General chat about Adventure Riding

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Post by lilleeng » Tue Jan 20, 2015 8:06 pm

I'm going to buy a new set of sprockets, and considering to move over to a stronger/slower bike in favor of top speed. My BMW F650 GS feels a bit weak at low RPM, so I hope this will give me a more offroad friendly bike. (?)

I've been looking at calculators such as http://www.gearingcommander.com without too much luck. I still wonder the benefits of getting a bigger back-sprocket, than a smaller front-sprocket? Or a combination? Can I add/loose one tooth without having to move away from a 112 chain?

Thanks for any knowledge!

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Location: Lake Macquarie, NSW.

Re: Sprocket-modification

Post by Out6ack » Wed Jan 21, 2015 1:23 pm

Going one tooth smaller on the front will make a surprisingly big difference(stronger). You generally get the approximate ballpark with the front sprocket and fine tune with the rear. Like on a 27 speed mountain bike to exaggerate the point. As you know, only replace chains and sprockets as a set. So you could either guess and buy the full set straight up or, personally, I would buy and install/sacrifice a cheap, one tooth smaller front sprocket into your worn set to determine it's close, then buy your quality FULL set of chain and sprockets (I always used chain gang) and adjust/guess the rear to fine tune (less rear teeth =faster). Keep that cheap sprocket as a spare.
You may run out of chain adjustment room at your swingarm for big changes and need to remove chain links. Those going larger on the front need to ensure chain clearance at the crank cases.
Hope this helps mate.

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Re: Sprocket-modification

Post by lilleeng » Fri Jan 23, 2015 10:05 pm

Thanks! Will definitively try it out!

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Location: @ the crossroads of Gwydir & Newell Hwys NSW

Re: Sprocket-modification

Post by madrus » Fri Jan 30, 2015 7:25 am

Riding my old DR on the open road, gearing is great (43 tooth rear)
When we did the east side track up Mt Kaputar, the bottom gears were a bit tall. When using first gear on the steeper places, the poor old clutch copped a bit of a "workout" :think:
If it were an easy fix, I'd just lower first gear! Unfortunately this is the real world.
I'm going to persevere with the current final drive gearing, as it's hard to find a happy medium.
Determine what is the most predominant type of riding you do and go with what is comfortable.
Regards Russ.
Team Blue- '04 WR450F & 2010 XT660Z (Tankere)

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