Bonneville America Forums Forums Technical Forums Accessories Help with this whole "Sprocket" thing ??

Guys - I know there's a lot of info on this here but I'm still confused. I have a couple of questions around Front and Rear Sprocket combination.

1 - Does the '06 Speedy have a 18th Front already ?
2 - Either way, what is the ideal Front / rear tooth combination for an '06 Speedy. 18/41, 18/42, 19/43, 17/41, 18/42 .....I'm 250lbs and ride solo 99% of the time. I guess it’s probably a “depends on what you like” answer but some opinions would be appreciated.
3 - Does anyone have one of the 'pretty' colored Rear's from Brent ? If so, are they the best out there or are there alternatives ?
4 - I assume switching the Rear out is not difficult ?

Thanks gang.

Can't answer number one
number two really does come down to personal preference and riding style. How do you split your mileage between highway and streets? A higher proportion of highway mileage might suggest a higher front sprocket for you. Are you an aggressive rider? If not, again a higher front sprocket might be more in order for you.

I have one of Brent's new rear sprockets, anodized black. For me, it really was the best option, as far as tooth count, color-coding, price, and speed of receipt. OE sprockets are expensive for what you're getting (IMHO), and they may not exactly be the fastest option. Sprocket Specialists take forever, I'll never buy from them again, I had Brent's sprocket in about 4 days, and it looks awesome.

If you have a motorcycle jack, switching out the rear sprocket is not that hard, and you can do it by yourself.

NJW
#2 - You forgot an option. I went to the 17/42 combination on my 05 SM. Gives me good highway speeds but still produces the torque I want with my current setup. (Thunderbikes, no airbox, K&N duals, 155 main, TBS needles) I really enjoyed the 17/42 setup while at the Branson RAT Raid. Stayed in 4th gear most of the time with speeds up to around 60-65 around twisties and hills. If you're looking for more highway cruising though the 18/42 would be my choice.

1- It was my understanding they were changing to 18/42 on the SM in 2006 and both SM and TA in 2007, BUT I have not gotten anyone to confirm. Take off the sprocket cover of your 06 SM and look. The tooth number is written on the sprocket.
2- Depends, as you said. Confirm which sprocket you have. How do you like the way it is now? If it is an 18, going to 17 will allow quicker starts in first, but run at a higher rpm possibly making you want a 6th to go to. If you have a 17 and feel like you wish you had a 6th, try the 18. Front counter sprockets only cost about $20. and are not hard to change.
3- Don't have, but prefer sticking to the stock steel rear sprocket. If you stick to the 42 rear, you will be able to buy Triumph complete chain and sprocket sets for future replacement at a reasonable cost either in 16, 17, or 18(soon).
4- Haven't done it for reasons stated.

My opinion - Seeing that you mainly ride solo, I would definitely give the 18 a try IF yours is a 17. Ride what you have for awhile so you can decide which direction you would like to go. I much prefer the 18 riding solo and traveling on the highway. I ride 2-up about 50% and might prefer the 17 for that, BUT I haven't taken the 18 off since I put on 9 months ago. Obviously, there are pros and cons to each choice. Some prefer the 16 which is way to low for me, and others prefer a 19 which is WAY too high for me. The only way for me to split the difference of what I do like would be to go to a 43 rear. The 18/43 would be a final drive of 2.39:1, a little lower than my 18/42 (2.33:1). The stock TA is 17/42 (2.47:1). The earlier SMs were 16/42 (2.63:1).

NJW, I have been curious myself about this sprocket thing and if you're going to change it let me know, you're not that far from me. Let's do a ride sometime.

I clock in at 250 also, more with gear, and I am happy with my 18T front. But they are cheap, buy two If you do a LOT of around town stop and go, a 17 might be better. But I really like not searching for 6th all the time. Also, I can stipp rip up the backroads in 3rd.

Thanks guys - good advice. I'll take a look at the Front to confirm if it's an 18 (sometimes it's the simple ideas that evade you ).
I would describe the majority of my riding as neither city or highway but more minor roads, NJ / PA / NY county roads, twisties when I can find them. I feel like I have plenty acceleration and low torque – but I’m still looking for that sixth gear when I reach the top of the curve so maybe a 19 front ???? I was really wondering – assuming I do have an 18 front already – if I went up or down a tooth on the rear and kept the 18 up front, could I achieve the desired result, even fine tune it so to speak.
By the way, I never doubted the quality or service for Brent's 'pretty, colored rears' - always had excellent service and quality. I was just wondering if they were more form over function; looks over durability ??? Just a thought. Anyways – thanks again.

Whichever you have, 16 or 17 go up one tooth on front sprocket. You'll like it. Leave the rear the way it is.
No reason in this world to change it.

jerry

Thaks again guys. I'll take a look at the front this weekend - see what I've got.

I'll 2nd what Roundslide said, it's all a matter of personal taste and riding style. I run a 17/41 now and it's just about perfect for me, and even 2 up with my wife. I tried an 18 and I didn't like it. Lost too much acceleration off the line.

It's cheap and easy to try out front sprockets. They're only $20 each plus shipping from Brent.

