mountainfun Posted August 24, 2021 Share Hi I have RaceFace SIXC carbon cranks, 170mm. Awesome, except that the pedal insert has come loose. (Thread not stripped.) Apparently that cannot be fixed, but any comments on that also welcome. What I was thinking is whether I can go extreme and shorten the cranks to say 162,5. This would involve cutting etc.. It would need to be done by a very seasoned carbon expert. I'm sure the right answer is "no", for various reasons, but I thought worth a shot. Thanks JL Edited August 24, 2021 by mountainfun Link to comment Share on other sites More sharing options...
Mamil Posted August 24, 2021 Share I'm no carbon expert at all but considering the cranks are one of the parts of the bike that take the most pressure I would be disinclined to trust my well being to something that had been so modified. Watching with interest for the proper bike people replies Rudi33, DieselnDust and Vetplant 3 Link to comment Share on other sites More sharing options...
lechatnoir Posted August 24, 2021 Share I'm with Mamil. Rather take the proper route and get new cranks. Whatever savings you have upfront are likely to be horribly offset if, or likely WHEN, the crank fails. I'm not an expert on carbon cranks, but I am an expert on Youtube moments and this is surely one waiting to happen DieselnDust, Vetplant, Sid the Sloth and 3 others 4 2 Link to comment Share on other sites More sharing options...
Stavros94 Posted August 24, 2021 Share @mountainfunpost a picture if possible ? Long Wheel Base 1 Link to comment Share on other sites More sharing options...
DieselnDust Posted August 24, 2021 Share One would have to be familiar with the detailed design of the crank to make a meaningful comment here. You may want to consult with the caron repair experts. By way of example, if the insert is bonded into the carbon arm it may be possible to move it and reconstruct the bonding area in the new location you require. If the pedal thread is tapped into a aluminium spine inside the crank then that threaded section will have to be retapped in the new location. Since its typically a 9/16 x 20tpi imperial thread the new thread will have to be tapped at least 20mm away so already the crank is a lot shorter than you require. Edited August 24, 2021 by DieselnDust Vetplant 1 Link to comment Share on other sites More sharing options...
TNT1 Posted August 24, 2021 Share 25 minutes ago, mountainfun said: Hi I have RaceFace SIXC carbon cranks, 170mm. Awesome, except that the pedal insert has come loose. (Thread not stripped.) Apparently that cannot be fixed, but any comments on that also welcome. Why can't that be fixed? That would be first prize, take it to one of the specialist carbon repair places and see? DieselnDust 1 Link to comment Share on other sites More sharing options...
ChunkyMonkey Posted August 24, 2021 Share Please put your first ride on GoPro….. after shortening the cranks… I need to see this…. ???????? Vetplant, Comrade J and Long Wheel Base 2 1 Link to comment Share on other sites More sharing options...
RobertWhitehead Posted August 24, 2021 Share I believe anything can be done and or fixed, my question is just whether or not it's going to be beneficial. I mean there's sooooo many other factors to consider, makes me wonder Vetplant 1 Link to comment Share on other sites More sharing options...
mountainfun Posted August 24, 2021 Share Thanks for all the comments, I really appreciate the quick replies. I'm on the same page, just wanted to see if any other options. I did speak to one of the carbon experts, and the advice corresponds! Link to comment Share on other sites More sharing options...
mountainfun Posted August 24, 2021 Share Link to comment Share on other sites More sharing options...
mountainfun Posted August 24, 2021 Share Link to comment Share on other sites More sharing options...
BogusOne Posted August 24, 2021 Share I have fixed many cranks in the past. Some with great success still in use after years of use, some not so successful. All depends on the user or intended use. Can it be done? Most definitely! Would I recommend it, definitely not, Not worth the effort or possible injury afterwards should anything go wrong. Can it be shortened? Most definitely. Would i Recommend it, possibly... Would I do it? Hell no. Just for the sake of having carbon cranks absolutely not. Plenty of cheaper brand new options available in alu that is just as good.... If you absolutely must have it shortened speak to Greame Kidson @CarbonNinja He is the only one that I would recommend to shorten carbon cranks. I know he has shortened cranks successfully in the past ???? DieselnDust, TNT1, Jewbacca and 3 others 6 Link to comment Share on other sites More sharing options...
Jewbacca Posted August 24, 2021 Share 2 minutes ago, BogusOne said: I have fixed many cranks in the past. Some with great success still in use after years of use, some not so successful. All depends on the user or intended use. Can it be done? Most definitely! Would I recommend it, definitely not, Not worth the effort or possible injury afterwards should anything go wrong. Can it be shortened? Most definitely. Would i Recommend it, possibly... Would I do it? Hell no. Just for the sake of having carbon cranks absolutely not. Plenty of cheaper brand new options available in alu that is just as good.... If you absolutely must have it shortened speak to Greame Kidson @CarbonNinja He is the only one that I would recommend to shorten carbon cranks. I know he has shortened cranks successfully in the past ???? I was in the middle of recommending Graeme when your reply popped up! BogusOne and DieselnDust 2 Link to comment Share on other sites More sharing options...
JA-Q001 Posted August 24, 2021 Share Do you want to shorten just to save the crank? Shortening is a very complicated and laboursome job. You cannot just drill a hole and tap it. It is quite easy and safe to just fix the loose insert. the hardest is cleaning the cavity, then drilling a hole to inject resin into the cavity formed by the loose insert and then keeping it aligned while setting, so that your pedal does not have a wobble. Graeme can fix it back to perfect for you, check his instagram, he has done it loads before. And PS, stop using crank boots. Edited August 24, 2021 by JA-Q001 TheoG and TNT1 1 1 Link to comment Share on other sites More sharing options...
TheoG Posted August 24, 2021 Share 15 minutes ago, JA-Q001 said: Do you want to shorten just to save the crank? Shortening is a very complicated and laboursome job. You cannot just drill a hole and tap it. It is quite easy and safe to just fix the loose insert. the hardest is cleaning the cavity, then drilling a hole to inject resin into the cavity formed by the loose insert and then keeping it aligned while setting, so that your pedal does not have a wobble. Graeme can fix it back to perfect for you, check his instagram, he has done it loads before. And PS, stop using crank boots. Agree. The insert was bonded in there originally anyway. No reason why its not possible for a carbon expert to build up and bond it in again. DieselnDust and Comrade J 2 Link to comment Share on other sites More sharing options...
stefmeister Posted August 24, 2021 Share Whenever I read something about Raceface carbon cranks, it's about them failing. DieselnDust and M L 2 Link to comment Share on other sites More sharing options...
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