Sprockets Rear Sprocket alignment??????

Discussion in 'Transmission / Drivetrain' started by Will Snow, Aug 17, 2009.

  1. Will Snow

    Will Snow Member

    I am not doing a very good with this.

    I am having trouble centering the spocket. I have read several sets of instructions, bought a special adapter that clamps to the rear hub of which the rear sprocket bolts to. I have attached a string to the rear axle and spun the wheel while checking the centering of the sprocket with the other end while in a vice. I also spun the wheel while mounted in the bike checking the sprocket being centered. I seem to get it fairly close but the chain still will tighten and loosen a little after I retighten the bolts.

    On this forum I have seen some nice work done and thought someone may have a tip to get it right on center.

    Bill Snow

  2. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    what adapter did you buy?

    where did you buy it from?

    what sprocket are you using with the adapter?

    did you drill any holes in the sprocket?
  3. Will Snow

    Will Snow Member


    I bought the adapter and 44 tooth sprocket from Live Fast Motors. I also asked for their best quality sprocket and was sent one that was chrome. Not sure better quality but looks good.

    The adpater comes in two haves and clamps to the hub using two bolts to tighten it down. Nine holes are drilled in the side of the adapter and threaded. The bolts that attach the sprocket screw into these nine holes. The holes in the sprocket where the bolts pass through are slotted, no need for any drilling.

    I have put a few motorized bicycles together with good success except for the Chinese chain drive. This will be my fourth Chinese engine I have installed. None had a smooth chain run which I blamed on low quality parts. This time it is a 4 cycle engine and think the parts are fairly good quality.
  4. biken stins

    biken stins Member

    Is your sprokets flat. Any warpage ?

    Might try to line it up useing only 3 of the bolts in a triangle manner. If that works the other bolts are changing the tension on the sprocket.

    We all look at the rear sprocket but there are two. Either can cause problems for a true alignment.
    Good luck
  5. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    what 4 cycle engine kit are you using?

  6. beachcruiser

    beachcruiser Member

    I have a livefast clam-shell adapter that is for multi-gear rear wheel.
    I installed the hub adapter and tighten down the 2 set screws and then
    put in the smaller set screw in the middle. I took the sprocket adapter and
    found the spot where it fit level. i had to put my 40 tooth sprocket dished in
    for the proper clearance for the bicycle I was using. I had to buy larger size
    washers to cover the 9 holes. I put one bolt in the middle on both sides and
    tighten down finger tight. I took a wooden ruler and went around the hub
    axle and measured and moved the sprocket until the measurments were all
    4 equal while making sure the hub adapter and sprocket were still sitting
    level. Installed the rest of the washers, lock-washers and hex end bolts,
    and tighten them down as much as I dared to while trying to keep equal pressure on all bolts
    I took my bike for about 2-mile HT ride and rechecked the sprocket bolts
    and had to retighten them considerably. After that they stayed pretty well tight. Yes my chain tightens and loosens a little but I keep a chain tensioner
    under the chain. It goes from not super tight to about 3/4 inch tension. I was thinking this was normal considering chain stretch. I don't know if this
    helps you much but that is my expierance with the livefast clam-shell.
  7. Will Snow

    Will Snow Member


    Well, I am putting your suggestions to use and yes, they do help.

    I gave the ruler a try using the three bolt triangle suggestion and getting pretty close. I am now spinning the wheel mounted on the bike frame, using an object attached to the frame and touching the top of the teeth as I turn the wheel. Think I may just get it right on center this time. Will also correct warp as suggested.

    The engine is a Shandong Huasheng Zhongtian. I started it up today and what a fine sounding little engine it is. First pull start, very smooth and quiet. Idles down very low and yet remains smooth. Have not tried to ride it yet but so far so good. If I can get this chain dialed in it should make a pretty good set up. Thank you for your suggestions

    Best Regards

    Bill Snow
  8. Just_Gasit

    Just_Gasit Member

    I just ordered a clam shell adapter from this place http://home.roadrunner.com/~bikeparts/
    Hopefully, all will work out well for me. My rag joint sprocket is a POS and does the slack, tight thing. I highly recommend tossing out your chinese chain and buying a quality chain. I already did and it helped a bunch even with the junk sprocket.
  9. Will Snow

    Will Snow Member

    I went to the site you ordered the adapter from, looks good. I see they also make their own sprockets, and where did you find the quality chain?

    Gear Box: Chain drive I believe.

