http://singletrackworld.com/forum/topic/cracks-in-cranks en-US Wed, 30 May 2012 01:18:07 +0000 http://bbpress.org/?v=1.0.2 q http://singletrackworld.com/forum/search.php http://singletrackworld.com/forum/topic/cracks-in-cranks/page/3#post-776810 Mon, 19 Oct 2009 23:22:46 +0000 no_eyed_deer 776810@http://singletrackworld.com/forum/ <p>On having a <em>&#39;flaking shaft&#39;</em>:</p> <p><blockquote>....though it would be the reason that i replace them (or <strong>the one i use with the wife</strong>)</blockquote></p> <p>...the mind boggles (tee hee!) <img src="http://singletrackworld.com/forum/my-plugins/bbcode-buttons/default/icon_lol.gif" title=":lol:" class="bb_smilies" alt=""/> </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/3#post-774414 Mon, 19 Oct 2009 13:22:27 +0000 monkeyp 774414@http://singletrackworld.com/forum/ <p>It all depends on the original design intent and what the assumptions were when the analysis was done on the design (assuming some structural analysis was carried out).</p> <p>If the analysis assumed this was a closed volume, then that will give different stress results to an open volume of metal. However, even if this was the case, then seeing as Shimano obviously know of the issue I would assume that any analysis has been re-visited with this in mind. In addition, assuming that the cranks have been physically tested (which I am certain they will have been) and that the test samples are representative of the whole population then this effect will have been considered in this process.</p> <p>Madison should be applauded for responding to the concerns so quickly and publicly. </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/3#post-774162 Mon, 19 Oct 2009 12:30:25 +0000 Stu_N 774162@http://singletrackworld.com/forum/ <p>The Madison bloke&#39;s explanation sounds entirely plausible to me. It&#39;s just a byproduct of how they are made - no different to machining marks on stems or beading on welds. </p> <p>I had a look at my XTs and one side has a fine line on it, on the other side the end of the crank is sort of not really there any more as it&#39;s presumably been grounded against rocks. </p> <p>Frankly the Shimano cranks are amazing things for the money and am not remotely worried. As for the bloke who reckons he&#39;d be better off on Middleburns <img src="http://singletrackworld.com/forum/my-plugins/bbcode-buttons/default/icon_lol.gif" title=":lol:" class="bb_smilies" alt=""/> though they do make great chainrings. </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/3#post-774040 Mon, 19 Oct 2009 12:02:30 +0000 alpin 774040@http://singletrackworld.com/forum/ <p>i&#39;ve got a crack! no flaking on my shaft, though.</p> <p>if it breaks, i&#39;ll get a replacement. </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/3#post-774038 Mon, 19 Oct 2009 12:01:43 +0000 owenfackrell 774038@http://singletrackworld.com/forum/ <p><blockquote>I think the flaking has come from when the bearings have seized without me realising and the tophats have spun on the shaft</blockquote><br /> That was my conclusion too except i know that mine have siezed in the past. </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/3#post-773992 Mon, 19 Oct 2009 11:46:38 +0000 woodsman 773992@http://singletrackworld.com/forum/ <p>I agree coffeeking, we&#39;re all trouble making bastards, and the importer and shop owner selling the products are of course technically and morally in the right!</p> <p>Anyone know where I can buy a cracked frame... </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/3#post-773962 Mon, 19 Oct 2009 11:28:19 +0000 Alb 773962@http://singletrackworld.com/forum/ <p>Hi Stato, you&#39;re correct in that the HTII crankarms are forged and not cast. This process is pretty complex and Shimano aren&#39;t too keen on digressing too much info on how exactly they&#39;re made (although information on the patent is readily available for all to see on the internet).</p> <p>It goes without saying that Shimano are world leaders in drop forged technology and have one of the highest QC levels in the industry. Rest assured the marks on the crankarms do not affect in any way the structural integrity of the crank - they&#39;re merely an unsightly byproduct of the manufacturing process. </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/3#post-773786 Mon, 19 Oct 2009 10:36:05 +0000 coffeeking 773786@http://singletrackworld.com/forum/ <p>Thanks all,</p> <p>I think the flaking has come from when the bearings have seized without me realising and the tophats have spun on the shaft. Annoying but doesn&#39;t seem to currently affect the performance of my new BB.</p> <p><blockquote>worry machine at work - some people just want to create problems. </blockquote></p> <p>yup, that&#39;s right, no-one had genuine concerns, they were just <em>trying</em> to create problems for no reason, even going to the effort of posting their images on a public forum to get more exposure... <img src="http://singletrackworld.com/forum/my-plugins/bbcode-buttons/default/icon_lol.gif" title=":lol:" class="bb_smilies" alt=""/> </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-773718 Mon, 19 Oct 2009 10:19:50 +0000 owenfackrell 773718@http://singletrackworld.com/forum/ <p><blockquote>Has anyone else (Alb?) found their shaft flaking off where it sits in the top hats?