2020 TT250 rear sprocket report

mtiberio · 06-12-2020, 10:35 AM

I got a 2020 TT250, and immediately knew I wanted to ditch the stock 50 tooth rear sprocket and try the 47 that I had leftover from my long gone 2016 TT250. It felt too wound tight up top. I run 99% street, and graded dirt roads and occasional stream crossing when I'm not on pavement. It was much better with th 47, but I wanted more. So I got a 45 from CSC mainly because I wanted their bolt and spacer kit as well. It was better, but the bike still felt wound tight in 5th. So I debated 43 or 42??? I decided 42, and it got installed yesterday. Yesterday was also the first time I remember using 3rd gear for more than a pass through from 2nd to 4th. 4th was better and 5th was great. Tops out about 70 indicated (63 actual, but I only have 500 miles). But the best news is it doesn't feel wound tight at those speeds. The tach first digit actually matches the speedo first digit now, although I assume the tach is correct. I should check it too. Bike has a mild re-jet otherwise stock.

Airhead · 06-12-2020, 11:12 AM

Good info. I recently changed to 45 at around 400 miles. It seems like a win-win with no discernible downside. Maybe at 1000 I'll try what you've done although I doubt it would increase top speed since I'm not exactly aerodynamic. Hope you update with your opinion after adding more mileage.

Choco · 06-23-2020, 03:21 PM

Quote:

Originally Posted by mtiberio

I got a 2020 TT250, and immediately knew I wanted to ditch the stock 50 tooth rear sprocket and try the 47 that I had leftover from my long gone 2016 TT250. It felt too wound tight up top. I run 99% street, and graded dirt roads and occasional stream crossing when I'm not on pavement. It was much better with th 47, but I wanted more. So I got a 45 from CSC mainly because I wanted their bolt and spacer kit as well. It was better, but the bike still felt would tight in 5th. So I debated 43 or 42??? I decided 42, and it got installed yesterday. Yesterday was also the first time I remember using 3rd gear for more than a pass through from 2nd to 4th. 4th was better and 5th was great. Tops out about 70 indicated (63 actual, but I only have 500 miles). But the best news is it doesn't feel wound tight at those speeds. The tach first digit actually matches the speedo first digit now, although I assume the tach is correct. I should check it too. Bike has a mild re-jet otherwise stock.

How do you feel the torque with that sprocket?
I want to go faster on mine but i want to ocationally take some steep hills
can you still go up hill no problem?

mtiberio · 06-23-2020, 07:54 PM

Define steep? No problems with anything paved or graded. I could see some gnarly single track trails where a tighter first might be better.

Choco · 06-24-2020, 12:57 AM

Quote:

Originally Posted by mtiberio

Define steep? No problems with anything paved or graded. I could see some gnarly single track trails where a tighter first might be better.

I mean if you going up a hill does it struggle?
I gone up to 65mph with the stock sprocket on a good day but would like to go 70mph all day if possible but i dont want to loose alot of acceleration. Ofcourse i know this is not a fast bike but i enjoy the little bit of power it has at the moment

mtiberio · 06-24-2020, 06:46 AM

Steep paved roads. I live where the Piedmont meets the coastal plain. Some decent hills. If I hit them at WFO, about 65 (real not speedo) speed will drop to about 56 on the worst. Still faster than 4th. Like I said the 43 is for cruising comfort. A 43, 44 or even 45 might be better on hills. Learn to work the draft like a NASCAR driver.

jerhomey · 06-24-2020, 11:47 AM

Quote:

Originally Posted by mtiberio

I got a 2020 TT250, and immediately knew I wanted to ditch the stock 50 tooth rear sprocket and try the 47 that I had leftover from my long gone 2016 TT250. It felt too wound tight up top. I run 99% street, and graded dirt roads and occasional stream crossing when I'm not on pavement. It was much better with th 47, but I wanted more. So I got a 45 from CSC mainly because I wanted their bolt and spacer kit as well. It was better, but the bike still felt would tight in 5th. So I debated 43 or 42??? I decided 42, and it got installed yesterday. Yesterday was also the first time I remember using 3rd gear for more than a pass through from 2nd to 4th. 4th was better and 5th was great. Tops out about 70 indicated (63 actual, but I only have 500 miles). But the best news is it doesn't feel wound tight at those speeds. The tach first digit actually matches the speedo first digit now, although I assume the tach is correct. I should check it too. Bike has a mild re-jet otherwise stock.