If you are searching for 6th then as mentioned go up a tooth. I did not think the 06 had an 18. I recently met a guy with an 06 and we discussed sprockets. I assumed he had the 16 like earlier speedies.

I have tried 16, 17, 18 and the belt drive. For my local riding I prefer the 16 but if I could actually ride a highway for any distance without traffic I would use the 17. The 18 is too much for me overall but the parkway ride is great, especially if you can cruise over 75.

So I confirmed the front sprocket on an '06 Speedy is an 18T. I'm going to try a 19 and see how she feels. I'll let you know.

I have a question as to what exactly adding a tooth or 2 to the front sprocket does. I understand it lowers the RPMs and makes for a somewhat smoother highway ride. My question is, does it add any actual MPH to the top end, or do you go the same speed, just at a lower RPM?

Also, it seems most have had mods done to thier bike that have added a few teeth. If I don't have several mods on my bike, will adding a tooth be too much of a strain? Or can I add a tooth and not feel like I'm starting off in second gear all the time?

1) Adding a tooth changes the final drive ratio to slightly higher gearing. Yes, it does add top end speed as rpms are the limiting factor.

2) You didn't mention what bike you have. A SM with a 16T or an America with a 17T, or a newer model with an 18T. If you have a Speedmaster (pre 2006) then going up to a 17 would be absolutely no problem. You might can go to an 18 (from a 16 or 17) if you don't mind starting off a little slower. Opening up the exhaust and re-jeting along with opening up the airbox will result in a noticeable increase in hp making it easier to start off with the higher gearing.

Think of it like riding a bicycle. It lets you go faster, but it is in theory a little harder to push. But these motors have plenty of grunt. I think guts will be a limmiting factor in top end

You should be ok without many mods, but there are a few very simple mods that most people do in the name of just plain better running motors that also help the power that should make it ok for ya.

Sorry, forgot to mention I have a 06 America. I haven't personally looked at the sprocket, but the info I see on the net says it's a 17 tooth. I think you guys answered my questions anyway. Thank you for the info, as this makes my decision easier to go ahead and get the sprocket and try it out.

Oh and I forgot, the sprocket is only 20 bucks... And a totally reversible mod. Always worth trying.

Some say the 18t provides a more "relaxed" ride on the highway. So the rpms are lower. It gives the bike longer legs in every gear, though. I would be racing around in 1st or 2nd trying to get in and out of the neighborhood. I liked it, but I don't know now how "relaxing" that really was.

When I changed chains, I bought the America chain/sprocket set, (17/42). Now I may be running higher rpms in 5th, but she likes it that way, and I don't search for 6th any more than I ever did. The tach helps, as seeing 70 mph and about 5k, you know your in 5th already. Seeing 6k or more, I know I can shift again.

But the 17t IS more relaxing at lower speeds, as I can now cruise in 2nd,3rd, and 4th in a much more relaxed manor. The engine has plenty of grunt for that, and the shorter front sprocket means plenty of power on tap when you want to twist it up.

Now that I have had the 16t,18t, and now 17t fronts, I have to say the 17t is probably where I'll be staying.

I ran a 19 toothed front against the factory rear sprocket for around 8,000 miles.

While it certainly does lower the RPMs, my lil ol 2 cents is it works the engine too hard around town and on a grade, even if you keep it tached up. I can't say for sure, but I would want to guess & believe a proper Triumph driveline engineer might say the 19 is probably not a great idea most of the time. Then again, I'm not exactly what you'd call a light load on the poor little seat. (In fact I could swear I heard it say "git off me ya fat bas****," just the other day.)

Your mileage may vary.

I ran a 19 toothed front against the factory rear sprocket for around 8,000 miles.

While it certainly does lower the RPMs, my lil ol 2 cents is it works the engine too hard around town and on a grade, even if you keep it tached up. I can't say for sure, but I would want to guess & believe a proper Triumph driveline engineer might say the 19 is probably not a great idea most of the time. Then again, I'm not exactly what you'd call a light load on the poor little seat. (In fact I could swear I heard it say "git off me ya fat bas****," just the other day.
...or was that my wife who said that? )

Your mileage may vary.

I like to double post too

I really glad that someone - Steven (NewJerseyWelsh) - confirmed that the 06 Speedmasters came with 18/42, which is a big jump from the original 16/42. It seems that the 06 Americas still had the 17/42. NOW, can we get someone to confirm that they are both 18/42 on the 07 models?

If they are, how long is it going to take for Triumph to come out with a chain kit with 18/42 sprockets?

I purchased my 06 speedmaster in april 06 just checked my front sprocket it is a 16 tooth rear is 42? When did they change. My owners manual says 16/42 for speedmaster 17/42 for america.Now i know why i beat my buddies harley with 95 inch motor. Doesn't bother me much on highway i stay around 70 mph most of the time.

I am now running a 16 tooth on ther front and a 41 tooth on the back. Of all the combinations I have tried, this is best for me. Good hole shots and great freeway.
Vic

I read that the Speedmasters were originally designed by Triumph for low end torque, which should explain the 16 toofer.