Bottom Bracket cutouts

[pubrunner]

I've seen on a couple of websites, some Italian frames where there are 'cutouts' underneath the bottom bracket.

What is the point of this ? Surely, there will only be a minimal weight saving and won't this provide an area for dirt and water to collect ?

 

[spandex]

There is no point for the function of the bike it is just for looks

 

[jimboalee]

Haven't got a Scoody Doo.
Beaten me.

Maybe that's where the team mechanic gets in to wind up the rubber bands.

 

[pubrunner]

There is no point for the function of the bike it is just for looks

But who is going to look under the bottom bracket ?

And won't it cause the bottom bracket to deteriorate faster ?

 

[itisaboutthebike]

to save weight

raleigh used to do it on thier 753 frames, plus a lot of italian builders. Old school campag BB's (and others ) came with a plastic sleeve to help prevent water ingress (either doen the seat tube or if the BB had cut-outs)

Not necessary mow on carbon bikes...........

 

[NickM]

It is to allow a steel frame to "breathe" - i.e. to dry out if water gets inside - so that it does not rust.

Of course, it only works for bikes which spend their lives in dry conditions when not being ridden.

 

[fossyant]

My Ribble has cut outs - it's drainage, although I haven't got any frames which leak...plenty of grease on the seat tube sorts that....

 

[itisaboutthebike]

It is to allow a steel frame to "breathe" - i.e. to dry out if water gets inside - so that it does not rust.

Er no they weren't..........frames used to have a small drainage hoel in the bottom for that.

Like I said the logitudinal cutouts (on steel BB's) were to save weight, there weren't for drainage.

 

[NickM]

Like I said the logitudinal cutouts (on steel BB's) were to save weight...

Fine by me if you choose to believe that...

 

[spandex]

But who is going to look under the bottom bracket ?

And won't it cause the bottom bracket to deteriorate faster ?

That's not the point you know it is there there is a web site called little fish bicycles but it seams to be down at the moment they do some really cool cut outs. As for doing in the BB the thing to do is to just give the shell a thin coat of grease so if and when it needs to come out you can read all the info on it.

 

[itisaboutthebike]

Fine by me if you choose to believe that...

So why would you have 3 or 4 cut-outs when 1 drain hole would be enough ?

So drilling the droputs (as was also done on 753 frames) was for drainage ?

 

[NickM]

You reckon a Cinelli spoiler bottom bracket shell is lighter than a plain one, then?

Drilling the dropouts was done for stupidity's sake, like lots of things in the cycling world. PMP cranks, anybody?

 

[itisaboutthebike]

You reckon a Cinelli spoiler bottom bracket shell is lighter than a plain one, then? Drilling the dropouts was done for stupidity's sake, like lots of things in the cycling world. PMP cranks, anybody?

First point - no. (although I'll check my Geoff Butler 753 in the garage which has a spoiler BB).

Second point - whilst in hindsight, some of the things are pretty stupid, but back in the late 70's when 753 had just been released, trying to save weight was becmoing obseeive, even in pro teams. Cut-out BB's and droputs were just some of the menthods empoyed. Raleigh even deveopled a new(lighter) paint formulation for it's 753 frames for the TI-raliegh squad.
I