</blockquote><br /> I have marks on my Hone ones (triples) where they fit the BB but it all seems fine to me though it would be the reason that i replace them (or the one i use with the wife). i also have the marks at the end of th ecranks but am not to worried about it as i can&#39;t see how it would lead to any kind of failier of the cranks. </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-773671 Mon, 19 Oct 2009 10:01:03 +0000 doof_doof 773671@http://singletrackworld.com/forum/ <p>No cracks on my aged Octalink XTs. </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-773533 Mon, 19 Oct 2009 08:58:45 +0000 STATO 773533@http://singletrackworld.com/forum/ <p>Albert from Madison - are the cranks cold forged? if they are then the inside surfaces of the extrusion may not be bonding properly on the cranks in the photos. As the ends are worked on (pedal thread and shaping of end) after this process any marks/evidence of this would only become visable when the cranks are put into use, appearing as cracks due to movement between the front and back of the crank. </p> <p>Be interesting to see if anyone with first gen hollowtech (octalink style bb) has found any cracks. </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-773494 Mon, 19 Oct 2009 08:38:38 +0000 geetee1972 773494@http://singletrackworld.com/forum/ <p><blockquote>Has anyone else (Alb?) found their shaft flaking off where it sits in the top hats? Mine is and I&#39;m concerned about it. While its only a surface coating, thats a fairly tight tolerance fit and any gaps will a) let gack down the shaft and b) could cause the shaft to spin in the tophat, wrecking it (if the bearings dont remain perfect).</blockquote></p> <p>Yeah I had this problem a while back. My shaft was flaking really badly. Everytime I went to the loo, great big flakes would come off. I think it was because I got gack down my shaft in the first place that caused the problem. Next time I will make sure I wear a tophat before putting my shaft into any other tight fits. <img src="http://singletrackworld.com/forum/my-plugins/bbcode-buttons/default/icon_biggrin.gif" title=":D" class="bb_smilies" alt=""/> </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-773402 Mon, 19 Oct 2009 02:08:54 +0000 no_eyed_deer 773402@http://singletrackworld.com/forum/ <p>(1) Strong, (2) light, (3) cheap.. <img src="http://singletrackworld.com/forum/my-plugins/bbcode-buttons/default/icon_wink.gif" title=":wink:" class="bb_smilies" alt=""/> </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-773057 Sun, 18 Oct 2009 21:34:42 +0000 jam bo 773057@http://singletrackworld.com/forum/ <p>checked my mk1 saints and they have the cracks. you can just about make them out on one side. </p> <p>the other side they are hidden by the gouges and chips missing where I keep smashing into rocks. </p> <p>not too concerned.... </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-772027 Sun, 18 Oct 2009 16:24:03 +0000 trail_rat 772027@http://singletrackworld.com/forum/ <p>have anyones failed yet ? how longs the system been out ? 5 years ? show me a failure caused by these pseudo cracks and i might worry </p> <p>worry machine at work - some people just want to create problems. </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-772010 Sun, 18 Oct 2009 16:12:22 +0000 woodsman 772010@http://singletrackworld.com/forum/ <p>BoardingBob - I should bloody hope not! <img src="http://singletrackworld.com/forum/my-plugins/bbcode-buttons/default/icon_wink.gif" title=":wink:" class="bb_smilies" alt=""/> </p> <p>Back to the subject in matter - you pays your money you make your choice etc etc. </p> <p>It ain&#39;t good what ever way you dress it up IMO. </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-771989 Sun, 18 Oct 2009 16:01:31 +0000 BoardinBob 771989@http://singletrackworld.com/forum/ <p><blockquote>Coffeeking</p> <p>Has anyone else found their shaft flaking off </p> <p></blockquote></p> <p>*snigger* </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-771980 Sun, 18 Oct 2009 15:55:20 +0000 Hairychested 771980@http://singletrackworld.com/forum/ <p>Old and battered Saints Mk.1 here - no &quot;cracks&quot;.<br /> All it means is that in a couple of years&#39; time I&#39;ll be changing them to Middleburn, simple. </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-771966 Sun, 18 Oct 2009 15:45:49 +0000 trail_rat 771966@http://singletrackworld.com/forum/ <p><blockquote>If the crack isn&#39;t visible when new and unused then it is a deterioration</blockquote></p> <p>SLX - XT and XTR in the shop all new and unused still in box - all bar XTR showing hte marks .... </p> <p>my XTs do not .... imho its not an issue. </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-771961 Sun, 18 Oct 2009 15:43:13 +0000 myheadsashed 771961@http://singletrackworld.com/forum/ <p>I check my saint cranks but they&#39;re a little battered so no joy there <img src="http://singletrackworld.com/forum/my-plugins/bbcode-buttons/default/icon_redface.gif" title=":oops:" class="bb_smilies" alt=""/> </p>