40 T rear sprocket

Twisty
Supporter
Supporter
Posts: 54
Joined: Thu Nov 23, 2017 6:15 pm
Country: USA
City: Chevy Chase, MD
Year: 2016

40 T rear sprocket

Post by Twisty » Tue Nov 28, 2017 8:50 pm

Hey,
I have a few questions about changing the rear sprocket to a 40 T. Forgive me in advance for the elementary questions, but I come from BMW's with shaft drives.
I assume the original rear sprocket has fewer teeth, correct?
I guess by increasing the number of teeth on the rear sprocket the bike gains torque but sacrifices speed, correct? So it allows smoother lower speeds in any particular gear?
Where did any of you purchase the 40T rear sprocket? Are there different options--different alloys vs steel, etc? Did you install it yourself? Difficult? Did you change the chain to make it fit? Is this something someone with fairly little motorcycle wrench experience can easily and safely do?
Thanks.
Peter

MarkLH69
125cc
125cc
Posts: 24
Joined: Sat Sep 30, 2017 2:30 pm
Country: Australia
City: Perth
Year: 2017

Re: 40 T rear sprocket

Post by MarkLH69 » Tue Nov 28, 2017 10:02 pm


It's bigger to lower the gearing. Stock is 38. I changed mine and the chain is just long enough with wheel right forward. Don't need to remove wheel, but do need to slide it forward so easier with a stand.

It makes 6th gear a bit more accessible, though it's still borderline for me in Australia with 110 Kmh speed limits.
I still mostly use 5th unless going a bit over ;l

Sent from my SM-T800 using Tapatalk



Twisty
Supporter
Supporter
Posts: 54
Joined: Thu Nov 23, 2017 6:15 pm
Country: USA
City: Chevy Chase, MD
Year: 2016

Re: 40 T rear sprocket

Post by Twisty » Tue Nov 28, 2017 11:13 pm

Is this something a dealer mechanic will do? Does it affect the warranty?

DaveNZ
990cc
990cc
Posts: 501
Joined: Thu Oct 13, 2016 10:20 pm
Country: New Zealand
City: New plymouth
Year: 2016

Re: 40 T rear sprocket

Post by DaveNZ » Wed Nov 29, 2017 3:52 am

it shouldn't effect the warrantee, its really easy to fit, i got my black steel 40 tooth sprocket of eBay. its smooths out the gear changes, makes 6th more useable, 120Km plus, you do use a little more gas, but because 6th is useable it helps. took me 15-20 mins to fit, mine went on easy, the more Kms your bike has done the easier to fit, as the extra stretch in the chain helps. i like the 40 tooth, as when your caining the bike, the gears feel closer together and you go through the gear changes with the quick shifter much faster :D When fitting the new sprocket, fit the chain to it first before you bolt it on, as theres not much slack in the chain. Oh PS, my bike still pulls 260K so you don't lose much speed, you may gain a little as acceleration is faster.
2016 1290GT-remus link and muffler, 2010 Black 1200 Multistrada full Termi system with mapping, 2005 SMR 640, full Titanium system, Mikuni flatside racing carb, 2 sets of wheels, 18 litre tank, and a nice soft seat.

fredm
125cc
125cc
Posts: 19
Joined: Mon Jan 30, 2017 7:06 am
Country: U.K.
City: Telford
Year: 2017

Re: 40 T rear sprocket

Post by fredm » Wed Nov 29, 2017 8:32 pm

As has been said fitting a 40 tooth is straight forward, just make sure the rear wheel is fully forward.

Image

This alloy Sitta sprocket has done around 3500 miles now and shows hardly any wear. The 40t makes top gear much more accessible here in the U.K. I'd recommend it.

A bit of extra orange is nice too. :D

Twisty
Supporter
Supporter
Posts: 54
Joined: Thu Nov 23, 2017 6:15 pm
Country: USA
City: Chevy Chase, MD
Year: 2016

Re: 40 T rear sprocket

Post by Twisty » Thu Nov 30, 2017 12:09 am

That orange Sikka sprocket looks great! So, knowing very little about motorcycle chains and sprockets (like I said, I’ve been a BMW shaft drive guy), you put the bike up on a rear wheel stand, bring the rear wheel forward to slacken the chain, unbolt the rear sprocket, remove it from the chain, insert the new sprocket in the chain, bolt it on, and pull the rear wheel back until there is proper tension on the chain? Is a torque wrench necessary for proper tension on the bolts? Do you use Locktite?
Thanks.
Peter

fredm
125cc
125cc
Posts: 19
Joined: Mon Jan 30, 2017 7:06 am
Country: U.K.
City: Telford
Year: 2017

Re: 40 T rear sprocket

Post by fredm » Thu Nov 30, 2017 7:19 am

The procedure you describe is correct. The tools should be in the tool kit and instructions on chain adjustment will be found in the owners manual, or on this forum I expect. Be carefull not to mark the swing arm when fitting the sprocket, it is close.
A torque wrench is always a good idea if you are unsure about how tight to go on a nut or screw. A tiny bit of Loctite 243 will be fine too.

