Triumphrat

kballowe · 06-12-2006, 09:34 AM

Alright, I just installed an 18-tooth front sprocket on my '05 Speedmaster. Typical riding is two lane between 50 and 60 mph. Running @ 50 on the flat or slight hill in 5th works just fine. Note that I never ride two-up on this one.

But, my question is this: Do you think that you're getting better or worse gas mileage? Mine was running about 55 mpg before the change.

Looks like it dropped the RPMs about 10% for a given speed and still has plenty of power when cruising the interstate at 70 mph up and down the hills. Turns about 4200 at 80. Not that I run at that speed, it's just that I had to see. :wink:

So, anyone with an 18-tooth wanting to go back to the 16?

dazco · 06-12-2006, 09:54 AM

I think it depends on the riding. Stoplight to stoplight in the big city probably would be worse, while freeway jaunts would doubtlessly be better. Overall, i dunno.

mag10 · 06-12-2006, 10:35 AM

you got 55 mpg! That is very good, I have never gotten better than 44 mpg.

I would not change out the 18 tooth unless my riding needs changed to 'in town' only.

dazco · 06-12-2006, 10:44 AM

Yeah, i forgot to address that.......are you sure about 55MPG? Most people find the twins get right about 42 with a mixture of riding and up to 3 or 4 MPG more for very easy riding. I've even heard of some getting as much as 50. But 55 would be so much more as to defy and explanation. Thats just too much varience between bikes of the same model or within the twin range of models even. The average being 42, that would mean you're getting 13 MPG more than the average ! Thats like the difference between a honda civic and a hot sportscar like a beemer or something. I'm not questioning you're honesty or anything like that at all, just wonder if you calculated wrong or something.

Normandy · 06-12-2006, 10:48 AM

When I put on the 17 T and ditched the 16 T last month; I was left thinking that I should have went 18T. The bike pulls so easily the low end torque is there but I drag the clutch more at lawn speed so I am leaving the 17 for now. It really doesn't need any more top end for the roads I drive. I would try an 18 if my dealer goes along with warranty mentioned awhile back - yea right.

kballowe · 06-12-2006, 11:18 AM

Well, that 55 mpg figure was the average of four tanks of 89 octane gasoline. I'm rural and ride mostly the two lane roads. Speed is normally between 50 and 60 mph. I have EPCO pipes, snorkel removed, K&N filter, factory pilot jets, 130 mains with factory needles turned out two turns. Not much traffic out here - off a LONG stretch of old Route 66.

My 1200 Sportster gets right at 50 mpg. Its got Vance & Hines Side Shots with a 45 pilot and 185 main, Kury air filter with K & N.

Either get dramatically worse mileage on the interstate.

Heck, I get 45 mpg from my Road King on the rural roads but about 37 on the interstate.

Where/how are you guys riding that you only get 40-something?

That was the reason I asked about the taller front sprocket. The engine runs free and easy up and down the hills with the 16 - and it seems like I'm twisting a little more throttle into it with the 18-tooth. The thing to do would be to run a few tanks of fuel through it and find out. Stay tuned.

kballowe · 06-12-2006, 11:50 AM

And another thing - how come the factory sprocket has all that rubber around it, and the replacement does not?

Shorty · 06-12-2006, 12:22 PM

I believe someone once mentioned that the rubber/plastic around the stock sprocket is there to eliminate noise. I really can't say for sure though. I guess it could also be some sort of Mfg process specific to whoever makes the stock sprockets for Triumph.

Shorty

mag10 · 06-12-2006, 12:46 PM

kballowe, how does your mileage get worse on the interstate? Usually mileage will get better when running at the constant speeds of the open road.

My best mpg has come from open road trips

kballowe · 06-12-2006, 02:04 PM

Let me 'splain my two-lane riding.... the closest town is ten miles and two stoplights. From there, I can ride about 70 miles to Jefferson City, all on a two-lane road and no stops. Normal speed is 55 to 60 mph. My interstate riding is about 75 mph. Both types are relatively steady speed, but I suppose the engine is working less at the lower speed.