SBP kit problem.

Discussion in 'Frame Mounted Engines' started by skatingsamurai, Mar 4, 2009.

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  1. so i installed everything but i have two problems.

    1- the crank set. after about 30 minutes of riding the actual bottom bracket seems to come loose and i have to retighten it on the left side each time this happens.

    2- the last two gears under torque seems two skip at completely random times. i look down when this happenes and nothing is really wrong but can only suspect that its either the clutch or the rear derailleur. it how can i adjust the last gears of the derailleur.

    any suggestions??

    thanks- steve

  2. lordoflightaz

    lordoflightaz Member

    I'm having your problem #1 as well. I replaced the bearing and change the BB to be one that you can taken off with normal wrench, the BB came off a Fuji Odessa.

    I also have #2 but that is just when I don't count the clicks right on my grip shifter and end up between gears.

    You know you are looking down too late, LOL.

    Pablo, Ghost, any thoughts. Is this a good place to use Loctite?
  3. yeah im wondering if for number 1 i should just continue to tighen the left side. everytime i do this, i bring in the BB closer to then engine. think i will try some loctite. im still lost as far as the "skipping" goes.
  4. Pablo

    Pablo Motored Bikes Sponsor

    1) What crankset are you using?

    2) Indeed that sounds like a derailleur adjustment problem. This will help:
  5. Ghost0

    Ghost0 Guest

    I think the issue with the bottom bracket is you just aren't getting it tight enough. I usually use a punch or a large screwdriver and a hammer to tighten the lock ring. I might use the correct spanner but I don't own one and the screwdriver and hammer works well.

    On the gear skipping sensation, that is usually caused by one of two things. Either your shifter on your rear derailleur isn't adjusted properly and it is jumping between two gears or your chains are touching. If this is only happening in the taller gears, 6th or 7th then it is probably the chains touching. If it is happening in the lower gears, 1st or 2nd then it is the derailleur. Pablo provided a link to adjust your derailleur.

    If it is the chains touching there are 4 things to try.
    1. Tighten the chain from the jackshaft to the chainring. If this is loose it may cause them to touch.
    2. Increase the spacing between the two chainrings. Take the washers from behind the lock nuts on the inner chainring and place them between the large chainring and the freewheel flange. This will increase the spacing between the chainrings.
    3. Remove some links from the bicycle chain. You no longer have 3 front chainrings for the derailleur spring to compensate for. You should be able to remove 4 links from your chain without a problem. This will increase tension in the chain and reduce the amount of wobble in the chain causing them to touch.
    4. Double check the jackshaft to chainring chain alignment. The jackshaft sprocket should be slightly outside true alignment which will increase the spacing between the chains reducing the chance of them touching.

    Hope this helps
  6. bluegoatwoods

    bluegoatwoods Well-Known Member

    Just maybe this will help;

    when I've had that derailleur skip it has seemed to be a problem with a sticking chain link.
    One that doesn't flex properly. Getting old and stiff.
  7. Pablo

    Pablo Motored Bikes Sponsor

    That happens more than folks know. Good suggestion.

    Mine never did it until I installed a new shifter cable. I had to dial in the cable tension to get it to stop.
  8. lordoflightaz

    lordoflightaz Member

    Where the heck is my sledge hammer? People will see me with Thor's Hammer cruising the avenues of Phoenix.
  9. HseLoMein

    HseLoMein Member

    Deja Vu

    Yes i have the same issue with the BB nut, about every 6 to 8 miles or when i feel the pedals wobble i tighten it up with a BB wrench 31mm size. I dont mind stopping to make adjustments, it gives time for the engine to relax.

    My deraileur does the same thing, but i attribute it to having a friction shifter and not knowing all the positions yet.
  10. Ghost0

    Ghost0 Guest

    Indexed shifters are almost a requirement. When you are pedaling you can feel when a gear change is complete and stop the shifter but when under engine power you cannot feel when the shift is complete so you don't know if you need to keep moving your lever or stop it. It will also require you get the correct shifter for your derailleur and cassette. If you use the wrong one the spacing will not be correct and it will never shift accurately and you will get caught between gears and that is no fun.

