Problem when I pedal

[MARK170881]

Wonder if someone can help me. I have recently sorted out the gears on my bike and they all seem to click into the right ring when I change them while on a bike stand.

Problem is when I start pedaling the pedals seem to 'give way' or slip when I start to pedal and put pressure on them.

Does anyone have any ideas what it may be? I'm hoping it's something I can fix (I.e don't cost me any money )

Forgot to say that all is well when on the small ring on the front set of cogs problems start when in the 2nd or 3rd ring

[bobtravers]

Your chain maybe too stretched out, or front chainrings are worn...

Take a ruler or measuring tape and get this method to see if your chain is stretched:
http://www.sheldonbrown.com/chains.html

take a look at the Measuring Chain Wear section

[MARK170881]

Hi thanks for the reply. I've taken a few pictures to see if this helps. I'm not 100% sure but it looks to me that the chain is not sitting in the teeth of the ring quite right. Could you let me know you thoughts

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pictures

[MARK170881]

I've now changed the chain on the bike since the pictures I posted last night..

I do have the same problem though. The pedal gives way as I put pressure on them to pull away, the front chain rings do still seem in decent condition..

I'm at a loss to what the problem may be....any ideas??

[MARK170881]

Pictures of front rings

[Bill]

Ok so the chain has been replaced, new? If it is be warned there are different size chains for different speeds of bikes. So if the chain you put on is for lets say 10speed (5gears in rear, 2 up front)and you have a 21 speed then that will not work. And vice versa. How many cogs you have in the rear? We see that you have 3 in the front. How the terminology works is if you have a 21speed then many people refer to the back as being 7spd (speed).

[MARK170881]

Hi Bill, Yeah the chain has been replaced new with a KMC Z8s chain, says it's suitable for a 18, 21 & 24 speed chain. I have 21 gears 3 up front and 7 at the back.

[MARK170881]

If it is my front set of gears cogs can you remove the them with out specialist tools?

[Bill]

You will definitely need a crank puller. Picture of the middle part on the crank would help out to make sure on that. The rings, well if you could also take a picture of them on the other side we could see if they are replaceable.

[GeorgeET]

Your chain is stretched and your sprockets worn. Looking at the wear IMO you should replace all three, chain front crank and rear cluster.
AS per how too see the repair guide on top of the page, and view one of Alex's videos......

[Bill]

He's got the chain part taken care just now awaiting the pics

[MARK170881]

Thanks for the replies..

Right, I've ordered a crank puller which should be with me Thursday £3.45 delivered (thank you ebay )

I've managed to source a new front crank that should be with me by the weekend.

I'll get the other pictures of the middle part of the crank & the other side when I get in from work tonight.

I'll also post a picture of the rear cluster tonight and could you let me know if you also think these will need replacing

[DaveM]

(11-12-2012, 10:09 AM)MARK170881 Wrote:  I'll also post a picture of the rear cluster tonight and could you let me know if you also think these will need replacing

Based on the condition of your old chain, I would say it is almost certain that your rear cluster needs to be changed. In fact, I think it's far more likely that it is the rear cluster mainly causing the skipping than the front chainrings.

[GeorgeET]

This is what a good set of chainrings should look like. Note the narrow valleys and wide teeth with rounded tips.

We have no information regarding your bike. More chainring photos will not help. The granny gear may be still be OK. AS I said before judging from wear you should replace entire drive train. Chain alone will not fix it. Is it road or mt bike , is it freewheel or cassette?

http://www.nashbar.com/bikes/Product_10053_10052_534510_-1___202430

http://sheldonbrown.com/free-k7.html

[MARK170881]

Pictures of front and rear gears

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Hi GeorgeET, it's a Diamond Back mountain bike with front and rear suspension.

going off your pics it does look like that the teeth are very worn

[MARK170881]

Picture of rear gears. Would I be right in saying that it is a Shimano Hyperglide Freewheel type?

[GeorgeET]

Yes that looks like a freewheel and you need special tools for removal. See repair guide above. I can see grease in there so servicing has been done. But you still need to replace it along with rest of the drive. Take your time to go through all the bearings, wheels, bottom bracket. (may be a good time to put in a Shimano UN54 sealed BB) and head. Likewise cables, shifters etc. I like waterproof marine grease used for boat trailers and automotive bearings. Something to keep you busy over winter.:-)

Looks like you got lots of good use out of this bike and refreshing it will give you lots more good years.

[MARK170881]

Ok I've ordered the bits

http://www.ebay.co.uk/itm/221117321334?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

http://www.ebay.co.uk/itm/290622450776?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

Think they'll be alright I've gone for budget ones due to the miles I do/terrain

I would like to say I've got a good use out of it but I bought it on the 'cheap' for £40. I've had to buy a 'cheapy' bike while I get this one repaired but your quite right will keep me very busy sorting it out

[GeorgeET]

They look fine, budget ones are just heavier and less shiny, mostly. The chain rings even have a chain guard. Good prices. As I recommended before check your bottom bracket if smooth just clean replace bearings and grease. Otherwise check out the Shimano UN54 or like sealed BB. Good luck you are well on the way...

[MARK170881]

Cheers for the advise guys I'll post pics once all the work is done