useless six gears?

[dbackmtg]

I recently bought a new road bike. It has a triple front crank. My chain rubs on the derailer up front on the biggest front sprocket when on any of the three largest back sprockets. It also rubs on the front derailer on the smallest front when in the three smallest back sprockets. I was told by the LBS that your just not suppose to use those gears. It just doesn't seem right. Any help will be appreciated.

 

[ToffoIsMe]

Using those gears not only makes the chain rub the front derailleur, but also puts it at an angle that it cannot safely use. Using those gears too much can cause your chain to pop, snap, or wear out quickly because of the angle it is on.

 

[the beef]

What you're describing is to be expected from any bike. When using gears, stay away from extremes (high in the front and low in the back, or vice versa) because it's very unhealthy for your chain and you also get that rattling noise. So basically those gear combinations should not be used.

 

[JohnO]

It also stresses the bearings in the rear hub. When I first started riding in college, I didn't know this either. After a few months, my rear wheel was loose on the axle.

Duly educated, I rode forth to sin no more, by staying out of the extremes.

 

[tourdelivermore]

I recently bought a new road bike. It has a triple front crank. My chain rubs on the derailer up front on the biggest front sprocket when on any of the three largest back sprockets. It also rubs on the front derailer on the smallest front when in the three smallest back sprockets. I was told by the LBS that your just not suppose to use those gears. It just doesn't seem right. Any help will be appreciated.

I agree with the posts re: cross-chaining, however, it should not be for three cogs on either side, only one.

I have an Ultegra triple. Using the feathering control of the front deraillieur, I can get to all available cogs without rubbing.

What is your front deraillieur?

 

[dbackmtg]

I agree with the posts re: cross-chaining, however, it should not be for three cogs on either side, only one.

I have an Ultegra triple. Using the feathering control of the front deraillieur, I can get to all available cogs without rubbing.

What is your front deraillieur?

shimano R 443 FB. I have a raleigh c-700 flat bar road bike.

 

[dbackmtg]

Thanks everyone. This makes me feel much better. I don't use these gears anyway. The chain is really stretched when their up there. I love this forum, I had two responses within minutes. I have a little more to this story I'm going to post.

 

[nomotornozen]

What you're describing is to be expected from any bike. When using gears, stay away from extremes (high in the front and low in the back, or vice versa) because it's very unhealthy for your chain and you also get that rattling noise. So basically those gear combinations should not be used.

How do you know which gears to avoid? And are the gears to be avoided the same on all bicycles?

 

[PartisanRanger]

I wish someone had told me this with my first road bike. I generally stayed in the middle ring but a fellow rider told me to switch more to the small ring (I have a triple) or else my derailleur would start messing up. I did this until it wouldn't even let me switch down anymore.

 

[bbattle]

How do you know which gears to avoid? And are the gears to be avoided the same on all bicycles?

Having the chain in the big ring up front and the big cogs in the back puts the chain in a diagonal line. This is what causes the excessive wear on the gears and the chain. The same is true for the chain being on the little ring and the smallest cogs in the back. The closer the chainline is to being straight, the less wear there will be.

 

[DiabloScott]

It also stresses the bearings in the rear hub.

I'm gonna call BS on that one. Your hub bearings don't know what gear you're in.

I always chuckle when I hear people say they got ripped off because they can't use "all 30" (or 20 or 18 or 27) gear combinations. The bike shops should probably explain this better to new riders.

 

[bbattle]

I'm gonna call BS on that one. Your hub bearings don't know what gear you're in.

I always chuckle when I hear people say they got ripped off because they can't use "all 30" (or 20 or 18 or 27) gear combinations. The bike shops should probably explain this better to new riders.

True. They should also point out that the gear combinations to be avoided are duplicated by other gear combinations. A 53-25 ~ 30-14 or 39-19. The 30-12 ~ 53-21 or 39-16.

 

[dbackmtg]

I'm gonna call BS on that one. Your hub bearings don't know what gear you're in.

I always chuckle when I hear people say they got ripped off because they can't use "all 30" (or 20 or 18 or 27) gear combinations. The bike shops should probably explain this better to new riders.

Who said anything about getting ripped off? It was just something I didn't understand, but now I do. Instead of chuckling why not help to answer the question.

 

[MountainPro]

Who said anything about getting ripped off? It was just something I didn't understand, but now I do. Instead of chuckling why not help to answer the question.

Scott is only trying to help,

there are some front shifters that will let you select a range of positions for your front derauller rather than just 1-2-3. So if your chain rubs when in certain gears you can move the shifter just a half shift. Campys do this.

Also when your chain is on the big cog at the chainset (front) and big cog at the rear (cassette) take a close look at your chain, Its almost getting twisted to fit into these gears, this lowers the life of the chain and will cause exessive wear on your cassette. Best to avoid that situation by selecting a more appropriate gear. If you need to shift down, the dont use the full range of your casette, try shifing to your middle chainring up front, it works better and the chain will turn smoother.

 

[HowardSteele]

I have only owned mountain bikes and over the years the gears have icreased 2x6,3x6,3x7,3x8 to my latest 3x9 shimao XT combination ,When MTBing all these gears are used and changing is done on steep climbs,Loose gravle and sometimes the mech's covered in mud.Obviouslly using the big small combination.My gears change smoothlly throughout 27 changes,no rubbing .
I don't see why your's shouldn't.