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Like Jerry, on std 15/41 sprockets I often found myself searching for a non-existent sixth gear on my 750.
For a while I toyed with fitting a gear indicator.
When the carbon wheels went on I was obliged to fit a new rear sprocket so I specified a 40t, which I ran for a couple of years.
This was much better in fifth gear, keeping the revs down a bit when fast cruising was required and reducing the tendency to search for that extra sixth gear.
It also had the additional benefit of making first gear more usable in town traffic as it was that bit taller and lasted longer, such that in stop/start traffic you could hang on to it rather than constantly changing in and out of second gear.
By this time the weight of the bike was down to just a tad over 160kg.
The ultralight wheels span up quickly too, due to their reduced inertia .. an effect which was more noticeable than I had expected.
Therefore I reckoned I could go to 15/39.
I've tried that for the last couple of months but its still a bit early to be certain whether I prefer it or not.
Motorway cruising is now a nicely relaxed affair though, and I seldom if ever hunt for that extra gear.
First gear is even longer, which personally I quite like but it may not suit all tastes.
I also quite like where that puts fourth gear, which seems just about right for your average twisty road (which I remember thinking on my way through from Douglas to Kirkmichael at this year's TT).
Its never that simple though, is it ?
Lately my attention has been directed towards the front sprocket.
I've had a casesaver fitted for a few years but there is almost no room for it in the 750 crankcases with the 15t sprocket fitted.
It will fit but the chain has a tendency to scrape it sometimes.
This happens mostly on the overrun when the top run of the chain goes slack and it is made worse as the chain ages, wears a little and develops the odd tighter spot .. which they all do to some extent.
Checking the bike over before leaving for the TT, I noticed some wear marks on a couple of inner link plates of the chain.
It was too late to do much about it, but as the 39t rear sprocket was hanging on the shed wall awaiting fitment, I stuck that on and also made a fine tweek to the chain alignment.
Well, I snapped that chain on that trip.
Luckily, at walking pace and only 50yds from my tent at the campsite, rather than half way up the motorway at speed.
Sorry for the long story but I mention all this because my latest decision has been to change to a 14t front sprocket, to give a bit more clearance on the casesaver.
I could of course remove the casesaver and keep the 15/39 or 15/40 gearing that I like but .. well .. I daren't.
And so, the upshot so far is that I'll be going to 14/39 and exploring the implications for chain/swingarm clearance with that set-up (I've had no clearance issues with the 15/39 btw ).
Drive ratios for these various sprocket combos are as follows ...
15/41 = 2.73:1
15/40 = 2.67:1
15/39 = 2.60:1
14/39 = 2,79:1
So you can see that my latest 14/39 set-up will be slightly worse than the original 15/41 ....doh !
I may try and squeeze a 38 rear on at some stage, but I suspect chain clearance on the swingarm will be critical by then.
Oh btw, this is with an ally swingarm fitted.
So there you go.
That's as much as I know, so far.
Personally I think that a casesaver is a pretty essential bit of kit and I don't want to ditch it.
Maybe I'll have to go back to sixth gear hunting or else fit that gear position indicator (just a top gear indicator would do, tbh).
But note .. Jerry in particular .. the casesaver clearance issues above relate to the later style 750 crankcases with separate clutch slave. .. like your original 750, Jerry.
It could be that the earlier style cases with integral clutch slave .. I believe, like your new 750, Jerry ? .. have more clearance around the front sprocket and might allow the 15t sprocket with casesaver to be fitted.
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