HD Rear Hub and Pull start for 2-strokes

Discussion in 'Spare Parts, Tools & Product Developement' started by Demosthenese, Mar 6, 2008.

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  1. Demosthenese

    Demosthenese Guest

    Hey all,

    found this today after scouring the internets for a vendor that could actually sell individual units, not lots of 200 from Bejing.


    Seems like he has the HD rear hubs that allow bolt on sprockets and avoid the spoke breakage for both the 4 and 2 stroke engines.

    The other thing that caught my eye was the pull-starter mod he has. Never seen, heard or IMAGINED that before.

    Store has good feedback from customers, but i haven't ordered anything from them yet.

    2 stroke rear Hub


    Pull start


  2. Papasaun

    Papasaun Guest

    Do some more research and homework!!! These parts can be had from sources alot closer to you than from over seas. Do a search here for those parts and see for yourself. Atleast look at the threads listed at the bottom of this one!!

  3. Demosthenese

    Demosthenese Guest

    Well fair enough on the pull start, i only posted it cause i had never heard of it before :). Apparently it's reasonably availiable. But i have tried fairly hard, and searched this site, and i haven't found a north american vendor for the solid rear 2 stroke hub yet. If anyone else has, please link here, i'm very interested in the product. My 80cc has enough torque to snap the bolts used to attach my sprocket to my disk brake hub, and i was using 4$ bolts. I'd love to get a hub designed for the application.
  4. Hollywood

    Hollywood Guest

    2 cent.I have and use a pull start on one of my bikes.First you have to have a wide crank and second thay are made real cheap.As for your sprocket application i don't know if it would work for you because i don't under stand your sprocket to your disk brake hub,but take a look at clam shell sprocket hub adapter they have at livefastmotors.com an see if it might work for you.
    Last edited by a moderator: Mar 9, 2008
  5. mickey

    mickey Guest

    Demosthenese, I think that this is a HD nonfreewheel hub. PM Birddog with questions. I don't think he will mind.
  6. Demosthenese

    Demosthenese Guest

    thanks for the clamshell info, if nothing else it's an alternate solution i wasn't aware of.

    I messaged the site all ready, but it seems to me like bicycle-engines is only selling the solid hub, not the solid axle and hub together. I can't see a place to buy the axle seperate, and i thought i saw another post about how they stopped carrying the 2 stroke hub version, but i may be crazy. I'll wait for them to get back to me.

    Any other sites everyone? This thing must exist somewhere!
  7. Alaskavan

    Alaskavan Guest

    Last edited by a moderator: Mar 9, 2008
  8. Demosthenese

    Demosthenese Guest

    thanks alaskavan, but am i incorrect in assuming that's the 4 stroke freewheel HD hub version?

    I discovered while researching this that the difference between the two different kinds of hd rear hub is an extra freewheel on the motor sprocket side. The 4 stroke pull start version has a freewheel on both sides of the hub, so that the motor need not turn while pedaling the bike. The 2 stroke version cannot have this since it would prevent pedal start of the engine, so it has a freewheel on the pedal crank side, and a solidly mounted engine sprocket on the other side.


    this is advertised on bicycle-engines as a "44T Sprocket & Solid Hub". Now, it may be that this comes with the hub and sprocket, but since the pic is only of the sprocket i wonder if the "hub" part is that metal piece in the center of the gear.


    this is advertised as a "48T Freewheel Axle Kit". It clearly comes with the axle as well as the sprocket, and i think this is what alaskavan has. It is a 4 stroke product due to the freewheel on the motor sprocket side. The freewheel appears to be in the sprocket, not on the wheel hub, so it may be that that hub mounts either of the two kinds of sprockets. But it doesn't look like it, and i don't know why it wouldn't be in the solid hub add picture if it was included. It is actually a totally different product from what i had originally linked which is;


    notice the hub has the 6 bolt holes directly drilled into it as well as a sprocket mounting surface which you could prbly fit any sprocket too with simple drilling.


    this is certainly a different thing then that which is offered by bicycle engines. don't know yet if b-e even has the 2 stroke version, and i do remember reading somewhere in SOME post that they didn't. Don't know which would be better, and maybe the clamshell alternative would work for me. What do people think about the hubs?

