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19 tooth front sprocket

27K views 68 replies 40 participants last post by  coachconnor 
#1 ·
Ordered up a 19 tooth front sprocket for my 2010 T-100 and plan to install it this weekend. I've never done this before and was hoping I might pick up some tips on the job. I haven't ponied up for the shop manual just yet, so any hints that may help me avoid any issues would be really appreciated.

Thanks!
 
#2 ·
The big countershaft nut has an even bigger washer that is bent to keep the countershaft nut from coming off. You will have to flatten that washer first. Then apply the rear brake and use a wrench to undo the nut. It should not be super tight, but it may be. The sprocket and the washer are keyed to fit on the sprocket. The only purpose of the nut is to snug the sprocket onto the countershaft. The washer prevents rotation of the nut. Youll need to loosen up the axle adjusters to get enough play to get the sprocket off the countershaft. Fit the new one to the chain and replace in reverse and dog ear the washer again onto one of the flat sides of the nut. Better yet, do two opposite sides and don't worry that you didn't tighten the nut enough.

Best thing is to get someone else to hold the rear brake down. You may need both hands and a pipe extension on the wrench to loosed that nut.

Easy leash.
 
#3 · (Edited)
me too -

my 19T is on it's way, as well...
I called a local Triumph dealership today to get a price on the sprocket washer (p/n: T1180181) that the manual says to replace when changing the sprocket gear, and they get $8 (plus tax) for that item. :eek: You might want to have that ordered ahead of time, since it takes them awhile (I was told 4-5 days) sometimes to get parts in. Or, simply try to reuse the old one, I guess.
I will also need to get a 36mm socket to get that nut off, and 132 newmans (98 foot pounds) of torque to put it back on. The rear tire shouldn't move while tightening this nut, so you have to put the bike in gear, or have someone mash on the brakes while you do it. I imagine I'll also have to move the rear tire up a bit to compensate for the larger diameter of the new sprocket gear and adjust the chain to the proper tension - which is now a little looser, from what I understand (?):confused:(?).
I have heard that the 1st gear shifting range will be a little different with this new gear on, but the 5th gear will be more robust at those highway speeds - which is what I'm aiming for. :cool: Good luck to us both!
 
#4 ·
i think you will be fine reusing the old washer.. atleast mine has been good for 3-4 sprocket changes..

and put the bike in 5:th gear when you turn loose the sprocket nut...And rear brake :)

and you will like the 19 setup :)
i have a 150/70-17 rear tire and that makes it almost like a 20 tooth front sprocket..
gr8 for longtrips :)
 
#6 ·
Keep in mind that if you've got a bike with the new electronic speedo, it'll be affected by changing the sprockets. I've heard somewhere that the dealer tool can correct this. I'm not sure if TuneECU can do it as well, or not.

Personally, I'm tempted to go down a tooth to get a bit more grunt down at the speeds I actually ride.
 
#8 ·
Personally, I'm tempted to go down a tooth to get a bit more grunt down at the speeds I actually ride.
It's addictive; I've got a 17t sprocket and wouldn't go back to an 18 or 19. Much better power delivery and acceleration. I don't really notice the slightly higher revs on the interstate, but even at 70+ mph, the acceleration will keep you grinning. I'm tempted to try a 16t just to see how it reacts on the backroads.
 
#9 · (Edited)
Yes, it is a 36 mm nut, tightened to 132 Nm.
BTW, putting the engine in gear is just a precaution so that when you accidentally let off the brake you don't hurt yourself and skin your knuckles or worse with all the force you are using on the nut. Leaving the bike in gear still means it will move if this happens.

That's why I had my wife get on the bike and stand on the brake pedal. It 15 seconds of her time.

As for teeth, different bikes had different teeth even stock. Most of the 790s had a 17. The Thrux was an 18. I have a 19, but then again I have a 1087.
 
#10 ·
Hey guys thanks a lot! This is just the sort of straightforward advice that makes owning one of these machines such a great experience. Great bike and great people!

Once I dig out of the 20" of snow outside my door, it's over to the Triumph dealer to pick up and extra washer. Knowing my luck I'll foul it up on a Sunday and have the whole mess on the floor for a couple of days while I run down the part. Great advice.
 
#11 ·
Something else to consider is tire size. Alot of us go to a 140/80 rear when the OEM 130/80 wears out. With the Avon Roadrider for example, the 140/80 is about 1" taller than the OEM Metzeler, which effectively adds a tooth to the front sprocket.
 
#13 ·
Easy13: alot of people dont take that in there calc...

metzler:130/80 - 17 ------------- 1933mm (76.10") on 1 revolution

metzler:140/80 - 17 ------------- 1981mm (77.99")

metzler:150/70 - 17 ------------- 1939mm (76.33")


I just relized that my rear tire DONT change the sprocket setup much.. almost OEM!!







sorry for my missleading info earlier!




