Mowgli Posted December 27, 2008 Report Share Posted December 27, 2008 Hey,Tried searching but couldn't find anything, apologies if i didn't look hard enough.my freewheel died today, not by skipping but by a third of the chain ring outer breaking clean off, see pics below......What could this be caused by? Has anyone had this happen before?Regards Quote Link to comment Share on other sites More sharing options...
J Trials 31 Posted December 27, 2008 Report Share Posted December 27, 2008 That's sick! No, mine has been fine for a long time. Runs smooth and have never had problems except for a skip whenever the chain got a little loose. Quote Link to comment Share on other sites More sharing options...
Adam-Griffin Posted December 27, 2008 Report Share Posted December 27, 2008 I believe Tom Booth had the same problem with his, think it was only a few days old aswell Maybe a manufacturing defect, best off giving Tensile/Onza a ring on Monday and seeing what they have to say, how old is it ? How did you manage it ? Quote Link to comment Share on other sites More sharing options...
PaRtZ Posted December 27, 2008 Report Share Posted December 27, 2008 savage, but im sure I saw something like that before Crap I hope mine doesn't suffer the same fate Quote Link to comment Share on other sites More sharing options...
Muel Posted December 27, 2008 Report Share Posted December 27, 2008 I'm pretty sure that it was just on one batch of them where the outer race was too brittle, just ring up Onza, I think they offer a free replacement, if not then it'll be the half price replacement. Quote Link to comment Share on other sites More sharing options...
Mowgli Posted December 27, 2008 Author Report Share Posted December 27, 2008 Yeah, i only got this in november.have emailed tarty as i bought it from them. luckily i just rode up this small bank when i first got out riding so i wasn't gaping or putting any major force on it. Quote Link to comment Share on other sites More sharing options...
Bionic Balls Posted December 27, 2008 Report Share Posted December 27, 2008 I'm pretty sure that it was just on one batch of them where the outer race was too brittle, just ring up Onza, I think they offer a free replacement, if not then it'll be the half price replacement.could be...very hard to tell from the pictures, but considering the time you've had it and how it's broken, it probably was just a brittle fracture- possibly a batch weren't heat treated properly...to be honest...i'm not sure how much effort onza put into investigating this sort of thing, but if it's happened to others (as the above suggests) they may consider replacing it. They did not like the idea of me looking at my broken cranks under an SEM...wonder what they were afraid of...?adam Quote Link to comment Share on other sites More sharing options...
Muel Posted December 27, 2008 Report Share Posted December 27, 2008 I did seem to remember it was that the heat treating/hardening process had gone a bit wrong on that batch, but I wasn't certain so I didn't want to say too much. Quote Link to comment Share on other sites More sharing options...
Jordan GU Posted December 27, 2008 Report Share Posted December 27, 2008 I have never seen any freewheel brake like that :oDid you hurt yourself when it broke. Quote Link to comment Share on other sites More sharing options...
Mowgli Posted December 27, 2008 Author Report Share Posted December 27, 2008 Did you hurt yourself when it broke.Nope Quote Link to comment Share on other sites More sharing options...
Jordan GU Posted December 27, 2008 Report Share Posted December 27, 2008 Nope Lucky you wernt about to do a 10ft drop Quote Link to comment Share on other sites More sharing options...
psycholist Posted December 28, 2008 Report Share Posted December 28, 2008 That looks like fatigue cracking with a ductile final failure. It's blurred, but there seems to be a discoloured area in the broken cross section which indicates an initial crack that was growing over time. The white grainy surface is a ductile failure in the remaining material. A brittle failure would have a shiny faceted surface... Nice work BTW ... Quote Link to comment Share on other sites More sharing options...
Tom_ Posted December 28, 2008 Report Share Posted December 28, 2008 That looks like fatigue cracking with a ductile final failure. It's blurred, but there seems to be a discoloured area in the broken cross section which indicates an initial crack that was growing over time. The white grainy surface is a ductile failure in the remaining material. A brittle failure would have a shiny faceted surface... Nice work BTW ...Well la, dee, da mr. Engineer Quote Link to comment Share on other sites More sharing options...
