What's the best way to stop water getting into the bottom bracket area from the frame. I'm thinking of silicone sealant in the frame tube holes in the BB area. I think water is getting down the seat tube because of the shimmed seat post. I could easily change that for a non shimmed one though.

I wouldn't that is there to let the inevitable water ingress out

Personally never found it a bother on my mtb though I have a proper bottom bracket (un53) which laughs at water

Ray, if it hasn't already got one, drill a small hole 2mm or so at the lowesr point of the BB shell. Much better to allow the water out and air in than try and seal the thing completely off.

It's possible to get seatpost clamps with a rubber seal but it's virtually impossible to get a total seal. Simplest way is to remove the seatpost periodically and turn the bike upside down then spray a bit of WD40 down the tube.
Either that or move to Cataluña

Ok, thanks. I'll check to see if there's a hole in the bottom of the BB, if not I'll drill one. I think I'll fit a different seat post so no need for a shim. The reason I ask is the bikes only done 200 mile and the drive side bearings buggered already. Both times I've had the cranks off water had been present.

You'd have to get a lot of water in there to flood a bearing. Assuming it is a HTII type there is also some protection from the sealed connector tube.

FWIW (and possibly not relevant in this case) I'd guess that 90% of the failed HTII type BBs I've seen have been due to over-enthusiastic use of the preload adjuster.

pistonbroke wrote: ↑Tue Jun 04, 2019 2:29 pm Either that or move to Cataluña

Wouldn't I just love to.

Ray Young wrote: ↑Tue Jun 04, 2019 2:50 pm Ok, thanks. I'll check to see if there's a hole in the bottom of the BB, if not I'll drill one. I think I'll fit a different seat post so no need for a shim. The reason I ask is the bikes only done 200 mile and the drive side bearings buggered already. Both times I've had the cranks off water had been present.

Ray... what BB are you using please? and what terrain was that 200 miles through...

FWIW when I used to have the bikeshop build my bikes (thankfully many many years ago) the BB never would last that long. Then suddenly when I had accumulated my tools and decided to do everything by self. The BB was lasting alot lot longer. I put it down to the fact the shop lad only ever used his arm for the torque settings whereas I used my dad torque wrench.

Also, like its been said already, you really dont wanna close up that drainage hole

Ray Young wrote: ↑Tue Jun 04, 2019 3:25 pm

pistonbroke wrote:Tue Jun 04, 2019 2:29 pm Either that or move to Cataluña

Wouldn't I just love to.

+1!!

Ray, you could be here for £45
https://www.jet2.com/en/cheap-flights/edinburgh/reus
Jurassic Sept flights from £25
https://www.easyjet.com/en/buy/flights
We run a 3 bed B&B and do bike hire and guiding for not much money

redefined_cycles wrote: ↑Tue Jun 04, 2019 3:42 pm Also, like its been said already, you really dont wanna close up that drainage hole

I don't think there is a drainage hole unless it's been blocked with paint when it was sprayed but I doubt that. I also do 99% of work on the bike myself and have done for many years.
I'm positive the water is getting down the seat tube when I wash the bike as the seat post shim has a gap in it. The crankset fitted is an unknown brand and I think the bearings may be cheap ones amd that's why they've gone so quickly. Odd that it's only one side that's gone though.
I've replaced them with Shimano xt ones and will check for a hole and drill one if needed as per Stu's advice. I'm also going to fit a seat post that doesn't need a shim to stop water getting down there in the first place.

pistonbroke wrote: ↑Tue Jun 04, 2019 8:42 pm Ray, you could be here for £45
https://www.jet2.com/en/cheap-flights/edinburgh/reus
Jurassic Sept flights from £25
https://www.easyjet.com/en/buy/flights
We run a 3 bed B&B and do bike hire and guiding for not much money

Thanks Duncan, I am in the early planning stage of a motorcycle trip to Spain for next year, your B&B would on it!
Rob.

A lot of BBs have a hole in them, but this is usually occupied by the screw which holds the gear cable guide in place.

