[CR] Gear ratio measurement

(Example: Production Builders:Peugeot:PY-10)

From: "John Purser" <john.purser@btconnect.com>
To: <classicrendezvous@bikelist.org>
References: <mailman.8428.1294328896.1396.classicrendezvous@bikelist.org>
Date: Fri, 7 Jan 2011 10:59:09 -0000
Subject: [CR] Gear ratio measurement


Do bear in mind (as I'm sure you will have) that the roll back distance is influence by the actual diameter of the wheel and tyre - when rolled back will depend on the section of the tubular fitted. With a tiny section tub, you may find the shorter roll back would allow a 1 tooth larger ring. Not cheating, just making sure you match the rules as stated. Not much, but something worth pointing out, even if just to keep our 'bloody bike anorak' status intact. Happy New Year to one and all John Purser nursing a broken collar bone and cycling nowhere around Sudbury Englandl

Message: 5 Date: Wed, 5 Jan 2011 15:25:00 -0800 (PST) From: old steel <hfbirm@bellsouth.net> Subject: Re: [CR] Gearing Advice for Junior Track To: sean flores <seaneee175@gmail.com>, classicrendezvous@bikelist.org Message-ID: <453870.92144.qm@web180309.mail.gq1.yahoo.com> Content-Type: text/plain; charset=utf-8

For racing in the USA, from the USCF rulebook: 1M6. Junior Gears. Road 17-18: 7.93 meters (26?)(52x14) 15-16: " 13-14: " 10-12: " Track 17-18: Unrestricted 15-16: 6.78 meters (22'3")(48x15) 13-14: 6.36 meters (20'10.5")(48x16) 10-12: 6.00 meters (19?8")(48x17) The gear limit for a rider is determined by the age of the rider and the discipline, and applies in all events in that discipline ? Since the kid will be nine on Dec 31, 2011?his racing age is 9 and is eligible for Youth only (<10 yr old) races.? But you might as?well use the restrictions for 10 year olds - 6.00 meters rollout (distance travelled with one turn of the crank) on the track.? The gear figures above assume a 700x23?tire, so you'll need to adjust the noted 48x17 accordingly.??The USCF rule book used to give the figure in gear inches as well, = 98 gear inches, so 6.00 meters ~ 74 gear inches.? So don't go over that limit and you'll be good.

Jim Carter Class C referee and the rollout?go-to at the Sunny King Crits every year. Mountain Brook, Alabama United States of America

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