Bionic Balls Posted December 28, 2008 Report Share Posted December 28, 2008 i'm not so sure... this picture: shows a thumbnail shaped darker area like you said (maybe fatigue...maybe just grease?)...but there's no way that it's a ductile failure in my mind.. Quote Link to comment Share on other sites More sharing options...
Bigman Posted December 28, 2008 Report Share Posted December 28, 2008 i'm not so sure... this picture: shows a thumbnail shaped darker area like you said (maybe fatigue...maybe just grease?)...but there's no way that it's a ductile failure in my mind..Got to agree with Adam, Doesn't look to be a ductile failure. But i have heard of a few going like this, as has already been mentioned there was a batch that seemed to have this problem.Adam Quote Link to comment Share on other sites More sharing options...
Tom Booth Posted December 28, 2008 Report Share Posted December 28, 2008 I believe Tom Booth had the same problem with his, think it was only a few days old aswell Twas me indeed I broke 3 I'm pretty sure that it was just on one batch of them where the outer race was too brittle, just ring up Onza, I think they offer a free replacement, if not then it'll be the half price replacement.The outer race missed the final stages of heat treatment on a batch, hence there prone to shattering etc (from the works of Joe at Onza)Nope Glad you didn't. I went face first into the wall I was gapping too. Bloodey hurt aswell Here's my first attempt thou... Quote Link to comment Share on other sites More sharing options...
Bionic Balls Posted December 28, 2008 Report Share Posted December 28, 2008 The outer race missed the final stages of heat treatment on a batch, hence there prone to shattering etc (from the works of Joe at Onza)haha...so sad i know...but that's exactly what i thought of- i was recently involved with the failure investigation of a high pressure steam valve casing from a power station in pakistan...exactly the same problem ..shoot me? Quote Link to comment Share on other sites More sharing options...
raimund-aut Posted December 29, 2008 Report Share Posted December 29, 2008 Something similar happened to me with a really cheap freewheel called esjot in 1995. The weird thing back then was that, after it exploded, I couldn't find any part of the outer chainring anymore. It exploded in a way that the pieces got lost somewhere in the lawn. And I bit a pallet. yummy. (ouch) Quote Link to comment Share on other sites More sharing options...
Lar Posted December 29, 2008 Report Share Posted December 29, 2008 I've not seen anything like that before, apart from my old dicta after i cut if with an angle grinder to get the fecker off my cranks. Just recently got a tensile though, so i hope it don't go the same way as above.... Quote Link to comment Share on other sites More sharing options...
Mowgli Posted December 30, 2008 Author Report Share Posted December 30, 2008 the darker area is just the grease etc from the inside of the freewheel, when it broke all the way through the metal was clean as a whistle. Quote Link to comment Share on other sites More sharing options...
craigjames Posted December 30, 2008 Report Share Posted December 30, 2008 ouch moggles, you basher. i jokes. mine was fine, i only stopped using it because it started to skip, as prawn said, get a king its the way forward. Quote Link to comment Share on other sites More sharing options...
eskimo Posted December 30, 2008 Report Share Posted December 30, 2008 I had one break exactly like that before. That was a long time ago and it was probably a Shimano or Dicta freewheel though. Quote Link to comment Share on other sites More sharing options...
downhill_rob2@hotmail.com Posted December 30, 2008 Report Share Posted December 30, 2008 (edited) Iv snapped 3 ACS claws like this back in the day, and one of my tensiles done the same lol, not a clue why...Is it FFW that your running btw? If it is, maybe its that thats causing it?King edit: haha, TF wont let me type F T W without it going into the stars like *** Edited December 30, 2008 by terror-error Quote Link to comment Share on other sites More sharing options...
Bionic Balls Posted December 30, 2008 Report Share Posted December 30, 2008 found this from 2005:http://www.trials-forum.co.uk/forum/index....c=57949&hl=had it a fair ol' while....<div class='bbimg'></div>Anyone know if white industries do warranty on stuff like that? Or is that part replaceable? cheers,adam it happens Quote Link to comment Share on other sites More sharing options...
Mike Poyzer @ Onza Posted December 30, 2008 Report Share Posted December 30, 2008 Just return it to us and we will send you a replacement FOC. Tensile Optimum, 2, Lowdham Street, Nottingham. NG3 2DP. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.