Highway Speeds and Rolling Resistance

Wind resistance is the worst enemy for the middleweights with hacks. Cutting down the windshield or running without it will make a noticable difference.

L.

TXmudman - 1/4/2012 3:24 PM
I struggle to cruise easily above 60 mph on my 750 Bonneville with my Velorex 563....

Hack'n: Wind resistance is the worst enemy for the middleweights with hacks. Cutting down the windshield or running without it will make a noticeable difference.

Same here with my little 883 Sportster, which also does not easily cruise above 60mph. We have shorter sidecar windshields primarily due to wind drag.

Thanks to both of you for your comments. I'll try running without the tall windshield.

I have no problem cruising at 70 with my Triumph 790 and the CSC rig although the aerodynamics of the CSC with windshield are a bit different than the Velorex. I also have a windshield on the bike. When you say Struggle, what exactly do you mean? Is the engine lugging, running hot ? You may need to change sprockets?

with 3 fingers on the right handlebar,..mine cruises down the highway all day at 70mph,..,...fighting against excess toe-in will certainly labour the bike and increase tire wear, wind resistance, road friction, and the fact you have added 250lbs to the right side of the bike, may require further adjustments and a look at your gearing set up for the added weight and wind load,..???? good luck crawf.

Boatzo - 1/5/2012 8:23 AM

I have no problem cruising at 70 with my Triumph 790 and the CSC rig although the aerodynamics of the CSC with windshield are a bit different than the Velorex. I also have a windshield on the bike. When you say Struggle, what exactly do you mean? Is the engine lugging, running hot ? You may need to change sprockets?

The engine is lugging. Gearing down is a good idea. My bike probably makes about 45 hp, which may be about 20 hp less than yours? The more I think about my current issues, the more I think they may be just related to wind resistance because at speeds of 50 and below, my bike seems really quick to accelerate. Still, the toe-in and it's relation to rolling resistance has me a bit concerned. But, I am beginning to think it is a moot point since no one else is terribly concerned about it. Thanks for your comments.

Carl,

Your toe in and lean out are about like mine, I don't think that is an issue. I would look into the sprocket thing. Do you go on the Triumph Forum http://www.triumphrat.net/forum.php ? Lots of good help and ideas there if you throw out a question.

Your tire pressures will have an effect also.

Boatzo - 1/5/2012 9:59 AM

Carl,

Your toe in and lean out are about like mine, I don't think that is an issue. I would look into the sprocket thing. Do you go on the Triumph Forum http://www.triumphrat.net/forum.php ? Lots of good help and ideas there if you throw out a question.

I do frequent that website. Thanks.

Mark in Idaho - 1/5/2012 10:33 AM

Your tire pressures will have an effect also.

Thanks. I hadn't given much consideration to that.

I have the same problem with my 883 Sportster with a Velorex. Didnt think about the windshield . But I have already made a short "summer" windshield cause one of my passengers rode in the hack in 98 degree temps and told me there is almost no air flow so thats why I made a short windshield. Now I think it may help me on the highway too. Thanks guys.

SwampFs's Sporty was the inspiration for my shorty windshield

On my Savage/Cozy rig the difference with and w/o the windshields on both is amazing. + 10 MPG, no pull from the car at 45+. They are still sitting wrapped for transit on the shelf. I removed them to trailer the rig here for the winter as I didn't shrink wrap the trailer load this year. Must have helped the MPG on the truck/trailer rig as I averaged 17.5 MPG ('03 Dodge crewcab with little V-8) from Moses Lake WA to San Tan Valley AZ running with cruise set at 65. Max

TXmudman - 1/5/2012 9:40 AM
The engine is lugging. Gearing down is a good idea. My bike probably makes about 45 hp....

We geared down our +/-45hp 883 Sportster tug about 4% by changing the front sprocket, err... front belt pulley, to one size smaller, with really good results. 1st gear is much better without much clutch slippage, and 5th gear is tractable even on an slight uphill grade at 50+mph. With stock gearing I couldn't shift into 5th gear at 50mph unless on a downhill grade. Interestingly, gas mileage improved maybe 1-2 mpg.

Thanks to all for the replys. It's very helpful.