So, Shimano don’t (properly) and neither do Hope. Are there any out there that do?

I want a bottom bracket shell that is easily serviceable so I can just replace the bearings with off the shelf ones. Preferably something that is designed to be serviceable so doesn’t have seals that break if they see a screwdriver etc.

Do the superstar ones? or the token ones? or the race face ones? or ebay chinese specials like Gub or Turner?

Need to fit a shimano crank.

seals that break if they see a screwdriver

stanley knife blade might result in less seal damage?

BETD do some replacement bearign type things and a tool to fit them;

http://www.mountainbikecomponents.co.uk/items.asp?CategoryID=237&Name=Hollowtech+II+bearing+upgrade

They’re £24, I can get a XT from crc for that with new cups. They are the wierd 24mm ID ones that are non standard if I’m reading correctly.

they all have to be 24mm ID as that’s the size of the axle isn’t it?

Superstar ones used to, but I was in the market for a new BB and wanted the same so i could service / replace bearings myself (I’ve got a dozen or so at home still), went to the SS site, and they are now selling some other brand.

So instead i ordered one from ebay, an Aerozine that I’m pretty sure is the same as the SS ones were.

If anyone has an old SS they don’t need, I’m still after one.

http://singletrackworld.com/forum/topic/superstar-shimano-compatible-bb

I think Rotor BBs take a 6805 bearing.

I think that race face use 6805 bearings that have a 25mm internal diameter and its the top hat that reduces the diameter down to the 24mm required for the axle.
I believe that some manufactures like hope use custom bearings that are 24mm ID and don’t have the top hat.
I had a race face one that the bearings went on and I designed and got a press tool made to remove and insert new bearings. It means you almost have a bottom bracket for life as the shells are much of a muchness. Last time I replaced them I used ina/fag which are about as good as bearings get bearings and it cost £24. They are still like new after 7 months of muddy riding.
I have a hope one that I bought due to the ease of changing the bearings expecting them to be 6805’s. I’m a bit disappointed to find out they are custom and most likely will have to be ordered from the web as I work very close to a bearing supplier who keeps stock of 6805’s.

Andy

My Superstar one takes 61805, which is the same dimensions as 6805……
Wouldn’t be surprised if they’ve changed them right enough, their bearings are made of cheese. Very soft cheese.

Hopes do take 6805 / 61805 bearings, but you need to get some top hat bushes to go with the bearings.
Im toying with getting some old shimano cups bored 1mm deeper to allow them to accept the std 7mm deep bearings, rather than their own 6mm ones. But at £16 for a new BB i dont know if can be arsed with the effort.

Looks like an opportunity for one of the machinist chaps.

Im in if someone can make some bottom bracket shells to the follow spec.

Take readily available bearings.

No Top hats required.

Bearings can be pressed in/out easily.

Have I missed anything, add to the spec if needed.

Have I missed anything, add to the spec if needed.

Seals… 😉

The only bearings I know that dont require top hats are enduro and hope, these are not off the shelf jobs, so are about £20(??) a set. The bearing shells are irrelevant to the use of top hats. Its the ID of the bearing that determines top hats (or not).
I think the easiest would be to just get some old shimano ones bored out to 7mm depth and a couple of slots filed in the inner lips to allow you press the old bearings out. Then you can use hope / enduro / 61805 / whatever bearings you fancy.

The older style token ones use 61805 (they have just changed to 24id bearings) but the top hats are very brittle.As would anything made of 0.5mm plastic will be tbh.
Rose sell Deore ones for £11

Some Tokens do, and the tophats are easy to remove, and not delicate- just changed one.

Gusset EXT24 if I remember rightly is also 6805… The tophats are a wee bit more delicate, but not so much as to be fragile- they just need more careful handling. (plus side is they have slightly better coverage than the Token one). Very similiar designs.

Uberbike BB’s have replaceable bearings and top hat seals so are probably 6805, you could email them to ask what size they use?

Oh sorry, I was wrong (apparently) 🙁

61805 and 6805 are the same thing – it’s just a difference in the way bearing manufacturers mark them up (I’m becoming quite a bearing geek these days as my mate works for a bearing supplier and I’m astounded at the markup between what he sells a “standard” bearing to a bike shop chain and the retail price for a “special high grade” MTB bearing….)

Get some good 6805/61805 bearings from a bearing supplier(FAG or INA are a good bet, I personally prefer INA), pop the seals, fill up with good grease. These will cost you a few quid each, tops.

A SRAM/Truvativ external shell will take this bearing size (so get a knackered SRAM shell from your LBS or a mate).

Then get a pair of these: http://superstar.tibolts.co.uk/product_info.php?cPath=23&products_id=450

Job done

🙂

Hey, sorry Rorschach, that looked a bit like I was having a go at you, I was assuming there’s 2 different models of Tokens when I typed it.

Uberbike BB’s have replaceable bearings and top hat seals so are probably 6805, you could email them to ask what size they use?

I emailed Uberbike and got this reply…

“The stainless steel BB bearings are 6805 and top hats are available at £3 each”

…so these BB’s are an option