Retrobike Forum Index

It is currently Sat Dec 03, 2016 4:46 pm

* Login   * Register * Search  * FAQ



Post new topic Reply to topic  [ 22 posts ]  Go to page Previous  1, 2, 3  Next
Author Message
PostPosted: Sun Oct 20, 2013 10:05 pm 
Retro Guru
User avatar

Joined: Sun Mar 17, 2013 10:25 pm
Posts: 1262
Italian shells are larger diameter, all other size cups fall right through, the threads will not engage.

Italian and some high-end French bikes use Italian BBs which are prone to problems due to the right-threaded fixed cup, which tends to unscrew itself in use.

Might be worth using some thread lock when fitting the cups


Top
 Profile  
 
PostPosted: Sun Oct 20, 2013 10:12 pm 
Retro Guru
User avatar

Joined: Sun Jul 25, 2010 12:22 pm
Posts: 1994
Location: North Ayrshire
casper2788 wrote:
rusty bodie wrote:
i bought one of these frames in 1988 and the post was 25.0mm and the bb was british thread. how weird your cups slide in. if memory serves me correctly, your frame must have italian bb threads.

The one i have taken out from my other frame which is an SLX is a dura ace 7400 1,37 x 24t axle 110mm even if italian thread on the TVT why would the cups slide in and out.


now you're testing the old grey matter! as i remember it, italian thread bb shells were a slightly larger diameter and i can remember trying to fit a british bb to an italian bb shell and the event you described was the result = the british bb unit is a narrower diameter than the italian one.

IF i remember correctly, that is!

:?


Top
 Profile  
 
PostPosted: Sun Oct 20, 2013 10:21 pm 
Dirt Disciple
User avatar

Joined: Sat Jun 30, 2012 3:18 pm
Posts: 98
Location: alfreton
47p2 wrote:
Italian shells are larger diameter, all other size cups fall right through, the threads will not engage.

Italian and some high-end French bikes use Italian BBs which are prone to problems due to the right-threaded fixed cup, which tends to unscrew itself in use.

Might be worth using some thread lock when fitting the cups

Just been reading about the cup unscrewing,good idea to use some thread lock something i'm not short of being a plumber.


Top
 Profile  
 
PostPosted: Mon Oct 21, 2013 9:32 am 
Retro Guru

Joined: Sun Aug 22, 2010 7:07 pm
Posts: 1321
Location: Cotswolds
The old Italian bottom bracket thread was 36mm x 24 tpi, both right hand thread. 24 TPI was used on many continental bike threads, I always thought this was because the original machine tools were from Birmingham and Coventry. Another Imperial standard is chain pitch.


Top
 Profile  
 
PostPosted: Mon Oct 21, 2013 6:48 pm 
Dirt Disciple
User avatar

Joined: Sat Jun 30, 2012 3:18 pm
Posts: 98
Location: alfreton
Thanks guys,so a 70mm italian thread it is but could anyone know what the ideal axle length i will need,the chainset is Dura ace 7402 double ring.


Top
 Profile  
 
PostPosted: Mon Oct 21, 2013 6:50 pm 
Retro Guru
User avatar

Joined: Sun Mar 17, 2013 10:25 pm
Posts: 1262
I'm going to say 113mm but I could be wrong


Top
 Profile  
 
PostPosted: Mon Oct 21, 2013 6:52 pm 
Dirt Disciple
User avatar

Joined: Sat Jun 30, 2012 3:18 pm
Posts: 98
Location: alfreton
47p2 wrote:
I'm going to say 113mm but I could be wrong

You may be right,just been on sheldon's web page and if i'm reading it right amongst all the figures 113 it could be,thanks


Top
 Profile  
 
PostPosted: Wed Oct 23, 2013 10:23 pm 
Retro Guru
User avatar

Joined: Sun Jul 25, 2010 12:22 pm
Posts: 1994
Location: North Ayrshire
got one sitting here - dura ace 7400 italian bb axle measuring 112mm end to end and 49mm between the collars.


Top
 Profile  
 
PostPosted: Wed Oct 23, 2013 10:43 pm 
Dirt Disciple
User avatar

Joined: Sat Jun 30, 2012 3:18 pm
Posts: 98
Location: alfreton
rusty bodie wrote:
got one sitting here - dura ace 7400 italian bb axle measuring 112mm end to end and 49mm between the collars.

Thanks but i decided just to get a shimano UN55 70/113 just lacking a seat post now though,i don't rate me chances of getting one,i won't be riding it anytime yet.


Top
 Profile  
 
PostPosted: Fri Oct 25, 2013 11:04 pm 
Dirt Disciple
User avatar

Joined: Sat Jun 30, 2012 3:18 pm
Posts: 98
Location: alfreton
originalshinkicker wrote:
casper2788 wrote:
Thought i would spend some time today swapping over my Dura ace 7402 groupset on to a Recent TVT carbone purchase and was doing well until i found out the b/b is to small and the 27.2 seat post is to big.Would anyone oblige and inform me what size they need to be,thanks.


It's several years since I worked on a TVT but if memory serves me well, seatpin size is same as Vitus/Alan, so may be 25.0mm

Which bit of the BB is too small. I recall the BB being British threaded but just can't remember exactly. What is the width of the shell you have, 68 or 70mm?

Neil

With your experiance with the TVT what would the grub screw be for behind the seat post lug when it has a bolt through anyway.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 22 posts ]  Go to page Previous  1, 2, 3  Next

All times are UTC [ DST ]


Who is online

Users browsing this forum: No registered users and 26 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  

About Us

Follow Retrobike

Other cool stuff

All content © 2005-2015 Retrobike unless otherwise stated.
Cookies Policy.
bikedeals - the best bike deals in one place
FatCOGS - Fat Chance Owner's Group

Powered by phpBB® Forum Software © phpBB Group