10-05-2014, 02:29 PM
I've written about installing the 19 tooth countershaft sprocket on my 2013 model to reduce engine rpms (and vibration) at highway speeds. It dropped the 70mph rpms from 4000 to about 3775, a noticeable improvement, but I wanted more.
The sprocket needed to be steel for it to last at all. The sprocket bolt pattern/inner diameter are common to a lot of big Hondas (VTR1000, '94-'95 CB1000, Blackbird) but none used anything smaller than 39T. I called all the US manufacturers, found one back East, but there were problems, and not all their fault.
I met Jim Alfaro of 7th Gear Design at the Venice Vintage show, saw the quality of his sprockets, and knew this was the answer. I gave him the dimensions and requirements, ordered it and got it in less than 2 weeks. The sprocket had to have lightening slots, and the stud holes had to be counter-bored to clear the nut flanges. It is about 7 ounces lighter than stock and looks just great - I should have bought 2 so I could hang one on the wall!
The last pic shows from left to right, 7th Gear Design, Stock, and less than satisfactory first (and 2nd) ones.
Installation was a breeze. Here's a tip - to loosen or tighten sprocket nuts, do it with the wheel in place. Stand on the right side, put your foot on the rear brake, use a 19mm socket and a 1/2" drive ratchet/breaker bar, and you can break loose the nuts with ease. If you take the wheel off before loosening the nuts, you will be fighting to hold the wheel. Reassemble and torque the nuts in the same way - 80 ft/lbs torque.
Now, 70 mph is about 3600 rpm, roll on torque is still strong, and vibes are noticeably more comfortable. (Yes, you can record accurate rpm/speed on the centerstand).
7th Gear Design also makes countershaft sprockets and aluminum rear sprockets with any type of lightening holes/slots. Price was $75 plus $12 shipping. I cannot say how happy I am with the outcome.
The sprocket needed to be steel for it to last at all. The sprocket bolt pattern/inner diameter are common to a lot of big Hondas (VTR1000, '94-'95 CB1000, Blackbird) but none used anything smaller than 39T. I called all the US manufacturers, found one back East, but there were problems, and not all their fault.
I met Jim Alfaro of 7th Gear Design at the Venice Vintage show, saw the quality of his sprockets, and knew this was the answer. I gave him the dimensions and requirements, ordered it and got it in less than 2 weeks. The sprocket had to have lightening slots, and the stud holes had to be counter-bored to clear the nut flanges. It is about 7 ounces lighter than stock and looks just great - I should have bought 2 so I could hang one on the wall!
The last pic shows from left to right, 7th Gear Design, Stock, and less than satisfactory first (and 2nd) ones.
Installation was a breeze. Here's a tip - to loosen or tighten sprocket nuts, do it with the wheel in place. Stand on the right side, put your foot on the rear brake, use a 19mm socket and a 1/2" drive ratchet/breaker bar, and you can break loose the nuts with ease. If you take the wheel off before loosening the nuts, you will be fighting to hold the wheel. Reassemble and torque the nuts in the same way - 80 ft/lbs torque.
Now, 70 mph is about 3600 rpm, roll on torque is still strong, and vibes are noticeably more comfortable. (Yes, you can record accurate rpm/speed on the centerstand).
7th Gear Design also makes countershaft sprockets and aluminum rear sprockets with any type of lightening holes/slots. Price was $75 plus $12 shipping. I cannot say how happy I am with the outcome.