decided to wrap excess carbon and then later sand it down, but it's just not practical to sand down completely. I'll clean it up the best I can. The crack was about 2/3rds up the chainstay.
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It looks cool when you spray it with alcohol for cleaning:
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I was thinking of just leaving it raw, but you know, UV...so I'll clear coat it a few times, then spray it black, then a few more clear coats.
It was straight, although it cracked pretty well on the seat-stay, it didn't crack all the way through the stay, so maybe 1/2, but that's just one stay and there's far more structure overall reinforcing it. I took the triangle off the bike and it was solid, not bent or unable to remove The portion of the structure coming up from the BB area has another arm that attaches to the seatstay, so it's fairly difficult for it to be out of alignment. It basically doesn't "bend"...it cracks.Looks solid.
Even if you wanted to replace it, do you think Turner would have any replacements? Sounded like he was low on linkages when I broke the DHR a few seasons ago...
Out of curiosity why no dummy hub in the rear axle to make sure its straight?
Need to sideload that wheel on some flattish turnsBack in Black. Ripping the local freeride/dh-ish trails, probably at about 70-80% speed (which cases jumps, so even better testing!). No signs of issues.
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Oh, I did much better than that, steep drop ins that you can almost, but not quite boost, where the wheel gets jammed into certain lines that aren't in the same direction you are going. Time will tell though, but I hit it pretty hard today.Need to sideload that wheel on some flattish turns
I told my airworthiness buddies I'm counting it towards my A&P. They asked me what autoclave I used.This repair needs a 337 form.
I had thought about asking what you used to pull vacuum, but then I imagined it winding up in the no context thread.I told my airworthiness buddies I'm counting it towards my A&P. They asked me what autoclave I used.
As with Plummet's repair of his RM on mtbr, we are wrapping to eliminate voids, there are a few ways to do this and some specifically made non-stick products for it that make it easier, probably not 100% void free, but IME with my previous repair, good enough. The hardener cures the resin just fine at 60F, the day I was doing it was at least 70 and bright sunshine, so I picked a good day (relative to what we have to work with). It says do not cure below 40 on it and there are other hardeners that supposedly work better at lower temps, but my general composite knowledge says cooler curings results in weaker structures.I had thought about asking what you used to pull vacuum, but then I imagined it winding up in the no context thread.
It's kind of mind-blowing to me, but damn if it doesn't seem to be working fine (on two bikes). Someone on MTBR threw up the "proper weave, cure method, blah blah blah", but west-system is pretty simple and you just over-build the part, not like you are trying to make it the same 3 or whatever layers it was originally, pack that shit on and make it stronger. It also only adds a tiny amount of weight, so might as well overbuild it.Nice work! It’s amazing how easy it is to repair carbon frames.
Electrical tape doesn’t stick to epoxy and you can poke lots of holes in it with a pin to let out some epoxy and get a lighter laminate. You can use electrical tape to stop the epoxy from going outside of your work area too.
Also, heat shrink release tape would be ideal for that seatstay repair and make the sanding process much easier and faster. But hopefully you don’t need do anymore repairs in the future. You heat up the tape with a hot air gun and it squeezes out more epoxy and increases compaction. It comes off real easy and is pretty cool stuff.
For more complex shapes a vacuum bag setup is necessary however depending on the break, I bet you could get creative with a tube for an inflatable bladder inside some electrical tape. You just need compaction and squeeze out some resin between the layers. Most breaks are on convex shapes which are easy to fix with tape methods.
Yeah me too! It‘s way easier than I ever thought! I repaired a couple frames with electrical tape and pinholes (BCD did this technique a lot)) and then later heat release tapes. Then, I got a vacuum bagging setup last winter and build 4 super wide pow snowboards this past winter. I couldn‘t believe how good they rode. I wanna make more stuff.It's kind of mind-blowing to me, but damn if it doesn't seem to be working fine (on two bikes). Someone on MTBR threw up the "proper weave, cure method, blah blah blah", but west-system is pretty simple and you just over-build the part, not like you are trying to make it the same 3 or whatever layers it was originally, pack that shit on and make it stronger. It also only adds a tiny amount of weight, so might as well overbuild it.
No, but a housemate of mine from college runs his own composites company. He had been doing automotive composites, but then the company moved to Detroit to better support oem for GM. He stayed in Vermont and has expanded into other realms. He gets some funding from DARPA these days.Anybody else playing with carbon?
Looks like it needs to go on a fiber-rich diet? Does Turner have any swingarms in stock?
That's still way too much for something that old. They'd have better luck probably parting out the swingarms for people like me, but it'd still have to be pretty cheap. That's good for DT though, he moved that inventory. AFAIK, seeing other people that have asked, there are no frames/swingarms left at Turner. They still supply some of the hardware and small parts, but all the big stuff is gone.Turner RFX 27.5" Full Suspension Frame
Turner RFX 27.5" Full Suspension Frame The Turner RFX, first introduced in 1999, began life as one of the first purpose-built ‘free ride’ bikes renowned for excellent descending manners and efficient pedaling in a world where few bikes could do both. Subsequent models set new standards for...cambriabike.com
So another year and a half?Plan to run this until a new frame arrives.
Well yeah, like why else would I go through all of this to fix it.So another year and a half?
Agreed.That's still way too much for something that old. They'd have better luck probably parting out the swingarms for people like me, but it'd still have to be pretty cheap. That's good for DT though, he moved that inventory. AFAIK, seeing other people that have asked, there are no frames/swingarms left at Turner. They still supply some of the hardware and small parts, but all the big stuff is gone.
No use in keeping this thing going indefinitely, everything has it's time. The other vertical support had evidence of the same process going on, except much less advanced. I was still in the process of sanding in the picture. There are a few other areas I want to beef up or that got some excessive nicks over the years. Plan to run this until a new frame arrives. I had a time where I was running kind of an excessively low spring rate and I have to wonder if the damage wasn't mainly caused by that. I'm also pretty hard on bikes though, so nothing gets babied.