Triban 3 chain rubbing?

[wealthysoup]

Hi Everyone,

I got a triban 3 from decathlon last month and when i use the biggest crank at the front (highest geared) the chain rubs against the front derailleur when im in the highest 3 or 4 gears. I took it back since then and somebody else set the gearing up but im still having the same problem.

Is this a typical problem with a triple or does it change over time as the bike is ridden? Do I need to take it back again to try to get it sorted?

Thanks,

Ryan

 

[stephen.rooke]

no expert but have you tried adjusting the h and l screws slightly to allow the derailleur to move more, a 1/4 turn might be enough.

 

[daSmirnov]

This is pretty standard on a lot of set-ups. Generally you should avoid using those gears and shift up to a bigger ring instead.

You might be able to tweak it a bit. I've got mine setup so I've lost my top gear, but can stay on the larger ring in a lower range of more often used gears.

 

[wealthysoup]

Hi dasmirnov, sorry I got my front gears the wrong way round. This happens when im on the biggest ring at the front and the smallest 3 rings at the back.

Stephen, I tried that before but it made no difference (the cable wasnt loosening enough to let it clear the derailleur properly), I tried to fix this and couldn't get it right so took it back to decathlon and a guy there set it up again for me.

 

[Rob500]

Hi Ryan.
When you went back to the shop did they not advise you to avoid using the small chainring with the cassette's highest gears?

 

[wealthysoup]

Hi Rob,

Think I just posted before you there. As I mentioned above this is using the biggest chainring with the highest gears (for some reason when im away from the bike I think that the smaller chainring at the front gears it higher)

 

[daSmirnov]

Yeah using the "extreme" gears, i.e. when the chain is most angled will cause noise as the chain rubs on the dérailleur cages. Bigger ring at the front and biggest cogs on the back will do this. And vice versa.

 

[Rob500]

Hi Ryan. Yeah, I think I just posted right after you.

I wouldn't have a clue how to fix that. . My Defy is a triple but I've never had any trouble that way. There's a thing I can do called 'Trimming' when the chain is rubbing. Can you do that on the Triban? Not exactly sure what's actually going on but perhaps a more savvy CCer will explain what it is.

 

[Edwards80]

Mine does do this occasionally but I have re-tensioned (if that is the right word) the cable on the FD and adjusted the limit screw and it has solved it. It really hates being cross-chained though as mentioned above.

Trimming does work on the 2300 groupset . . . but I'm not sure it's a 'feature', if that makes sense. You can give the lever a nudge and it will get rid of the noise in some instances.

 

[Recycler]

I've got a triple and rarely use the cross chain extremes when I'm on the large and small rings.

Most of the time I just use the top 4 or 5 gears on the big ring , the bottom 4 or 5 on the small ring, and most of the whole range on the centre ring. The gears which I don't use are more or less duplicated elsewhere on the gear set.

As I understand it the cross chain extremes just result in more chain wear.

 

[Sellyb]

I purchased my bike brand new, supposedly checked by the mechanics, but it starts rubbing when the small front chain ring meets the fourth largest rear chain ring. Surely numbers one or two would be more reasonable for it to start rubbing. I've seen these high & low limit screws and have tweaked them a bit but can't see the derailleur moving, so I've screwed them back to where they originally were. Why doesn't the derailleur move? Sorry but I've never adjusted a bike before. It's not happy at the other end of the spectrum either.

 

[wealthysoup]

Thanks Rob and Edwards. Tried the trimming technique you mentioned and it stops the rubbing in a couple of the gears but not the highest 2, presumably its a trip back to the bike shop to get this sorted? Recycler, I'm not crossing the chain.

 

[Recycler]

I purchased my bike brand new, supposedly checked by the mechanics, but it starts rubbing when the small front chain ring meets the fourth largest rear chain ring. Surely numbers one or two would be more reasonable for it to start rubbing. I've seen these high & low limit screws and have tweaked them a bit but can't see the derailleur moving, so I've screwed them back to where they originally were. Why doesn't the derailleur move? Sorry but I've never adjusted a bike before. It's not happy at the other end of the spectrum either.

The high and low adjustments will only work when the chain is on the top or bottom sprocket.

 

[Hacienda71]

You should not need to touch your limit screws. This is only required if your chain is dropping of the most extreme cogs and if set up correctly when the bike was bought will not have changed.

 

[mcshroom]

If it's a clamp on mech you may find it's not quite straight (slightly inward at the back). This could also cause that sort of rubbing