Man up, and go singlespeed, so you can remove the bolt/guide

belugabob wrote: ↑Wed Jun 05, 2019 1:47 pm A lot of BBs have a hole in them, but this is usually occupied by the screw which holds the gear cable guide in place.

Man up, and go singlespeed, so you can remove the bolt/guide

Sorry but I'm too old to "man up" so I fitted a seat post that didn't need a shim and drilled a hole in the bottom bracket as suggested by Stu. On removing the crankset to drill the hole guess what.........water. The bike had only been washed once since I last had the crankset off and I was careful around the seat post area too. Hopefully this will sort it but I'll keep an eye on it.

Ray Young wrote: ↑Sun Jun 09, 2019 1:28 pm

belugabob wrote: ↑Wed Jun 05, 2019 1:47 pm A lot of BBs have a hole in them, but this is usually occupied by the screw which holds the gear cable guide in place.

Man up, and go singlespeed, so you can remove the bolt/guide

Sorry but I'm too old to "man up" so I fitted a seat post that didn't need a shim and drilled a hole in the bottom bracket as suggested by Stu. On removing the crankset to drill the hole guess what.........water. The bike had only been washed once since I last had the crankset off and I was careful around the seat post area too. Hopefully this will sort it but I'll keep an eye on it.

Drilling that hole should sort it out now Ray. Especially since you've hopefully drilled st the lowermost point of where the water can reach...

Just a side note (only because I tend not to ever use but recently have started using). That plastic sleeve that comes with Shimano BBs that joins one side of the bottom bracket to the other. Its supposed to protect from water ingres to the bearings I believe I've only started using it cos of the Di2 wiring now that goes inside that BB area and with the sleeve there less liklihood of the wires catching the spindle!

The plastic sleeve is an integral part of the design (I mentioned it in an earlier post up there ^^^^).
Why would you choose not to use it?

ScotRoutes wrote: ↑Sun Jun 09, 2019 2:46 pm The plastic sleeve is an integral part of the design (I mentioned it in an earlier post up there ^^^^).
Why would you choose not to use it?

Colin*. It has worked well for me over the years and bottom brackets always lasted well without it promise not to laff .... I used to think it saved a few grams. Weighed it this last time (when I decided to add it after last BB had, to be fair, lasted me 5000 miles without it) as decided its not worth the risk of the di2 cables getting caught on spindle.... Weight was about 3g I think

*sorry didnt realise you'd already mentioned it

Yep, hole in lowest point and plastic sleeve on. Jobs a good un, .

A very simple solution that I tried from my early mtb days. Find a snug fitting old cycle inner tube on the seat post, cut it about 75-100mm long and slide it up the seatpost. Re fit post to correct height. Roll back 50mm of the inner tube on itself, slide it down to meet the seat tube. Roll it back over the seat tube clamp and ensure you also cover the seat tube slot... Voila! A very neat cheap seal! Regards RBBB.

Cyclepeasant wrote: ↑Sat Jun 15, 2019 12:22 am A very simple solution that I tried from my early mtb days. Find a snug fitting old cycle inner tube on the seat post, cut it about 75-100mm long and slide it up the seatpost. Re fit post to correct height. Roll back 50mm of the inner tube on itself, slide it down to meet the seat tube. Roll it back over the seat tube clamp and ensure you also cover the seat tube slot... Voila! A very neat cheap seal! Regards RBBB.

I like that, don't think I've an inner tube thin enough though.

Try obtaining a used /punctured Road or commuter inner tube from your local friendly LBS! Plentiful I would imagine! Regards RBBB

Cyclepeasant wrote: ↑Sat Jun 15, 2019 1:36 pm Try obtaining a used /punctured Road or commuter inner tube from your local friendly LBS! Plentiful I would imagine! Regards RBBB

Or just keep an eye out for a discarded one, at the side of the road.

(Yes, I know that MTB riders throws them into frees, too - anybody who throws tubes away, like this, has no respect for the environment and/or are not tight enough to patch a tube)