98 Superhawk
 

I have a 98 honda superhawk and want to get better fuel mileage without ruining the way it looks so I want to start by changing the rear sprocket.
I have already gone from a 16 to 17 tooth sprocket on the front and put on a 39 from the stock 41 but can't find anything smaller any ideas?
Thanks
Jon

I think that may be about it.

A 1000cc twin is only going to do so well in the MPG department no matter what you do. If you really want good numbers sell it and buy a CBR250R.

Otherwise just have fun with it.

I enjoy my big vtwin too much to ride anything else but I know the engine could be spinning allot slower and still pull hills good and i can always downshift if it doesn't. I would like to get down to 30 teeth on the rear

I had a '97 Superhawk. Awful awful awful on fuel. A tiny fuel tank doesn't help for range. All I can say is good luck.
Gear it WAY higher and try to keep the revs very low, relying on the gobs of torque it has to spare. Very very difficult to do, considering how amazing that engine sounds at high revs!

VT1000f made my short list, but the little tank nixed it for me as well. Narrowed down to used FZ1 or new Bandit 1100. FZ1 won for me. Nephew had a SV1000 fun ride, not a lot to do with your Hawk, don't worry about the gearing, look for good deals on tires, they cost about as much per mile as gas. And insurance.

I took a quick look at JT sprockets website on your behalf, there is an 18 tooth front sprocket available which has the same fitting dimensions as the superhawk, catalogue number JTF 339. I can't say for sure if there will be enough clearance for the larger sprocket, JTS are very helpful it might be worth asking their advice.

Regards,
Ironside.

If the 18 will fit without hitting the cases or the guides, I'd go with that.
16/41 is a 2.563
17/39 is a 2.294 or 11% less revs
18/39 is a 2.167 or 18% less revs

If you want more efficiency, than that, you'll have to re-jet and/or downsize the carbs.
Then the only thing you can really do after that is reduce friction and weight (both rotating and non-rotating).

This would be a good bike to consider - Ecotrons EFI conversions on it. Probably could use the EFI Throttle Bodies off an RC51.

Or you could just get something that started off getting big numbers - like a CBR250.

You will never overcome that much more displacement/power than is required to propel a typical motorcycle at a moderate speed.

Just have fun with it, because there's really no reasonable way to make it get seriously high MPG numbers.

Some of us would kill a cbr250 and don't want to just buy a new or another bike.. I can add my luggage to a Superhawk and still go touring on it, much like with my VFR.
That's not something I can do with a cbr250.
The OP already has a Superhawk and is not chomping at the bit for another bike, so why not make useful suggestions.

I'd bet that with the right parts you can get descent mileage from it.
Sure its a large-ish V-twin, but that doesn't meant it can't operate more efficiently than it did when it left Honda's factory.

He didn't say he wanted to add luggage and go touring, he said he wanted better mileage. If mileage is a concern, riding a BIG (1000cc) V-Twin isn't a great choice.

Getting into major mods like you suggested in order to get slightly better mileage from a 1000cc motorcycle is not a useful suggestion.

I think my comment of "just ride it and have fun" is a useful suggestion.

Ya I am planning on going efi like you are talking about plus adding a turbo to increase volumetric efficiency like naturalextraction did
http://ecomodder.com/forum/showthrea...wer-26379.html

Oh and no luggage bags on the bike I hate the way they look I just wear a backpack
BTW my last bike was a 99 vfr and witch I consider to be the best bike ever!

Well smaller capacity is better, its also obvious that mileage isn't his only concern when it came to his choice of motorcycle.

Have you had a big Honda twin? I have. I owned their racebike for the street, a RC51 also know as a RVT1000SP2.
When I bought the bike it had stock gearing 16/40 (or 2.50:1 ), stock efi, slipping clutch and the fuel sender did not work, so I found out quickly that it had a range of about 125 miles on the 4.8 gallon tank - or - about 26 mpg.
The slipping clutch meant I had to make small smooth throttle inputs, so I was pretty sure that the bike wasn't going to get better mileage, once I could whack the throttle open.
So I fixed the clutch,
fixed the gas tank sender to know when I hit reserve (1.2 gallons),
replaced sprockets 17/39 (or 2.29),
added a Power Commander III (with a more 'street' tune),
installed a taller rear tire 190/55zr17 (over the 190/50zr17),
added a progressive 1/4 turn throttle (over the stock 1/6th),
reversed the radiator fans (to solve overheating issues),
and last, replaced all the air filters.
That meant that I had a bike that was marginally slower to 100mph than my friends rc51's, but I was getting 165 miles before the reserve light would light up. That's than 43 mpg.

Now if I could have had gear by gear mapping of a Power Commander V, a smaller rear sprocket, adjustable fuel pressure regulator, smaller injectors, a better airbox design, a rear suspension link, lighter wheels and brake rotors - I'm sure I could have managed even better mileage.

Okay, so no luggage, but you are thinking EFI. Still your adding your weight plus a backpack to the bike.

If Supersprox.com can make 36 tooth rear sprockets for an rc51 which has a larger center hole and bolt circle than a SuperHawk, I'm sure they can make a 35/36/37 tooth rear for a SuperHawk.

And for best mixture when you go EFI, I'd go with a highest pressure system you can get with the smallest injectors.

I'd also consider the 190/55 tire, because your probably going to want to add a suspension link that will raise the rear of the bike, giving you plenty of clearance for the taller tire.

I know what a RC-51 is, but haven't owned one.

If I did, I wouldn't be overly concerned about the mileage - that's not the point of a RC-51. It's not designed or tuned in any way, shape, or form for mileage. Getting "good" mileage wasn't one of Honda's design goals.

You certainly did your share of modding to it, and did make a significant gain in mileage.

So you reduced the performance, but increased the mileage, with all those mods. For that bike, I don't know if that's a fair trade.

I don't think doing all the mods you suggested to the Superhawk in order to increase the mileage is a fair trade, or productive, either.

There are too many factors against you with a 1000cc motorcycle engine to expect performance and mileage at the same time. Just pick one.

RC-51 aka RVT1000, aka VTR100R or the R model of the superhawk (VTR1000F).

I bought that bike to take to the track, not for its mileage, but the range on that V-twin was far too short to enjoy the bike on the street or the track.
That was why I modified it the way I did.
Not to get insanely good mileage from it, but at least get it into the range of reasonable mileage.
I wanted to be able to ride most of the day at a trackday, working on suspension settings and my riding, not worrying about "Did I refill the tank during the last break?".
Rode a CBR250R today, not as great a mileage machine as some here think.