[Anon]

OK, so I've got my primary off right now because I'm converting to kickstart only after my sprag assembly magnificently self-destructed.  I've had an 18 tooth sprocket sitting on the shelf for like a year and a half and now is the perfect time to make the swap.  The only problem is I'm now torn as to whether I really want to swap or not.  My bike is a 2006 Deluxe with a 535 alloy barrel kit, classic exhaust, K&N filter in the airbox, and stock (but re-jetted) carb.

Obviously it's making more power than it did stock, so it should be able to take advantage of the higher gearing.  My question to you is, has anyone gone to a larger sprocket and preferred the stock gearing?  I don't do high speed driving, but wouldn't mind my 50-60mph cruising being a little less buzzy.  I also don't want to make 1st gear too tall for off pavement riding (not that I'm necessarily looking to turn my bike into a trials/scrambler type of bike).  How big a difference does one tooth actually make?

Eamon

[ace.cafe]

Yea.

It will handle it, no problem.
About 3-4mph difference for the same rpm in top gear. Or in other terms, you'll do about 250 rpm lower at the same road speeds as before.
Just enough to take the "buzz" off at cruising speeds, and your modded motor will handle it just fine.

[Ice]

IIRC the AVL bikes came with an 18 tooth sprocket.

I think you will like it.

[bob bezin]

your bike is a perfect candidate for a 18 tooth.my original mods were : 535 jug  k&n filter ,34mm carb ,british exhaust and a 19 tooth sprocket. it was pretty good but sometimes i wondered if an 18 would have been better then i went fireball and 19 is perfect  as long as you have it apart GO FOR IT.

[Rick O'Shea]

Eamon, I have a 19 tooth on mine AND it's less modified than yours,AND I live in the mountains @ 2500' to 5500', AND I weigh 200 lbs. You'll really like the 18T.

[baird4444]

yes you'll like the 18. The best argument for it is the one that Dan Holmes presents....
   although you will enjoy the slightly lower rpm's on the road; what you will really appreciate is that the shifting points will fall more in line with OUR speed limits. If for no other reason this is a good one.
           - Mike

[Anon]

OK, it seems there is no good reason not to do it.   

Any tricks to removing the big nut on the gearbox sprocket (5 speed)?  It looks like there is some kind a bent washer behind it.  Do you just rely on the rear brake to keep the sprocket in place while you attempt to loosen the nut?   

Eamon

[RBHoge]

Eamon,

Like you I have had an 18 tooth sprocket in my took box for about a year. (just too lazy to make the change .  I plan to get around to it this spring when I freshen up everything for the summer.

My 2008 Classic Deluxe has no "Mods" other than the "Short" exhaust, and K&N cone filter, I have gone up a tooth on almost every bike I have owned. It just seems to take some of the "Hurried" feeling out of the ride. Just have to remember to keep abreast of clutch maintenance.

[ace.cafe]

OK, it seems there is no good reason not to do it.  

Any tricks to removing the big nut on the gearbox sprocket (5 speed)?  It looks like there is some kind a bent washer behind it.  Do you just rely on the rear brake to keep the sprocket in place while you attempt to loosen the nut?  

Eamon

Tap that bent part of the washer flat. That is a locking-tab type washer, and you need to bend it back up against the nut after you replace the sprocket and tighten the nut back up.
Then get yourself a big 2" wrench and crank that sucker off.
You will have to use the chain on the sprocket to stop the gearbox from turning when you are loosening/tightening that nut. So I don't take off the chain until I have loosened the nut.
You just have somebody hold the brake pedal down, so that the wheel can't move, and that will prevent the sprocket shaft from turning. Then you can crank off the nut.
When you put it back on again, put the sprocket on the shaft and put the chain on it, and hand-tighten the nut as far as you can. Then have somebody stand on the brake pedal again, and tighten that sucker up. Then bend the washer back up to lock it after it's all tight.
Voila'!

BTW, it's supposed to be torqued to 40 ft/lbs, but I don't know anybody who has a 2" deep socket that deep. I sure don't.
So, tighten it up as close to what "feels like 40 ft/lbs" as best you can, and go with it.

[cyrusb]

Yes, the 18 is better than the 17,but I run the 19 with less mods than you and it pulls it just fine. In fact the 19, plus the usual mods, gave my bullet the soul it never had. My only regret was that I  waited 2 years to do it.

[single]

Ya,what they all said.

[Anon]

Thanks guys, that's all pretty much what I thought.  No reason not to do it now that I've got it torn down this far.

I've got a kick start only inner primary to put on as well.  Chumma, if you're reading, the sprag assembly I bought from you is going back into a box!  I've taken your advice and am just ditching the whole thing.  I am betting that a fair bit of weight comes off the bike by going to kick start only.  I think I'll just hold onto the starter motor and the spare sprag assembly as cheap spares to pass along to whoever needs them.

Eamon

[abe]

I just went through this procedure and couldn't be happier.  I have a amal 30, goldstar pipe, and ace air canister.  Order the new inner primary got rid of the hump and put on a 19 tooth sprocket with 3 HD Clutch springs, I cant believe the difference it feels like a new bike and it feels right. 

If your not going to get a new inner primary I found a plug that looks factory if you need it.  I did the same mod for a buddy of mine.

good luck,

abe

[single]

Ya,I plan on going to a 19 tooth also.I can barely detect a difference in take-off but the overall feel and cruise is much better with the 18.

