Press fit BB advice

mattyboy199

Guys,

My press fit BB on my TCR 2 has been creaking for far to long now, i want to replace it myself however cant find a reasonably priced removal tool. I have used similar tools for headsets in the past on my mtb & removal is very easy to do. I'm also unsure of sizing of the BB cups, would it just be a case of checking the diameter/BB shell on the frame ?

All help will be appreciated.

Matt

markwb79

If its the same as my TCR. Its a the 86.5mm pressfit BB. I recently changed mine, and used the back end of a wrench and a hander to gentle knock it out.

Used a proper tool to put the new one in though.

mattyboy199

My TCR 2 is 2011 & an aluminium frame. I cant see how you would get the cups out without a cup removal tool as the tools are designed to expand once through the opposite side cup & distributes force evenly.

Monty Dog

Giant uses a variation of BB86 - it's a common press-fit standard. If you're planning on replacing the BB, then you can simply drift out the old BB, no special tools required.

mattyboy199

what do you mean by drift ?

Monty Dog

A straight or tapered metal bar with a flat end and preferably a chamfered edge. Some press-fit BBs are simply the cartridge bearings pressed into a plastic housing and there's little inside to engage with a bearing puller. You just simply have to 'bash' them out - the risk of using a screwdriver or similar is that you could gouge the inside of the BB shell.

mattyboy199

ok so this KCNC BB is the correct fitment

http://www.ebay.co.uk/itm/KCNC-BB90-PF9 ... 1e7c3d9de9

maddog 2

you need a BB86 unit that fits a 86.5mm BB shell. In other words, your frame is 86.5mm wide.

One like this http://www.ebay.co.uk/itm/KCNC-Press-Fi ... 3f278ec989

This is sometimes called BB90, which confuses everyone because Trek do a proprietary BB with the same name.

Shimano BB86 units are okay. They aren't particularly quick spinning or anything flash but they are pretty good for the money.

Don't get a BB92 one, as that is MTB spec, and wider (mtb chainsets are wider than road ones).

[some BBs can handle both widths, as they have a slidey central tube. Some BBs are just the cups, so don't have a central tube, so can do any width]

schlepcycling

I found this to be a useful guide http://www.youtube.com/watch?v=AftPKuX_tyo

mattyboy199

Right chaps had a go at getting this BB today, all sorted ! its a shimano unit with BB71-41 printed on the cups does this have any relevence to size ?

shell size is 87mm wide with an internal diameter of 41mm

maddog 2

41 refers to the 41mm ID

71 refers to Ultegra level spec of the unit itself.

It's the right one. Now do you have a headset/BB press?

mattyboy199

Well I ended up opting for a shimano unit purely because its plastic and likely to be a lot easier to remove than the ally KCNC unit. I have a headset press the rest is plain sailing thanks for the help

Captain Fagor

I have to fit a BB86 into a Giant TCR Advanced SL at some point (I'm in no rush). Rather than spend a lot of money on the proper tool for a one-off job (or pay LBS £25 which seems OTT), I was wondering: couldn't I just buy a hex-headed bolt and nut with appropriately sized washers? It looks like M20 bolts plus washers would be in the right ball park size-wise (37mm OD washer) to fit inside the press fit cups.

Any tips from other tight-fisted workshoppers appreciated!

desweller

Washers aren't very stiff...I'd probably just gently tap it in with a soft mallet. I have fitted a lot of bearings to machines without needing all the special tools that people seem to need for bicycles.

Captain Fagor

Hmm - hadn't thought of a mallet. I'll wait and see what others say, but I wouldn't rule that approach out. The cups can be pushed in a fair distance by hand, so hopefully the potential to go askew is reduced.