Im looking to do something similar as mine is mostly a commute to work bike in the summer. Did you have to change your chain ? and if so what did you go with. Thanks

mtiberio · 06-24-2020, 04:19 PM

Quote:

Originally Posted by jerhomey

Im looking to do something similar as mine is mostly a commute to work bike in the summer. Did you have to change your chain ? and if so what did you go with. Thanks

Chain adjusters can handle it. At some point I might cut off a link.

jerhomey · 06-29-2020, 11:30 AM

Quote:

Originally Posted by mtiberio

I got a 2020 TT250, and immediately knew I wanted to ditch the stock 50 tooth rear sprocket and try the 47 that I had leftover from my long gone 2016 TT250. It felt too wound tight up top. I run 99% street, and graded dirt roads and occasional stream crossing when I'm not on pavement. It was much better with th 47, but I wanted more. So I got a 45 from CSC mainly because I wanted their bolt and spacer kit as well. It was better, but the bike still felt wound tight in 5th. So I debated 43 or 42??? I decided 42, and it got installed yesterday. Yesterday was also the first time I remember using 3rd gear for more than a pass through from 2nd to 4th. 4th was better and 5th was great. Tops out about 70 indicated (63 actual, but I only have 500 miles). But the best news is it doesn't feel wound tight at those speeds. The tach first digit actually matches the speedo first digit now, although I assume the tach is correct. I should check it too. Bike has a mild re-jet otherwise stock.

Which sproket did you order off amazon im assuming ? I bought the 45 from csc as well but want to try a 42 . Thanks !!!

mtiberio · 06-29-2020, 06:15 PM

Just search JTR269-42, the number 42 after the dash is the # teeth. Default 428

simonjester · 05-11-2021, 12:03 AM

Quote:

Originally Posted by mtiberio

Just search JTR269-42, the number 42 after the dash is the # teeth. Default 428

So you can get this off Amazon?

mtiberio · 05-11-2021, 07:03 AM

Quote:

Originally Posted by simonjester

So you can get this off Amazon?

https://www.amazon.com/gp/product/B0068O5N5Y

43 is, don't know why 42 not listed anymore

06-12-2020, 10:35 AM	#1
mtiberio Join Date: Jun 2016 Location: Arlington, VA Posts: 258	2020 TT250 rear sprocket report I got a 2020 TT250, and immediately knew I wanted to ditch the stock 50 tooth rear sprocket and try the 47 that I had leftover from my long gone 2016 TT250. It felt too wound tight up top. I run 99% street, and graded dirt roads and occasional stream crossing when I'm not on pavement. It was much better with th 47, but I wanted more. So I got a 45 from CSC mainly because I wanted their bolt and spacer kit as well. It was better, but the bike still felt wound tight in 5th. So I debated 43 or 42??? I decided 42, and it got installed yesterday. Yesterday was also the first time I remember using 3rd gear for more than a pass through from 2nd to 4th. 4th was better and 5th was great. Tops out about 70 indicated (63 actual, but I only have 500 miles). But the best news is it doesn't feel wound tight at those speeds. The tach first digit actually matches the speedo first digit now, although I assume the tach is correct. I should check it too. Bike has a mild re-jet otherwise stock. __________________ 4 time WERA SuperVintage Roadracing National Champion, SCTA Land Speed Record Holder, 3rd AMA Motorcycle GP of Miami Last edited by mtiberio; 06-24-2020 at 04:20 PM.
	2

06-12-2020, 11:12 AM	#2
Airhead Join Date: Dec 2019 Location: Oregon Posts: 8	Good info. I recently changed to 45 at around 400 miles. It seems like a win-win with no discernible downside. Maybe at 1000 I'll try what you've done although I doubt it would increase top speed since I'm not exactly aerodynamic. Hope you update with your opinion after adding more mileage. __________________ 2019 CSC TT250, stock carb w/jet kit, muffler mods
	0

06-23-2020, 07:54 PM	#4
mtiberio Join Date: Jun 2016 Location: Arlington, VA Posts: 258	Define steep? No problems with anything paved or graded. I could see some gnarly single track trails where a tighter first might be better. __________________ 4 time WERA SuperVintage Roadracing National Champion, SCTA Land Speed Record Holder, 3rd AMA Motorcycle GP of Miami
	0

06-24-2020, 06:46 AM	#6
mtiberio Join Date: Jun 2016 Location: Arlington, VA Posts: 258	Steep paved roads. I live where the Piedmont meets the coastal plain. Some decent hills. If I hit them at WFO, about 65 (real not speedo) speed will drop to about 56 on the worst. Still faster than 4th. Like I said the 43 is for cruising comfort. A 43, 44 or even 45 might be better on hills. Learn to work the draft like a NASCAR driver. __________________ 4 time WERA SuperVintage Roadracing National Champion, SCTA Land Speed Record Holder, 3rd AMA Motorcycle GP of Miami
	0

06-29-2020, 06:15 PM	#10
mtiberio Join Date: Jun 2016 Location: Arlington, VA Posts: 258	Just search JTR269-42, the number 42 after the dash is the # teeth. Default 428 __________________ 4 time WERA SuperVintage Roadracing National Champion, SCTA Land Speed Record Holder, 3rd AMA Motorcycle GP of Miami
	0