[neil]

Hi Eamon:

I noticed your comment about a reduction in the overall weight of your bike after you remove the electric start including the denso motor the sprags and the inner primary. I've done all this and am pretty sure you will rid the bike of 20 to 25 pounds of un-needed metal. I did the CMW eletronic ignition and manual decompressor. Bike starts easily and overall handling is better. If I get into the primary again in the future, I'll probably get an 18 tooth gear for the box. I live in NH where there is lots of hills etc and I'm climbing much of the time during my rides and I'm not sure the bike would make it without too much shifting down to 4th etc,

 Drilling for the inner primary and tapping is fairly straightforward. I neglected to put a shim between the inner primary and the footpeg, when I was locating the bolt holes, so my clearance is tight. If I was doing it again I'd be more careful about locating the holes for the new bolts. Over all though I'm really pleased.

 Neil

[Anon]

yes you'll like the 18. The best argument for it is the one that Dan Holmes presents....
   although you will enjoy the slightly lower rpm's on the road; what you will really appreciate is that the shifting points will fall more in line with OUR speed limits. If for no other reason this is a good one.
           - Mike

I meant to follow up on this after I put on the 18 tooth sprocket.  I think the Dan Holmes quote above is a great description of the difference this makes.  It just seems to move the shifting points to right where they should be.

Eamon

[neil]

I've thought of changing up to an 18 tooth, but everytime i'm out in the country riding on the "twisties" I realize that they are accompanied by the "hillies". Roads where I live in NH have ups and downs , usually seems like more ups then downs, so I think I will forego the change. I'd rather be able to climb the hills without more shifting. Also don't want to lug the bike with a higher tooth drive sprocket. Most of my riding is done with the speedo needle straight up at 50 mph and with TLS brakes faster is not safer.

Neil

[Anon]

I've thought of changing up to an 18 tooth, but everytime i'm out in the country riding on the "twisties" I realize that they are accompanied by the "hillies". Roads where I live in NH have ups and downs , usually seems like more ups then downs, so I think I will forego the change. I'd rather be able to climb the hills without more shifting. Also don't want to lug the bike with a higher tooth drive sprocket. Most of my riding is done with the speedo needle straight up at 50 mph and with TLS brakes faster is not safer.

Neil

Well, I don't think it's a recommended change to make unless one has done some mods that increase the power.  I've a 535cc piston and alloy barrel with the freer flowing "Classic Exhaust" system, and a Power Arc ignition.  It's not one of Ace or Chumma's Fireball Bullets, but it handles the larger sprocket with still plenty more power on tap than it had stock.  Believe me, I'm not lugging it up hills!  In fact, I am less tempted to lug it because the lower gears are all a little taller now, so I feel like I fly up hills compared to before.  I do think a larger sprocket might make lugging it more likely on a stock bike though.

Eamon

[MotoJ]

Well, I don't think it's a recommended change to make unless one has done some mods that increase the power.  I've a 535cc piston and alloy barrel with the freer flowing "Classic Exhaust" system, and a Power Arc ignition.  It's not one of Ace or Chumma's Fireball Bullets, but it handles the larger sprocket with still plenty more power on tap than it had stock.  Believe me, I'm not lugging it up hills!  In fact, I am less tempted to lug it because the lower gears are all a little taller now, so I feel like I fly up hills compared to before.  I do think a larger sprocket might make lugging it more likely on a stock bike though.

Eamon

Whew, I fell better now! I just went through the arduous process of new sprockets, chain, and clutch plates. I decided to go with the stock 17T again, because of the twisty/hillies I ride, as well as the get the heck out of the intersections as fast as possible-ies. Reading this thread made me think maybe I goofed by not going up a tooth until I got to Eamon's last post.

[Anon]

Whew, I fell better now! I just went through the arduous process of new sprockets, chain, and clutch plates. I decided to go with the stock 17T again, because of the twisty/hillies I ride, as well as the get the heck out of the intersections as fast as possible-ies. Reading this thread made me think maybe I goofed by not going up a tooth until I got to Eamon's last post.

Yeah, I think the stock bike is geared just right, unless you live somewhere totally flat.  It is a lot of work just to make the sprocket change, so I waited to do it until I was also doing a electric start to kickstart only conversion.  Sorry you went through all that work only to have to go back to where you started.  At least you know what to do if you ever need to go in there again!

Eamon

[MotoJ]

Well, I did have to change the drive sprocket- both were trashed. While  I was doing it I thought about going to the 18T but decided to leave well enough alone, since there's so many hills where I am. The acceleration is important too- in the city any little bit of get-the-hell-outta-the-way oomph is good to have.

[BIO BLT]

Slightly off topic... to all 535 conversion owners...did you fit the 2mm spacer below the barrel when you did the conversion.  My recent 535 conversion( together with 18 tooth sprocket) is suffering detonation, so thinking of removing the barrel and fitting the spacer to reduce the compression. Have read all Ace's posts on the subject. Still running in but don't feel able to use the extra power yet, due to the detonation, so can't really comment on the gearing yet.. but I think it's going to be better...have been surprised by increase in vibration since the conversion but hoping this will reduce once we reduce the compression a bit and finish the run in. Would also appreciate any comments from those who have gone before.

[t120rbullet]

My recent 535 conversion( together with 18 tooth sprocket) is suffering detonation,

Retard the timing a bit.
CJ

[Anon]

Slightly off topic... to all 535 conversion owners...did you fit the 2mm spacer below the barrel when you did the conversion.

I had one ready, but ended up not needing it.  Do you know if you have the 8.5:1 high compression piston?  I think that is the one with the high dome on the piston.  Mine is the lower domed one, which I think is a supposed to be something more like 7.25:1.  I used two gaskets at the base of the barrel.  I have a Power Arc electronic ignition set to it's default timing curve, and have had no pinging in the three thousand miles or so I've put on the 535 setup.

I'd try CJ's suggestion and just see if slightly retarding the timing fixes it up.  There's minimal effort involved.  If that doesn't do it, then you may need the spacer and/or higher octane gas.  Are you on electronic ignition, or points?

Eamon