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Technical & Reference Section => Tech and Restoration => Topic started by: BENDYCAT ELEVENTEEN on October 28, 2013, 02:43 PM

Title: bearings, cups and sizes - needing some help !
Post by: BENDYCAT ELEVENTEEN on October 28, 2013, 02:43 PM
Right just doing up some bearing cups for my redline cranks
I think these came from a late 80's/90's set

cups are slight dome and have the redline decals (half over style) each side on the face of the cups

the bearing that are in there at the mo are gone - but they are 6904 DU

I'm trying to clean them up and polish the cups and stick them with a new set of '09 redline 180 cranks

the Old axle and the new axle are finding it difficult to go into the old bearing just to check it, as it's fricking tight  ???

my question is - can some one help me find some new bearing for the old cups that will fit - as I have seen some 6904 but they have a different code at the end of the number ? is this a different diameter on the inside ?

please can any one help ?

cheers B  :angel:
Title: Re: bearings, cups and sizes - needing some help !
Post by: Oldboyburner on October 28, 2013, 07:00 PM
Ge in touch with retrorich78 his mate makes bearings billy
Title: Re: bearings, cups and sizes - needing some help !
Post by: BENDYCAT ELEVENTEEN on October 28, 2013, 09:08 PM
Right think I have worked it out  :crazy2:

6904 is 20x37x9mm

which means that I need shims like the one's already stuck in one bearing and the other is well stuck on the axle  :2gunsfiring_v1:

so please does any one have the two little shims that sit inside of the bearing to fill out on the 19mm axle - please  :angel:
Title: Re: bearings, cups and sizes - needing some help !
Post by: BENDYCAT ELEVENTEEN on October 29, 2013, 12:13 AM
(http://www.radbmx.co.uk/archive/albums/tt183/ELEVENTEENBENDYCAT/BMX%20Parts/1adb2e5e-dbcf-4871-803d-775768b0de2c_zps6ee29ab7.jpg) (http://s610.photobucket.com/user/ELEVENTEENBENDYCAT/media/BMX%20Parts/1adb2e5e-dbcf-4871-803d-775768b0de2c_zps6ee29ab7.jpg.html)
Title: Re: bearings, cups and sizes - needing some help !
Post by: rodriguez on October 29, 2013, 01:07 AM
(http://i692.photobucket.com/albums/vv281/rodgy1970/spanishbearings_zpsa71061ed.jpg) (http://s692.photobucket.com/user/rodgy1970/media/spanishbearings_zpsa71061ed.jpg.html)

There's no sign of those shims on the redline site

http://www.redlinebicycles.com/components/bottom-brackets

This might be a cheap way to go if you can't find any

http://www.ebay.co.uk/itm/BMX-Bottom-Bracket-Counterfitt-Spanish-BB-19MM-Black-/400570674600?pt=UK_sportsleisure_cycling_bikeparts_SR&hash=item5d43df6da8
Title: Re: bearings, cups and sizes - needing some help !
Post by: BENDYCAT ELEVENTEEN on October 29, 2013, 09:07 AM
I think that the bearing in that set are going to be the same - 6904 is a certain size ?
Title: Re: bearings, cups and sizes - needing some help !
Post by: Dannywhac on October 29, 2013, 09:14 AM
Why not welly out the bearings that are in the cups, measure the outside diameter and thickness of the bearings and measure the diameter of your axle, then buy the corresponding bearing on eBay ans slap them in the cups - way easier than trying to find them there shims.
Title: Re: bearings, cups and sizes - needing some help !
Post by: fischflo on October 29, 2013, 10:06 AM
I think that the bearing in that set are going to be the same - 6904 is a certain size ?

