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Technical & Reference Section => Tech and Restoration => Topic started by: oberonspacefruit on June 19, 2006, 08:49 AM
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so. i have a frame. american sealed bb, put in at the factory.
newschool redline cranks. tuffneck chainwheel, also brand new.
so why, when i turn the crank, does the chain become tighter at a certain point?
you would think that the chainring was off centre, but its got the top hat washer on it, and as i said its brand new.
and at the other end its a brand new cassette hub.
how can it be doing this?
im going to try another sprocket to see if that helps.
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these are only could be ideas crank and sprocket out of line
hub set in wheel out of line wheel could look straight but hub on the scew
bent chain ring or chain wheel
rear end bent im only guessin mate just puttin ideas to check.
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Try this:
Draw a perfect circle the same size as your chainring, then pop your chainring over to see if it is perfectly round? Some where actual designed slightly oval.
If its not this then double check that you have it positioned correctly on the spider / power disk?
If however its a one piece chainring - ignor everything I have just typed! ;D
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rear end shouldnt be bent, its a new frame.
i suppose it may be hub out of line, ive re spoked it myself, but at the end of the day, even if you took the rim and spokes off, the hub should theoretically in the same place?
if the crank and sprocket where out of line , would it be tight all the time?
this one is loose for 3/4 of the chain then suddennly tight, which is why i thought it was chainring related, but i dont know.
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Try this:
Draw a perfect circle the same size as your chainring, then pop your chainring over to see if it is perfectly round? Some where actual designed slightly oval.
If its not this then double check that you have it positioned correctly on the spider / power disk?
If however its a one piece chainring - ignor everything I have just typed! ;D
lol, yeah its a one piece tuffneck. redline crosstype...surely a new one should be ok.and theres only one way to fit it on the top hat washer. and theres only one way for that to go on the crank spindle...
i could understand horizontal misalignment, but not vertical.....
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a few more quick ideas . First check your chainring. take the chain off and spin it to checck for dings and dips.
Iam guessing that that will be ok. on my profiles the bolt boss that holds the chain ring, not the central crank spindle hole ., has been welded on slightly lower. the result being it puts a slight sway in the chainring when tightened . might be the same on yours.
check that you have good alignment with the chainring and freewhweel , cassette cog. this is best done by putting the bike upside down on a bench/ table and looking along the chain at eye level. use some crank spacers to shift the chainring/ crank arm in and out along the spindle . give us a shout if you need some more spacers. sometimes you need a few depending on the bike . i think i have a bout 4 or 5 on mine .
check that your rear end is straight and not twisted . I once had a haro sport that was a bit twisted . i had the bike from newso it had been welded that way and the back wheel was always a pain to set up.
having done all of the above , use 1 or , if the problem is still there 2 good quality chain tensioners. also , if needed use some good quality washers to close up any big gaps between the frame and cone / sindle axle hardware. set the back wheel up with the tensioners . tighten everything up and don't mess with it.
my back wheel is the same , but it is ok once set up.
phil did you grind the drop outs from 10 to 14mm, if so this might be a problem area with the wheel not sitting straight.
the problem might also be with your chain. i wiould check with another chain from one of your other bikes . they sometimes stretch or develop tight spots. you can't beat a shiny , clean new chain.
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chuck on another wheel or chainwheel that is good pain i no but best way to find prob.
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try a new split link on chain
i had a similar prob and found out the link was to blame for my tight spot
so i had a good used one and that cured my prob
cheers russ :4_17_5:
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Have you tried a new chain on it. Knowing the powerhouse that you are, you may have stretched the links when snapping out of the gate. LOL
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its a brand new chain.
every component is brand new. thanks for all your comments tho guys.
its not a tight spot, its a tight 2 inches....
it honestly seems like the hole in the chainring is out of kilter, making the chain stretch when it gets to the part of the revolution where it would be most off centre...
i think the spacers may be wrong, but would this make it tight a one point or all of it?
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Take the chain ring off. Draw around it and the centre hole. Rotate it 90 degrees and line the teeth marks up and draw the position of the centre hole, repeat twice more. You will see whether the hole is not centred. Are you sure the top hat washer is correctly positioned in the hole, or that is the correct sized washer to fit the hole/spindle correctly ?
You could bring it round on Friday so we can look before we go to my bro's to play poker.
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leave the bloody bike alone phil ;D.
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Take the chain ring off. Draw around it and the centre hole. Rotate it 90 degrees and line the teeth marks up and draw the position of the centre hole, repeat twice more. You will see whether the hole is not centred. Are you sure the top hat washer is correctly positioned in the hole, or that is the correct sized washer to fit the hole/spindle correctly ?
You could bring it round on Friday so we can look before we go to my bro's to play poker.
heh heh...so its poker night on friday is it? who's house is it at?
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leave the bloody bike alone phil ;D.
in your heart of hearts dave, you know that could never happen.
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before we go to my bro's
heh heh...so its poker night on friday is it? who's house is it at?
Hmmmmmm, reading glasses on Mr Fruit.
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Phil - this your 06 Sport?
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Don`t worry about it, all my bikes have a tight spot on the chain, just ride it :daumenhoch:
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wish my wife had a tight spot!
15years together theres none left.. :(
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Don`t worry about it, all my bikes have a tight spot on the chain, just ride it :daumenhoch:
I've never seen a bike without one!!
Phil take the chain off spin the bike on its seat/bars and turn the crank. watch the movement of the chainrign (from the rear wheel looking along the chainring to the front wheel) betcha any money it aint true. Voila, that is what is causing your tight area. Like I said, I'm yet to see a bike without one. Some are just worse than others.
Do as Bill says and just ride it.
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swap the back wheel off another bike , if this cures it then you know its not the back wheel
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you cant beat two tight inches phil...especially if its the last two inches....
if they are proline cranks phil, you will need to reduce the thickness of your shim, i have no doubt its that that is making your sprocket move side to side and tighten the chain, had the same thing on my master....give it a try you slag
Dave
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ive got the exact same prob on me bulldog just ignored it and pretend it isnt there and so far it hasnt broke nowt ?