Bike Maintenance

EMPM

Hi,

Can anybody tell me if there are any good sites or books that can show you how to do a bit of bike maintenance.

My problem is I have a tiagra triple crankset and when im on the biggest cog along with the biggest cog on the back the chain rubs against the front derailer. Is this a case of im not meant to use this combination or is there some way i can fix this.

I know there are some screws on the derailer, but i dont want to adjust them without knowing what im doing.

Any help would be greatly appreaciated

Thanks

tunney

Not meant to use big on the front, big on the big, and likewise small and small.

davej

It surely isn't the case that you "aren't meant to use this combination" ?
Perhaps the derailleur needs adjusting ?

Check this site out: http://en.wikibooks.org/wiki/Bicycles/Maintenance_and_Repair

davej

daymobrew

davej wrote:

It surely isn't the case that you "aren't meant to use this combination" ?

It is the case that you should not use that combination. It is probably listed in the bike's manual.

Check ParkTool Repair Help. It has a list of articles on Derailleur adjustment.

ba

i have the same problem with my tiagra/sora.i had them adjusted professionally after making a mess of it myself.

i believe its harder to avoid this rubbing on cheaper components. so i would avoid using such gear combinations imo.

tunney

Nope pretty much is a case of not meant to use it. For a number of reasons, strangely enough I've recently read that using combinations that stress the chain horizontally like big-big, small-small, actually can soak up watts. Generally there are redundant ratios.

EMPM

Thanks for all the replys,

I did maybe think it was the combination, im still getting use to the bike, its the first time ive had a triple crankset (not to keen on it).

davej

tunney wrote:

Nope pretty much is a case of not meant to use it. For a number of reasons, strangely enough I've recently read that using combinations that stress the chain horizontally like big-big, small-small, actually can soak up watts. Generally there are redundant ratios.

Fair enough.

I take the general points about chain stress and redundant ratios, but is it normal for the chain to rub against the front deraileur when in this gear?

davej

daymobrew

davej wrote:

I take the general points about chain stress and redundant ratios, but is it normal for the chain to rub against the front deraileur when in this gear?

Yes, it normal for the chain to rub. If the front derailleur was wide enough not to rub, you'd have a very hard time changing front gears. As I'm sure you know, the front derailleur intentionally rubs against the chain to move it to a different chainring.

oobydooby

Hayes' Bike Book is excellent IMO. Covers almost all maintenance. You can get it in most bike shops or bookshops. Big blue hardback, about 25 euro.

cunnins4

As stated above, not meant to use that combination. The manual with my ultegra groupset highlights this, so it's not a question of the quality of the Tiagra stuff, it's just not a combination you should use. Just drop it down to the smaller chainring at the front and down a few at the back and you'll find a similar gearing. AFAIK the chain should always be as straight as possible, otherwise added stresses build up in the chain. I'm sure it isn't the most economical way to cycle either.