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Technical & Reference Section => Tech and Restoration => Topic started by: laidback on October 18, 2013, 01:07 PM

Title: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: laidback on October 18, 2013, 01:07 PM
Hi guys,

Well the list of things to fix is growing! I've recently acquired a nice set of Tuff 2's, however the front alloy hub is ever so slightly pushed in on one side, from overtightening the bearing cups.

I've read threads about fixing these, however have not found a definitive answer/method to fix them. Can anyone help?

Here's the hub in question:

(http://www.radbmx.co.uk/archive/albums/o114/lowback/IMG_2406_zps83646535.jpg) (http://s118.photobucket.com/user/lowback/media/IMG_2406_zps83646535.jpg.html)

I have also dismantled the rear suntour coaster, as it was
Stiff and full of crap, and have discovered that the bearing cup on the 'arm' side is heavily pitted. The wheel won't run smooth like this, so am just wondering what my options are to fix it? Replacements are hard to come
By from what I've seen...
(http://www.radbmx.co.uk/archive/albums/o114/lowback/Mobile%20Uploads/image_zps087cebe5.jpg) (http://s118.photobucket.com/user/lowback/media/Mobile%20Uploads/image_zps087cebe5.jpg.html)


Any advice/links to threads etc appreciated!

Cheers.:)
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: Rabdul06 on October 18, 2013, 02:14 PM
   Front hub - Unfortunately you are going to have to drill out the rivets and remove the hub. You can then either straighten the flange and replace with some bolts, or use a Skyway hub replacement kit, which pop up from time to time on eBay, here, Museum etc. I have a replacement kit on my rear Tuff and its fine. I wouldnt try pulling the flange out though.

  Rear hub - You could find an old cracked/beaten tuff and remove the coaster parts  or replace it with an Un-Brake type conversion kit.  Sorry I dont know too much about these so maybe someone else can chime in.....

   If all else fails chuck them in the fridge - Historic BMX rumors show that this not only straightens Tuffs out but also de-pits bearing surfaces and pulls out hubs.........apparently  ::)

  Good luck fella.
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: Julian347 on October 18, 2013, 02:27 PM
I think there's a thread somewhere on here about pulling out bent flanges  :daumenhoch:
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: sawzall on October 18, 2013, 05:00 PM
i made a tool up to pull out crushed hubs so they can be done without removing hubs :daumenhoch:
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: laidback on October 18, 2013, 05:17 PM
i made a tool up to pull out crushed hubs so they can be done without removing hubs :daumenhoch:

That's just what I wanted to hear sawzall! Have you any info on how it is made? Would you lend it out? Pm me if you like: :daumenhoch:
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: Oldboyburner on October 20, 2013, 09:42 AM
I use a press at work to push flange on skyway out
Works a treat
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: Sid1972 on October 20, 2013, 10:20 AM
I have done them with a small copper drive, through the spindle hole just to tap them back out.

Worked a treat.  ;)
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: Bfellows on October 20, 2013, 10:37 AM
I'm going to have a random front black tuff in the very near future with nice and straight hubs!  Going to be a couple of weeks as i'm off on my hols in a couple of days.  Let me know if you're interested and i'll sort you something out when I get back  :daumenhoch:

See here http://www.radbmx.co.uk/forum/index.php/topic,167222.msg1672983.html#msg1672983

and here http://www.radbmx.co.uk/forum/index.php/topic,167012.msg1670386.html#msg1670386

and you'll see why.........  ;)
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: laidback on October 20, 2013, 10:53 AM
Thanks for the replys!

Sid- im trying to get my head around how to do this, by doing what you suggest,  wouldnt it push the other side in as you're hitting it? I don't have access to a press, but ideally need something to push them all out from the centre so they are even. Can you let me know how you did it in a bit more detail...Fuzzy sunday morning head !:crazy2:

Bfellows- I already have an orphan alloy hubbed front tuff, but it has the skyway lettering on the braking surface, so won't make an exact pair..If the price is good i may be interested, but i'm getting slightly overwhelmed with wheels at the minute, keep me posted :daumenhoch:
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: Bfellows on October 20, 2013, 11:03 AM
I feel your pain.......

