Bending Bottom Bracket?

[Arfcollins]

My first commute on my new Cycle to Work bike, picked up on Saturday. It's a Cube Cross Comp and I'm very pleased with the ride, but there is a niggling noise, which although not loud I can still hear despite listening to Radio 4 on the boombox strapped to the front offside rack. The car battery that drives it is on the nearside rack and balances it nicely.

When I pedal hard the front cog is rubbing oh so slightly on the front mech, though only on the downstroke of the left pedal. I can only conclude that either the bottom bracket or the frame is flexing for this to happen. I expect I can tweak the lateral position of the mech to get rid of it, but I'm curious as to whether this is a common experience.

 

[Bromptonaut]

No advice specific to the Cube Cross I'd say this is pretty common on triple chainwheel set ups. Should be able to trim it out with the adjuster and by avoiding to sharp chain angles (eg largest front cog to largest rear).

 

[betty swollocks]

In some gears the chain may well rub on the front mech especially if the chain is flexing across too extremely. Do not use gears where this happens,
Unlikely that the b/b or frame is flexing - more likely the chainrings, esp the big one.
You may be able to trim the front mech to stop some of the rubbing.

 

[Jezston]

Wait you have a stereo and a car battery strapped to your front wheel? That's quite a lot of weight isn't it?!? Why not just use a personal stereo?

 

[iendicott]

Wait you have a stereo and a car battery strapped to your front wheel? That's quite a lot of weight isn't it?!? Why not just use a personal stereo?

Exactly , everyone elso was over looking this

 

[magnatom]

I think the problem is caused by the electromagnet in the 500 Watt subwoofer and the blue underside lights interacting with and causing interference in your boombox. This problem can only be solved by upping the dial to 11 so you can't hear the rubbing, or in fac, a Boeing 747 flying 30 metres above your head.

Sorted

.

 

[jonny jeez]

My first commute on my new Cycle to Work bike, picked up on Saturday. It's a Cube Cross Comp and I'm very pleased with the ride, but there is a niggling noise, which although not loud I can still hear despite listening to Radio 4 on the boombox strapped to the front offside rack. The car battery that drives it is on the nearside rack and balances it nicely.

When I pedal hard the front cog is rubbing oh so slightly on the front mech, though only on the downstroke of the left pedal. I can only conclude that either the bottom bracket or the frame is flexing for this to happen. I expect I can tweak the lateral position of the mech to get rid of it, but I'm curious as to whether this is a common experience.

this is a joke ...right?

please tell me you've heard of MP3 players?

 

[psmiffy]

It has got to be safer than using headphones

I am pretty deaf so I do not worry about strange noises coming from the BB area - but agree with the general collective that it is not the BB - easier enough to trim the front derailler using the limit screw so that the chin does not rub even at extreme chain angles

 

[Arfcollins]

I think the problem is caused by the electromagnet in the 500 Watt subwoofer and the blue underside lights interacting with and causing interference in your boombox. This problem can only be solved by upping the dial to 11 so you can't hear the rubbing, or in fac, a Boeing 747 flying 30 metres above your head.

Sorted

.

I checked but the volume only goes to 10. Just as well, as if it went up to 11 it would probably be as dangerous as wearing ear-phones.

Thanks everyone for your advice re the rubbing.

 

[hackbike 666]

Exactly , everyone elso was over looking this

I think this is just another joke.