Custom Bike Making

Citizen_Erased

I was thinking about about making a custom <mountain> bike from scratch or customising an existing one. I was wondering could anyone supply me with info or links to about how the system works ie how to get parts that match up like the forks and stem etc. Any other info at all would also be welcomed.
Cheers in advance.

rob1891

How much experience of maintaining you current bike do you have? I'd look for a book on maintainence first. The parktool.com website has good directions on using the tools they sell but I don't know about general maintainence sites. I have this book, I find it adiquate:

http://www.amazon.co.uk/exec/obidos/ASIN/0756602955/qid=1119554124/sr=1-1/ref=sr_1_27_1/202-6559835-5810211

The headset is the only thing I can think of that is that difficult. Though the latest headset I bought was easy to fit (FSA Orbit UF). Some of them need a bearing race (a ring the bearings will roll on) tightly fitted onto the bottom of the fork steerer tube. Bike shops have a special tool for all this, but that costs money. I use a piece of steel tubing, but it doesn't always work.

Do you have any specific questions other than the fork/stem one? I'll try and answer that anyway:

If you are buying new stuff you'll be looking at 1' 1/8" inch all around. That is the diameter of the fork steer tube, the stem clamp and the inner diameter of the headset. The steer tube on the frame is a standard size and the headset should fit into it fine.

Fork travel should match the frame to some extent, this will be available from the frame manufacturer (find a full bike they sell with said frame and see what type of fork they use).

Stem length is difficult to judge, buy a cheap one that is close to where you think your handlebar should be, keep buying cheap until you find something that fits.

There are loads of different products to research, buy from chainreactioncycles.com and read reviews on mtbr.com. You'll probably spend a lot of hours looking over things.

Citizen_Erased

Thanks , that's really cleared alot of things up for me. I don't seem to have any problem with bike maintanence as far as things have gone up until now. So what your saying is most things should match up anyways so say the crank arms and pedals should just match up etc... I suppose wiring up the system would be the only other hitch apart from what you have mentioned. Will it just be a case of cutting the plastic cover to match the things on the frame or will I have to fit guides for them myself. I'd guess that would depend on the frame really but to be sure. And I intend to use disk brakes if there is any thing I should know about them? Back on the topic of forks, what about them forks that have two lengths of shocks , what problems come with them because I'll probably go for them too?

Alkers

What do you mean by two lengths? If you mean the suspension come up to the handlebars you more than likely don't need them unless you're planning on downhilling.

mockerydawg

Research the disc brakes throughly, especially if you are looking at getting a hydraulic set. Look for ease of maintainence and make sure you know the oil type for the system you go with. Some (Hope) use Dot 5 brake oil, whereas others (Shimano) use only mineral oil. The oils are not interchangable.
Also be careful of putting a disc with too large a diameter on the suspension fork. For example a fork made for a 160mm disc may fail and is not under warranty with a 205mm disc. Just something to bear in mind.
Good luck with the build, its very satisfying when you first ride it!

Alkers

I wouldn't bother with cable-pull discs either.

rob1891

So what your saying is most things should match up anyways so say the crank arms and pedals should just match up etc...

Crank arms and pedals will match up however bottom bracket and crank will have to be bought to match. The types I can recall off hand are Square taper, ISIS and assorted shimano types that are usually sold as a pair the bottom bracket & crankset (i.e. XT & XTR cranks/BBs won't mix).

Actually getting the right sized BB might be another puzzle. The diameter of the BB is easy, just measure the width of the bottom bracket shell on the frame (probably 68mm) but the length of the BB axle is harder. Manufacturer's website for the particular crank is probably the best bet. Middleburn recommend a 108mm axle length for their cranks but there is a caveat that if your frame is odd it still might not fit! Ouch Some crank & bb info:

http://www.middleburn.co.uk/tech.htm

Will it just be a case of cutting the plastic cover to match the things on the frame or will I have to fit guides for them myself.

When you get your cable sets they'll be long enough to fit your frame, cutting them is a little difficult as you tend to crush them at the same time, I usually use a dremmel to slice through them. A bit of overkill. Care with a sharp hacksaw works fine.

Back on the topic of forks, what about them forks that have two lengths of shocks , what problems come with them because I'll probably go for them too?

You mean something like lockdown where you can lower the amount of travel while riding the bike ... i.e. two travel lengths? When the fork is locked down you'll be climbing a hill, with the front end of the bike lowered control while climbing will be a tiny bit easier. So that's no problem at all. As I said, you should buy the fork to match the frame. Basically you don't want to raise the front of the frame too much with a 150mm fork if it's has been designed with 105mm in mind.

What kind of bike are you building btw, XC, DH ... frame etc?

Citizen_Erased

I'm thinking fixed frame with front shocks. I had a full suspension bike before but it worped and twisted to much when accelerating (although that was probably because I couldnt adjust the shock) What I might actually do is my brother has a fixed frame and fork raleigh that has been replaced by an updated version. I might try use that as a base . It will need new front forks , completely new crank/bb/axel mechanism and I'm not sure if the back forks are made to accept disk brakes. It's not about at the mo , you see.

edit: the bike I might use as a base has the square taper system but this has created problems in the past. It has worn completely out of shape until the hole looked like a star at the base of the crank arm. Would it possible to replace this with the ISIS system?

FergusF

Citizen_Erased wrote:

edit: the bike I might use as a base has the square taper system but this has created problems in the past. It has worn completely out of shape until the hole looked like a star at the base of the crank arm. Would it possible to replace this with the ISIS system?

Yes, it should be possible to fit an ISIS bb of the same size in place of the square taper, just make sure you get the correct size and buy matching cranks.

Citizen_Erased

Cool , Thanks.

Bunny

Dont buy parts in Ireland... you´ll be ripped off..

Just read MTB magazines for a month, become obsessed with parts, weight, looks etc, then find a cheap MTB shop in the UK and get them to build the bike with the custom parts you pick out.. a particular aim is good, e.g. you can go for extreme lightweight bike, or a chunky DH bike or whatever, will cost you though but is good fun, remember though the more perfect and shiney the bike the less likely you will be to actually ride the thing and get it scratched and dirty..

Mucco

I find chain reaction cycles to be good and relatively cheap. And they're in Ireland!
www.chainreactioncycles.com