tag:blogger.com,1999:blog-18676999.post2737008671683949446..comments2024-02-27T01:52:06.519-08:00Comments on Kent's Bike Blog: A Broken Rim MysteryKent Petersonhttp://www.blogger.com/profile/12906603746565831689noreply@blogger.comBlogger16125tag:blogger.com,1999:blog-18676999.post-52475044683263725522013-02-20T14:37:41.519-08:002013-02-20T14:37:41.519-08:00The Consumer Product Safety Comission, CPSC has fi...The Consumer Product Safety Comission, CPSC has filed my report on potentially dangerous bicycle rims with a groove cut on the inside of the rim: http://saferproducts.gov<br />where you can search the report number: 20121207-34770-1289152<br />For pictures of a blown-out rim and a new rim with the grove, at the report end click the related files for this report: Attach_-_H12C0062_att_1[1]_Redacted.pdfDavid Smith The Bicycling Storehttp://thebicyclingstore.comnoreply@blogger.comtag:blogger.com,1999:blog-18676999.post-39538422180613471102011-03-21T02:17:59.471-07:002011-03-21T02:17:59.471-07:00Same thing happened to me on Giant MTB. Brakes wer...Same thing happened to me on Giant MTB. Brakes were not worn so that is not problem. I think its because of the groove in the rim.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-18676999.post-83806601792775322732011-02-22T10:45:08.290-08:002011-02-22T10:45:08.290-08:00I suffered a similar problem on a $500 mountain bi...I suffered a similar problem on a $500 mountain bike that was only seven months old. <br /><br />http://www.rahul.net/abe/bike/rim-split<br /><br />Sure, I ride on bumpy trails, but I am not abusive. I chalked it up to just cheap, substandard construction, typical on bikes of this class. I've never had a stock, machine-built wheel last more than about half a year.Dave Abercrombiehttps://www.blogger.com/profile/13480651551795199755noreply@blogger.comtag:blogger.com,1999:blog-18676999.post-54153202323562317562010-11-25T20:57:05.312-08:002010-11-25T20:57:05.312-08:00That is one seriously ugly bike. Might be cheaper ...That is one seriously ugly bike. Might be cheaper and kinder to tell him it died on the operating table.David Killickhttps://www.blogger.com/profile/05781752978497832434noreply@blogger.comtag:blogger.com,1999:blog-18676999.post-79622561184414680412010-11-23T23:00:41.341-08:002010-11-23T23:00:41.341-08:00@kfg:..or an engineer? And the word verification s...@kfg:..or an engineer? And the word verification says "jokedie". Should I exercise caution?<br />Kent, my 5 cents is on all factors combining to overload the poor wheel.Johann Rissikhttp://fiforiders.blogspot.com/noreply@blogger.comtag:blogger.com,1999:blog-18676999.post-83899519918032782182010-11-23T20:41:10.207-08:002010-11-23T20:41:10.207-08:00He also needs a wider rim with a larger volume tir...He also needs a wider rim with a larger volume tire and lower pressure. Not sure if the Rans will take a wider tire though.charliehttps://www.blogger.com/profile/15299833237823186333noreply@blogger.comtag:blogger.com,1999:blog-18676999.post-30233386980347624052010-11-21T11:44:22.334-08:002010-11-21T11:44:22.334-08:00Hey, Kent, one more crackpot theory for you...
