Yes the extra links are necessary, they won't nullify the gearing change either, it's just a longer chain to support the bigger rear sprocket. You could have gone -1 in the front and +1 rear without the need for any chain modification. -1 up front is roughly equivalent to +3 teeth in The rear, gear ratio wise.
Or just -1 up front no chain mods either.

Sent from my Pixel 2 XL using Tapatalk

 

are these riveted links if they are all should be good, i might ask how many miles has the chain done, as putting new sprockets on old chains is not good practice
it is not recommended to use spring clip links let alone 2

 

These 2 additional links were taking from another 525 chain, not sure if riveted. The original chain is new with 350 km and the 40 t sprocket is new

 

ok all should be good then

 

How does that make the down low torque/punch feel vs the OEM sprockets.

On my last bike (Honda 919) the previous owner had a 17/44 set up and I went to a 15/43 (OEM was 16/43). It took a bit off the top end and made the bike a bit buzzier, but I loved it.

That is one thing I miss about my 919, it made 60 ft-lb’s to the rear wheel but 50 was available from about 2k rpm. The torque curve was almost a flat line.

The SDGT is obviously much faster and torquier, but from 2k-5k rpm the 919 gave the sensation that it was accelerating faster (not that it is, but it felt like it). At 5k, no comparison, as that is when the GT feels ready to rip your arms off.

I hadn’t considered going down a tooth up front, but it probably wouldn’t mess with fueling enough to cause problems if that was the only mod, just the speedo. And the front sprocket is super easy.

6th gear is so tall, that I barely use it for my style of riding anyway, so I’m not that concerned about the top end.

Just wondering if there is a difference in the sensation/feel of torque in the 2k-5k rev range?

 

if you lower gearing further if your not careful you will be popping wheelies all the time
yes it will feel quicker

 

On the Honda RC51 the -1 front +1 rear gearing change has been such a common mod that the primary RC51 parts supplier made sure to keep the 'kit' on hand: Both sprockets and new chain. Stock the RC51 lugged like mad around town like it was bogging, feeling like the gears were too far apart. Switch to -1F +1R and wah lah it's a normal bike that also now accelerates faster.

Stock for that bike is 16F 40R and so guys commonly go to 15F 41R. Some guys do opt for 42R, but from what I understand anything higher and it becomes a wheelie machine / stunt bike. Never tried one. Sounds like fun!

 

G'day to all from down under ....:grin2:

I have a 017 SDGT and I fitted the 40tooth rear sprocket from Supersprox.

It went on in less than 15-20mins (that quick change system is errrrr very quick :wink2.

Big however is that you/whoever, might have installed the sprocket incorrectly...... I lost my pics when my Laptop got sick..... sorry..... but the guts is - put the pretty side to the inside..... and look down the chain when installed to confirm F-R sprockets are in line....... inspect the oem 38t sprocket and you will see the wear marks from the hub & the bolts........ I almost fell for the pretty side out error until I double checked the marks on the original.

By the way..... I didn't need a longer chain.... I adjusted the rear axle all the way in, put the chain on the sprocket before placing on the hub, tightened the bolts, then reset the chain slack to the book setting. I had done about 5000kms before I was able to buy a 40T, maybe that helped....

Also...... be warned...... fitting a 16t front sprocket is not the way to go unless you want to pull wheelies all the time (a 16t front = a 43t rear..... as the GT is only slightly over geared it only needs +1 or +2 teeth on the rear - or 1/2 a tooth on the front....:grin2:..... which is not possible). The rear sprocket is the easiest and cheapest to change anyway and a 40t rear will bring 6th gear back into play for 110kph speed zones with an increase of 200-250rpms in 5th for 100kph....... it won't rev it's head off and actually makes the GT smoother by keeping the motor in the engine's sweet spot.

Do it...... it works....... a 39t rear would suit guys who have minimal low speed traffic zones and more highway work (approx +180rpm @100kph in 5th)...... the standard 17/38 is best suited to Autostrada's in Europe with unlimited (?) speed zones......:clap:

Wish I still had those pics....... they are posted on the other forum... KTM Super Twins.... 0

Ahaa...... I can do this........ here they are.......

 

Also...... be warned...... fitting a 16t front sprocket is not the way to go unless you want to pull wheelies all the time (a 16t front = a 43t rear..... as the GT is only slightly over geared it only needs +1 or +2 teeth on the rear - or 1/2 a tooth on the front....:grin2:..... which is not possible)

ahh! wait a minute, not so fast.

Check with cors187 ... I'm sure he can get you that 16 and a half tooth sprocket. How bout it cors187?

 

I put a +1 tooth front on and that has worked well for me. It did seem that after 4k miles there was enough grit in the rear wheel cam that it took several tries to move the wheel forward enough to get enough slack to R/R the sprocket. Maybe that's the problem your installer had.

 

Hi Chip, have I got this wrong or...... so you went from the oem 17t to an 18t front sprocket on an SDGT?

I'm assuming you have an SD-R because going +1 on the front of the GT is nuts :wink2:.

It's so simple to use the quick change system (ie the rear end) and as the GT was fine as a 5 speeder in oem gearing, going +2 on the rear is almost perfect - allows 6th to be used in everyday highway 110kph speed zones, and does not affect the feel or torque in the lower gears (though the engine needs approx 5k kms before it is free enough to use that big overdrive gear without struggling to maintain a 110kph cruise).

For those still sitting on the fence....... you won't loose anything with a 40t for real world traffic and highway riding but you will gain a smoother ride with no loss of fuel economy....... for those who race or have more open territory to explore, you probably aren't thinking about gearing mods anyway. Just remember to check the sprocket goes 'pretty' side in...... there's no instruction warning in the packaging :frown2:.

Cheers from Australia.

 

Photos of 40T Supersprox showing correct install

Hi all,

Was mucking around on another forum and realized I could download a pic from one forum site and upload to another :laugh2:....... so anyway, if you want to double check the correct way to position the rear sprocket (no warning on packet or instructions) ......... essentially the pretty dished/chamfered side inwards (pity, it looks nice).

 

:laugh2::laugh2:...:grin2:



Looking back in hindsight...... and with a 16f 40r sprocket, it's not the big bad thing the forums thought it was...... I got towed along with the myth until I worked up the courage to simply try it myself, so now I know a bit more than I did way back in 2018.......

If I can wear out my chain, I will be going to a 17/42 set with a new longer chain like I've read the 1290 SAR runs (but I haven't checked details), but so far my chain with 16/40 sproxs is still looking new at 33.5k kms and 4 years........