Triumphrat

stu

Over the weekend switched from the 17 wheelie tooth to a 19, and I really can't tell much difference in acceleration after the first 100yds or so, but it has stopped me trying to change into 6th gear at 60mph.

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Stu


TORs, NARK, thruxton needles, 140mains.40 pilots 2.75 turns out, procom igniter, 17T

NewOldSkool

Stu,
Did your bike come with a 17 or 18 tooth one stock. I am not sure what my bike has on it... it is stock. But i am thinking to up it by one. Do you know if it has to much effect on gas?

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Iraq is stupid!!!

ohiorider

My .02 worth - I switched from 17 to 18 tooth countershaft sprocket. Bike got approx 50mpg overall with the 17T. It got about 50mpg with the 18. I switched back to 17T.

You should install it and draw your own conclusions. Many of us riding 790cc engines with slightly more radical cam timing than the 865cc engines prefer the 17T, since it lets the bike run easily in the higher rpm range. However, there are others that prefer the slower lope of the engine with the 18 tooth. As for me, I like to hear her wind a bit higher, and work a bit less hard.

If I change my cam timing to make it more like the 865, I may consider adding one tooth (back to 18) or maybe less radical, drop one tooth on the rear sprocket. I'll decide that in the next couple of weeks, when I pull cams to swap out a few shims.

BTW - I still plan to document (dyno) the stock cam timing and modified timing.

Bob

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2003 T100 (790cc) Lucifer Org and Silv: 122/42 jets, TORs, 17T, UNI filter, no AI, Polaris bellmouth, Metzeler ME880 tires, Progressive 440 shocks (105/150 springs),11-1126 fork springs, gaiters, MotoTwin low bars, 6024 lamp, htd grips, 12v outlet.

Loxpump

Well another discussion about sprockets. I have all 3 sizes. The 17T has been a box on the shelf from day one. I swore by the 19T, got 50+mpg and liked the reduced rpm's at cruising speed, but most of my riding isn't freeways so I switched back to the 18T for a try. What the heck it's an easy swap. I think I'm staying with the 18T. I think the 19T lowers the rpm about 250 or so at highway speed. I'm still in 4th alot in the twisties and she seems to run fine, and no noticeable drop in mpg with the 18T over the 19T. I think they need to invent a derailleur system like mountain bikes have so you can switch sprockets on the fly.

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Stop Global Whining!
Semper Fi!

Cynr1023

I've got a 07 bonnie black, it came with a 18 tooth and I really enjoyed it, then switched to a 19 tooth and I like it too. I haven't tested the 19 out on twisties yet so the jury is still out. Not lots of twisties in central Texas, have to go find some.

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2007 Bonnie Black
NB Drag Bars, Napoleon Bar-Ends, 19t Front Sproket, Bobbed front and rear fender, Lucas style taillight and bullet signal lights, blacked headers (hey, it's different than from when I got it), Matte Black Side Covers, and fenders, Red seat "embossing", Pazzo Racing Black anodized short levers, BC Predator exhaust, ARK & a rejet, AI removed
OTW: painted tank and headlight bucket w/ screen

stu

When I got my bike I was the third owner and it had an 18T, but I think the 02 came stock with the 17. I think doing the NARK, TORs etc. gives enough extra HP, and the thruxton needles eliminate the midrange torque drop seen with the old stock needles to justify the 19T. However, I may not get better MPG as it seems I get best mileage around 4000RPM for whatever reason.Also the roads here in Central Florida are flat and straight so hill climbing, tight twisties aren't an issue(unfortunately)

[ This message was edited by: stu on 2007-06-18 22:05 ]

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Stu


TORs, NARK, thruxton needles, 140mains.40 pilots 2.75 turns out, procom igniter, 17T

Cynr1023

I can sympathize with you on the flat straight roads. Central Texas isn't exactly full of corners either. I'm heading down to Southern Florida in a few weeks what type of riding cn I expect?

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2007 Bonnie Black
NB Drag Bars, Napoleon Bar-Ends, 19t Front Sproket, Bobbed front and rear fender, Lucas style taillight and bullet signal lights, blacked headers (hey, it's different than from when I got it), Matte Black Side Covers, and fenders, Red seat "embossing", Pazzo Racing Black anodized short levers, BC Predator exhaust, ARK & a rejet, AI removed
OTW: painted tank and headlight bucket w/ screen

BeastInBlack

I have the 19t and I still want another gear :/

Airbox cut, norman hyde togas, head skimmed/gasflowed.

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Every sunday is mad sunday.......

2112

if you're cruising 75 mph with a 19 tooth will
it feel like you're cruising 65 with a 17 tooth?

rodburner

No it will feel like your cruuzing at 95 with the 17. But you`ll still be doing 75.

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Ruining a perfectly good Bonnie since 2004.