i think rods ebay thingy shud work - its 37mm bearing (like yours) and for 19mm axle (like yours), it has corresponding spacer

only thing maybe thickness of the bearing....... 6904RS seems to be 9mm

qustion is: what is yours?  :daumenhoch:

if same .......id risk it :D

oh, and the RS or DU refers to the sort of sealing i think; think rs means rubber sealing on 1 side...
Title: Re: bearings, cups and sizes - needing some help !
Post by: rodriguez on October 29, 2013, 12:10 PM
I think that the bearing in that set are going to be the same - 6904 is a certain size ?

i think rods ebay thingy shud work - its 37mm bearing (like yours) and for 19mm axle (like yours), it has corresponding spacer

only thing maybe thickness of the bearing....... 6904RS seems to be 9mm

qustion is: what is yours?  :daumenhoch:

if same .......id risk it :D

6904rs seems to be the standard size.

http://www.bmx-forum.com/t/124658/guide-bearing-codes

If you get a bearing with a 19mm ID you won't be able to get the axle into it, the ID would need to be 19.5mm for the axle to slide in.

Has anyone else ever come across those shims for a redline axle?
Title: Re: bearings, cups and sizes - needing some help !
Post by: fischflo on October 29, 2013, 01:17 PM
dunno if you can backorder this or if its close enough
http://www.customriders.com/prodshow.asp?prodid=5118&cat=10&parent=1001&sid=3

511810837    3/4" aprox 19.05mm

call em on the telephone 01462 650740                tip by our very own 'bof' :-* gibbem a ring
Title: Re: bearings, cups and sizes - needing some help !
Post by: BENDYCAT ELEVENTEEN on October 29, 2013, 10:40 PM
bearing cup is 37mm and it's 9mm deep

the trouble comes when I slide the 19mm axle into a 20mm hole bearing ? it rattles  "bump"


when looking at all the 6904 bearings they are 37x9x20mm - so it gains 1mm  ???

hence needing the shins that cam with the 90's redline crank that I have but can not get off  :2gunsfiring_v1: - yer good luck on that   one  ::)

so what size are the insides of the new redline bearings then - do they rattle or will a new set just fit right away - prob not as I just thought of that the bear cup will be a different size to what I have - but what size is the hole ?


any ideas peeps  ???
Title: Re: bearings, cups and sizes - needing some help !
Post by: john4130 on October 29, 2013, 11:09 PM
can't you use a bit of heat to get the old shims off? or a big fookin hammer.  ;)
Title: Re: bearings, cups and sizes - needing some help !
Post by: BENDYCAT ELEVENTEEN on October 29, 2013, 11:20 PM
gonna try, but they look well and truly stuck  :surprise:

what size is bearing the new redline BB they do on ebay ?
Title: Re: bearings, cups and sizes - needing some help !
Post by: fischflo on October 30, 2013, 01:22 AM
the set rod suggested (10quid) already contains the right bearing AND the right shim to fit a 19mm axle like yours
Whats wrong with that?

b) that shop i suggested may have the shims themselves (3,5gbp) ---- to spare you a few quid in comparison to the (complete)set rod posted a link to ::). i'd just ask if they will fit a redline 19mm axle, and if they still have a set lying around. Personally id go with the ebay set

and: Your lbs might have those shims, too ;)

Title: Re: bearings, cups and sizes - needing some help !
Post by: BENDYCAT ELEVENTEEN on October 30, 2013, 01:40 AM
yer gonna have a look at the one's Rod put up - also Gary posted with a link with some shims

 :crazy2: starting to fry my brain looking at bearings  :D :uglystupid2: ;D
Title: Re: bearings, cups and sizes - needing some help !
Post by: fischflo on October 30, 2013, 02:31 AM
same here :crazy2: - i just looked at this:
http://www.ebay.com/itm/REDLINE-BICYCLES-SPANISH-BOTTOM-BRACKET-19MM-BICYCLE-CRANK-BEARING-KIT-/321094435583?pt=Cycling_Parts_Accessories&hash=item4ac2b842ff

and looking at the bearings it reads: r12-2rs i think .... and that would be 19mmx41.275mmx11.1mm  :wtf:

so now its even different spanish bb ....? :crazy2:

and : isn't yours an AMERICAN BB (=Pro size) anyway? .....as it has cups?!?