I&...Hey, Kent, one more crackpot theory for you...<br /><br />I'm seeing a "wheel within a wheel" effect in my mind here, with the wear indicator groove as the dividing line between the two. There's a lot of weight on the tire, so it doesn't want to budge. Then the hub applies a ton of torque via the spokes to the inner portion of the rim. I imagine the effect on that rim would be similar (although less extreme) to when an underinflated tire gets spun around the rim, damaging the valve stem.<br /><br />That's not going to blow the rim by itself, but combine it with the weakening factors others have mentioned (tire pressure flexing that wear groove) and kerblammo.<br /><br />Glad the rider's OK -- these sorts of blowouts can be deadly if they happen at the wrong time.<br /><br />Jason "Armchair Mechanic" Nunemaker, in Des Moines, IAJason T. Nunemakerhttps://www.blogger.com/profile/14140597732588714945noreply@blogger.comtag:blogger.com,1999:blog-18676999.post-14477082914161076682010-11-19T23:53:10.043-08:002010-11-19T23:53:10.043-08:00My theory, which you are free to incorporate into ...My theory, which you are free to incorporate into your own as you see fit, is that gouging a grove into the side of a rim is such a dumbass thing to do that a lawyer must have thought it up.kfgnoreply@blogger.comtag:blogger.com,1999:blog-18676999.post-12821782462795789812010-11-19T04:15:43.142-08:002010-11-19T04:15:43.142-08:00If it were my bike, I'd look for a way to move...If it were my bike, I'd look for a way to move the battery into the front triangle. I pity that back wheelAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-18676999.post-43044416063898784132010-11-18T08:49:43.464-08:002010-11-18T08:49:43.464-08:00as John alluded to, perhaps an oversized tire infl...as John alluded to, perhaps an oversized tire inflated to a high pressure to compensate for the rear weight bias of the bike plus the added weight of the hub and battery.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-18676999.post-27841838932547412362010-11-18T04:25:41.345-08:002010-11-18T04:25:41.345-08:00No experience with this but your theory seems soun...No experience with this but your theory seems sound. It makes sense that a crease in the metal would create a flex point that would eventually weaken and break.Bobhttps://www.blogger.com/profile/09963284276467415798noreply@blogger.comtag:blogger.com,1999:blog-18676999.post-2850843823021759592010-11-18T02:18:26.289-08:002010-11-18T02:18:26.289-08:00I haven't ridden a recumbent all my life but m...I haven't ridden a recumbent all my life but my wild guess would be because his weight was put mainly on the rear wheel? Hope you find the right answer to your mysterious question. Did you fixed it already?Pedals Cyclinghttp://www.pedalscycling.co/noreply@blogger.comtag:blogger.com,1999:blog-18676999.post-21453846556228212042010-11-17T19:55:46.885-08:002010-11-17T19:55:46.885-08:00I've seen some discussion among the 29er crowd...I've seen some discussion among the 29er crowd having this issue when using tires that are too large for the rim. The rumor is that oversize tires on not oversized rims are okay if the pressure is kept low...Unknownhttps://www.blogger.com/profile/08439755689251122950noreply@blogger.comtag:blogger.com,1999:blog-18676999.post-18146247379179577362010-11-17T11:57:27.010-08:002010-11-17T11:57:27.010-08:00I had the same problem on my small wheeled, foldin...I had the same problem on my small wheeled, folding bike. Two rims split on it. <br /><br />The problem seemed to be related to two factors:<br /><br />more weight on the rear wheel - the folder weight distribution was biased rearward. (demonstrated by my ability to wheelie and an occasional rear endo when climbing a steep grade)<br /><br />Wide tires placing greater horizontal, 90° to wheel plane, force on the rims.<br /><br />The recumbent seems to share the weight distribution problem. Perhaps it shares the tire issue also.Michael R pdxhttps://www.blogger.com/profile/07842366368669547609noreply@blogger.comtag:blogger.com,1999:blog-18676999.post-81879084692164343032010-11-17T11:40:23.981-08:002010-11-17T11:40:23.981-08:00Thanks for the heads up Eric. We haven't rebui...Thanks for the heads up Eric. We haven't rebuilt the wheel yet. One more thing to factor in!Kent Petersonhttps://www.blogger.com/profile/01607372827627527450noreply@blogger.comtag:blogger.com,1999:blog-18676999.post-35937506165025745402010-11-17T11:30:56.589-08:002010-11-17T11:30:56.589-08:00Hey Kent,
Don't know if you've already reb...Hey Kent,<br />Don't know if you've already rebuilt this, but the BionX hubs are drilled for 13ga spokes. You need to use 13/14 butted spokes, otherwise you'll get lots of spoke breakage at the elbow. Sapim makes them.Erichttp://www.jrabikeshop.comnoreply@blogger.com