Hawk 250 - Is It Ok To Just Change Rear Sprocket?
 

So I would like to do the 17/45 sprocket changes that everyone recommends to gain some top-end speed on the highway on my Hawk 250. But I am nervous about going bigger on the front sprocket in the event of a chain failure resulting in a damaged case. Probably a one-in-a-million-rare chance but I dont want to chance it.

So I was informed that I can go with a 40-tooth rear sprocket and leave the stock front sprocket in place for the same gearing result as 17/45. Does this sound accurate? And will there be any disadvantage to changing just the rear sprocket to a 40-tooth? Just wondering if there are any disadvantages since people usually change both sprockets for this change, thanks.

40 tooth rear will be very close to the 17/45 combo with 15/40 being slightly lower. That's what I run when I go strictly off road. You can always change the front to a 16 or 17 later on if you plan on just street riding. Here is a link to a sprocket calculator. just type in Hawk in the filter and then select Hawk 250. http://woodsware.aciwebs.com/gears/ You can play around with that to figure out what you want to do. I'm currently running 16/40 because I have been doing about 50/50 on and off road cruising 55-60 mph on the highway.

Thanks a lot JerryHawk250. If I run a 40-tooth rear sprocket with a stock front sprocket, how do I determine how many links my chain should have? Because I also plan on buying a high quality chain for my Hawk 250 and wondering how many link chain I should order for a stock front + 40-tooth rear sprocket setup. Thanks!!

I'm still running the stock chain and only removed 2 links which makes it 128 links. 128 works with 15,16 and 17 front with the 40 rear.

Great! Thanks so much for your help!!

Only reason you would need to change both sprockets and chain is if your current sprockets are showing some wear.

I find this website to be handy: http://www.sprocketcalculator.com/