Johan Bornman Posted July 17, 2009 Posted July 17, 2009 Workshop stories: Chain measure tool.<?: prefix = o ns = "urn:schemas-microsoft-com:office:office" /> Unless you?ve been living under a rock here on The Hub you?ll know that the best way of getting maximum life out of your drivetrain is to religiously measure your chain across 12 links and monitor its progress up to the point where it reaches 12 and 1 1/16th of an inch. At this point it should be replaced. If it has reached 12 and 1/8th of an inch, it has ruined the cassette. If you are still puzzled at this stage, search for 12 inches (but make sure Safe Search is on). Anyway, the dilemma we have with this method is the scarcity of 13 inch rulers. Firstly, inches are a no-no in this metric country of ours and if you do find one, it stops at 12 inches, not giving you the benefit of a few extra milli?..errr, little lines. Thanks to a fellow Hubber, Peach, I have made a major breakthrough in making chain measurement a cinch. Remember, that ?major? is in the eye of the beholder. In this case, I?m the beholder. Peach ordered some stuff from CRC and wanted to reach the magical R3 000 mark to get free shipping and kindly offered to add stuff to his order. I had an itchy spot and decided to order a ParkTool Spoke length gauge. I?ve been waiting for the tardy local agent to get these for more than a year now and decided to bypass him. The local agent couldn't get me this ruler for more than a year...CRC to the rescue. When the ruler arrived, I discovered something fantastic about the ruler. It had a little lead-in section before point Zero started and?it measured up to 12 inches and 5 /16th! Very unusual for a ruler company to give you 5 extra little lines for free, but lo and behold, there they were. Most steel rulers start at Zero. The ParkTool one has a generous lead-in before zero. The ParkTool one is on the right. I immediately started to re-purpose the ruler for chain measurement. Here?s what I did. I selected a single-sided flat file from my collection. Don?t use a double-sided file like this. You?re filing into aluminium and it is easy to file side-ways as well as downwards. I then filed a little step, 1mm ?.sorry, 1/16 on an inch deep, right next to the Zero arrow. I modified the ruler's Zero point so that it has a step at Zero. The arrowhead is Zero. I then had a beer and measured a chain. The step now acts as a convenient stop for the ruler to hook against a plate or pin on the chain, leaving you free to concentrate on the 12-inch business end of this tool. Is that convenient or what? The little step hooks secure on the slightly protruding pin and lets you concentrate on the other end. The 12-inch arrow should line up perfectly with whatever position it was you started from. If not, the chain has started to wear. Now it is just a question of whether it has a) worn less than 1/16th of an inch (keep the chain), worn 1/16th (replace it) or elongated /8th of an inch (replace chain and cassette). This chain is still good, in spite of its cosmetic rust. Someone chucked this one out prematurely. You can read more about this little bargain in the For Sale section. Going for a song. This chain has worn exactly 1/16th of an inch and should now be replaced. For a small fee I?ll allow ParkTool to modify their ruler so that it not only measures spokes and ball bearings and cotters (who still uses cotters?), but also chains. My friends here on The Hub have my permission to do this themselves. And before you ask?this won?t invalidate the guarantee.
AndreZA Posted July 17, 2009 Posted July 17, 2009 JB, I think you should start releasing you own brand of tools under the Yellow saddle name. Surely it can not be too difficult to find a manufacturer in Taiwan.
Guest Big H Posted July 17, 2009 Posted July 17, 2009 Probleem is net my 12" lineaal is van spring steel gemaak en het nou net twee vyle opge..... dinges op die lineaal. JB jy het nie 'n indemnity klousule op jou goeie raad gehad nie en ek stuur vir jou die rekening. As jy my jou nuut gemodified lineaal stuur sal ek die onaangenaamheid van die rekening los!!!!!!!! PS .... jy het ook nie gewaarsku dat ek NIE EEN van my versameling chain checkers mag gebruik nie. Daar is dalk nog 'n rekening vir die cassette en ketting ook op pad. ...... soooo stuur daai blou lineaal sonner om te veel tee te praat...... ok!!!!!!!!!Big H2009-07-17 08:33:15
Christopher Brunsdon Posted July 17, 2009 Posted July 17, 2009 Awesome JB - I was going to order one of these myself from my LBS for the exact same reason. Like the idea of how you modded yours!!! 5 stars
slowtwitch Posted July 17, 2009 Posted July 17, 2009 Well done JohanLuckely I've got you of those "cheaper" Park Tool chain checkers
Guest Big H Posted July 17, 2009 Posted July 17, 2009 Ek sal maar die ankle graainder op my staal linnejaal moet gebruik!!!!!!! Big H2009-07-17 09:19:24
capecyclist Posted July 17, 2009 Posted July 17, 2009 someone here has got far too much free time on his hands. my chain measuring tool from Park works just fine.
Guest Big H Posted July 17, 2009 Posted July 17, 2009 Dun Man and Capecyclist and all the other "unwashed" ...... your chain chekkas does NOT work better. I will leave it to Johan to explain when he gets on line later....... watch this topic!!!!!!!
Johan Bornman Posted July 17, 2009 Author Posted July 17, 2009 Hendrik, jy lieg deur jou ore. Ek weet, want jy het nie 'n SS lineaal wat nie by Zero begin nie. Maar ingeval ek my bek verbypraat, stuur 'n foto en ek stuur vir jou 'n naaice Nicholson vyl as 'n vergiffenis geskenk. Rest of you with your chain checkers....you're the ones I refer to having lived under a rock. We've just had a huge chain measurement debate here not three weeks ago, and then three weeks before that and three weeks before that and... .and... and... Search for: Everything you need to know about chains - author Johan Bornman. Anyway, here's a summary of the faults of commercial chain checkers. http://pardo.net/bike/pic/fail-004/000.html Anyone chipping in for a mass order of Blue rulers? Something I omitted to tell you, is that one of my students came up with the most ingenious chain checker of all times. I cannot fault it at all. He came up with the idea within 24 hours of my talk on chain health and, within 7 days he had a working prototype. This checker was unique and very, very good. I advised him to first document his work and apply for a patent before I'll reveal the design. I can't wait to see the controversy that will cause in the world of pocket chain checkers.
Christopher Brunsdon Posted July 17, 2009 Posted July 17, 2009 Johan I read that prado.net article a few months back before the whole debate and I rather enjoyed all the threads after that. Guess everyone should first make an effort to understand "chain stretch" before they start rambling on about chain checker tools. * When I saw the spoke ruler on CRC 2 weeks back I incorrectly assumed it might double up as a chain checker - see it just needed a JB mod first !cbrunsdon2009-07-17 11:24:11
Johan Bornman Posted July 17, 2009 Author Posted July 17, 2009 Ja, I wish more people will read that. It is a real gem of a document. I used to preach the gospel drawing little pictures, making "O"s in the sky etc etc and then my galzed-over audience went straight out and bought a ParkTool CC-3. Now I just gooi the link at them and done with it.
straatvark Posted July 17, 2009 Posted July 17, 2009 Anyone chipping in for a mass order of Blue rulers? I'm going to order myself one - birthday in August The missus is coming to SA (CT) 1ste week in August and this is small to pack so let me know.straatvark2009-07-17 11:34:04
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