Chain & sprockets

Message

Peter Grange · #1 Post by **Peter Grange** » Mon Jul 28, 2008 8:36 pm

Got to replace the chain & sprockets on my Falco, what size sprockets would anyone recommend?

Its geared at 5K rpm at 90 at present, seems too high to me as I end up mainly only using 5th.

Peter

sabestian · #2 Post by **sabestian** » Mon Jul 28, 2008 8:42 pm

welcome, my favourite is 16/43. 15/41 was a touch short.

D-Rider · #3 Post by **D-Rider** » Mon Jul 28, 2008 9:29 pm

I'm running 15:41 - virtually the same as 16:44 which is also a popular choice.

If you don't want to go that far, then Sabs recommendation is probably a good option.

HisNibbs · #4 Post by **HisNibbs** » Mon Jul 28, 2008 10:39 pm

Depends what you are doing.

tried 16/44 which is pretty good for town work and ultimate scratchin but have gone back to 16/42 for long distance motorway commuting.It is less frantic and a bit more tourer than it was.

GRFalco · #5 Post by **GRFalco** » Tue Jul 29, 2008 1:32 pm

What on earth are you lot burbling on about?

Syltiz · #6 Post by **Syltiz** » Tue Jul 29, 2008 1:46 pm

GRFalco wrote:What on earth are you lot burbling on about?

Front and rear sprockets... and the number of teeth thereon

D-Rider · #7 Post by **D-Rider** » Tue Jul 29, 2008 1:50 pm

GRFalco wrote:What on earth are you lot burbling on about?

Final drive ratios
The first number is the number of teeth on the gearbox sprocket, the second the number of teeth on the rear wheel sprocket.

BTW changing gearing does not mess up the speedo as the speedo sensor works off of the rear wheel.

EDIT .... looks as though Syltiz beat me to it!

woodbutcher · #8 Post by **woodbutcher** » Tue Jul 29, 2008 3:40 pm

running 15/43 at moment just right for me

#9 Post by **mangocrazy** » Tue Jul 29, 2008 4:40 pm

Pardon my ignorance, but what is standard f/r?

D-Rider · #10 Post by **D-Rider** » Tue Jul 29, 2008 5:22 pm

mangocrazy wrote:Pardon my ignorance, but what is standard f/r?

16:41

HowardQ · #11 Post by **HowardQ** » Tue Jul 29, 2008 9:18 pm

The standard 16 : 41 is generally accepted by most people as being a bit too high geared. I once worked this out, but from memory, this leaves it geared for a theoretical 175mph max, a bit too overgeared for most people.
When I first changed mine I decided to go for a 15 tooth front like most others, but my local Priller dealer said he would not recommend this, as it left the chain too close to the swingarm. Not sure he was right as many people have done this, but it does leave it a bit close, so made a snap decision to go just one tooth up on the rear, (standard Mille 42 tooth steel rear sprocket), as I still wanted to keep it relaxed for long trips.
This leaves it geared for theoretical 170mph max. I was pretty happy with this, but don't find myself using 6th too often on "fun" runs.
Will probably try the 15 : 41 next time, As Andy says 16 : 44 is near enough the same.
My main concern is chain lengths. When my dealer suggested the 42 tooth rear sprocket he also advised a longer Mille chain, as he did not think a standard Falco one would quite fit. So fitted the Mille unit, which left it well towards the end of its adjustment on a new chain. This meant I had to leave it to bed in and stretch for 2 or 3 thousand miles then buy a new soft link and shorten it, which was a bit of messing around.
What has everybody else done chain wise, nobody ever seems to mention different chain lengths?
I suppose a 15 : 42 (1 up on rear, 1 down on front), would leave it about the right length for the standard chain but that's a bit too low geared for me. Obviously any newbies looking at changing gearing need to make sure they get the right length chain.
My guess is that the (longer) standard Mille chain would probably just fit with 16 : 44 setup. Anybody ever done a table for this?
Then again fit a Mille swinger and it changes again!

Would be nice to do a "Sticky" for this to confirm all the options and leave it for reference in the Techie section.

D-Rider · #12 Post by **D-Rider** » Tue Jul 29, 2008 9:49 pm

I have done a bit of a comparison on some of the gearing issues - particularly the 15:41 and 16:44 options. I did update it with some info on gearing that Sab suggested ... so here it is dug out again:

D-Rider wrote:Falco Gearing – Comparison of 15/41 and 16/44 final ratios

Standard Gearing is 16/41

Max Chain Bend Radius and Angle Between Links

Standard 16t sprocket:

Bend radius (at chain pins) = 40.4mm
Angle between chain segments while on sprocket = 22.5 degrees

15t sprocket:

Bend radius (at chain pins) = 37.9mm
Angle between chain segments while on sprocket = 24 degrees

Comparison of Ratios:

16/41 gearing = 0.3902 (standard)
16/44 gearing = 0.3636
15/41 gearing = 0.3658

Those suggested by Sab are:
16/43 gearing = 0.3721
15/40 gearing = 0.3750

Compared to standard gearing:

16/44 gearing is a reduction of 6.82%
15/41 gearing is a reduction of 6.25%

Relative difference in Reduced Gearing Options:

The relative difference between 16/44 and 15/41 ratios is only:
1-(0.3636/0.3658) = 1- 0.9939
= 0.0060
or 0.6% different - so engine characteristics at any speed will essentially be identical.

As you can see, the 15t sprocket will lower the chain height above the swinger by no more than 2.5mm.

Alkydale · #13 Post by **Alkydale** » Tue Jul 29, 2008 11:22 pm

My brain hurts

sabestian · #14 Post by **sabestian** » Wed Jul 30, 2008 11:54 am

Alkydale wrote:My brain hurts

At least you know you've got one. I've never been sure.

Firestarter · #15 Post by **Firestarter** » Wed Jul 30, 2008 12:20 pm

D-Rider wrote:
D-Rider wrote:Relative difference in Reduced Gearing Options:

The relative difference between 16/44 and 15/41 ratios is only:
1-(0.3636/0.3658) = 1- 0.9939
= 0.0060
or 0.6% different - so engine characteristics at any speed will essentially be identical.
As you can see, the 15t sprocket will lower the chain height above the swinger by no more than 2.5mm.

OK, two more things that I'd like to know on this - the ratios are essentially the same, so in terms of changing gearing, either set chosen will give a similar effect. Question is:

- would the increased bend radius make a significant difference in chain wear due to increased strain (when using 15t)?
- using a 15/41 combo means you can use the same length chain (IIRC), is this the case for 16/44?