750 Sport gearing

andygbsmith · Post by **andygbsmith** » Tue Sep 15, 2009 7:00 am

My Sport has 15T front and 36T Rear and I find it to low geared.
Whats the standard gearing ?
Will A 16T front fit and clear the cases OK?
Does anyone use a Oring chain and does it clear the cases.
Any help cheers.
Andy

Post by **BevHevSteve** » Tue Sep 15, 2009 12:31 pm

Hi Andy, no problems using oring chains on your bike, or 16 tooth front sprocket. Only the early sand cast cases had problems and needed 15 teeth and a non oring chain.

your sport would have 16/36 originally.

I have front and rear sprockets and kits, and several chain options both oring and no oring chains in stock

http://shop.bevelheaven.com/SearchResul ... egoryID=15

machten · Post by **machten** » Wed Sep 16, 2009 9:51 am

Hi,

I only came across this last night whilst looking for something else. According to Falloon's Ducati Twins Restoration Guide the 71-73 Sport and GT had a primary gearing of 29/71 and a secondary of 16/36. The 74 Sport (accepting all the "normal" Ducati variances) is stated as having a primary gearing of 32/70 and a secondary of 16/36.

I was never aware before of a change in primary gearing. Anyway, something to take into consideration on the secondary gearing.

Kev

machten · Post by **machten** » Wed Sep 16, 2009 9:53 am

Sorry, that should of course be 72-73 Sport not 71-73. Typo!!!

machten · Post by **machten** » Wed Sep 16, 2009 7:53 pm

the 71-73 Sport and GT had a primary gearing of 29/71 and a secondary of 16/36. The 74 Sport (accepting all the "normal" Ducati variances) is stated as having a primary gearing of 32/70 and a secondary of 16/36.

Excuse my ignorance here, but why would they have done that? Is that to address clutch slip or something?

andygbsmith · Post by **andygbsmith** » Fri Sep 18, 2009 4:06 pm

Thanks for all the info. I didn't know about the primary gearing change between model years either.
Many thanks. I will go for a 16 tooth front and take it from there.
Andy

rwhc80 · Post by **rwhc80** » Fri Sep 25, 2009 6:59 am

Andy,

With a 16 tooth front sprocket you are more likely to wear your cases from chain back lash than if you run a 15 tooth front front. you can obtain almost the same ratio as 16/36 by installing a 34 tooth rear sprocket with your 15 tooth front. this is not only cheaper but will avoid potential case damage, which is a common problem. alternately you need a case saver or wear block.