Pressfit BB loose in Mtb frame

[wessie12]

Good day guys 

Looking for hubland advice 

I have 2019 Silverback Sesta frame with a pressfit bottom bracket.  Noticed that the non drive side has a play on the BB shell. I have no idea how it happened. The BB is literally loose.Is there any way to fix this ? was thinking in the line of loctite,  a shim or something but I would appreciate any advice  from someone who sorted this out

[David Marshall]

6 minutes ago, wessie12 said:

Good day guys 

Looking for hubland advice 

I have 2019 Silverback Sesta frame with a pressfit bottom bracket.  Noticed that the non drive side has a play on the BB shell. I have no idea how it happened. The BB is literally loose.Is there any way to fix this ? was thinking in the line of loctite,  a shim or something but I would appreciate any advice  from someone who sorted this out

It is not an uncommon problem and usually happens only on the non drive side. This is because of the torque differential between the crank arms.

You have a couple of options.

You can fit the bb with some paste like epoxy (I use Epidermix 372 - because that is what I have) or else with a gap filling Loctite (like Loctite 638). Neither of these products are cheap as the pack sizes are relatively large.

A preferred option is to fit a screw together pressfit bb.  Enduro have the full range so you should be able to get from a bike shop.  There are other brands (Token, Praxis, Wheels Manufacturing). Also not cheap but they are a once off purchase.

The advantage of these is that you can replace the bearings without removing the screw together shell.

Back in the day we used to shim loose headset cups with a sliver of aluminium cut from a beer can. It had to be imported beer because the local cans were too thick. Now days any cold drink can will do. You always had some of the shim left protruding which you could remove with a sharp blade.

This should work for a bb as well.

[love2fly]

1 hour ago, David Marshall said:

It is not an uncommon problem and usually happens only on the non drive side. This is because of the torque differential between the crank arms.

You have a couple of options.

You can fit the bb with some paste like epoxy (I use Epidermix 372 - because that is what I have) or else with a gap filling Loctite (like Loctite 638). Neither of these products are cheap as the pack sizes are relatively large.

A preferred option is to fit a screw together pressfit bb.  Enduro have the full range so you should be able to get from a bike shop.  There are other brands (Token, Praxis, Wheels Manufacturing). Also not cheap but they are a once off purchase.

The advantage of these is that you can replace the bearings without removing the screw together shell.

Back in the day we used to shim loose headset cups with a sliver of aluminium cut from a beer can. It had to be imported beer because the local cans were too thick. Now days any cold drink can will do. You always had some of the shim left protruding which you could remove with a sharp blade.

This should work for a bb as well.

I switched to the Wheels Manufacturing option years ago on my MTB. Great option. 

[DieselnDust]

LOCTIRE 638 bearing retaining compound and a thread together BB like those mentioned above is the answer.

The alternative is a carbon repair shop which is a more expensive options but will sort the problem for good.

[cadenceblur]

Thread revival

picked up some play in the BB area of my bike, thinking of taking it to CBR In Durbanville 

is this an easy repair?

Edited April 13 by cadenceblur

[DieselnDust]

Is the bb cup moving?

[cadenceblur]

48 minutes ago, DieselnDust said:

Is the bb cup moving?

There is excessive play on the crank

[Michael S]

Sound like new bike day to me

[DieselnDust]

30 minutes ago, cadenceblur said:

There is excessive play on the crank.

SRAM crank with bb preload adjuster? If yes, dial that in the "+" direction half a turn and see if it takes it out.

If Shimano crank, which model is it because they had different preload adjusters

If dialing up the preload doesn't work then it could be the bearings are dry and shot an need to be replaced.

 

If you hold the crank arms at the pedals and push them laterally and only the crank moves, its bearing wear

If the BB cup moves it s the BB cup to bb shell interface. That should be a warranty claim. If out of warranty then a carbon repairer might be able to help

[babse]

14 hours ago, cadenceblur said:

Thread revival

picked up some play in the BB area of my bike, thinking taking it to CBR In Durbanville 

is this an easy repay?

Local lbs could do the above if you cannot do yourself.

I have had a BB epoxy'd in without much hassle. 

[Mook]

16 minutes ago, DieselnDust said:

SRAM crank with bb preload adjuster? If yes, dial that in the "+" direction half a turn and see if it takes it out.

If Shimano crank, which model is it because they had different preload adjusters

If dialing up the preload doesn't work then it could be the bearings are dry and shot an need to be replaced.

 

If you hold the crank arms at the pedals and push them laterally and only the crank moves, its bearing wear

If the BB cup moves it s the BB cup to bb shell interface. That should be a warranty claim. If out of warranty then a carbon repairer might be able to help

circa 2010 Truvativ GXP crankset on my Spez drove me against the walls with non-drive side play. No pre-load tensioners back then other than spacers. Eventually binned the SRAM and went to Shimano. Never a day's issues since then.

[cadenceblur]

58 minutes ago, DieselnDust said:

SRAM crank with bb preload adjuster? If yes, dial that in the "+" direction half a turn and see if it takes it out.

If Shimano crank, which model is it because they had different preload adjusters

If dialing up the preload doesn't work then it could be the bearings are dry and shot an need to be replaced.

 

If you hold the crank arms at the pedals and push them laterally and only the crank moves, its bearing wear

If the BB cup moves it s the BB cup to bb shell interface. That should be a warranty claim. If out of warranty then a carbon repairer might be able to help

 

47 minutes ago, babse said:

Local lbs could do the above if you cannot do yourself.

I have had a BB epoxy'd in without much hassle. 

it's a Shimano threaded BB

Yeah, I think the epoxy option might be on the cards. Frame is out of warranty.

[DieselnDust]

1 minute ago, cadenceblur said:

 

it's a Shimano threaded BB

Yeah, I think the epoxy option might be on the cards. Frame is out of warranty.

yeah, that sounds like the way to go. Insurance will pursue the same route just at their cost followed by jacking the premium.

What frame is this? 

[cadenceblur]

1 minute ago, DieselnDust said:

yeah, that sounds like the way to go. Insurance will pursue the same route just at their cost followed by jacking the premium.

What frame is this? 

It's a hardtail frame I bought from a company called BXT off Alibaba.

Had it for close on 7 years.  

Will take it to CBR for them to have a look.

[babse]

Just now, cadenceblur said:

It's a hardtail frame I bought from a company called BXT off Alibaba.

Had it for close on 7 years.  

Will take it to CBR for them to have a look.

they will most likely quote you for a carbon repair and respray which will cost more than the value of the frame...

[DieselnDust]

2 minutes ago, babse said:

they will most likely quote you for a carbon repair and respray which will cost more than the value of the frame...

true, there is a bit of work involved. To do the job properly the cup will have to be removed, the bond areas on frame and cup cleaned, BB will need to have material replaced (glass) and then the AL cup bonded back in place assuming the galvanic corrosion isn't so bad that the cup is a write off