Triple chainring help

[The Brewer]

Because of budget restraints I'm forced to do my own maintenance and the Cube peloton pro needs help.
Its now two years old and is now my winter/commuter bike, been a cracking bike and hopefully for a few more winters.
Its a triple ( hilly round here ) on 105 50/39/30 teeth, thats as technical as I go.
The 50 and 39 rings are slipping and need replacing. I have a cheap bike tool set from Lidl £29.99, but will I need other specialist tools for replacing? Also what prices am I looking at?....cheaper the better, but would like a good quality
It killed me dragging the Giant out in the bad weather on Friday so need to get things sorted soon.

Cheers Sean

 

[young Ed]

Because of budget restraints I'm forced to do my own maintenance and the Cube peloton pro needs help.
Its now two years old and is now my winter/commuter bike, been a cracking bike and hopefully for a few more winters.
Its a triple ( hilly round here ) on 105 50/39/30 teeth, thats as technical as I go.
The 50 and 39 rings are slipping and need replacing. I have a cheap bike tool set from Lidl £29.99, but will I need other specialist tools for replacing. Also what prices am I looking at....cheaper the better, but would like a good quality
It killed me dragging the Giant out in the bad weather on Friday so need to get things sorted soon.

Cheers Sean

not owning your bike and having never owned one or even seen one in real life, is the BB square taper or splined? it is possible with cranks still on but is easier with them off. you may well need a chain ring spanner to put on the nut on the back of your chainrings
http://www.ebay.co.uk/itm/Shimano-C...sure_Cycling_BikeLocks_SR&hash=item2a3393ab59
(link is for a shimano one if your chain rings are non shimano i can't guarantee that it will fit but i'm sure someone will be along soon to tell you)

youtube is your friend on this one just search 'replacing chainrings' or at least along those lines
Cheers Ed

 

[Pale Rider]

Worth being certain it is the rings that need replacing before you go any further.

A more likely cause of skipping on a two-year-old bike is a worn chain.

Gold standard maintenance is to replace sprockets/chain rings at the same time as the chain.

Few people do that, so I would be inclined to try a new chain on its own - cheaper and simpler.

 

[The Brewer]

Sorry Pale rider I should of said its a new chain with a new cassette too

 

[oldfatfool]

How knackered was the chain to wear a 50 ring bad enough to slip!

 

[The Brewer]

How knackered was the chain to wear a 50 ring bad enough to slip!

Its slipping when I start off and when I apply lots of weight. New chain and a new cassette what else could be the problem ?

 

[midliferider]

My technical knowledge is what I have gathered from reading books.

I am very doubtful that your problem is worn out rings. First question is what do you exactly mean by slipping?
Does that mean your chain does not stay in the ring when riding?

 

[slowmotion]

If you do need to replace those two rings, you may well be able to do so without removing the cranks or tinkering with the bottom bracket. The 39 tooth one needs a bit of head-scratching to get it over the crank but I eventally managed on my 105 triple. The Shimano replacement rings cost about £28 and £18.

 

[The Brewer]

The chain can come off, but it usually stays on... it just seems to slip

 

[midliferider]

The chain can come off, but it usually stays on... it just seems to slip

Hmm, I think you need some adjustment to gears.
I will do that before embarking on changing rings.
I have an old bike that I play around with gears, brakes etc when I am bored just to learn. I have seen, chain slipping, when gears are not adjusted properly.

 

[The Brewer]

Gonna have a potter in the shed and hopefully get it ready for a 50mile trip tomorrow....fingers crossed

 

[Banjo]

If the chain is coming off its likely you need to adjust the stop screws to limit the travel of your front derailleur. Google on Shimano front derailleur adjustment should get you a selection of how to do it utube videos.

 

[oldfatfool]

Another vote for badly adjusted gears. As a point don't set off in big ring little ring, make sure when you stop you are in at least the middle chain ring/ larger cassette ring.

 

[The Brewer]

Having googled the rings do seem okay.... Must do more maintenance to get better

 

[mcshroom]

Did you shorten the chain when you fitted the new one? An over-length chain could do that sort of thing.

Otherwise, take a good look at the teeth on the chainring. If they really are worn then they should look like little sloping shark-fins: -