piddy
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| posted on 4/6/09 at 10:57 PM |
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I want to ride my bicycle
Any bicycle experts out there?
When riding my mountain bike it rides fine while I take it easy, but when I put a lot of effort in like standing on the peddles or riding up a hill,
the chain seems to slip. I decided to change the chain to see if it improved things, It then seems to slip all of the time but in smaller jumps if
that make sense.
I therefore tried the rear wheel from my son’s bike; this has made the problem revert back to the original (rides ok until I put a lot of effort
in)
I was going to get a new cassette until I tried my sons back wheel now I’m not so sure.
Any help ideas appreciated.
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blakep82
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| posted on 4/6/09 at 10:59 PM |
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i would think that little sprocket at the back, i forget what its called, but it moves back and forward, is that spring maybe a little weak? has it
always done this? or is it a new bike?
that little wheel keep the tension on the chain
[Edited on 4/6/09 by blakep82]
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sprouts-car
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| posted on 4/6/09 at 11:07 PM |
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Another possibility is the ratchet inside the rear gears. Just an idea..
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piddy
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| posted on 4/6/09 at 11:12 PM |
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Hi. You mean the Rear Derailleur.
The bike is about seven years old I had the chain, rear cassette and Derailleur changed about three years ago so maybe they all need changing
again.
I did think about the racket bit but dismissed it when the problem continued with a second wheel.
[Edited on 4/6/09 by piddy]
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RK
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| posted on 4/6/09 at 11:30 PM |
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It's the derailleur adjustment screw. There are two of them, one for up and one for down. A bike store can do it in five minutes, or you can
experiment. A small turn will do wonders.
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blakep82
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| posted on 4/6/09 at 11:34 PM |
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wouldn't the derailleurs make it skip onto another gear, rather than skipping teeth on the same gear?
________________________
IVA manual link http://www.businesslink.gov.uk/bdotg/action/detail?type=RESOURCES&itemId=1081997083
don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
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PhilCross66
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| posted on 4/6/09 at 11:43 PM |
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Maybe its just on the point of shifting gear, maybe try a little more cable tension since they always come slack over time.
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RK
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| posted on 4/6/09 at 11:57 PM |
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It is likely not the same gear that is skipping, although it seems like it. Try it anyways; it's easy. Easier than building a car by a fair
ways!
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andkilde
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| posted on 5/6/09 at 01:21 AM |
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Could be a worn chainring as well -- have a peek at the teeth on the front chainrings, if they're worn you'll be able to see it compared
to the others. Usually the middle ring goes first on an MTB, the inners get buggered up occasionally as well but only if you do a lot of hard
climbing. Outers seem to last forever by comparison.
Another possibility is a sticky link, you'll get good and dirty diagnosing and fixing this -- I'd swipe a pair of your wife's
washing up gloves -- work each link with your fingers and feel for stiffness or grit/rust between the side plates. Depending on how bad it is a good
cleaning and oiling can cure it but it may need replacing. A new chain can also have this problem, usually the connecting link is a bit snug compared
with the rest, a bit of wiggling will usually loosen it up.
Chains can also stretch, you local bikeshop with have a stretch gauge (just a fancy ruler TBH) or you can google the specs and check with a pair of
calipers.
I'm pretty sure you'd know if the derailleurs were out of adjustment and you were skipping between gears.
Cheers, Ted
[Edited on 5/6/09 by andkilde]
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gazza285
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| posted on 5/6/09 at 05:02 AM |
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If you have a new chain, you need a new cassette as well, as the profile of the teeth wears with the chain. Used to get this all the time when I
worked in a bike shop. Front sprockets need to be very worn for these to jump so unlikely.
DO NOT PUT ON KNOB OR BOLLOCKS!
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brianthemagical
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| posted on 5/6/09 at 06:52 AM |
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If it's the front rings then it'll do it at the same point in the pedal stroke every time, i.e. east to spot.
My opnion is that it's the rear deralier not keeping the tension. If the pivots wear and such like then there's too much play in the
bodies for it to be efective. I had this on one of my bikes, Deore rear mech, all be it after about 5 years of abuse. Can you try the one off your
sons bike?
