HF 2.5, Needs rear wheel sproket setup?

Discussion in '4-Stroke Engines' started by Rgvkid, May 2, 2010.

  1. Rgvkid

    Rgvkid Member

    Im planning a frame build for a beach cruiser using an HF2.5. Im worried about the power and rear wheel strength. Has anyone had problems with the 2.5 HF and rear wheel hub? What is a good sproket setup for the rear wheel or should the hub be upgraded?

    I might even go with a non resuspension mountain bike. I have a Walmart Roadmaster sitting around but not sure how strong the wheels are. All other nuts and bolts on the road master will be Blue Locktighted.

  2. Gh0stRider

    Gh0stRider New Member

    What kind of gear reduction are you using from the engine to the rear sprocket?
  3. Rgvkid

    Rgvkid Member

    Not sure the ratio yet but it will have a jack shaft. I know the 2.5 hp is torqueyer then other engines so Im hoping i won't have future problems using the stock or if i'll need an upgraded hub. I'll Still be using the pedals. There are a few setups being sold with the setup i'll be doing but i can make all the pieces for the drivetrain myself aside from the rear sproket.
  4. arkives1

    arkives1 Member

    HF 2.5 needs rear sprocket setup

    HI, You'll definitely need a jackshaft and perhaps a centrifugal clutch somewhere in the drive train, that might ease the torque a bit by starting slower. Jpilot has a neat gearratio software here on this forum, it will allow you to figure out what gearing you may need.(its a free download) That engine has a speed of 3600rpm and can actually go a bit faster than that. With a jackshaft and shifting set up you can use the multispeed cluster on the pedal side of the bike to change gears. Sickbike parts makes an excellent shift kit although I've not heard of anyone using it with this engine. You probably will need to gear down further than the standard shift kit will allow, the gear ratio software will help with all that. I've used it on a couple of bikes now and very successful with it. I hope you'll keep us posted on your progress. If I can be of any assistance on how I did mine, feel free to message me.
  5. Rgvkid

    Rgvkid Member

    Thanks guys for the info. Im not concerned about the setup or gear ratio right now. My only concern is the rear hub sproket setup. I'd like to use a #40 chain because but im afraid it will be too big so im going with a #35 instead.

    For instance, kinda pricey but will i have to get a wheel like this to adaquate for the HF 2.5 power and sproket setup?. Or is there another more reasonable?

    How about this? but i would still need to get it relaced which i don't think i'd try to do on my own to save a buck. But it says for a 415 chain. Im afraid that might be too small for a 2.5 HF
    Last edited: May 3, 2010
  6. loquin

    loquin Active Member

    Also, consider a clam-shell sprocket mount, rather than the rag-joint sprocket.

    one source is creative engineering.
  7. Rgvkid

    Rgvkid Member

    Sweet Loquin! That looks like a great and simple setup in which i can utilize a #35 sproket. Now my only concern is if the spokes will hold up to the 2.5 torque. Not sure how many spokes it will have yet.
  8. tjs323626

    tjs323626 Member

  9. RusticoRay

    RusticoRay Member

    I used a workman wheel part number 4136A under industrial bicyle parts . Rear wheel with good coaster brake. Shimano cb110 hub. Also Creative Engineering adapter and sprocket. 140.00 for both peices but solid and the torque of the HF wont bend the wheel, **** the large pot holes around the New England roads wont bend them. Good luck with your build.
  10. Rgvkid

    Rgvkid Member

    Thanks Guys, Im looking into both.