Wanted: bottom bracket. 116mm?

hello. i have a gazelle champion mondial circa '78 but my bottom bracket is shitty and bowed in some way, so the chain/crank scrape against my front deraileur every turn, but not constantly. SO ANNOYING and certainly problematic. also, if anyone has one of them weird pin-spanner things to remove my piece of.... old thing, then this would be greatly appriciated. I'm GUESSING it's 116mm, but if i'm wrong please call me up on that. plus i'm riding 8-speed so if possible, wide. thanks.

sorry to sound so stupid but i know nothing about bb's unfortunately. teach me....

p.s. i'm trying to build up my arabesque groupset. i need calipers and crankset to complete. reasonable prices please

Anyways, this you need to know: you need British thread (Gazelle) and JIS taper (Shimano Arabesque).. You could use a small screwdriver and a hammer to get the indented cup out, homemade solution which works a treat.. Lenghtwise, I hope other forumengers can enlighten you.. But, I guess the best way is to get the spindle out and measure it.. Good luck!

thanks. i did try the old screwdriver and hammer trick but got scared because i chipped the nice paintwork. my friend let me use his spanner but it's stuck pretty tight. anyone got a BB i can buy?

Most BBs I encounter on old, used bikes only come out with the help of a bench vice. I clamp the BB tool in the vice facing upwards, lower the frame onto it, and then turn the frame by applying force to the places where tubes intersect (holding both ends of the top tube works well).

If you have no vice then you might need a long spanner and will have to jump on it. But for gods sake check the threading here: http://sheldonbrown.com/cribsheet-bottombrackets.html. You don't want to tighten it further!

You do indeed need 116mm. Velobase is your friend. And make sure it's JIS or it'll sit way too far in-board.

thank you very much Ndeipi. Does anyone out there have what i need here? it's english threaded. i know that much. yeah i had this tiny pin spanner and it was difficult. i might try your bench vice idea

For the drive side (right side when looking from the back) you can use a large threaded bolt. Put it through the hole in the cup and tighten the nuts on either side. Because the thread is reversed on the drive side (on English thread) as you tighten the nuts it'll take out the cup.
This requires you to have removed the non-drive side first, which can be tricky but if you can get that out (big spanner) then the drive side is easy.
If the cranks are 'cottered' (have pins through the crank arms and the spindle) then you can use an allen key and a hammer, or use a crank puller. Mine has a hex key on it that fits cotters perfectly. I'm not sure if that's what it's for, but it works!
Or do you mean you need one of these http://www.getprice.com.au/images/uploadimg/1402/7803.jpg ?
I have one and a big spanner if you want to come round and use it at some point.

When it comes to buying a BB, just buy a new one. They're not that expensive!

dglshrn, that's a really elegant solution to removing a drive side cup. I will deffo use that if I hit a tight spot in the future.

I think it might be Sheldon's originally, works perfectly though. The only trouble is, it can be a bit of a bugger to get the now tightened nuts off, as one is hard to reach because it's inside the cup. It's hard to get them apart without ruining the thread on the bolt (which admittedly only needs to be on one end!)

thanks for the handy messages. but i really need this soon, this bastard one i have is ruining my FD since it's making this noise and obviously scraping way too much.

What do you need though? Tools? Is it a cup and cone BB or a shimano/campy sealed type?
Buy a UN54 from ebay, and if all else fails get down to your LBS and get them to remove the current one. If your cranks are cottered they're not going to work with a modern BB though.

they aren't cottered. i've got golden arrow cranks at the moment. and some maxy ones. yeah, i think i'll just buy a simple one for now.

i typed in UN54 on eBay and was faced with this http://www.ebay.co.uk/itm/Mens-N2N-UN54-Fitted-Wonderjock-Pouch-Jock-Strap-/190535964768?pt=UK_Men_s_Underwear&var=&hash=item721763efad

...not entirely sure how this will help my situation?