(http://www.radbmx.co.uk/archive/albums/ae142/brettfellows/image1_zps0862e313.jpeg) (http://s966.photobucket.com/user/brettfellows/media/image1_zps0862e313.jpeg.html)

If you do decide to drill out I have a spare alloy hub as well  :daumenhoch:  I'm sure we can do swapsies or something......
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: gary4130 on October 20, 2013, 12:40 PM
any of those tuffs for sale mate? got a coaster hub -just need the tuff to bolt it to  ;)
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: laidback on October 20, 2013, 02:16 PM
Still trying to get my head around making some kind of puller for the hub.  I notice inside the hub is a plastic sleeve that the axle passes through. am i going to damage the hub if i move this around to get better access to the back of the flange? not too clued up with how these hubs are made up. Is it just two flanges riveted through the body of the wheel, and the sleeve places in the middle?

Also, can you tap the bearing race out from the back of the flange, or am i likely to damage the hub this way?
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: Sid1972 on October 20, 2013, 02:22 PM
Remove the spindle and bearing cups (tap these out from the inside) then u need a copper drive not much fatter than a screw driver, put this through the spindle hole so your placing it against the cupped hub on the inside and hit it with a mallet. You need to keep working round the hub in circles and keep checking the outer edge with a square or level.

This with marked the inside of the hub but you cannot see anything when built. If both sides are cupped turn it over to repeat the process.  ;)
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: laidback on October 20, 2013, 04:35 PM
Thanks Sid!

Hub stripped down, I pushed the plastic tube out the way. I'm using a small cold chisel, which is knackered.  Taped up the flat end (the bit you strike with hammer) to soften it and avoid unnecessary damage to the inside of the flange. As it's old and knackered, i'm using the flat end against the flange.  It's taking a while, but i'm nearly there.  Looks pretty good by eye.  I'll get a small spirit level on it later and post up the results :daumenhoch:
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: Sid1972 on October 20, 2013, 04:46 PM
Told u mate, easy....  ;)
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: laidback on October 20, 2013, 06:48 PM
All done. Cleaned and put back together. Spins smoothly and is nice and true. Job done!

The only slight issue is that one of the bearing cups wouldn't go in flush with the hub and is proud by a couple of mm.  It wouldn't go in any further, and i didn't want to whack it harder and  risk crushing the hub again :uglystupid2:

Results:

Before:(http://www.radbmx.co.uk/archive/albums/o114/lowback/IMG_2406_zps83646535.jpg) (http://s118.photobucket.com/user/lowback/media/IMG_2406_zps83646535.jpg.html)

After:(http://www.radbmx.co.uk/archive/albums/o114/lowback/IMG_2503_zps894f5a46.jpg)[/URL

Cleaned and assembled:[URL=http://s118.photobucket.com/user/lowback/media/IMG_2504_zps53fb25bd.jpg.html](http://www.radbmx.co.uk/archive/albums/o114/lowback/IMG_2504_zps53fb25bd.jpg) (http://s118.photobucket.com/user/lowback/media/IMG_2503_zps894f5a46.jpg.html)

It's not perfect, but its as good as i think i'll get it. :)
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: Sid1972 on October 20, 2013, 07:08 PM
Good job, I would be tempted to keep going. As for the bearing cup, flat piece of wood over it and knock it back in. U will not dish it back in, trust me.  :daumenhoch:
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: kang on October 21, 2013, 10:30 AM
Hi laidback, if your coaster is the 4 shoe variety I'm pretty sure I have a decent replacement part somewhere, though not going to be able to get to it until the weekend. If you don't mind hanging on till then you're more than welcome to have it
 :daumenhoch:
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: laidback on October 21, 2013, 11:11 AM
Kang, you are a star, you've cheered me up on a miserable Monday morning! Yes it's a four shoe brake. I'll send you a PM :daumenhoch:
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: Rabdul06 on October 21, 2013, 07:16 PM

   Good to know! Guess Im full of sh1te..... :-[

   Figured the hub would have cracked but I guess the flanges arent as tough as I thought they were. Good job.
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: laidback on October 22, 2013, 10:09 AM
Thanks for the heads-up TFI, i'll have a look  :)
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: laidback on November 10, 2013, 10:49 PM
Well., I've managed to do a load of little jobs on the bike/bits this weekend, including finishing the resto on my Tuff 2's.