back to the drawing board: ,,, here the diffferent kinds of bb ->http://www.danscomp.com/serve/products|charts/bearingchart.htm

>>>>>>>>>>>BUT. you initially said you need a 6904 bearing (= 20x37x9mm), and rods set had bearing with those dimensions, right .......aaaaa .....aaa ... eh hehe :crazy2:

Title: Re: bearings, cups and sizes - needing some help !
Post by: BENDYCAT ELEVENTEEN on November 03, 2013, 07:32 PM
Just want the say a BIG THANKS to Rod  :daumenhoch: for finding me a link and posting up the spec on the bearings
I pressed them in and they fitted like a treat -the inside in nice and smooth on the axle

job sorted and all is cool

cheers B  :4_17_5:


These are the cup from a 80's /90 redline set - polished due to a little wear
(http://i610.photobucket.com/albums/tt183/ELEVENTEENBENDYCAT/4F09B912-1485-4337-B5EA-8D7929F593EA-1881-000001F525492BE3_zpsaac0fa71.jpg) (http://s610.photobucket.com/user/ELEVENTEENBENDYCAT/media/4F09B912-1485-4337-B5EA-8D7929F593EA-1881-000001F525492BE3_zpsaac0fa71.jpg.html)
Title: Re: bearings, cups and sizes - needing some help !
Post by: adenough on November 03, 2013, 08:05 PM
just what im looking for...

(http://i1336.photobucket.com/albums/o654/adenough72/DSC00850_zps4e109416.jpg) (http://s1336.photobucket.com/user/adenough72/media/DSC00850_zps4e109416.jpg.html)
Title: Re: bearings, cups and sizes - needing some help !
Post by: garran on November 03, 2013, 08:08 PM
dont know if this is of any help, i bought a bb set for my flights, it has grooved inserts on the bearings to fit the profile of the spindle,not sure of the year still have the box which says "flight group sealed bottom bracket" think it was late 80s/early 90s

(http://www.radbmx.co.uk/archive/albums/z203/garran01/KGrHqZHJEsFBkf5hFSVBQljl8KlJQ60_12_zps0f501e9c.jpg) (http://s193.photobucket.com/user/garran01/media/KGrHqZHJEsFBkf5hFSVBQljl8KlJQ60_12_zps0f501e9c.jpg.html)

ps i dont have them anymore(sold on my complete big daddy for £200, i know i've told you all before, still gutted and have nightmares!!)
Title: Re: bearings, cups and sizes - needing some help !
Post by: rodriguez on November 03, 2013, 08:13 PM
Just want the say a BIG THANKS to Rod  :daumenhoch: for finding me a link and posting up the spec on the bearings
I pressed them in and they fitted like a treat -the inside in nice and smooth on the axle

job sorted and all is cool

cheers B  :4_17_5:


These are the cup from a 80's /90 redline set - polished due to a little wear
(http://i610.photobucket.com/albums/tt183/ELEVENTEENBENDYCAT/4F09B912-1485-4337-B5EA-8D7929F593EA-1881-000001F525492BE3_zpsaac0fa71.jpg) (http://s610.photobucket.com/user/ELEVENTEENBENDYCAT/media/4F09B912-1485-4337-B5EA-8D7929F593EA-1881-000001F525492BE3_zpsaac0fa71.jpg.html)

Cheers Bendy glad to help   :daumenhoch:
Title: Re: bearings, cups and sizes - needing some help !
Post by: adenough on November 03, 2013, 10:02 PM
Cheers Bendy for the post & Rod for the link..sorted!  :daumenhoch:
Title: Re: bearings, cups and sizes - needing some help !
Post by: BENDYCAT ELEVENTEEN on November 03, 2013, 10:22 PM
 :daumenhoch:
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