    We should find a defining alternative to the spoke attachment.

    To clarify my situation, i have been attaching my sprocket directly to the disk brake attachment on my rear wheel. The sprocket can be attached simply with disk brake bolts, which are absurdly strong and cost 2-4$ each. It works very well in that obviously i've never broken a spoke :p. On the other hand, i have destroyed two rims by either shearing off all 6 bolts at once (that happened twice on one rim because i was using standard hardware store bolts, but i re-drilled and re-tapped the holes on it after the first time), or by actually tearing them out of their threaded housing, possibly due to slight looseness (this happened to a 200$ MB rim bought from my local MB store mounted with disk brake bolts, washers and lock tight). Im using a 34 tooth spoke, so i suppose there is a lot of torque going to the bolts, but i'm very careful about slamming the thing into gear. I don't use the idle, so my engine goes off at every light (for stealth in Ottawa, Ontario) and i pedal start it back on while slowly releasing the clutch. I'm never accelerating from a standstill with just the motor in other words, so it really surprised me to see it break the second time when i was using the most expensive rim and bolts available. I figured since they were built to survive extreme stopping conditions the torque of smooth accelaration wouldn't be an issue compared to normal extreme bike conditions, like slamming on the back brakes at 30-40km/h. I'm sure they are AT LEAST rated for that. This makes me think that perhaps, even though i was checking them carefully every day and locktighted them well with washers and vibration reducer thingys, maybe the bolts may have been loose and this may have caused the failure. Either way, i really don't like the spoke attachment, and i don't know if i'll invest another 200$ in a rim if it'll only last 2 months. I need a viable alternative; the snow may be 8 feet deep now, but spring is coming :p.
  9. Demosthenese

    Demosthenese Guest

    just got this back from b-e:

    We do sell the solid axle hub you will need to buy the hub sprocket
    and drum brake to make it work if you'd like you can call in your order
    and I will be able to walk you through it if you'd like.

    thanks for the prompt reply from them, and i guess even though their site is a bit confusing, they do indeed carry the part.

  10. reclaimer

    reclaimer Guest

    Thanks for posting that.

    I've been having trouble mounting the stock rear sprocket. It is the old 5 bolt jobber. It fit a small freewheel hub well. My current ride has a big coaster hub, which it doesn't fit very well. I can get it close but thats it, lol.

    Not being a fan of coaster brakes, I did the free coaster mod. Leaving me with no brake or any place on the bike to mount a rear brake.

    Ordered the 44t, solid hub and brake. Two problems one solution, Hopefully.
  11. Alaskavan

    Alaskavan Guest

    Glad you got some info. I must have been playing space cadet.
  12. reclaimer

    reclaimer Guest

    I got my hub today.

    It seems to be about the same size as my coaster hub, so the spokes might be reusable? I'm going to give changing it myself a shot.

    Looking at it I'm thinking the hub is the same as the freewheel version. The sprocket is just different. Makes me think if you were to go 4stroke . Maybe you could just get the freewheel sprocket. Heres some pics of it. maybe someone with the free version could comment on similarities.

    edit: I'd just like to add this is my 2nd order from b-e and both times the shipping has been very fast.

    Attached Files:

    Last edited by a moderator: Mar 13, 2008
  13. Demosthenese

    Demosthenese Guest

    hey reclaimer,

    since you just got one i hope you don't mind me asking a couple questions.

    1. Is there a way to swap the supplied sprocket with another one?
    2. How easy is it to mount your own spokes (assuming you do it)
    3. Will the brake mount to a non-stock sprocket
    4. Is there any room to mount a multiple gear freewheel on the pedal side? Or are you limited to a single gear?

