17/40 sprocket setup for hawk 250

[Zapkin]

Well, since it has become abundantly clear that I won't be taking the Hawk off road anymore, I am interested in getting the RPM's as low as possible for street riding. I've seen several people on Amazon switch to the 17/40 setup. I understand I will lose some oomph. But my question is, will my 128 tooth chain fit? I've seen on Amazon that the 17/40 and 128 tooth chains are often bought together, but I wanted to ask you guys before ordering. Thanks.

[JerryHawk250]

A 128 link chain will work.

[Bill Hilly]

In my opinion , a 40/17 is not going to be a very good combination for you , nor for most people. I know you changed rear tire, and it reduced your gearing a little, but a 42-43/17 is really about as high as you should go. Some people that use the 40/17 have bikes like the TBR7, which has a smaller rear wheel, but on a Hawk, with an internally stock motor, and a hefty rider, living in a hilly part of the country, it's just going to make it hard to take off, and especially hard to take off from an upward slope. I think it would be harder on the bike than the few extra rpm that you want to reduce. I see post on the Facebook groups were people are recommending " crazy" combinations like 34/17. Jerry ran sprockets that ,if I remember right were 40/17, and was one of the few that was able to benefit from them, but he had a hotter motor, is under 200lbs, and lives in Louisiana.

[ProDigit]

Originally Posted by Bill Hilly

In my opinion , a 40/17 is not going to be a very good combination for you , nor for most people. I know you changed rear tire, and it reduced your gearing a little, but a 42-43/17 is really about as high as you should go. Some people that use the 40/17 have bikes like the TBR7, which has a smaller rear wheel, but on a Hawk, with an internally stock motor, and a hefty rider, living in a hilly part of the country, it's just going to make it hard to take off, and especially hard to take off from an upward slope. I think it would be harder on the bike than the few extra rpm that you want to reduce. I see post on the Facebook groups were people are recommending " crazy" combinations like 34/17. Jerry ran sprockets that ,if I remember right were 40/17, and was one of the few that was able to benefit from them, but he had a hotter motor, is under 200lbs, and lives in Louisiana.

What rpm range you're getting at what speed?
You should be aiming towards 1k rpm every 10 mph, or 5k rpm at 50mph.
On my Xpect I run a 17/36t as ideal lowest gear. Been asking if the hawk has the same gear ratio as the Xpect, or not, and if it does, you should go with a 36-38t rather than a 40+t.

[Zapkin]

Originally Posted by Bill Hilly

In my opinion , a 40/17 is not going to be a very good combination for you , nor for most people. I know you changed rear tire, and it reduced your gearing a little, but a 42-43/17 is really about as high as you should go. Some people that use the 40/17 have bikes like the TBR7, which has a smaller rear wheel, but on a Hawk, with an internally stock motor, and a hefty rider, living in a hilly part of the country, it's just going to make it hard to take off, and especially hard to take off from an upward slope. I think it would be harder on the bike than the few extra rpm that you want to reduce. I see post on the Facebook groups were people are recommending " crazy" combinations like 34/17. Jerry ran sprockets that ,if I remember right were 40/17, and was one of the few that was able to benefit from them, but he had a hotter motor, is under 200lbs, and lives in Louisiana.

thanks Bill, perhaps I will try the 42 but I have pretty much lost my desire to do any exploring and just want easy to ride around town now. I have the 17/44 on it now and its buzzing pretty freakin hard at 55-60. Annoying. It was not as pronounced before I put the new tires on. next weekend my friend and I are going to give it a good looking over. I can do most of it myself, but he is younger, stronger and has more mechanical skill than my elderly, atrophied brain. hehehe (i might be exaggerating on that part)

[JerryHawk250]

With the 40 tooth rear sprocket, you can always drop down to 16 or 15 tooth front if you find it to tall of a gearing. I use to swap the front sprocket when going from street to off road. Easy to swap back and forth.

[JerryHawk250]

Originally Posted by ProDigit

What rpm range you're getting at what speed?
You should be aiming towards 1k rpm every 10 mph, or 5k rpm at 50mph.
On my Xpect I run a 17/36t as ideal lowest gear. Been asking if the hawk has the same gear ratio as the Xpect, or not, and if it does, you should go with a 36-38t rather than a 40+t.

The Xpect has a smaller diameter rear tire than the hawk. The 40 tooth on the Hawk will be close to the 37-38 tooth on the xpect.

[Dusman]

I ran a 17/40 sprocket set-up on the Hawk for about 4 years after porting and polishing the head of my CG250 engine and loved it. I could comfortably run 65-70 mph all day long on my local highways without overstressing the engine. If you're running primarily on the street and doing occasional light off roading (i.e., double track dirt or gravel roads, riding across fields, etc.), then 17/40 is excellent.

[Do©Hawk]

Originally Posted by Zapkin

Well, since it has become abundantly clear that I won't be taking the Hawk off road anymore

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