Monday, 10 October 2016

Dissembling a mountain bike and rebuilding it onto a new frame.

Let start with a little memorial for my old mountain bike....

There it is! It served me well over many years only to have a humiliating death at the roadside. I'm grateful for that humiliating death as the frame simply sheered when I was pedalling uphill at about 5mph. I was on my way to the woods to put it through its paces and that could have resulted in a nasty injury for me!

Here is what happened to the frame:

That was the end of that frame. Out of warranty I reached out to Halfords and to cut a long story short, they offered a frame replacement at a discount if I returned the frame for inspection. The catch was that as it was an old bike. they didn't have a dual suspension but that was a) affordable & b) with 26" tyres.

I went for a hardtail instead as it was £90. Over £150 and I though I may as well spend a few hundred and get a new bike which didn't appeal. It was a Voodoo Hoodoo 2011 frame in red which I thought looked nice as well.

Here i'm going to document all the little annoying bits you don't think about when doing this sort of thing. I got caught out in a few places.

Tools list:

Crank puller & Bottom bracket remover -
Headset cup press - (or fashioned from thread, bolts and washers)
Allen keys -
Pliers - (holding / cutting gear wires)

Muc-Off 8-in1 Bicycle Cleaning Kit - (highly recommend)

Lets start with the basics:

Easy to remove items

Anyone can pretty much get to this point with no issues. Especially with quick release wheels and a few simple Aellen keys.

  • Remove seatpost with Allen key. Most likely 8mm
  • Remove quick release wheels
  • Remove handbars. Simply loosen two bolts with the Allen key. 
  • Remove the front and back disc brake blocks with the Allen key. 
  • The derailleurs with have Allen key bolts to loosen the gear wire, undo these and then you can remove the derailleurs. 
The only this I would advise caution with here is the rear derailleur. It has a bolt and nut that need to be taken with it that hangs the part from the frame. As you can see in the pic below the derailleur arm hangs flush with the bike frame for support and is bolted further up. 

Pedals and bottom bracket
Now for the parts that you think might be simple but can cause problems if you don't have the right tools. Looking at the pic below it looks like to get the pedal off its going to be simply another Allen key job. Well thats just part of it. Once the cap is off the pedals are wedged on the bracket. Your going to need a crank puller for this job! 
UK amazon link here: I've seen some people lever these off or even kick them off but thats likely going to damage the bottom bracket. What this does is basically screw in the black bit (pictured above) to where the cap you removed was (that center part of the crank in the pic below). Then you screw the silver top down through the black bit so that it pushes the pedal away from the bottom bracket and the crank + pedal are removed from the bike. The lever is to help do this as it'll take some effort. 

Now I was cheap and bought the puller on the left without the bottom bracket remover pictured there in the middle (above). Big mistake as I then needed that and had to get it separately. 

If you look at the centre of the chainrings the hole has teeth where this was sitting on the bracket. This is what keeps the pedals secure and helps transfer the power smoothly in a circular motion.

 Time for a clean!!! I can't recommend Muc-Off cleaning products enough for this. Cut through the grime and grease so well! Muc-Off 8-in1 Bicycle Cleaning Kit -

Careful with the chainring bolts. I ended up ruining one by not getting the thread right and had to buy some more.

The front fork.

Now I didn't take a picture of the disassembly of the front fork but this is where most of my frustrations were as mine had rusted a little and with all the parts it was proving insanely hard to get the top headset parts out. Rest assured this should be easy but might take some plying with a screw driver. I managed to damage it enough to send bearings everywhere so I was buying a new headset at this point. Also if you intend to keep the whole headset, your going to need something which can expand out the caps which might well be hard pressed into the frame. Good luck with that. I went for a complete new headset for ease. I went for a standard FSA one - . Make sure you get your type right and measure properly.

Just a few parts when putting the new headset on. It's mostly easy. The only things I would recommend is a) use a proper press for the cups into the frame as they need to go in evenly and not bend. If you bend them so might compromise the smoothness of the bearings. Also if you didn't take off the part of the headset that is pressed into the fork at the very bottom, you either need to take that off and use the new one. You can get away with using old one and don't stack the new one on top also. 
When I first did this I stacked the bottom part its old counter part and was getting forward and backward movement in the lower part of the fork as the fork was not seated properly. Careful of this. The fork should turn smoothly and have no un-normal movements / looseness.


The bottom bracket is so easy with the remover that I cleaned it and put it straight onto the new frame. Then pressed the pedals on with relative easy. 

I hit a few problems here with Halfords. They had said this frame was ideal for me to put my old parts back onto. It looks like the seatpost was an issue as 27.2mm was needed and my old one was larger. Luckily these are cheap as I already had to get a new headset. 

I also realised the front derailleur had the same problem and could not find a decent shim for the SRAM X5 to fit on this narrower frame so went and bought a cheap Shimano XT M780 Top Swing 3x10 Front Mech to go with it.  What also turned out to be a great feature on it is that it can take top and bottom gear wire pull routing as I didn't realise this frame was bottom pull. 

When buying a frame be sure to look at the frames holds for wire housing as this will determine which was you will be taking your brakes and gears. I was confused as mine had two cable housing holders near the handles but nothing underneath for when the wire got to the bracket.

I needed a Bottom Bracket Mount Plastic Gear Cable Guide - which you can see installed below with the wire going through. One channels the wire up to the front derailleur and the other towards the rear.

This article is to be continued but here are some more pics in the meantime:

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