RADBMX.CO.UK
Technical & Reference Section => Tech and Restoration => Topic started by: ED209 on September 06, 2013, 06:47 PM
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Heres one for all those who scooped a bargain Boa @ MK :daumenhoch:
ACS Boa 10mm to 6mm spindle swap
Important - before you start! make sure you work over a cloth / blanket as 68 tiny ball bearings will fall out as you take the brake apart!!!
Here we go ...
- Remove the front 'sealed mech' cap with your fingers. If the tiny threaded bit the cap screws onto stays in the brake and you need it out theres a tiny allen key head on the end of it to unscrew it with.
(http://www.radbmx.co.uk/archive/albums/i63/209ed/IMG_2497_zpsded99a9e.jpg) (http://s69.photobucket.com/user/209ed/media/IMG_2497_zpsded99a9e.jpg.html)
- Unscrew the mounting nuts and rear spring holder.
- Hold the front of the spindle with a spanner whilst slotting a small allen key into the holes in the rear lock nut and unscrew ( theres no allen head in those holes ... you just use it as a lever ) - REMEMBER to do this SLOWLY and over the cloth / blanket as all the ball bearings in the brake will fall out as it becomes loose.
(http://www.radbmx.co.uk/archive/albums/i63/209ed/IMG_2498_zps20f2865f.jpg) (http://s69.photobucket.com/user/209ed/media/IMG_2498_zps20f2865f.jpg.html)
- As you carefully remove the arms from the spindle REMEMBER the direction of the seals and the order that they are mounted in. All the seals can be re used in the spindle swap.
(http://www.radbmx.co.uk/archive/albums/i63/209ed/IMG_2499_zps2a21bf10.jpg) (http://s69.photobucket.com/user/209ed/media/IMG_2499_zps2a21bf10.jpg.html)
( I wanted to strip the arms on my brake so I popped them in a bit a Synstrip and gave them a light polish )
(http://www.radbmx.co.uk/archive/albums/i63/209ed/IMG_2501_zps5ed6a01d.jpg) (http://s69.photobucket.com/user/209ed/media/IMG_2501_zps5ed6a01d.jpg.html)
(http://www.radbmx.co.uk/archive/albums/i63/209ed/IMG_2502_zpsdf9c559c.jpg) (http://s69.photobucket.com/user/209ed/media/IMG_2502_zpsdf9c559c.jpg.html)
- Divide the bearings into 4 piles of 17. If the bearing races have dropped out of the brake arms use a blob of grease to stick them in again.
- Using a good amount of grease place the bearings back into the races on each side of each brake arm ... if you have a greasy finger this is useful for picking the bearings up. Get them roughly in position then use the small allen key again to position them... smooth the grease over to finish. This is fiddly but not as bad as it seems :-)
(http://www.radbmx.co.uk/archive/albums/i63/209ed/IMG_2503_zps9593760d.jpg) (http://s69.photobucket.com/user/209ed/media/IMG_2503_zps9593760d.jpg.html)
- Once you have done this for both sides of the brake CAREFULLY remount the new spindle getting the seals in the right position and right way round. Do the final tightening GENTLY as the bearings can easy pop out or you can mash the seals ... slow and steady :-)
(http://www.radbmx.co.uk/archive/albums/i63/209ed/IMG_2504_zps36a2c2ed.jpg) (http://s69.photobucket.com/user/209ed/media/IMG_2504_zps36a2c2ed.jpg.html)
(http://www.radbmx.co.uk/archive/albums/i63/209ed/IMG_2505_zps1efc0273.jpg) (http://s69.photobucket.com/user/209ed/media/IMG_2505_zps1efc0273.jpg.html)
- Tighten everything up and again screw the spring mount back in.
(http://www.radbmx.co.uk/archive/albums/i63/209ed/IMG_2507_zps80790787.jpg) (http://s69.photobucket.com/user/209ed/media/IMG_2507_zps80790787.jpg.html)
- Polish up to clean up any remains of the grease.