The SItta sprockets are Italian and very good quality in my opinion.

MR C
675cc
675cc
Posts: 257
Joined: Fri May 06, 2016 7:28 am
Country: UK
City: Derbyshire
Year: 2016

Re: 40 T rear sprocket

Post by MR C » Thu Nov 30, 2017 8:19 am

Twisty wrote: Is a torque wrench necessary for proper tension on the bolts?
Thanks.
Peter
The sprox nuts are 36nm

Twisty
Supporter
Supporter
Posts: 54
Joined: Thu Nov 23, 2017 6:15 pm
Country: USA
City: Chevy Chase, MD
Year: 2016

Re: 40 T rear sprocket

Post by Twisty » Fri Dec 01, 2017 6:47 pm

Thanks guys.

Twisty
Supporter
Supporter
Posts: 54
Joined: Thu Nov 23, 2017 6:15 pm
Country: USA
City: Chevy Chase, MD
Year: 2016

Re: 40 T rear sprocket

Post by Twisty » Sat Dec 02, 2017 10:39 pm

So steel vs. aluminum? I assume the advantage of aluminum is weight savings? I would assume steel is more durable? Can any report problems with quick wear on aluminum sprockets? The orange Sitta rear sprocket looks really great.

MR C
675cc
675cc
Posts: 257
Joined: Fri May 06, 2016 7:28 am
Country: UK
City: Derbyshire
Year: 2016

Re: 40 T rear sprocket

Post by MR C » Sat Dec 02, 2017 11:47 pm

After 7k it's still as new
Image

DaveNZ
990cc
990cc
Posts: 501
Joined: Thu Oct 13, 2016 10:20 pm
Country: New Zealand
City: New plymouth
Year: 2016

Re: 40 T rear sprocket

Post by DaveNZ » Sun Dec 03, 2017 3:16 am

Steel,10,000Ks and like new, either would do the job.
Attachments
IMG_2225.jpg
2016 1290GT-remus link and muffler, 2010 Black 1200 Multistrada full Termi system with mapping, 2005 SMR 640, full Titanium system, Mikuni flatside racing carb, 2 sets of wheels, 18 litre tank, and a nice soft seat.

Twisty
Supporter
Supporter
Posts: 54
Joined: Thu Nov 23, 2017 6:15 pm
Country: USA
City: Chevy Chase, MD
Year: 2016

Re: 40 T rear sprocket

Post by Twisty » Sat Dec 09, 2017 6:26 pm

Here’s an aluminum alloy 40T sprocket for half the price of a Sitta. But it says it’s for a Super Duke R. Would this fit a GT?
http://vi.raptor.ebaydesc.com/ws/eBayIS ... 6000&ver=0
Also I see some 42 T sprockets available for the GT. Does anyone have experience or opinions on a 42T rear sprocket?
Thanks.
Peter

DaveNZ
990cc
990cc
Posts: 501
Joined: Thu Oct 13, 2016 10:20 pm
Country: New Zealand
City: New plymouth
Year: 2016

Re: 40 T rear sprocket

Post by DaveNZ » Sat Dec 09, 2017 6:49 pm

I definitely wouldn't put a 42 tooth on, you will loose all the feel of the torque from this engine, you won't feel the drive from this motor pushing big gears, plus your chain won't reach. its also why i didn't put a 1 tooth smaller sprocket on the front, which equals about a 3 tooth change on the back, just a too larger step for this type of motor.
2016 1290GT-remus link and muffler, 2010 Black 1200 Multistrada full Termi system with mapping, 2005 SMR 640, full Titanium system, Mikuni flatside racing carb, 2 sets of wheels, 18 litre tank, and a nice soft seat.

MR C
675cc
675cc
Posts: 257
Joined: Fri May 06, 2016 7:28 am
Country: UK
City: Derbyshire
Year: 2016

40 T rear sprocket

Post by MR C » Sat Dec 09, 2017 7:38 pm

Any sprocket for a super duke R will fit the important bit is 525, having tried one down on the front it was shite, it lost the lovely nature of the torquey engine and made me ride it like a complete twat.