    Alaskavan, since it has been revealed that the hub is the same as yours, did you have any success in mounting multiple gears on the pedal side? Also what size wheel is this hub made for? I assume that can be adjusted by spoke length, but that may be a naive assumption.

    Thanks a lot for the pics though man, seeing it like that from different angles really helps. Keep us posted!
  14. reclaimer

    reclaimer Guest

    I was able to install the hub tonight. I'd never done it before, wasn't really that hard. Took me 2.5 hours but I wasn't in any hurry.It does still need some truing though.

    just took the old(new) one out and laced the new hub in with the same spokes. Not sure you could just do that, if your wheel has a freewheel hub.

    I don't really know anything about multi vs single speed freewheels, as far as how they attach. So I cant comment on that.

    The motor driven sprocket has a 6 bolt pattern. It bolts on to a keyed adapter that slides onto the hub. The brake threads on and holds the sprocket in place. I would think kings could make you one. Making your own, I don't know. It needs to be the right thickness so it doesn't have play, between the brake and hub flange.
  15. reclaimer

    reclaimer Guest


    If you look at the pic of the treads. the sproket slides onto the fatter part. then the brake threads onto the narrower section thus holding the spocket on.

    Looking at it now you could use any thickness sprocket. Because the collar the sprocket bolts to takes up the space.

    edit: Also you might like to know, I think if ya did break bolts, they would just come right out. No drilling or buying new parts aside from bolts. Thats gotta be a plus.

    I used this link to get through it.
    Last edited by a moderator: Mar 13, 2008
  16. Alaskavan

    Alaskavan Guest

    It looks to be pretty much the same, but without the freewheel, and with a slot for a key. I put a 7 gear freewheel on mine. It was wide enough that I left off the strap brake to save that space. The freewheel and the sprocket I got have a 5-hole bolt patern (which may cause a little trouble, since I want to change sprocket size). I also flipped the axle around to gain length where I needed it (described in the thread about this hub).
  17. reclaimer

    reclaimer Guest

    I was wondering if yours had the slot cut in to it. Hmm 7 gears huh....what to do.

    after a quick check bicycle chain slips right on the 44t.
    Last edited by a moderator: Mar 13, 2008
  18. Alaskavan

    Alaskavan Guest

    Yes. I just checked. There is a keyway in mine. If you go multiple gears, keep in mind that you might have to spread your stays.
  19. reclaimer

    reclaimer Guest

    I had the same thought, and I really need to keep the brake. I think its the single life for me.

    edit: I think i'm going to have to spread them some as it is.
    Last edited by a moderator: Mar 13, 2008
  20. Demosthenese

    Demosthenese Guest

    thanks for the explanation and help guys, this thread has really helped me understand the hd hub a lot better. I totally see what i can expect from it now.

    Reclaimer, that info on any sprocket size working was priceless; not getting a 36/34t sprocket was a deal breaker for me. I'm willing to machine the thing a bit, but i was worried the sprocket had intergrated crucial parts or something, or that width would have to be exact.

    And alskavan, thanks for the info on the 7 speed functionality. I went through your post on reversing the axel, seems like a simple solution to the pedal side gear issue, i'll want to do it to mine. I do want multiple gears on my pedal side, since i pedal it around the areas with cops in Ottawa. I want to use the strap brake too, you seem to have indicated you can only get 7 gears in with the brake off. Do you think you could fit 5 with it on? 3? I have two gears at the pedals, so even 3 gears on the back wheel would represent a fair variation in gear ratio.

    All in all though, i think this will work perfectly for my bike. It should ship with the kits, IMHO. The only difficult part is lacing your own spokes, which doesn't look very hard, just meticulous and exact. Once they're laced, i'm just gonna take it to my local bike store and have them true it up properly. That'll probably just cost 5-10 bucks labour, and it seems to look like the hardest part in building the wheel. Anyway, great thread, we are defining the available non-spoke-clamp options :)