My bottom bracket is making a hell of a racket...

[T4tomo]

So last weekend I was out on a ride and getting a bit of clicking and clacking from the BB area which developed into grinding and graunching and that horrible metal on metal sound particularly when applying a bit of pressure to the pedals.
Having pretty much eliminated the pedals or loose chainring bolts or crankarms I thought I'd better inspect the BB so stripped in down yesterday morning.
Can anyone spot anything wrong with it? 😉

 

[Deleted member 1258]

Thats well knackered.

 

[PeteXXX]

Gaffer Tape it and pop it back in. Loads of miles left on that!

 

[T4tomo]

I'm quite pleased I managed to nurse it home for 15 miles after the racket started.

 

[fossyant]

That's one of the newer Shimano square tapers - I've the UN300 now in my MTB and it's the same construction. The older ones, UN55 etc, have the non-drive side bearing in the casing.

One to watch this !

 

[T4tomo]

That's one of the newer Shimano square tapers - I've the UN300 now in my MTB and it's the same construction. The older ones, UN55 etc, have the non-drive side bearing in the casing.

One to watch this !

No it isn't, it was a RPM 7420 (which i think are made by FSA).

a UN300 will be going in to replace it.

 

[si_c]

Oof. That's unlucky.

I think you were helped getting home by it being a sealed bearing unit, I've had a cheaper BB with caged bearings disintegrate on me mid-ride, resulting in the cage shredding itself and the bearings going loose inside the unit. Fortunately I was near a station I could walk to.

 

[fossyant]

No it isn't, it was a RPM 7420 (which i think are made by FSA).

a UN300 will be going in to replace it.

Oh, I hope the new Shimano ones are better then (I've a UN300) - they have a similar construction, although the non-drive side cup is fairly deep.

 

[T4tomo]

Oof. That's unlucky.

I think you were helped getting home by it being a sealed bearing unit, I've had a cheaper BB with caged bearings disintegrate on me mid-ride, resulting in the cage shredding itself and the bearings going loose inside the unit. Fortunately I was near a station I could walk to.

The OH was away for the day too, so it would have been a long push home or an expensive taxi !

 

[T4tomo]

Its hard to tell as I was off the bike for a couple of months with an ankle injury, so taking it easy when I resumed in November, and my elevation per mile can vary a bit, but my average speed has been down on expectations of late, which i'd put down to age and fitness and general winter mehness, but a draggy BB may have been a factor. I will to see how it goes once the new BB arrives and I've put the crankset back together.

 

[CharleyFarley]

I bought a new Specialized Fatboy in 2016. A thousand miles on it, and while on a lengthy ride the BB started squealing; it sounded like someone talking, and it was embarrassing as I rode by people at bus stops. I removed the dust seal and pressed some grease into it. Now with 10,880 miles on it, it's still as slick as snot on a frosty board. I just wish it wasn't a press fit BB as I like to do my own repairs. If and when it goes bad, I'll take it to a bike shop for the work to be done.

 

[Ajax Bay]

it's still as slick as snot on a frosty board

So it still sticks a lot, then?

 

[CharleyFarley]

So it still sticks a lot, then?

You've never stepped onto fresh snot on a frosty board, have you? I don't recommend it.

 

[rogerzilla]

The UN300 doesn't have a good reputation so far. Shimano are trying to relegate square taper to the bottom end of the market because all you ungrateful people should be using HT2

 

[Blue Hills]

The UN300 doesn't have a good reputation so far. Shimano are trying to relegate square taper to the bottom end of the market because all you ungrateful people should be using HT2

Can you say more on the reputation/reports?
Do shimano have any theories/pitch on how the UN300 may be better/an improvement?
What do the reports say?
Must say I saw little reason to abolish the UN55 - thought most of my bikes would be running it to the end.
I did pick up one for about £4.50 and another for about £7.50 as spares from the bay as soon as I realised - prices now gone up of course.