should gears rub

[glenna1984]

While having my gears adjusted, the bicycle mechanic doing the work said "It is normal for the lower (back) gears to cause the chain to rub while the chain is on the big ring.

He was talking about 4 or 5 of the lower gears, not just the lowest.

He said the same was true with the granny gear and the outer rings on the back.

Is this correct?

 

[shannons dad]

While having my gears adjusted, the bicycle mechanic doing the work said "It is normal for the lower (back) gears to cause the chain to rub while the chain is on the big ring.

He was talking about 4 or 5 of the lower gears, not just the lowest.

He said the same was true with the granny gear and the outer rings on the back.

Is this correct?

Not really. The chain should just clear the front derailleur cage when in the smallest or biggest rear sprockets. You might get some slight rubbing under load, but that's because of the frame flexing. Adjusting the hi/lo screws can often solve the problem and maybe a bit of adjustment in cable tension.

 

[boudreaux]

Not really. The chain should just clear the front derailleur cage when in the smallest or biggest rear sprockets. You might get some slight rubbing under load, but that's because of the frame flexing. Adjusting the hi/lo screws can often solve the problem and maybe a bit of adjustment in cable tension.

BS!! Are you ever going to get a clue? Derailer rub is not uncommon in the extreme combinatioms even with a double,depending on chainstay length. It can be more of an issue with a triple. Fiddling with an otherwise well shifting FD is not the cure. Using the trim funcion in the front shifter can always fix it with campy but some Shimano STI have limited options and the early shimano 7 and 8 speed triple SIT had no trim option,but the new sora stuff has limited trim. If his shifter has trim,he should be using it.

 

[glenna1984]

BS!! Are you ever going to get a clue? Derailer rub is not uncommon in the extreme combinatioms even with a double,depending on chainstay length. It can be more of an issue with a triple. Fiddling with an otherwise well shifting FD is not the cure. Using the trim funcion in the front shifter can always fix it with campy but some Shimano STI have limited options and the early shimano 7 and 8 speed triple SIT had no trim option,but the new sora stuff has limited trim. If his shifter has trim,he should be using it.

To clarify a bit...the rear derailer Shimano Ultegra 9 gear.
I understand the part about rub in EXTREME gears, but I am talking about the 5 lowest rear gears, while in the big ring in the front.

I do trim, but it does not seem to work regularly.

 

[Don Shipp]

To clarify a bit...the rear derailer Shimano Ultegra 9 gear.
I understand the part about rub in EXTREME gears, but I am talking about the 5 lowest rear gears, while in the big ring in the front.

I do trim, but it does not seem to work regularly.

There are other variables, such as stay length, axle length and so on; the practical question to ask is whether there are any gears you can't use that aren't duplicated on the middle ring. I think that you shouldn't be getting rubbing across 5 sprockets.

 

[boudreaux]

To clarify a bit...the rear derailer Shimano Ultegra 9 gear.
I understand the part about rub in EXTREME gears, but I am talking about the 5 lowest rear gears, while in the big ring in the front.

I do trim, but it does not seem to work regularly.

It should be regular as prune juice, and it fixes rub when cross chaining with my triples even tho I shouldn't be doing it. If trim doesn't work as intended,you likely still have adjustment issues or operator error. You shouldn't be in the 2 biggest cogs when in the big ring with a triple,but you should have full use of the smaller 7.

 

[shannons dad]

To clarify a bit...the rear derailer Shimano Ultegra 9 gear.
I understand the part about rub in EXTREME gears, but I am talking about the 5 lowest rear gears, while in the big ring in the front.

I do trim, but it does not seem to work regularly.

It might seem an obvious answer, but is the front mech running straight in-line with your chainset? Check your big ring to make sure it isn't bent too.

 

[shannons dad]

It should be regular as prune juice, and it fixes rub when cross chaining with my triples even tho I shouldn't be doing it. If trim doesn't work as intended,you likely still have adjustment issues or operator error. You shouldn't be in the 2 biggest cogs when in the big ring with a triple,but you should have full use of the smaller 7.

OPERATOR ERROR? IT'S A PEDAL BIKE! NOT A FRIGGIN' SPACE ROCKET!!! DUH!

 

[Don Shipp]

OPERATOR ERROR? IT'S A PEDAL BIKE! NOT A FRIGGIN' SPACE ROCKET!!! DUH!

Bicycle maintenance may not be rocket science but it does lie outside the sphere of competence for many cyclists. Without actually seeing the set-up it is not possible to say what the solution is, the bike shop had that advantage and should have been more helpful.

 

[Don Shipp]

Not really. The chain should just clear the front derailleur cage when in the smallest or biggest rear sprockets. You might get some slight rubbing under load, but that's because of the frame flexing. Adjusting the hi/lo screws can often solve the problem and maybe a bit of adjustment in cable tension.

Rubbing can occur if the frame is flexing, which will be greatest when big gears are being forced round. The solution is to spin smaller gears.

 

[boudreaux]

OPERATOR ERROR? IT'S A PEDAL BIKE! NOT A FRIGGIN' SPACE ROCKET!!! DUH!

Shifting gears is beyond the abilities and comprehension for some.Throw in trim and their brain just explodes...trust me.

 

[butchh]

We are a forum, and a forum is for exchange of information to help one another. We missed the boat here. Did anyone ask what bike this was? Which year? No.

To better help, please advise what brand of bike, the year, and maybe the size. Many members and guests will likely have experience with the same model and will be able to help.

 

[boudreaux]

We are a forum, and a forum is for exchange of information to help one another. We missed the boat here. Did anyone ask what bike this was? Which year? No.

To better help, please advise what brand of bike, the year, and maybe the size. Many members and guests will likely have experience with the same model and will be able to help.

Do you have a mouse in your pocket?

 

[glenna1984]

Interesting replies. Yes, I can pedal, shift gears and adjust the trim simultaneously.

The Bicycle is a 2002 or 2003 Fuji Team made from Scandium.
It has worked fine until recently.

 

[shannons dad]

Interesting replies. Yes, I can pedal, shift gears and adjust the trim simultaneously.

The Bicycle is a 2002 or 2003 Fuji Team made from Scandium.
It has worked fine until recently.

Not being funny, but if it was working fine, why were the gears being adjusted? If it was just routine maintenance and the gears were fine, your mechanic has fu(ked about with something he shouldn't have. Unless you can fix it yourself, take it back and get him to sort it out, or, if he's an idiot, take it to another shop where it can be straightened out.

 

[glenna1984]

Not being funny, but if it was working fine, why were the gears being adjusted? If it was just routine maintenance and the gears were fine, your mechanic has fu(ked about with something he shouldn't have. Unless you can fix it yourself, take it back and get him to sort it out, or, if he's an idiot, take it to another shop where it can be straightened out.

Spoke to another biking friend...tightened the cable with the barrel adjustment...and the problem went away.

Yes, it was working fine, then did not work. Then we fooled with the adjustments.

Also yes, this mechanic is no longer my mechanic.

Thanks Everyone.