(http://www.radbmx.co.uk/archive/albums/i63/209ed/IMG_2506_zps250b833f.jpg) (http://s69.photobucket.com/user/209ed/media/IMG_2506_zps250b833f.jpg.html)
Job done :-)
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ask costa
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lots of grease,they try to fall out not hard just tricky.done loads
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lots of grease,they try to fall out not hard just tricky.done loads
x2
If it's a used one, don't start to take it apart until you've got it over a bowl - them bearings shit everywhere if they're not greased. When you undo the retainer nut on the back, push the front of the axle (holding the arms in your fingers) so bearings that fall out will only come out from the bit of the brake at the rear, and from where you want them to :)
That and curse as you realise the placcy bearing seals are fooked. They'll still go back together though. Built to last them Boas :LolLolLolLol:
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its a new one Dannsta.
How do you get the retaining nut off the back? ... the one with the holes drilled in it?
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Thats the fella - I've always used (after unscrewing the placcy front bit) a set of mole-grips on the front nut, then use either a small allan key/jewellers screwdriver in the holes on the back nut (failing that another mole-grip) on the rear nut. Basically hold the front of the Boa in place and unthread the rear nut :daumenhoch:
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Its not too bad a job to be fair Ed, I did it to a boa that I bought off Olly.
One thing I will add though in addition to the bearings going everywhere.....i think there are 68 bearings in a boalol, is to remember which way the seals go round on top of the bearings.
I made the mistake of getting it all back together, tightening it up only to watch the seals buckle and the bearings tried to exit from all angles lol.
Be on guard.....and keep your cool.....2 very important factors for the job lol
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Another tip is don't attempt is while looking after an 18 month old, it needs full concentration first time round "nono"
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Another tip is don't attempt is while looking after an 18 month old, it needs full concentration first time round "nono"
Very good point! Lol
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thank you one and all ... off now to tinker :daumenhoch:
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thank you one and all ... off now to tinker :daumenhoch:
you done it yet ???
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Stripped it down.
Stripped the paint off the calipers and gave them a light polish.
Waiting for the new spindle off Costa!
Full photo story to follow.
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I was going to get one with 10mm spindal and drill my forks is that a bad idea....??
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I would try and do the conversion before you start drilling mate, its pretty final once youve drilled
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is it still possible to run a cable down for potts if i do drill them...
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Hmmm I think it would be too tight to be honest. Its tight enough with a 6mm ;D
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is it still possible to run a cable down for potts if i do drill them...
Depends on the forks. My Bashy sport worked fine with fat axle, but I image some forks might struggle.
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All done :angel: How-to uploaded :daumenhoch:
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Nice work Ed. Done a few myself and its not the most fun Ive ever had. :LolLolLolLol:
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good work ed
you can pump my air bed up anyday big boy.
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Great little thread there Ed! Top work mate :daumenhoch:
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good work ed
you can pump my air bed up anyday big boy.
mmmmmm yes please Dan :bow:
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Nice thread :daumenhoch:
Now make it sticky with your fat greasy finger ;)
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Nice thread :daumenhoch:
Now make it sticky with your fat greasy finger ;)
Ed had other plans for his greasy finger
:surprise:
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Wadz's boa bearings are all over the floor at T1 :LolLolLolLol: boing! :LolLolLolLol:
ed's been on his sticky fingers for ages, just run away when he says "ere sniff this "
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Dose anyone still sell the swap kits?
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Dose anyone still sell the swap kits?
Steve Costa used to have them but he seems to have disappeared!
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i'm sure i heard something about drilling out 5p pieces and using them instead of the bearings back in the 90's. may have been rob ridge before he got sealed bearings for them and offered upgrades for riders.
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I know this is a old thread..
Has anyone a link to obtain the convertion kit.
Have emailed a guy from Germany who sold loads on ebay and just replied got none left..
Cheers all..
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Has anyone got Any of the 10mm to 6mm kits available for sale
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Has anyone got Any of the 10mm to 6mm kits available for sale
Have you seen this thread in the For Sale section?
http://www.radbmx.co.uk/forum/index.php/topic,192870.0.html (http://www.radbmx.co.uk/forum/index.php/topic,192870.0.html)
Get your name down for one :daumenhoch: