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As the title says, in the near future I will be putting a 5 speed transmission possibly from a cl160 (I believe). Has anyone done this to their CB160? If so do you have any pictures of what was done to further guide me. Thanks, Dustin.
 

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I haven't done it, but the one-year sloper 175 had a 5-speed and racers in the PNW make the swap. Pretty sure the CL160 has 4 gears too, and it's only the 175 sloper that has 5.
 

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Yeah, pretty sure all 160s were 4 speeds. Interesting to know the sloper shared enough of the design to allow the 5 speed trans from it to be used in the 160s, never thought about it or realized
 

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It's pretty easy to do, you have to build up, with weld, the upper crankcase in two spots, face them flat and drill/tap two holes for the shift drum retainer. After that it just bolts together.
 

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Never had any pictures, no camera in those days. A buddy of mine was running a 160 flat tracker, and he put it together for a spare motor. I got it from him. Never did use it, I gave it to a guy who was building 160 road race motor.
 

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If you poke around the CB160 racing-oriented websites from Seattle and Portland I think you'll find something. It's been a few years since I have, but I remember seeing some info.
 

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The 160 trans uses a locater bolt in the upper case, fitting in a groove in the shift drum to hold it in place. That spot is taken up by the third shift fork in the five speed trans, hence the need to put the locating parts on the end of the drum. The easiest way to do the swap is to use the 175 crankcase along with the gears and just bolt it together.
 

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I'm inclined to think that building up a 175 sloper would be an easier project (if you can find a decent one to use) than to try to modify the 160 casing. Using the 175 casing sounds like the easier way to go too. Still, there's always that challenge...
 

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If you didn't care about the engine#s, the case swap is the easy way to go. If you want it to look original on the outside then modify the upper case. You could even use 175 pistons/cylinder for a little displacement boost.
 

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The 160 trans uses a locater bolt in the upper case, fitting in a groove in the shift drum to hold it in place. That spot is taken up by the third shift fork in the five speed trans, hence the need to put the locating parts on the end of the drum. The easiest way to do the swap is to use the 175 crankcase along with the gears and just bolt it together.
Hi Mike, just curious will the vert 175 transmission fit into the modded cb160 cases or do the parts need to be from the sloper CL?
 

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Simon, The sloper and vert 5-speeds are built on the same (part number) shafts, so presumably are interchangeable.....
 

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The 160 trans uses a locater bolt in the upper case, fitting in a groove in the shift drum to hold it in place. That spot is taken up by the third shift fork in the five speed trans, hence the need to put the locating parts on the end of the drum. The easiest way to do the swap is to use the 175 crankcase along with the gears and just bolt it together.
Hi Mike, just curious will the vert 175 transmission fit into the modded cb160 cases or do the parts need to be from the sloper CL?
 

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My concern would be rather or not the stock 160 would have enough power to pull 5th gear. I’m running standard gearing and it seems like I do a lot of shifting between 4th and 3rd. I do live in a fairly hilly area so that may have something to do with it.:D
 

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Top gear in the 160 is 1.04:1, 10.1:1 overall. 5th gear in the five speed is 1:1, it would be 9.975:1 with the stock 160 sprockets. One more tooth on the rear sprocket would give you an overall final gear ratio of 10.23 overall, about 2% lower than the standard four speed setup.
 

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Didn’t realize it was so close. What’s the advantage of going through all the work to get a 5 speed in the 160 case?
 

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I haven't looked at the ratios in the 160, but in the 4 speed 450 the gap between first and second is larger than the same gap on the 5 speed (meaning larger drop in rpm) - most 4 speeds are not close-ratio between first and second (at least in my experience) and I believe it was because at lower mph, the engine can more easily overcome a larger drop in revs during acceleration than at higher speeds/higher gearing when wind resistance and overall higher gear ratios require more horsepower to pull
 

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Five speeds with the same top gear ratio brings the gears closer together, makes it easier to keep the rpms in the sweet spot. Makes for a nicer ride, better gears for steep hills passing cars,etc .
 
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Simon, The sloper and vert 5-speeds are built on the same (part number) shafts, so presumably are interchangeable.....
Thanks Steve, then presumably they'll take the cb200 gears as well. Which means you'd get minusculy better numbers swapping in the cb200 5 th at 0.960:1
 
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