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How do you service a BMX? Part 1

Wire Brushed Raw Steel BMX Parts

Servicing a BMX, your step by step go to guide…

 

So your bikes rattling, and a bit stiff, suffered a bit outside and probably a little worse for wear, does it need servicing and some tlc… Have you got rusty Bolts too?
Simple to do you need a strip down and rebuild, it breath a new lease of life into your steed and give it back that sure footed feeling.

Start by giving it a good wash, it’s easier to work on a cleaner bike, even if the dirt looks thin and dry, it’ll shift quickly with a wash and look better once it’s done.

So, first things first, get busy pulling it apart…

Step-by-Step Strip Down

  • Check the seatpost moves, and adjust it a bit maybe to;
  • Pop it in the workstand…
  • Remove the pedals
  • Disconnect the brakes
  • Loosen the Rear Wheel for chain slackening
  • Remove the cranks and Bottom Bracket
  • Remove the wheels
  • Remove the Brake Cables, then pads, then remove the Brake Calipers
    (take care not to separate the springs from the arms, their asymetrical mix them up and your brakes won’t work, worse still you might break  your brakes…)
  • Remove the Handlebar Stem, and Handlebars together, catching the forks
    (watch out! strap a leg to the downtube with a zip-tie to save yourself some toes)
  • Separate the parts on the bars

You should now be left with an almost bare frame… Maybe headset bearing cups and B/B cups remain, the seatpost can come out last, and go back in first, as will any cups you will need to replace.

The Tools Required

So what tools will you need to get this far? Only a few;

  • 4mm, 5mm, 6mm, 8mm Allen Keys
  • 15mm or 17mm / 19mm Spanners
  • Large Adjustable and or Plate Spanner
  • A small screwdriver / pry lever
  • A Cross Head Screwdriver

Now you’ll need to clean all the grime and muck off it, you’ll be surprised where it’s got to… Good old soapy water isn’t a bad start, but there’s good alternatives and GT85 will gut through most grime and grease a lot quicker at this stage.

 

Inspecting the damage

Once you’ve got everything cleaned up, you’ll be wondering whats good and what’s worn out, it’s often obvious but if it’s not I’ll cover it all here.

Deep cleaning, and servicing requires some wire wool, and a wire brush for cleaning any stubborn corrosion.

This is the crown race that’s been abused, and this is the good one replacing it.

The bearing surface should be free from pitting and raised bumps, these will feel bad when your steer and may cause further issues as sudden wear can occur at this point.

Anything that can’t be removed with some wire wool will tell you how you’re doing, if the surface wear is extreme or uneven it’s time for a replacement part.

Acceptable level of wear will show now signs of pitting or degraded surfaces, they should show a polish when clean, you should notice a wear path but it should be free from damage.

If your bearings are at all discoloured, pitted, rusty etc… It’s time to change them too, the retaining cage as well if it’s not cleanable, you can remove it adding extra balls to account for the added room and further increasing the life of the cups.

 

Sealed headsets are a bit different, and will require new bearing sets. These are often one of a few standards so it’s always worth checking the spec properly, they’re often marked with a bearing code for ACB Bearings this is important as the wrong size will damage your frame.

 

 

Cleaning for Painting

 

Wire Brushed Raw Steel BMX Parts
Parts Prepared for painting Wire Brushed Raw Steel BMX Parts

 

 

 

 

 

 

 

 

 

 

 

Painting for Finish

You’ll need a clean dust free, still but ideally open warm air environment but lets be too idealistic about what we want and work with what we’ve got.

Finished & Painted Parts for a BMX Rebuild
Finished & Painted Parts for a BMX Rebuild
Painted Bolts in a Wooden holding block
Painted Bolts in a Wooden holding block

A clean & dust free space will mean your parts have a good finish, even and solid paint finish that will stand up to the fresh abuse it will likely receive.

Applying paint in thin layers working you way around in coats will mean a nice consistent glossy (or matt finish) with good coverage and no drips, focusing too much on coverage will mean overspray and drips… In worst cases it will mean nothing works!

Reassembly of Painted Parts

 

Starting with the Cups if they’ve ben removed, then crowns, the B/B, Headset and Forks are the first things to get installed and we’ll cover that in Part 2, that’s it for now folks…

 

 

 

 

 

 

 

 

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What are the Correct Replacement Bolts for mounting your Bicycle Kickstands? 3/8″ – 16 TPI BSW Whitworth

What are the Correct Replacement Bolts for mounting your Bicycle Kickstands? 3/8″ – 16 TPI BSW Whitworth

Replacement Bolts for mounting your Kickstands are most likely a 16G 3/8″ Whitworth 55 deg Thread with a nominal metric diameter of 9.525mm, so close enough to M10 x 1.5mm but not quite, you’ll probably have trouble getting it to start although it may bit a little it’ll jam if you really try it or just take off the first thread.

