my back tyre rubs on frame ? also cracking sound from bottom

CUBEical

I have been noticing my back tyre rubbing on the frame slightly when i apply a lot of force ,tried tightening and re setting the wheel, what could it be? also getting cracking/creaking noise coming from the bottom bracket/crank? its not pedals as i got them replaced thinking it was them? thanks

nicklouse

is the tyre central?

lose cranks.dead bearings in bb or pedals.

frame flexing.

Mindermast

It could as well be a soft tyre - low spoke tension. If this isn't a new bike and only started recently, it could be the rear hub or the freewheel. And perhaps the bottom bracked got lose around the same time.

If you flex the wheel, can you feel the hub moving against the axle? Any unusual sound when you rotate the wheel?

Also check the bottom bracket: Try to flex the cranks. Even if you only feel a slight movement, it should be adjusted. Of course, this wouldn't cause the wheel to rub against the frame.

Worst nightmare explanation: Frame cracked.

CUBEical

nicklouse wrote:

is the tyre central?

I WILL CHECK IT AS I HAVE FIXED A PUNCTURE ON IT RECENTLY SO MAY HAVE A BUBBLE IN IT, BUT I AM 99% SURE IT DOES NOT RUB UNLESS I PEDAL HARD ??

lose cranks.dead bearings in bb or pedals.

I HAVE TIGHTENED THE CRANK ARMS WILL CHECK INDIVIDUAL CRANKS TODAY , I GOT THE PEDAL I THOUGHT IT WAS REPLACED AT THE SHOP I BROUGHT THEM FROM STILL HAPPENING. I AM GOING TO TAKE IT APART AND INSPECT THE BEARINGS IN BB MAY GET A NEW ONE AS IT WAS QUITE HEAVY TO TURN BEFORE PUTTING IT BACK TOGETHER WHEN I DID THE REBUILD IS THIS NORMAL?

frame flexing
HOW WOULD I CHECK THIS ?.

Mindermast wrote:

It could as well be a soft tyre
I THOUGHT OF THIS PUMPED IT UP WILL SEE IF I CAN PUT BIT MORE IN WHAT PRESSURE IDEALLY SHOULD IT BE AT ?

- low spoke tension.
HOW WOULD I CHECK THIS AND FIX ?

If you flex the wheel, can you feel the hub moving against the axle? Any unusual sound when you rotate the wheel?

THE WHEELS ROCK FORWARD AND BACK EXCESSIVELY WHEN DISC BRAKES ARE APPLIED FULLY. I THOUGHT THIS WAS STRANGE BUT MAN AT WILCOS SAID IT WAS NORMAL?

Also check the bottom bracket: Try to flex the cranks. Even if you only feel a slight movement, it should be adjusted. Of course, this wouldn't cause the wheel to rub against the frame.

TIGHTENED THE CRANK ARMS WILL LOOK AT THE INDIVIDUAL CRANKS TODAY

Worst nightmare explanation: Frame cracked

I HOPE NOT .

Thanks for both of your inputs, i hope this is ok as a reply thought it would be easy to do it this way

Mindermast

Don't put too much air into your tyres. If they feel hard, they won't touch the frame because of low pressure. Tyre pressure has become even more mystical recently, people ride anything from above max. to below min. and claim that it makes them faster.

If you have another bike, compare the spoke tension. Hard to say what is right though. Lower spoke tension allows the wheel to flex more. But there is a limit, and if the rim is too flexible, the wheel will flex even with highest possible spoke tension.

The wheels moving forward and back EXCESSIVELY sounds strange. Does the brake disk move too?

By the way, what is the tyre width? How much space is there between tyre and frame?

CUBEical

The disc brake stays still when the wheel moves, i must say the bearings in the front wheel do feel shot when you move it around you can feel them grinding a little but that does not explain why the back wheel does it to. The tyre width is 2.4 there is minimal space, i have just been out working on it now i took the whole crank set off cleaned and tightened (they were not even loose) took out the bb cleaned and re greased. replaced it all, the cracking and creaking was still happening so i turned the bike upside down and looked at the wheel i saw that it was a little off centred. i loosened the wheel and instead of pushing it down in the holder of the frame on both sides i just set it so the wheel was in the middle. Now here is were it gets interesting, the creaking and cracking noise has stopped and the wheel has not rubbed yet but i am yet to take it out for a proper ride, what has puzzled me the most is the cracking has stopped all because i have centred the wheel. How strange ? I thought it was the bb as that is looking and feeling pretty dead, I am going to start up a new thread on what best upgrade i could get for a bb.

nicklouse

if the wheel moves and the disc does not then your wheels need a rebuild/re-tension.

your tyre could just be too big.

and just moving your wheel in the drop outs will not fix a thing as soon as you ride off it will move back to sit as it was in the drop outs.

Ouija

The slight rocking back and forth when applying brakes is usually a sign of two things.

1) The bolts holding the disk to the hub aren't on tight enough, allowing the hub to move slightly against the disk (because the holes on the disk are slightly wider than the bolts that go through them).

2) Skewers not on tight enough. On the front wheel, this can cause a slight twist in the forks under braking, causing the right leg to move further forward than the left, causing the wheel to rock forward and to the left as you push the bike forwards and back and to the right if you pull backwards on the bike (can fool you into thinking the headset isn't preloaded tight enough when it is).

The wheel not being centred between the forks/frame can also be caused by not enough of the axle sticking out from one side of the wheel. This can cause it to not sit in the drop out correctly so that it's really resting on the quick release skewer on one side. Since the skewer is narrower in diameter than the axle it passes through, that side of the wheel will move back in the drop out by a few millimetres causing the whole wheel to be skewed off to one side (causing tyres to rub against frame and disk rotors to rub against brake calipers etc). Axles can wind their way from one side of the hub to the other slightly over time, but it's usually caused by incorrect re-installation after re-greasing/maintenance of the bearings.