Something wrong with my bike..?

Sewinman

Seems to be a problem with my Trek. This morning in the small ring it did not want to 'bite' properly when i pedalled and it felt like the chain or gearing slipped 3 or 4 times with every revolution. I changed the gear to the big ring and it stopped doing it. I more or less cycled fixed in a fairly high gear in the big ring without furthur drama.

Any ideas!?

UndercoverElephant

Have you tried a chain wear tool?

el_presidente

knackered chain ring, or more left-field possibly ice on your chain ring? My brakes were frozen first thing this morning after washing the bike then leaving it out

il_principe

Worn teeth on the chainring/cassette? Or perhaps your cables need tightening.

Bikefotos

Might be that some ice has formed on the cables, causing shifting problems when the cable is slacker (lower gears). Had a similar problem on my MTB last week when my brakes froze as well!! Cable v-brakes not hydraulic!

Must make sure I lube it properly after washing!!

Sewinman

I doubt it is ice as it was happening as soon as I left home this morning. I will have a look and see if i can see any wearing. Funny how these problems suddenly appear.

Thanks for the advice.

Wryneck

I had exactly the same problem yesterday - I know the sprokets/chain/rearmech are not worn - they are new. I suspect some moisture in the cable froze. Liberal spraying of GT85 last night sorted the problem out. OK this morn.

amnezia

Check the L Limit screw on the Front Derailleur, if its not set correctly the derailleur can pull the chain away from the small cog.

Sewinman

Had a good look at it during lunch. The problem is down to the second smallest cassette having a tooth that is bent almost entirely over and is pressing into the smallest ring on the cassette. :shock: :shock: That gearing would be my normal usage in the small chain ring. The chain jumps all over the place in those gears. When i moved to the big ring this morning i must have changed down a bit and away from the affected area of the casette.

Some more Qs for you good people:

How did that happen!?

Can you change parts of a cassette or do i need a new one? Could i fix it myself or is it a trip to the LBS?

Thanks in advance.

Wallace1492

Sewinman wrote:

Had a good look at it during lunch. The problem is down to the second smallest cassette having a tooth that is bent almost entirely over and is pressing into the smallest ring on the cassette. :shock: :shock: That gearing would be my normal usage in the small chain ring. The chain jumps all over the place in those gears. When i moved to the big ring this morning i must have changed down a bit and away from the affected area of the casette.

Some more Qs for you good people:

How did that happen!?

Can you change parts of a cassette or do i need a new one? Could i fix it myself or is it a trip to the LBS?

Thanks in advance.

Wrong use of gears!! If you on the small ring at the front you should be on middle ring to largest on the cassette, otherwise you are stretching the chain. That seems irrelevent though, as chain stretch should not bend a tooth.

I honestly do not know if you can repair this. Try LBS, worse case scenario it's a new cassette.

http://sheldonbrown.com/gears.html

iain_j

I somehow bent a couple of sprocket teeth on my old BSO years ago. Don't know how it happened, and no amount of bending with a screwdriver and bashing with a hammer would bend it back.

I'd suspect the LBS can just replace the individual sprocket.

il_principe

Sewinman wrote:

Had a good look at it during lunch. The problem is down to the second smallest cassette having a tooth that is bent almost entirely over and is pressing into the smallest ring on the cassette. :shock: :shock: That gearing would be my normal usage in the small chain ring. The chain jumps all over the place in those gears. When i moved to the big ring this morning i must have changed down a bit and away from the affected area of the cassette.

Some more Qs for you good people:

How did that happen!?

Can you change parts of a cassette or do i need a new one? Could i fix it myself or is it a trip to the LBS?

Thanks in advance.

In theory the cog is replaceable - but this depends on the make and model, some cassettes are one piece (ie cheap Shimano and SRAM Red), others are made up of separate cogs. If it's the latter then the LBS may help although some would advise against mixing brand new cogs with older, worn ones. Feck know's how it happened, but if the cassette and chain have done a decent amount of mileage perhaps it's time to change both...

