[John250R]

Well, I finally got the 92 1100 wheels swapped onto my '86 750, thanks to all of you who helped me along in this easy but time consuming job. I have one more question though. The rear cush drive came with a brand new 44 tooth sprocket, I am running a 13 front and a 180/55-17 tire. It runs about 7000rpm when the speedo shows 80mph (haven't checked its accuracy yet). I usually cruise a little slower on the highway probably around 70-75mph which would be about 6500rpm. Is this too much for the old gixxer to handle for a 30-40 minute stint on my way to work? I love the extra torque I am getting with this setup but I don't want to kill the motor over it. Thanks again to all of you for your help, you know who you are. As soon as I get some pics I'll post them.

John

 

[twinner]

I didn't notice the change in rpm's after I did the 17" change. I figure the horsepower/torque is still waiting at the same points on the curves so I didn't give a thought. You are correct though, it will be running higher rpms for the same speed. I just don't know if it is 50 or 500 rpms.

Sorry I'm not much help.

 

[John250R]

Simon,

Thanks for your help anyway (with at least 5 previous questions). What I am really looking to find out is if cruising at 6500 or so is going to damage the motor. I think it'll be fine but if someone knowledgeable says it is too much then I'll go up a tooth on the front. It really is amazing how much better the bike handles with the new wheel and tire combo, it feels like I'm riding a bike thats ten years newer.

John

 

[bcjohn]

John, if you're doing around 80mph at 6500, that shouldn't be very hard on the machine. But I do cringe at the thought of a 13 tooth on the front. That is going to kill your chain/sprockets muy pronto. 14t on the front is normally thought of as being the lowest choice (borderline).

 

[John250R]

BC, I hear what you are saying about the front sprocket but it is too late now, I am almost all the way foward on the adjustment> When it is time for a new chain and sprocket set I will follow your advice. I thought I was OK because I only went down one on the front but I guess it was too much for maximum chain wear. I also figured I'd be OK with the RPM's but I would rather be safe than sorry. Thanks fellas.

John

 

[MDill]

I've got stock gearing on my bike (92 750) and it does about 6000rpm at 75mph, sounds like the same as you. I really wouldn't worry about it, 6k may seem like a lot in car terms but the short stroke of the bike engine keeps piston speeds down to safe levels. Remember your bike redlines at 12.5k. I do a lot of freeway cruising and I've got 40k miles on mine with no major work and no burning oil so clearly the bike can take it.

Matt