    I am still puzzled by the BB coming loose. If you think about it, the spindle isn't even moving unless you are pedaling. It really can't loosen up unless it just wasn't tight in the first place. I know Pablo, myself and any of my friends with the kit have never had their BB loosen up.
  11. Pablo

    Pablo Motored Bikes Sponsor

    That's kinda why I asked what kind of BB/crankset we are talking about. At first I assumed it was the low cost YST conversion, but that's not the case.
  12. HseLoMein

    HseLoMein Member

    Yeah and index shifter would be nice, but it is next to impossible to find a thumb style index shifter esp for a 7 speed. I have a Rapid Fire shifter but the levers do not clear the Throttle linkages. Does anyone have a spare they are willing to part with? I wonder what others have done to over come this?

    I have a pretty good system of feeling out the different gears. First i start in 1st only when peadling from a dead stop, once the speed is up to around 15mph, i shift to 4th gear, and during most of my travelling i use gears 4 and 7, there is no need to use gears 1-3 unless you are recovering from a sop or major slowdown. The way i feel (hear) the grears is to listen to the changes in idle speed or rev speed as its coming back down to idle.

    My BB convertion ii have is this . The BB nut coming off i due to vibration, and vibration only, the other day when i was idiling at a stop light i watched my clutch lock button spin and change directions due to frequency of vibration. I have also watched other nuts vibrate apart. It could also be due to grease on the threads, im pretty sure some transferred during installation.

    I also get a plusing vibration esp in the higher gears, but i think its due to a slightly out off center crank sprocket. and i can live with it.
  13. Skyliner70cc

    Skyliner70cc Active Member

    I bought five 7 speed thumb shifters from Fleabay last month. I personally prefer the 7 speed twist shifter on the left handlebar and a centrifugal clutch so i doesn't interfere with the manual clutch lever.
  14. Ghost0

    Ghost0 Guest

    HseLoMein, it does not surprise me that BB loosens, I would definitely use locktite on that one. The standard ones should not be a problem.

    I agree with Sky, a grip shift on the left is the way to go no doubt about it. Here is a link to where I got mine.
    Just select the one for your cassette and you are off.
  15. lordoflightaz

    lordoflightaz Member

    Don't all those go on the right side? Do you install yours upside down? I tried that on my other bike and it confused the heck out of me.
  16. Ghost0

    Ghost0 Guest

    You can mount them on either side and it shouldn't be confusing other than the numbers are upside down, 1st is still first and 7th is still 7th. It comes very natural to me but I came from a car racing background so it make sense to me, pull back to up shift and push forward to downshift, just like a sequential gear box in a race car.
  17. lordoflightaz

    lordoflightaz Member

    The shifter I used clicks like 9 time, it was the front off of a Walmart "Roadmaster". I actually have the one you mentioned above, it was on the right side of my other bike. I might give that a try after some other projects.

    For me I live in the "world of right handed people" and have dealt with stuff being backward all the time. I would take a "left" throttle and "right" clutch if I could find them.
  18. hey yeah, its a new bike so there is no way it could be sticking.

    and its the cheap crank set. as far as that goes, i used some thread locker and it seemed to have worked fine. ill keep you all updated on that. but i cant seem for the life of me to get this derailluer dialed in...dont know what to do. i wonder how hard putting a newer one would be. its a better one but i have no idea it its compatable. its a shimano tourino or something...
  19. yeah i have one of those twist shifters and there alright...think i might want to look into one of those centrifugal rear gears because im tired of this skipping ****. how much are they and are they hard to install?
  20. Ghost0

    Ghost0 Guest

    I would take it to my local bike shop and ask if they can help you adjust the derailleur. It may be that your shifter and derailleur are not compatible. Or if you have an extra derailleur they may be able to tell you if it is more compatible with your shifter.