Grrrrrrrr from Bottom bracket

Bikerbhoy

Ok folks assistance and advice needed on the following......... Tearing down off Sallys today towards Kilbride just came to end of really fast decent so started to apply some pedal power yes 60ks plus what a buzz got to a point where I freewheeled and to my horror Grrrrrrrrrr this real grinding sound from BB area pedal again gone freewheel again Grrrrr back.Now as I carried on down to N81 it came and went as I freewheeled but returned again at bottom of embankment and at all points freewheeled along Tallaght Bypass.

on inspection at home cant find a thing wrong or hear anything like that Grrrrr sound cranks are rock solid ,,,Im in a cafuffle to be honest ....any ideas ?????

Lumen

Check your rear hub.

kona

Bikerbhoy wrote: »

Ok folks assistance and advice needed on the following......... Tearing down off Sallys today towards Kilbride just came to end of really fast decent so started to apply some pedal power yes 60ks plus what a buzz got to a point where I freewheeled and to my horror Grrrrrrrrrr this real grinding sound from BB area pedal again gone freewheel again Grrrrr back.Now as I carried on down to N81 it came and went as I freewheeled but returned again at bottom of embankment and at all points freewheeled along Tallaght Bypass.

on inspection at home cant find a thing wrong or hear anything like that Grrrrr sound cranks are rock solid ,,,Im in a cafuffle to be honest ....any ideas ?????

I would be looking at your Hub too. Nothing wrong with your BB, If the noise only comes when you are NOT pedalling.

Try and see if its speed related. 60kmph+ is quite a high RPM, what Bike/ wheelset is it?

Bikerbhoy

Lumen wrote: »

Check your rear hub.

its seems fine

Bikerbhoy

kona wrote: »

I would be looking at your Hub too. Nothing wrong with your BB, If the noise only comes when you are NOT pedalling.

Try and see if its speed related. 60kmph+ is quite a high RPM, what Bike/ wheelset is it?

Yeah I initally thought that too but seemed to be feeling vibration through pedals when making this noise .????????

Dolan Mythos on Mavic Aksiums

victorcarrera

Try to reproduce symptoms like this.
Raise rear wheel off ground and spin using cranks.
While wheel is spinning rotate the crank slowly to rotate hub body.
My reasoning is, that I had a faulty rear hub body that only made noise at a particular point of rotation when freewheeling.

Also some other posters on here have had problems during cold weather with the grease in the hub freezing. Was it cold up there today?

Bikerbhoy

victorcarrera wrote: »

Also some other posters on here have had problems during cold weather with the grease in the hub freezing. Was it cold up there today?

Mmmm thats interesting....Yeah baltic and to make it even colder i went up to the mast at kippure had to turn around at the top come straight back down no sightseeing today it was painful to be honest..but yeah overall it was cold

Lumen

Bikerbhoy wrote: »

its seems fine

OK, but if you have a spare rear wheel, stick that on just to eliminate the possibility.

I was chasing BB creaks for months before discovering my rear freehub bearings were shot, and your description does point to the freehub.

Bikerbhoy

Lumen wrote: »

OK, but if you have a spare rear wheel, stick that on just to eliminate the possibility.

I was chasing BB creaks for months before discovering my rear freehub bearings were shot, and your description does point to the freehub.

thats the plan for tomorrow allright will report back with findings thanks everyone for comments so far

tunney

Its your freehub bearings.

Rear hubs have two sets of bearings, one for the spinning of the wheel relative to the frame. One for the spinning of the wheel body relative to the freehub body. This is what allows you freewheel.

Pop off the cassette, generally its a 8mm allen key to undo the axle and release the freehub. Take the freehub body off very carefully as there are small springs on the "teeth" between the hub and freehub, clean, lube and fit it back together. problem solved.