It’s the kind of bolt you want to do up nice and tight, often util the mounting plate flexes under the bolt head, around 20 N.m / 14-15 lbf.ft Torque

 

The Correct Bolt

3/8″ 16G Whitworth 55 deg, 2″ Long, HEX Bolt (14mm Spanner, not 9/16″) with a Full Thread, preferably BZP Bright Zinc Plated, or Stainless Steel

Major
diameter
Thread
pitch
Minor
diameter
75% tap
drill size
(in) (mm) (in−1) (mm) (in) (mm) (in) (mm)
3/8 9.525 16 1.588 0.2950 7.493 516 8.0
0.375 9.82 16.333 1.588 0.3212 8.16 2164 8.2

 

So where do you get one of these? It’s a rather obsolete, and unobtainable part as bolts go, it’s a hard find. It’s the kind of thing you’ll find in a large selection pack of bolts, if you’re lucky you’ll have one in with your M10 bolts or close to hand.

 

What if I can’t find the correct bolt?

What’s best to do if you can’t find this rather obsolete bolt, what if I can’t find the correct bolt? Well given it’s size that it’s very easy to tap if you’ve got a bolt and tap set, I’d recommend that.  It just so happens the hole size is a good fit for the ISO Metric M10 x 1.5mm Bolt Thread Tap being around 8.25mm ID it’s a fraction undersize, but use lots of cutting fluid and it’ll make a good thread. This doesn’t work if you’ve got a striped thread, or if ,maybe the hole on your Chainstay welded or brazed-on kickstand plate

There are of course taps & dies available if you’ve got a bolt with only a short section of thread, and you may find you can get away with a bolt 1/2″ shorter if you’ve got narrow gauge tubing as the 2″ tends to be a bit longer than required once fully installed, it does however make installation easier and slightly less fiddly having a 2″ bolt.

 

I’ve seen the topic covered on bike forums . net and after tapping a thread, then finding a couple of Full Thread 2″ x 3/8″ 16 BSW Bolts it made sense to make some sense of it all, as forums are full of small snippets and often lend off topic confusion to the matter. Old bikes are full of strange threads, and a lot of older threads are now hard to come by.
I hope you’ve found this useful, obviously there will be changes to the metric bolts already from many manufacturers and if you’re lucky you’ll never need to come across this article. I’ve just spent a bit of time writing up this article on the mundane topic of these bolts and if it gets enough hit’s and attention I’ll get in some bolts maybe, but it gives a good idea of how to work around the problem and should give enough info to explain everything you’ll give up looking for normally unless you wonder around with a bolt in your pocket or use thread gauges…

You can find our range of Kickstands here.

 

If of course as you are reading this in the modern times, things are mainly and almost exclusively made using more standardised metric threads, ISO Metric M10 x 1.5mm Bolt Full Threaded should do the trick for most stands, but you can’t always be right can you!

There’s always the good old reliable addition of Loctite, or a thread locking compound, and if you’ve gone down the route of tapping your threads out I’d recommend using some… If nothing else, it’ll make sure your hard work works for a long time yet.

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Alex’s Totally Affordable Vintage Road Bike Restoration Project. Part 1 – Finding something to restore

So Hi, I’m Alex and this is the start of a series of blog posts documenting the restoration of a vintage road bike, interspersed with pictures of my cat,she’s called CATFACE, this is her. (yes grumpy is her default expression)

 

Well first of all for this restoration project to get started I’m going to need a frame to restore. So “To eBay” I thought, where I sifted through countless frame and fork sets in various states of decay. Until eventually I came across this lovely little vintage frame covered in what looks like multiple layers of bad paint jobs. It was listed at £20 plus £10 p&p, which unlike a lot of the listings I looked at was p&p reflecting the actual cost of posting a frame! If you’re buying one yourself then really £15 is the absolute upper limit of what it should cost to send (assuming this is in the U.K.) this frame’s £10 p&p was reasonable . After a bit of back and forth negotiating we eventually agreed on £18 and he’ll throw in a seat post.

Below you can see the pictures from the listing. As you can probably tell it looks like it has a bit of a bent drop out, though nothing the awesome power of gas pliers can’t deal with! The forks also may or may not be a bit bent out of shape.

 

 

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BSA – Aligning Damaged Dropouts, Frame and Forks

Rear Dropout on the Drive Side had been opened up and the forks were also slightly twisted and the drop out was also opened up on one side.

We simply managed to close the gap in the dropout using extra large adjustable pliers, shielded with folded card to protect the metalwork (although to be honest at this stage there’s nothing to protect) we don’t want any gauge and scores or marks we want to file down any imperfections as we go.

The forks were easily pulled back into shape and balanced perfectly just using hand forces the forward leg was corrected and dropout closed up a touch on the one side.

Next stage, Sanding down…

Continue reading BSA – Aligning Damaged Dropouts, Frame and Forks

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BSA – Buying Parts, Cranks and Bar Tape

Cranks chosen on price, these came in just under £20 with a reasonable ratio to work well against 16 teeth at the rear simple and silver.

Square Taper Bottom Bracket required, I’ll have to wait until I can find something short enough to assemble it, this need something in the range of 68mm X 101mm. Yikes!

 

Grips, covered with Brown! Handlebar Tape… Cost £3.56 Bargain! China Strikes again…

Cheap as chips but it’ll do the job, and work well with British Racing Green for the frame colour.

Grip Tape