- Location
- Yuba City, CA
The time finally came for me to replace my rear CEAT tire. 5600 miles and it was starting to get smooth in the center. I ordered a Shinko E705 from Amazon a couple weeks back in preparation for this event. If you're curious about it's specs, I capped this from shinkotireusa.com:
It looks like 130/90/17 could fit if one wanted a fatter tire, but I went with the factory 120/90. It was $84 shipped when I bought it which was a decent deal. A friend at a motorcycle shop offered to do the tire for me while I was working, so I took the rear wheel off and drove my old diesel Benz to work, dropping the wheel off at my friend's shop. I removed the sprocket holder from the wheel before I dropped it off, ofc.
I wanted to replace the factory 38T sprocket with a 36T sprocket I purchased from Hitchcock's. This will drop my RPMs by ~400 in 5th gear from what they are stock. There are 2 reasons I did this rather than change the (cheaper) front sprocket: 1, 2 teeth on the rear sprocket isn't as much as a change as 1 tooth on front. Hark:
The sprocket is bolted to the holder with 8MM hex bolts backed by 14MM nuts. I removed the factory steel 38T and bolted on my 36T aluminum beauty:
...
Got my wheel back with tire installed and put everything back together. I noticed I technically gained about a half inch of wheelbase because my axle is now slightly past the middle of range after setting chain slack. Geared up and went for a ride. The rear feels taller (new tire is 3/4 inch diameter larger than worn CEAT), the gearing is definitely taller, and the bike feels considerably less stressed at 55MPH. After pulling over to inspect everything and get the oil to at least 50C, I got on the highway to see what she'd do over 60MPH. At one point Toto was easily holding 75MPH, which is far beyond what I would have taken her before. I really just did this to lower RPM at 60MPH or less. There is some impact on acceleration, and I really noticed it accelerating in 4th and 5th against a headwind lol. Maybe I should do a cam or something
It looks like 130/90/17 could fit if one wanted a fatter tire, but I went with the factory 120/90. It was $84 shipped when I bought it which was a decent deal. A friend at a motorcycle shop offered to do the tire for me while I was working, so I took the rear wheel off and drove my old diesel Benz to work, dropping the wheel off at my friend's shop. I removed the sprocket holder from the wheel before I dropped it off, ofc.
I wanted to replace the factory 38T sprocket with a 36T sprocket I purchased from Hitchcock's. This will drop my RPMs by ~400 in 5th gear from what they are stock. There are 2 reasons I did this rather than change the (cheaper) front sprocket: 1, 2 teeth on the rear sprocket isn't as much as a change as 1 tooth on front. Hark:
Hence, my acceleration won't be slowed as much with a 36T rear as it would stepping up to a 16T front. Which leads me to the second reason I did this: my axle adjustment was already almost max forward, I would have had to add links to my chain to install a 16T! That aint happening, so here we go.14/38 = 12.08MPH per 1000RPM = 6.28:1 Overall Ratio = 60.4MPH @5K RPM
14/36 = 12.76 per 1000 = 5.95:1 = 63.8MPH
15/38 = 12.96 per 1000 = 5.86:1 = 64.8MPH (factory)
15/36 = 13.68 per 1000 = 5.55:1 = 68.4MPH
16/38 = 13.82 per 1000 = 5.49:1 = 69.1MPH
16/36 = 14.58 per 1000 = 5.20:1 = 72.9MPH
The sprocket is bolted to the holder with 8MM hex bolts backed by 14MM nuts. I removed the factory steel 38T and bolted on my 36T aluminum beauty:
...
Got my wheel back with tire installed and put everything back together. I noticed I technically gained about a half inch of wheelbase because my axle is now slightly past the middle of range after setting chain slack. Geared up and went for a ride. The rear feels taller (new tire is 3/4 inch diameter larger than worn CEAT), the gearing is definitely taller, and the bike feels considerably less stressed at 55MPH. After pulling over to inspect everything and get the oil to at least 50C, I got on the highway to see what she'd do over 60MPH. At one point Toto was easily holding 75MPH, which is far beyond what I would have taken her before. I really just did this to lower RPM at 60MPH or less. There is some impact on acceleration, and I really noticed it accelerating in 4th and 5th against a headwind lol. Maybe I should do a cam or something