I want to lower the gearing on my ISDT bike by changing the gearbox internals, it can only be done with the low gear pair- does anyone know what choices were originally available, I know of 18/30 and 22/26, going on counting the comparative revolutions of the shafts mine appears to be 20/28, is this possible? And does anyone have suitable pair going spare? All mods to the bike are reversible and no "cosmetic" alterations are considered., to keep it as original as possible but a bit more rider friendly.
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Peter,
As far as I'm aware all the Albion boxes had 30/18 bottom gear pairs, I've never come across 28/20 or 26/22. Late Jack Knight gears had a 25/15 pairing, while you could fit these (shaft centres are the same) the shafts are totally different.
To get a lower first you would have to change the gearbox sprocket and/or the rear wheel sprocket. To retain the the same top speed you would have to fit the extra wide set, depending on what else you have in the box.
Druid -
Basically I want a lower first gear without altering the top, ie a wider set, I can cope with lowering second and third but overall lowering as in a trials bike would not be suitable.Comment
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Peter,
You'll have to have a look at your internals. If the sleeve gear is 30T then you have the very wide ratios, if its 28T you have the intermediate set. Most ISDT bikes had the very wide set but Chris may have changed them in the past.
DruidComment
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I am off to see Steve at VS. on friday.Comment
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