http://singletrackworld.com/forum/tags/xt-too en-US Sun, 12 Feb 2012 06:20:03 +0000 http://bbpress.org/?v=1.0.2 q http://singletrackworld.com/forum/search.php http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-776810 Mon, 19 Oct 2009 22:22:46 +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/2#post-774414 Mon, 19 Oct 2009 12:22:27 +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/2#post-774162 Mon, 19 Oct 2009 11:30:25 +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/2#post-774040 Mon, 19 Oct 2009 11:02:30 +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/2#post-774038 Mon, 19 Oct 2009 11:01:43 +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/2#post-773992 Mon, 19 Oct 2009 10:46:38 +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/2#post-773962 Mon, 19 Oct 2009 10:28:19 +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/2#post-773786 Mon, 19 Oct 2009 09:36:05 +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 09:19:50 +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 09:01:03 +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 07:58:45 +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 07:38:38 +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 01:08:54 +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 20:34:42 +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 15:24:03 +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 15:12:22 +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 15:01:31 +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 14:55:20 +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 14:45:49 +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 14:43:13 +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> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-771934 Sun, 18 Oct 2009 14:34:01 +0000 woodsman 771934@http://singletrackworld.com/forum/ <p>If the crack isn&#39;t visible when new and unused then it is a deterioration. I had a look at riding buddies slx after reading this thread, and it was more of a jagged seperation or de-lamination (if you don&#39;t want to call it a crack) than a mark! </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-771907 Sun, 18 Oct 2009 14:09:50 +0000 grumm 771907@http://singletrackworld.com/forum/ <p>yeah I&#39;m really not bothered about the crack - don&#39;t like the sound of the axle wear thing though. </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-771901 Sun, 18 Oct 2009 14:06:39 +0000 davefarmer 771901@http://singletrackworld.com/forum/ <p>but, how else would you expect them to make a hollow alluminium crank?</p> <p>Extrude, then squish together, but you see the mark</p> <p>Extrude, squish together, wrap in crabon to cover all manufacturing marks? Adding cost and weight?</p> <p>I reckon Shimano make the best performing cranksets, at a very good price, on the market at the moment. </p> <p>A small mark (not crack) at the end of the arm due to a manufacturing process is fine by me. </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-771891 Sun, 18 Oct 2009 13:59:16 +0000 naokfreek 771891@http://singletrackworld.com/forum/ <p>Ck, i have that on some oldish lx ht2&#39;s so much so that with direct contact bb like hope, there is play within the axle/bearing interface, fine with a shimano bb though, but still clearly visable as a worn groove on the axle.. </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-771796 Sun, 18 Oct 2009 12:30:40 +0000 woodsman 771796@http://singletrackworld.com/forum/ <p>I won&#39;t be buying the slx double chainset I had in mind. Maddison - it&#39;s a cop out, it&#39;s not a quality product, and whats going to happen over time, these cranks haven&#39;t exactly been around for long. </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-771682 Sun, 18 Oct 2009 11:12:38 +0000 coffeeking 771682@http://singletrackworld.com/forum/ <p>No-one else had this? </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-770504 Sat, 17 Oct 2009 17:24:33 +0000 coffeeking 770504@http://singletrackworld.com/forum/ <p>Well thats that cleared up, though I&#39;d have thought it odd to leave the join visible in that manner. Certainly had me baffled as to the stresses that might be causing a crack there!</p> <p>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).</p> <p><img src="http://www.jbuckle.homeip.net/images/crank.jpg"> </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-767003 Fri, 16 Oct 2009 11:06:19 +0000 grumm 767003@http://singletrackworld.com/forum/ <p>I dunno, I can&#39;t say I&#39;m too bothered if they&#39;re not going to break. I probably would have never thought about it if I hadn&#39;t read this thread. </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-766988 Fri, 16 Oct 2009 11:04:14 +0000 b17 766988@http://singletrackworld.com/forum/ <p>how is it a design flaw? surely they are functionally fine then, just show a mark where the tube has been forged together? </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-766978 Fri, 16 Oct 2009 11:01:36 +0000 Shandy 766978@http://singletrackworld.com/forum/ <p>So, Shimano cranks don&#39;t have an inherent design flaw, and it hasn&#39;t been discovered on this very website?