    Where did I buy the kit? EBay, from Boy Go Fast, BUT, Don't think I would purchase from them again. I have replaced some of their kit items with better quality from other dealers. This forum lists several dealers and many have been reviewed. Probably a good place to start. You will note, Boy Go Fast does not have a good review. So, knowing that, why did I buy from them?
    That's easy ---- just being my usual self, cheap and dumb and paying a lot more in the long run.

    Bill Snow

    Fresno, california
  10. Just_Gasit

    Just_Gasit Member

    Quality chain? Search KMC 415HD chain. Many places out there to get it. About 15.00 US with shipping. I've read here that some hardware and tractor supply stores carry it too. I checked a lawnmower shop first but the price was way too much. Just avoid the chinese imported stuff and you'll be fine. BTW, the 415HD (HD=heavy duty) stuff should replace the standard plain 415 if that's what your kit came with.
  11. Will Snow

    Will Snow Member


    Finished. The chain run turned out pretty good. The whole setup seems to be performing fairly well. I think I will go for a better quality chain and check the places suggested by Gasit.

    The gear box sticks out more than I like and it gets HOT!, is my only complaint but I will just get used to that. This is the 12th bike I put together starting in the early 80's to present. This one is truning out to be one of the better projects.

    Well,that should do it. As a result of your help I am pleased in the way it finished up.

    Best Regards

    Bill Snow
  12. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    the gearing on that BGF 4 stroke chain box kit is way too high with a 44 tooth sprocket
    others have tried and either burned their clutch up or just not pulled until the speed was fairly high

    i think it needs a 56 tooth to work properly

    read mmachine posts about this same gearbox http://www.motoredbikes.com/member.php?u=8310

    what are the teeth counts on all 4 sprockets?
    Last edited: Aug 18, 2009
  13. Will Snow

    Will Snow Member

    Where I live it is flatland and on all my motorized bicycles I peddle when I start out. By the time the engine has taken over the clutch is fully engaged and Perhaps I have enough speed up after peddling that it pulls ok.
    I took it for a fairly long ride and it seems to be doing very well in the tork and rpm department. It is not a power house but I ride it as a fast bicycle ( 18-22 mph), at lease faster than I peddle. I have a hoped up motorized bicycle that will do nearly 70 mpg and I ride that mostly at 18-25mpg. I suppose I also like the slower turning putt putt chug a lug rpm sound.

    You make a good point, I know to lug an engine is not good either . Thank you for bringing that up, I'll keep a watch on it. Beachcruiser found a website that machines their own sprockets and I may try one if this don't work out.

    Best Regards

    Bill Snow
  14. GTodd

    GTodd New Member

    Hi Guys. GT,
    My kit quility was not the best. My chain guart had dents,sprocket has rust under the crome. Stud bots short on threads and u-bolt threads under sized.Im still duilding the bike I wonder what Ill find by the time im done. BGF wonted me to pay return shipping so Ill gust fix the stuff my self. Ordering a Hub adapt.and hd rear wheel for it. Im not going to use the ragg mount this time. Whats the best rear coster rim to get? I have a schwinn delmar.. Thanks GT
  15. Will Snow

    Will Snow Member


    Sorry to hear how poor the kit is but I am not surprised. Like you, I did a lot of things to make it operate as it should. I even replaced the chain drive with the new belt drive and probably spent enough money on that and several other parts that I could have bought one of the nice quality kits. I could never get it to the place that I trusted it or even liked it. I ended up selling the bike cheap.

    I have 3 other motorized bicycles and 1 recumbent trike of which are all good quality bikes with quality kits. They are very reliable, in the class of a Honda. They all start and run great, I have no need to go back and fix or readjust something. I have had 4 of the Chinese Kits and except for the 4 cycle Chinese engine I did not like any of them. I have nothing but good to say about that 4 cycle motor, it has performed very good for me.

    I would suggest that you do not dump very much money in that kit unless you want to see how well you can get to work just for the fun of it and spending the money is not a big deal.

    Good luck on whatever you decide to do.
  16. Mozenrath

    Mozenrath New Member

    Here's how I aligned my sprocket.

    Once the sprocket was placed on the wheel, I turned the bicycle upside down and placed the wheel on the bike. I then spun the wheel and while it was spinning I held the tip of a sharpie marker against the face of the sprocket to draw a line around it as it spun. The parts of the line I drew that warped the circle showed where I needed the sprocket. After doing this a few times, I got the sprocket straight enough that I haven't had a single issue with the chain coming off or the tensioner being pulled into the spokes.