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oldtimer
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| posted on 5/6/09 at 06:58 AM |
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So, any or all a combination of the above. Easiest check is that all the teeth on front chainring, cassette and deraileur guide wheels are all
there/not worn/ not broken. If it's between gears and slipping, as stated, adjust the cable tension to rear deraileur. Really it's time
to take it to a bike shop then unless you want to start deraileur adjustments - google is your friend here again.
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tomgregory2000
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| posted on 5/6/09 at 07:01 AM |
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The rear sprockets wear to match the chain.
So if you put a new chain on it wont match the worn sprockets.
We carry about 4-5 chains for each bike and swap them so all the gear wears at the same time and keeps cost down a bit.
So the only cure is to replace the rear cassette as said before the front should be fine but the rear will be fecked
Tommy
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02GF74
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| posted on 5/6/09 at 07:09 AM |
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any one or more of the above.
chain is considered reaplaceable when it has beomce 0.75 % longer than original - and should be replaced once it has reached 1 %.
doesn't sound like a lot but enough to cuase problems.
if you replace at those limits, you can get away with using hte same casette - I have managed to get 3 chains on the same casette (the more expensive
bit).
front rings also wear but these have to be really bad before the chain start to skip.
I would be surprised if it was the derailleur since the skupping would occur more often,m not just when it is under heavy load.
who fitted the chain - is the link join correct? doubt that is the problem but worht checking.
also ther are 8,9,19 and 11 speed systems, up to 8 speed use the same chain but 9, 10 and 11 (not sure about 11) use specific chains for those gears
and are narrower.
again I doubt this is you problem b ut something to be aware of - 9 speed chains can be use on 8 but not other way round.
IMO new cassette and new chain and correctly adjust rear derailleur should fix the problem.
NB swapping wheels assumes the cassette is in the same place - not necessarily so - hence the derailuer and shifter may need minor tweaking to align
the chain.
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fov
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| posted on 5/6/09 at 07:11 AM |
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Could it be the rear free wheeling hub?
Ive seen them go a few times where it would slip and 'free wheel' when it should be locked.
Other than that id say swap the rear cassette.
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Daddylonglegs
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| posted on 5/6/09 at 07:12 AM |
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Stick a Blade engine in it 
OK, I'm off now.....
It looks like the Midget is winning at the moment......
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AndyGT
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| posted on 5/6/09 at 08:09 AM |
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As above re cassette and chains. Unlikely to be chainwheel on cranks although possible. I used to ride 15000 miles a year and only ever changed the
cassette and chain at the end of the winter. On my racing bike I would change them for each race but that was down to ratio choices not wear.
Give it all a good spray of WD40 or some thin oil. The derailleurs included. Lift the rear wheel and pedal forwards a little but also do a lot of
rear pedalling before riding the bike. Give it a few miles and I think your problem will clear itself. Clean the chain once it has been riden a few
times and NOT before.
This is the best "locost" option before buying cassettes etc.
Good luck
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piddy
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| posted on 5/6/09 at 09:18 AM |
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Thanks for all the advice. I'll give it all a try and see how I get on
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thorpey182
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| posted on 5/6/09 at 11:04 AM |
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quote:
Originally posted by fov
Could it be the rear free wheeling hub?
Ive seen them go a few times where it would slip and 'free wheel' when it should be locked.
Other than that id say swap the rear cassette.
The freewheel would also be my vote. Had a few go on various bikes. My 1st point of call would be a new freewheel as it's the cheapest option!
If that doesn't solve it then it's time to dig a little deeper.
Light, Strong, Cheap - Choose any two.
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brianthemagical
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| posted on 5/6/09 at 02:32 PM |
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Cheapest/simplest option is single speed.
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MikeRJ
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| posted on 5/6/09 at 04:34 PM |
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quote:
Originally posted by thorpey182
The freewheel would also be my vote. Had a few go on various bikes. My 1st point of call would be a new freewheel as it's the cheapest option!
If that doesn't solve it then it's time to dig a little deeper.
He'd be extremely unlucky to have a faulty freewheel hub on both his own and his sons bike IMO. Much more likely the problem is a knackered
chain or derailleur wear/adjustment problems.
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