</p> <p> <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-766955 Fri, 16 Oct 2009 10:56:32 +0000 Rolls 766955@http://singletrackworld.com/forum/ <p>Oh Gwad... - going to check my XT / XTR cranks very carefully over the weekend... </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-766779 Fri, 16 Oct 2009 10:22:34 +0000 Alb 766779@http://singletrackworld.com/forum/ <p>Hi everyone, Albert from Madison here. </p> <p>Understandably some of you are concerned about what might appear to be cracks at the tips of your crankarms just below the pedal inserts.</p> <p>This was brought to Shimano&#39;s attention some time ago and upon further investigation they were identified as forging marks (Stato&#39;s hit the nail on the head with his explaination). This is why so many of you will have discovered them upon further investigation. </p> <p>Rest assured these marks do not in any way affect the performance or durability of the cranks/chainsets and to date no cranks have been returned to us with actual cracks at the end of the crank arm.</p> <p>Thanks<br /> Albert<br /> (Madison) </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-766315 Fri, 16 Oct 2009 08:27:31 +0000 STATO 766315@http://singletrackworld.com/forum/ <p>I still think youd be within your rights to ask for a replacement if your cranks look as bad as the first pic in this thread tho. No matter what the manufac process is you shouldnt be forced into a situation where you worry about wether a crack is going to get worse and possibly injure you, not matter how unlikely it is. </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-766294 Fri, 16 Oct 2009 08:21:38 +0000 Nobby 766294@http://singletrackworld.com/forum/ <p>Thanks for that Stato - makes perfect sense. </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-766229 Fri, 16 Oct 2009 08:03:58 +0000 IanMunro 766229@http://singletrackworld.com/forum/ <p>Good thinking stato. </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-766213 Fri, 16 Oct 2009 08:00:23 +0000 STATO 766213@http://singletrackworld.com/forum/ <p><blockquote>I thought they were hollow forged - which then raises another question - where is the forging split line.</blockquote></p> <p>Ive been thinking about this a bit more and i reckon i know what there cracks are. The cranks are made from an extruded tube and i reckon the poster above has got it right, its just the join where the inside surfaces of the tube are squished together, leading to a weaker join in the middle of the crank compared to the solid parent material at the edges. Im (now ive thought about it) pretty sure those cracks wont extend any further than the pictures we have here.</p> <p><a href="http://www.flickr.com/photos/dickyelsdon/4016443040/"><img src="http://farm3.static.flickr.com/2790/4016443040_48dfa98de2.jpg"></a></p> <p>EDIT: The crack cant easilly extend past the end of the join made in the hollow forge process, it would take a significant impact/force to force the crack to extend into the edges of the crack, prob about the same size force that would snap a normal crank! Of course if the crack entend from the end of the crank arm upto the pedal threads then if your pedal works loose it could have the leverage to peel the front part of the crank arm off (though theyd have been screwed anyway as a loose pedal would ruin the threads)</p> <p>Those with cracks in XT cranks, can you take your pedal off and see if the crack can be seen in the threads? </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-766210 Fri, 16 Oct 2009 07:59:32 +0000 grumm 766210@http://singletrackworld.com/forum/ <p>Either get in touch with who you bought in from or try and forget about it and hope they don&#39;t break I suppose. </p> http://singletrackworld.com/forum/topic/cracks-in-cranks/page/2#post-766204 Fri, 16 Oct 2009 07:56:36 +0000 jackal 766204@http://singletrackworld.com/forum/ <p>Whats the best course of action for us now then..?<br /> <img src="http://singletrackworld.com/forum/my-plugins/bbcode-buttons/default/icon_confused.gif" title=":?" class="bb_smilies" alt=""/> </p> http://singletrackworld.com/forum/topic/cracks-in-cranks#post-766159 Fri, 16 Oct 2009 07:37:44 +0000 chopperT 766159@http://singletrackworld.com/forum/ <p><img src="http://farm4.static.flickr.com/3526/4016410806_8bf14c00d1.jpg"><img src="http://farm3.static.flickr.com/2798/4016409992_d078ba6871.jpg"><img src="http://farm3.static.flickr.com/2442/4016410378_721a0467b2.jpg"></p> <p>Photos of the XT770, non drive side. Much smaller than the others, but exactly the same, same chevron lead in, then single crack. you may not see it on these flickr images, but there OK on my big pics.<br /> the 760 is too fine to photo, but pretty sure it will show with dye-pen inspection. </p> http://singletrackworld.com/forum/topic/cracks-in-cranks#post-766158 Fri, 16 Oct 2009 07:36:46 +0000 jackal 766158@http://singletrackworld.com/forum/ <p><blockquote>Has anyone heard of any actual failures?</blockquote></p> <p>I&#39;m very interseted in this too.<br /> I&#39;ve just asked that same question on my sdh post (link on previous post) about slx cranks cracking.<br /> I&#39;m guessing no one has had any fail yet. </p>