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Discussion Starter #1
I need a new chain since I installed my CB650 wheels and the rear gear is a 40T compared to 35 on the CM400T's rear wheel. I was hoping I could swap gears but as I found out. Everything on the 650's wheel is bigger compared to the 400's...axle, drum hub and rear gear... I got the drum covered, swingarm ground out to fit the 650's axle. I just decided to get a new chain since the old one well is old and pretty rusty and notice it already has two master links on it which I thought was kinda weird. I don't do any racing or really beat that hard and hell, I've yet to get over 65 on the bike. Do I really need an O-ring chain or a non o-ring. Do they last longer or less maint. needed? I'm fairly new to cycles so this is new to me. I suppose I could get a smaller gear but the stock chain is pretty nasty and is the 25 extra bucks worth it? 50 for an o-ring and 25 for a non.
 

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Going up 5 teeth in the rear is really going to affect your speed. I would recommend that you get a smaller rear sprocket for the 650 wheel if you can find one and get a new non-o-ring chain. You might as well replace the front sprocket while you are at it. New chains and sprockets if properly lubed and adjusted will last a really long time on a 400. I would try to keep your gear ratio close to stock, unless the overall diameter of the 650 wheel and tire is significantly different from the 400. Then you will need to adjust accordingly.

Ken
 

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Discussion Starter #3
Is that something that a Honda stealership or a bike shop would stock or an ebay item most likely? Or can I pull it off another bike? Like I said the CM400's rear gear wouldn't fit unless I bored out the center of the gear a good half inch and then enlarged the holes for the bolts that hold it to the hub?
 

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I would go to the salvage yard( since you live close to a big one) with the 650 sprocket in hand and look around at the other Honda rear wheels and find a sprocket that is smaller with the same bolt pattern. Or if you know what year and model cb650 the wheel came off of you could just order what you need from Dennis Kirk. I just looked on Dennis Kirk and all the cb650s use the same rear sprocket bolt pattern as the SOHC CB750s and the early through 82 DOHC cb750K. I usually get an order from them the next day.
 

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Discussion Starter #5
I was looking around on Denniskirk and the smallest I could find was a 37T. What would you suggest for gears front and rear after bumping up the wheel size by an inch both front and rear? The front is a 16 and rear was a 35?
 

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quote:Originally posted by Pinche Chingadera

the CM400's rear gear wouldn't fit unless I bored out the center of the gear a good half inch and then enlarged the holes for the bolts that hold it to the hub?
this sounds pretty easy. drill press for the bolts. then find a shop with a lathe for the center bore.
on a cm400, i wouldn't go o ring. the o rings are much fatter looking chains and weigh more. many people feel you lose some power with them, but gain a little reliability.
 

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Some of this depends on what the diameter difference is in the tire on the 650 wheel is compared to the tire(not wheel) diameter of the 400 that you took off. A 37 might work fine on the rear.

Ken
 

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Discussion Starter #8
Their both 130/90's....16 and 17. I may just drill out the 35 sprocket cause I'm pinching pennies right now and need it to ride to work. I think I may just end up buying a 15 for the front and getting the 37 for the rear and a new chain come this paycheck coming up. I just want it to be a bit snappier then it is now.
 

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The 130/90/17 is going to have a larger diameter than the 16, so it wouldn't hurt to go with a 16/37 combo. That might end up close t stock. I agree that trying the 15 front would be worth it, to see if you can get a little better accel. You may find that you want to change back to the 16 if you ar oing to be doing any long distance riding.

Ken
 

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Discussion Starter #10
Well I got the 35 to fit with some help from my stepfather and his drill press. Drill out the hub stud holes and then he gave me some carbide grinding bits to hog the bore. It only took me half an hour to bore out a 1/4" all the way around the inside of the sprocket. This is just to hold me over till I can get my new chain and sprockets. Atleast I got everything working and oh yeah. A CB650 rear wheel doesn't just bolt onto a CM400T's swingarm. Hahahahaha. But atleast I have bigger brakes for the rear and those nasty 5 spoke wheels are gone.
 
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