Final transmission part to fit is the cassette and chain and frankly we're wondering - like many of you - why we haven't talked about wheels yet. Basically we were hoping to have some wheels together by now but the tubeless rims we were after aren't available yet, so we're just running on some Rolf stunt doubles for the time being. As soon as we get the bits we'll get our wheels together and tell you all about them, hell, we might even learn to build them ourselves.

Anyway, cassette time

What?

The block of cogs that sit on the rear hub for the chain to go round.

Which?

SRAM ESP 9.0

Why?

They came with the upgrade set, but they're good value anyway. Even though they're steel not titanium like XTR they are still very light thanks to a composite cog carrier. All the usual ramps and chain helping profiles are there but we'll see whether they offer the same shifting performance as Shimano once we get some proper miles in. The 34 tooth bottom cog gives us some serious wall climbing potential, which might be enough to ditch the inner chainring when we're fit and fast in summer.

How?

The block slides onto the splined body smoothly, but we normally apply a little grease to help it. The only slightly tricky bit is lining up the small indent with the small spline on the body, otherwise it won't go on. Once the main carrier section is on add the smaller cogs (again check the indent so they all line up for smooth shifting) making sure you slide the approriate spacers between them.

The lockring actually screws into the inside face of the freehub, so grease this too.
Fitting lockrings requires another special tool. Most are toothed block and spanner jobs but we've got a handy version that braces against the seatstay and lets you wind it on that way. It's called a Pamir Hypercracker but unfortunately we haven't seen one for ages, so you might have to ask around or just get your local shop to fit it. Tighten it as hard as you can, to make sure there's no wobble in the casette.

Now you're on to fitting the chain;

What?

Long metal string of plates and rollers (normally 116 links) that links your legs to your rear wheel. Nine speed requires it's own chain with thinner links to fit the thinner gaps between gears.

Which?

Sachs / Sedis / SRAM PC 99 Power Chain

Why?

Even if we hadn't been trying to avoid Shimano just for fun, we'd have gone for a Sachs / Sedis chain anyway. They've always been our favourites in terms of reliability and no they come with an easy split "power link" too. Beats the 'special joining pin required' Shimano chains into a cocked hat for regular maintenance.

How?

We'd normally just match the length of a replacement chain to the chain we were taking off, but as this is an all new bike that isn't an option. To make sure you've got enough links to cope with any accidental gear shift you need to check it's long enough to wrap round big chainring and big sprocket at the back.

First you'll need to thread it through the rear mech though. Always make sure it runs the right way through the jockey wheels - Thats round the front of the top one and round the back of the bottom one - and doesn't catch on any of the keeper tabs on the jockey wheel cage. Once it's through there shift to place it round the largest sprocket and largest chainring. Pull the rear mech forward as far as possible and note the point of overlap.

Drop the chain off the big cogs to give yourself some slack and then split the chain at the marked point using a chain tool. The power chain needs two roller ends to join it, while Shimano chains need one roller end and one plated end, so make sure you break the chain in the right place. Now rejoin the chain in the manufacturers approved fashion, flex it sideways a few times to check it's secure and moving freely.

By the way don't make a habit of using that big to big gear combination as it will wear stuff out double quick, but should you end up there accidentally at least you know you won't bust anything.

Now all you have to do is index the gears;

Shift into the smallest cog at the back. Now click the shifter up a gear. If it doesn't move, but just jumps and rattles, increase the cable tension. If it moves up two gears reduce the tension.

SRAM only use a barrel adjuster at the shifter end, while Shimano normally have shifter and mech adjusters. A small turn on these adjusters can make a big difference though, so go slowly and carefully. Keep repeating this process until the gears shift smoothly through the whole range. If you're having to wind on loads of tension, unbolt the inner cable and pull it tighter before starting again.

To make sure the chain stays on the cassette you'll need to set thte top and bottom 'stop screws'. These are on the main body of SRAM mechs or the back of the knuckle on Shimano mechs. Again trial and error will find a setting where the gears can move far enough for clean shifting without falling off the casette and getting jammed.

We're now just a few finishing touches away from the first ride, and hopefully all the final ingredients should arrive today. Keep watching this space.