As you know, i straightened the hub on the front a couple of weeks ago, and have been slowly rebuilding the rear after stripping and cleaning/replacing worn out parts of the coaster brake (thanks Kang). It's a bit of a ball ache, but once you get your head around it, they're not too bad.  Lots of grease is your friend (so i've read).

The front (apart from the pushed in hub) wasn't too bad, but the rear had been previously painted blue (which had been partially cleaned off prior to me taking delivery of them) so i had to remove the paint/clean it all and rebuild it.

Here's how they were:
(http://www.radbmx.co.uk/archive/albums/o114/lowback/Mobile%20Uploads/image_zpsb79b97e1.jpg) (http://s118.photobucket.com/user/lowback/media/Mobile%20Uploads/image_zpsb79b97e1.jpg.html)

On taking delivery:
(http://www.radbmx.co.uk/archive/albums/o114/lowback/Mobile%20Uploads/image_zps725a3fb1.jpg) (http://s118.photobucket.com/user/lowback/media/Mobile%20Uploads/image_zps725a3fb1.jpg.html)
(http://www.radbmx.co.uk/archive/albums/o114/lowback/Mobile%20Uploads/image_zps8786dd81.jpg) (http://s118.photobucket.com/user/lowback/media/Mobile%20Uploads/image_zps8786dd81.jpg.html)

And how they finished up:
(http://www.radbmx.co.uk/archive/albums/o114/lowback/Mobile%20Uploads/image_zpse8375a7c.jpg) (http://s118.photobucket.com/user/lowback/media/Mobile%20Uploads/image_zpse8375a7c.jpg.html)
(http://www.radbmx.co.uk/archive/albums/o114/lowback/Mobile%20Uploads/image_zps558e2506.jpg) (http://s118.photobucket.com/user/lowback/media/Mobile%20Uploads/image_zps558e2506.jpg.html)
(http://www.radbmx.co.uk/archive/albums/o114/lowback/Mobile%20Uploads/image_zpsb1490163.jpg) (http://s118.photobucket.com/user/lowback/media/Mobile%20Uploads/image_zpsb1490163.jpg.html)

Quite pleased with the result  :)

Quick question for those who know about coasters: I noticed (before i stripped the coaster down, and after rebuild) that it didn't spin as freely as a non coaster brake, and it feels like there is a tiny bit of resistance.  Is this normal for coasters? I'm guessing it's because the hub is packed with components and grease.  I haven't overtightened the bearings and they are as loose as i could get them without the axle being wobbly.

Cheers,

Paul.
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: Bfellows on November 10, 2013, 10:55 PM
Nice work fella  :daumenhoch: what did you use to strip the blue paint?
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: laidback on November 10, 2013, 11:04 PM
Luckily most of it came off with soap and water, and the more stubborn bits i used thinners and a rag. Not sure if this is the best method, but it worked for me :daumenhoch:
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: dordymush on November 10, 2013, 11:59 PM
glad you never mirror polished the hubs.
pet hate of mine that  :yahoo_silent:
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: kang on November 14, 2013, 09:21 PM
Nice  8)
From what you've said, the coaster sounds fine to me. Take them for a spin to let things settle in, anything ominous should come to light then as well.  :daumenhoch:
Title: Re: Straightening pushed in alloy skyway hub/rebuilding suntour coaster brake
Post by: Sid1972 on November 17, 2013, 07:36 PM
They look awesome and so much better then bolting the alloy hubs on. Amazing what a knockomiter with do.  ;)
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