Sewinman

Thanks for the help. Think a little TLC at the LBS is called for.

cjcp

You might have damaged it when putting the rear wheel back into the drop-outs. Just a theory though.

Better just to get a new cassette.

itboffin

iain_j wrote:

I somehow bent a couple of sprocket teeth on my old BSO years ago. Don't know how it happened, and no amount of bending with a screwdriver and bashing with a hammer would bend it back.

I'd suspect the LBS can just replace the individual sprocket.

Getting the LBS to change your spockets :shock: good god man next thing you know you'll be catching the bus to work :roll: :P

greg66_tri_v2.0

Sewinman wrote:

How did that happen!?

Can you change parts of a cassette or do i need a new one? Could i fix it myself or is it a trip to the LBS?

Thanks in advance.

How did you bend a single tooth on a single sprocket of a cassette? Feck knows, but it really doesn't matter, as you're gonna need a new cassette and chain. Yes, in pple you can swap out the individual sprocket, but you have to find one first (and they tend to be sold in Christmas tree shaped bunches of 9 or 10 or 11) and then you'll have one that's brand new, a lot that are worn and a chain that's worn. Likelihood is that your worn chain will skip on your new sprocket.

Chain and cassette swap is a diy job, if you have the tools (a chain whip, a cassette removal tool, a long spanner that fits the chain removal tool, and (possibly) a tool to open & close the chain).

SmellTheGlove

Sewinman wrote:

...a little TLC at the LBS is called for.

"Would sir like the while-you-wait service..?"

Sewinman

Was having some weird skipping with the Wilier, checked the casette and I have shreared off half the teeth on the smallest cog! Its done about a 1000 miles max

How did that happen!?

MonkeyMonster

WTF are you doing to your bikes mate

Bad luck though

The cannon needs some serious tlc and that tick in me bb is back - fecker.

Sewinman

I know, I am like Lennie from of Mice and men with bikes... :roll:

always_tyred

Sewinman wrote:

I know, I am like Lennie from of Mice and men with bikes... :roll:

Not Lennie from the Simpsons, then?

Is it the same cassette that you bent the tooth on, Sewinman?

Sewinman

Always Tyred wrote:

Sewinman wrote:

I know, I am like Lennie from of Mice and men with bikes... :roll:

Not Lennie from the Simpsons, then?

Is it the same cassette that you bent the tooth on, Sewinman?

No, this is on my 'good' bike.

always_tyred

:shock:
Wow - you are officially unlucky.

Is it a titanium cassette or something like that?

Sewinman

Always Tyred wrote:

:shock:
Wow - you are officially unlucky.

Is it a titanium cassette or something like that?

No, low range Campag. Am thinking it must be something I have been doing.

Soul Boy

I'm guessing extreme chain lines, but only guessing.

always_tyred

Soul Boy wrote:

I'm guessing extreme chain lines, but only guessing.

Even so, I've never heard of that result. There's excessive wear and then there's disintegration.

Sewinman

Soul Boy wrote:

I'm guessing extreme chain lines, but only guessing.

My favourite gear was the small ring at the front and the smallest ring on my casette.

Would that have done it?

jonginge

Possibly. Although your result is pretty extreme after only 1k miles.
http://sheldonbrown.com/gears.html (last para)

You could probably find a similar ratio in the big ring but using the middle of the cassette. There's a gear calculator on Sheldon's site.

This is quite unlikely but you could also check the cog isn't/hasn't been rubbing against the chainstay. It could also be that the campag cassette is made of cardboard :P

always_tyred

Yes. Campag stuff is a rip-off.

Ooops wrong thread.

Soul Boy

Maybe you're just a brute

MonkeyMonster

Soul Boy wrote:

Maybe you're just a brute

you haven't met him have you 8)

CP maybe...