Street Hawk
 

Ok so, before anyone yells at me, I have 2 wheelsets, one for on road and one for off. The on road is just because I like to mod stuff. At any rate here are the mods that are relevant in my current build (on-road):

• 17T front sprocket

• 43T rear sprocket

• 128 Link Chain (size: 428, cut to length with a dremel and chain breaker)

• Bridgestone Battlax BT45 90/90-21 (difference from stock)

• Bridgestone Battlax BT45 110/90-18 (difference from stock)

• Stock carb with 110 main jet

• Motocheez's airbox flow mod

• Stock exhaust

• Front fork brace mod

Speed was measured using the digital cluster we all know and love. Elevation is 750'.

The digital cluster claims I hit 68mph before having to slow down due to morning traffic on my commute. I'll find some longer, flatter roads after work today as I suspect I can eek about 5 more mph out of it.



tl;dr - My top speed was 68 in 5th at 7,000 RPM



Finally, here's how it all looks:
http://i.imgur.com/1KlOArj.jpg

I can dig it...less rolling resistance, why not. Careful out there, don't trust them! Ain't it funny how they wait for you to get closer, then pull out :wtf:

Very nice!

More or less exactly what I was planning to do with mine with the tires. Nice! Pretty much everything else is exactly how I have it on my bike lol. I still need to do the fork brace.


Who cares about if you have dirt tires or not anyway, let them yell and complain. There is no rule that says you have to have dirt bike style tires on these, and those BT45's will last a LOT longer than any dual sport tire. I got 8000 miles out of the rear tire on my twice as heavy and 4 times more powerful Goldwing on a BT45. They will handle, brake, and ride a lot better on the road.

Get some exhaust work done and you will likely hit 70, maybe even a bit more.

Fair enough! I think the fork brace helps (though I didn't try to hit 70 before the brace).

Glad to hear it on the BT45's, these fit quite nicely (though I personally hate getting tubeless style tires onto any rims). My plan is to use them to kick around town/commute and save the knobbies for ADV trips.

Yeah, my next things to do are:
- Valve Clearances
- Clean out centrifugal oil filter
- Install bark busters
- Aftermarket Exhaust
- 115 main jet (maybe swap to Mikuni)

Don't worry about the tubes in a BT45. My Goldwing runs tubes and I never had a problem. The general rule of thumb with running tubes in a tubless tire is that the speed rating of the tire drops 1 rank. So if it is V rated, it should be treated as H rated. The BT45 is rated at speeds almost double what your bike is capable of, so even with a tube you won't come close lol.

I hit 71 on level ground with almost no wind! Briefly brushed 75 on a downhill and then 65 on an uphill!

Time to order that exhaust and upjet!

Just out of curiosity, was this GPS verified speed? I am sure it is close to accurate, but if your new front tire has a smaller diameter then your speedo will read just a tad higher than it did before.

Not yet! I forgot to grab the GPS so this is just digtal speedo readings, I will report back with GPS speed ASAP :)

Update, ran out with GPS, looks like speedo is 2mph higher than true speed.

70 Flat
72 Downhill
65 Uphill
75 Downhill drafting a truck ;)

Sorry it took me so long to get this, I had swapped back to the knobbies for a trip!

Anyone know the specs of hawk 250 front wheel off the top of their head

What specs are you looking for...ARH

Size of wheel

:tup:

So if anybody is curious about the gearing with the road tires listed here, just like my 120/80-18 Shinko 705's, a 110/90-18 with a 43 tooth sprocket is close to the same final drive ratio as a stock 110/100-18 with a 45 tooth sprocket thanks to the shorter diameter of the road tire.

You could toss a 41 tooth sprocket on the rear wheel with the BT45's and be geared just like a stock tire would be with a 43 sprocket. In fact, it gives 5th gear an almost direct correlation between MPH and RPM. so 40mph is 4000rpm, 50 is 5000, 60 is 6000. etc.

this is a great thread. I was thinking of putting more street oriented tires on mine. Looks cool!