.
 
#17 ·
Easy13: alot of people dont take that in there calc...

metzler:130/80 - 17 ------------- 1933mm (76.10") on 1 revolution

metzler:140/80 - 17 ------------- 1981mm (77.99")

metzler:150/70 - 17 ------------- 1939mm (76.33")


I just relized that my rear tire DONT change the sprocket setup much.. almost OEM!!





sorry for my missleading info earlier!




.
According to the Avon brochure, the Avons must be taller. The Azaro I put on is listed as follows:
avon azaro 140/80ZR17 655 diameter or 2058 mm circumference
roadrider rear 130/80/17 645 diameter or 2027 mm circumference

Looks like I picked almost 4% more with the switch to the Azaro than I would have had I stayed with the Metzler. In either case...at 145 lb I sure like my 19 tooth plus the rear 140/80 Azaro.


Best,
FacileFossil
 
#16 ·
Here's an old post of mine describing how I change sprockets

I copy and paste stuff from this forum into Word documents. Here's one where I copied and pasted myself nearly 5 years ago. Sort of describes how you can do this job solo.
-------------------------------------------------------------------------------------
Here's a quickie. You might want to search the website for something that goes into more detail if you're not used to working on motorcycles.

Tools required:
-36mm - 1/2" drive socket
-breaker bar - 1/2" drive
-torque wrench capable of handling over 100ft/lb or 132nm
-correct sockets and wrenches to remove sprocket cover
-correct sockets to loosen rear axle so chain can be adjusted
for larger sprocket

Steps (from memory - double check against shop manual)
-bike on centerstand
-sprocket cover removed
-unbend locking tab that secures sprocket nut
-sit in the saddle .... that means you!
-with 36mm socket on breaker bar, reach down and place
socket on 36mm nut
-hold rear brake securely while loosening 36mm nut to keep
countershaft from rotating. It's tight!

-with nut and lock washer removed, pull sprocket off shaft
-lightly grease the splines on the countershaft
-slip new sprocket in chain, and slide sprocket onto countershaft.
-(at this stage, you may have to loosen rear axle to loosen chain
enough to allow you to install larger sprocket).
-make sure sprocket is seated properly on countershaft.
-tighten 36mm nut enough so you can adjust chain. Retighten
rear axle nut and adjuster lock nuts when properly adjusted.
-sit in saddle and hold rear brake.
-using torque wrench set to 132nm or 98ft/lb, tighten 36mm nut.
-bend locking tab against nut flat so it cannot come loose.

If you plan to do your own work, including normal maintenance, I'd recommend purchasing either the Triumph Service Manual, or Haynes Repair Manual.

Note - some of us on the site like to let the engine run a bit faster and ride with the 17T. Others like to run at lower rpm. I personally like the 17T on my 2003 T100. After riding with 18T for 8,000 miles, I switched back to 17T. It suits my kind of riding and the type roads where I spend most of my time (some Interstate, getting to the good two lane roads). 4500-5000rpm at 75-80mph isn't hurting anything. The Bonnie is a relatively short stroke engine, even when compared to my W650 (68mm vs 83mm).
 
#32 ·
I copy and paste stuff from this forum into Word documents. Here's one where I copied and pasted myself nearly 5 years ago. Sort of describes how you can do this job solo.
-------------------------------------------------------------------------------------
Here's a quickie. You might want to search the website for something that goes into more detail if you're not used to working on motorcycles.

Tools required:
-36mm - 1/2" drive socket
-breaker bar - 1/2" drive
-torque wrench capable of handling over 100ft/lb or 132nm
-correct sockets and wrenches to remove sprocket cover
-correct sockets to loosen rear axle so chain can be adjusted
for larger sprocket

Steps (from memory - double check against shop manual)
-bike on centerstand
-sprocket cover removed
-unbend locking tab that secures sprocket nut
-sit in the saddle .... that means you!
-with 36mm socket on breaker bar, reach down and place
socket on 36mm nut
-hold rear brake securely while loosening 36mm nut to keep
countershaft from rotating. It's tight!

-with nut and lock washer removed, pull sprocket off shaft
-lightly grease the splines on the countershaft
-slip new sprocket in chain, and slide sprocket onto countershaft.
-(at this stage, you may have to loosen rear axle to loosen chain
enough to allow you to install larger sprocket).
-make sure sprocket is seated properly on countershaft.
-tighten 36mm nut enough so you can adjust chain. Retighten
rear axle nut and adjuster lock nuts when properly adjusted.
-sit in saddle and hold rear brake.
-using torque wrench set to 132nm or 98ft/lb, tighten 36mm nut.
-bend locking tab against nut flat so it cannot come loose.