Twisty
Supporter
Supporter
Posts: 54
Joined: Thu Nov 23, 2017 6:15 pm
Country: USA
City: Chevy Chase, MD
Year: 2016

Re: 40 T rear sprocket

Post by Twisty » Sun Dec 24, 2017 11:13 pm

So I changed to a 40T Supersprox Aluminum Alloy rear sprocket. As everyone said, it was pretty straight forward even though I've never even adjusted a chain before.
I took her out today and I must say it has vastly improved the riding experience for me. In addition, as many have said here, I'm slowly learning how to properly operate this machine. It needs to accelerate hard. It does not like to be below 4000 RPM. It likes to shift higher than 5000 RPM.
With the 40T rear sprocket and my dawning understanding of how to push the bike hard but smooth, I'm beginning to recognize the brilliance of this machine. It's a lot of fun! I look forward to really pushing her once she gets her 600 mile service and then I can open her up past 6000 RPM.
Now that I'm getting used to the bike, I'm really beginning to appreciate how flickable it is. It's almost effortless to make this bike fall into a turn--you practically just have to think about turning in and it does it! Wow!
Thanks for your help guys.
Attachments
SmallRearSprocket.jpg

SuperDukeGT
125cc
125cc
Posts: 17
Joined: Sat Jun 03, 2017 1:48 am
Country: Canada
City: Nanaimo
Year: 2017
Colour: Black & Orange

Re: 40 T rear sprocket

Post by SuperDukeGT » Tue Dec 26, 2017 7:33 pm

I've ordered a 40T rear and a 16T front sprockets for my GT after looking at the Gear Commander website and trying to determine how best to utilize 6th gear on North American roads without going 90+ mph. I see that a lot of you guys have opted for the 40T rear only and not changed the front. To my thinking, this would not significantly change the gearing down enough to make a difference. Comments welcomed from those on the forum that have experience with sprocket mods. Thanks in advance.

Twisty
Supporter
Supporter
Posts: 54
Joined: Thu Nov 23, 2017 6:15 pm
Country: USA
City: Chevy Chase, MD
Year: 2016

Re: 40 T rear sprocket

Post by Twisty » Tue Dec 26, 2017 8:24 pm

Some have noted that changing to a 16T front sprocket was too extreme. Most have felt just a 2-tooth change in the rear does the trick. I’m curious how a 41T or 42T rear sprocket would affect the bike since the 40T was such a positive change. I’m not so into sheer speed as I am into low end torque and acceleration.

MR C
675cc
675cc
Posts: 257
Joined: Fri May 06, 2016 7:28 am
Country: UK
City: Derbyshire
Year: 2016

Re: 40 T rear sprocket

Post by MR C » Tue Dec 26, 2017 9:20 pm

SuperDukeGT wrote:I've ordered a 40T rear and a 16T front sprockets for my GT after looking at the Gear Commander website and trying to determine how best to utilize 6th gear on North American roads without going 90+ mph. I see that a lot of you guys have opted for the 40T rear only and not changed the front. To my thinking, this would not significantly change the gearing down enough to make a difference. Comments welcomed from those on the forum that have experience with sprocket mods. Thanks in advance.
If you want a street bike do the front sprox only, if you want to retain the torque and a usable 6th gear do the rear sprox only, if you crazy than do both together .

I've done front 16t and it was shite, the best compromise is the 40t rear.

Aussie Dave
990cc
990cc
Posts: 545
Joined: Sat Mar 04, 2017 7:30 am
Country: Australia
City: Brisbane
Year: 2017

Re: 40 T rear sprocket

Post by Aussie Dave » Thu Dec 28, 2017 6:03 am

Yeah....wot Mr C says is right.......1st cog standard gearing is about right.....and the rest are fine until you get to 5th which is ok but maybe just a smidge high......then there is the 700 rpm leap to 6th......autobahn only ratio.

Since the rear is a fast quick-change (ie 15mins) system, then stick to a 40T - that will give gearing about the same as 1/2 a tooth on the front sprocket which will keep the nice gearing in the lower cogs, and make 4-5-6 happier (well 6th will never be happy unless you are at warp speed)..... ;)

I'm still stuck in limbo as no one has any steel sprockets in stock (40T sold out in US.....Aussie shops not interested, Euro sites can't sell to Aus if there is a local agent...... :roll: ) - ahh one day i'll get there, but I'm happy with using it as a 5 speed tranny ;)
Last edited by Aussie Dave on Sun Dec 31, 2017 12:42 am, edited 1 time in total.
Current delights...1290GT-2017, CBR1100XX-2005

Prev loves...Capo1200TP-014, CBR11xx-002, 2xFZR1000genisis-94, FJ1200-89, FJ1100-84, XS1100P, VF1000F-83, CX500, VF750S, KZ1000J1-81, KZ1000ST-79, CB750F2-77, CB360T-74, CB175.. started it all in 1974 ;)

Post Reply