trialsrfun Posted January 28, 2020 Report Share Posted January 28, 2020 (edited) Couple of Bantam build questions please, Is it a good idea to swap around the existing 2nd and 3rd gears, I found a diagram of how to do this on the web but if that lowers second then what happens to third gear. Is it instead better to buy the aftermarket second gear set which is I believe 20/27 ? Which ignition system and crankshaft weight is the one to get All BSA Bantam engine build hints and tips welcomed Edited January 28, 2020 by trialsrfun Quote Link to comment Share on other sites More sharing options...
wiggy Posted January 28, 2020 Report Share Posted January 28, 2020 (edited) 6 hours ago, trialsrfun said: Couple of Bantam build questions please, Is it a good idea to swap around the existing 2nd and 3rd gears, I found a diagram of how to do this on the web but if that lowers second then what happens to third gear. Is it instead better to buy the aftermarket second gear set which is I believe 20/27 ? Which ignition system and crankshaft weight is the one to get All BSA Bantam engine build hints and tips welcomed This lowers the 2nd and 3rd gears then a big jump up to the top gear I have used this for 18 years and the bike has done many pre 65 Scottish events (around 8). The bike has only ever broke down once in all of the years me and my daughters have abused it. Pvl ignition with no weight ts 185 piston standard clutch. Edited January 28, 2020 by wiggy Dad isn't good with computers... Quote Link to comment Share on other sites More sharing options...
trialsrfun Posted January 28, 2020 Author Report Share Posted January 28, 2020 Hi Wiggy a great story of a bike that has obviously given lots of pleasure to you and your family. Thank you for the information regarding the gears is second low enough to be useful in sections if you need a bit more speed than 1st Quote Link to comment Share on other sites More sharing options...
ikb Posted January 29, 2020 Report Share Posted January 29, 2020 See attached picture showing all of the ratios, the swapped second gear can be used in sections ok depending on your sprocket sizes and rider weight . The best thing about the low second gear kit is the higher top gear! Hope the spread sheet makes sense Quote Link to comment Share on other sites More sharing options...
paulmac Posted January 29, 2020 Report Share Posted January 29, 2020 Best set up I have found for a D14 includes the gear switch as above, Electrex World ignition, B175 centre plug head, Rex Caunt 187 cc big bore piston kit, standard clutch Drayton exhaust and air box, Amal Premier carb, 12 t primary sprocket Hope this helps. Cheers Quote Link to comment Share on other sites More sharing options...
trialsrfun Posted January 29, 2020 Author Report Share Posted January 29, 2020 (edited) 10 hours ago, ikb said: See attached picture showing all of the ratios, the swapped second gear can be used in sections ok depending on your sprocket sizes and rider weight . The best thing about the low second gear kit is the higher top gear! Hope the spread sheet makes sense Thanks for the spreadsheet ikb very interesting and Paulmac for the set up you have. It would be interesting to know who first realised that the Bantam gears could be interchanged to give alternate ratios. I read that one major reason why BSA did not produce a trials version of the Bantam was because of the high cost of manufacturing gear clusters as used on the works bike's, yet surely BSA must have known that this could be achieved using the part's they already had. Edited January 29, 2020 by trialsrfun 1 Quote Link to comment Share on other sites More sharing options...
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