If you plan to do your own work, including normal maintenance, I'd recommend purchasing either the Triumph Service Manual, or Haynes Repair Manual.

Note - some of us on the site like to let the engine run a bit faster and ride with the 17T. Others like to run at lower rpm. I personally like the 17T on my 2003 T100. After riding with 18T for 8,000 miles, I switched back to 17T. It suits my kind of riding and the type roads where I spend most of my time (some Interstate, getting to the good two lane roads). 4500-5000rpm at 75-80mph isn't hurting anything. The Bonnie is a relatively short stroke engine, even when compared to my W650 (68mm vs 83mm).
What a great post, better than the manual.

Plasma.
 
#18 ·
Question on 16 tooth as mentioned above. Since most of my riding will be done on back country roads with a steep gravel lane to gain access, I'm considering a 16. No riding on interstates, doubtful if it will ever see 70 mph. Are there any wear or clearance issues when dropping two teeth on a 2009 SE.
 
#23 ·
Unless you are a heavy guy I cant see why anyone would go from a 18 to a 17 or 16.You have 5 gears you can use .The only time the 16 or 17 is quicker then the 18 is in 1st gear under 5000 rpms.Yea they might sound like there quicker but they dont show much on a stop watch.If you ride around at 30 mph you dont need a 865 cc bike anyway lol.
 
#24 ·
You clearly haven't spent much time on a track, in the dirt or in the twisties, Mike. Shorter gears allow the engine to rev quicker, accelerate quicker and respond better to throttle inputs. In effect it gives you a closer ratio tranny. It's why a moderate drag motor with 4.56 gears will smoke a more powerful engine running 4.11 or 3.73 gears.
I can understand why you wouldn't want a 17 or shorter gear on your 1087; you're pushing alot of HP/Tq and shorter gears would probably render it unstreetable. It's probably enough of a challenge to keep the front wheel in the ground as it is. lol.
 
#25 ·
put a watch on your bike in say 1/8 or a 1/4 mile I have done that when I had a stock bike.I allso grew up with dirt bikes (by the way these arent dirt bikes) .I allso raced drag bikes years ago.I know the 17 feels faster but what feels faster is not allways faster on the watch.Do some testing I have.stock a 865 motor runs out of power at around 7000 to 7500 rpm so you dont have much rpm to work with packing lower gear ratio makes it run out of power quicker.If you ride the bike right once it hits 5000 rpm on a drag race it should never see that low of rpm again.You speed shift it at 7500 it shouldnt drop to more then 6500.The more hp you have the less it drops.The heavyer the load on the bike the more the rpm drops.It works the same on drag cars a 4000 lb car with 600 hp will run a lower gear then a 3000 lb car with 600 hp.
 
#31 ·
It has the tightest torque specification on the whole bike= 132 Nm (98 Ft/Lbs).

For comparison the rear axle is just 85 Nm (63 Ft/Lbs) and that's considered very tight.

Get someone to hold the rear brake on as hard as they can and tighten it up very firmly. The tab washer should keep it there.
 
#34 ·
Nice thing is once you have a good high-torque wrench you can do things like torque the lug nuts on your car more accurately...which leads to doing winter/summer changeovers ourself...which saves money and pays for the torque wrench in 1 season.
 
#35 ·
I tried changing my 17 to 18 this weekend but couldn't get the 36mm nut off. I had my niece stand on the rear brake, while I stood with all of my 170 lbs. on the ratchet handle, all to no avail.
Since I had my dealer R&R this nut due to a countershaft seal issue, I'm pretty certain that they've overtightened it. I have a compressor on the way and plan to rent a rattle-gun. Has anyone tried this approach?
Thanks,
Sparky
 
#48 ·
David - If this was directed at me... I sure took a good hard look at the threading; nuts like these sometimes are lefty-tighty, righty-loosy for safety's sake, but this appears to be normal. My compressor in now in the boot/trunk of my cage, and this weekend I will do battle with the nut. ;)
-Sparky
 
#40 ·
OldNSlow,
You can "borrow" a torque wrench from AutoZone, I have a friend who works for them, he said that they have different stuff like slide hammers too. They'll just hold a hundred bucks or so of your money until you bring it back.
 
#53 · (Edited)
I went up to a 19T for 12 months but went back to a 18T. Other than purely for highway riding, a 18T is the best compromise for acceleration and some top gear riding. Its worth a try to find what best suits your riding as the 19T sprocket is only $25. For those 'young guys' under 50 yrs, you'll be back to 18T ;)
 
#54 ·
The first front sprocket I changed using a 3 foot long piece of pipe as a breaker bar. Had the wife sit on the bike and apply the rear brake. Still a PITA.

The second time (working on my son's bike) I got smart. Bought a $50 electric impact driver (1/2" drive) from Harbor Freight. Spun that nut right off in about 2 seconds.
 
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