Buying options

My lightweight, short race kit fits into a
2litre bag. The heavier, more versatile long
race kit goes in a 3 litre bag. 

This is an argument that tends to get an airing about once every month or two on the forums. The options, pros and cons of different types of kit when looking to be safe on the hill when fell running (or come within kit requirements), it all falls into 3 fairly broad categories.

Light is Right

The first is the hyperlight, racing snake approach. Getting the stuff you need (or are obliged to take) into the smallest and lightest possible bag... whilst, of course, keeping within regulations. 

The advantage of this is that you are able to carry all the stuff you apparently might need for the minimum possible weight. Brilliant, until you get caught out in some pretty foul weather. 

Yes, I know that you have a top which is labelled "waterproof" and has taped seams, and I know that those waterproof trousers are indeed "waterproof", however, there is a big difference between what it says on the label and how it feels out there on the hill. 

2 examples - 

the main parts of the kit unpacked. 

The first, being on St. Sunday crag with a mate, he in a lightweight race approved waterproof top, me in an eVent top, blowing a gale, hammering with rain. I was happy. He was not, and ended up buying the same top as me when we got back down the hill. 

The second, putting on a pair of waterproof trousers- again in hammering rain and gusty wind - me, slightly heavier trousers with heavy duty zips - boom - straight on and not a bother. Friend- pair of lightweight proof trousers - but with lightweight zips that got caught on the fabric every 4 cms - not a happy, or indeed, dry bunny by the time he finally got them done up. 

That being said, if every gram is precious to you, if you want to run fast fast fast, and generally get off the hill before the weather turns gnarly, by all means - light is indeed right. 

If you are going to be out in all weathers, and don't mind carrying a bit more weight and being slightly more bulky - perhaps the Functional is right is the correct approach

Functional is right

a decent zip

To be honest, this is the camp I tend to subscribe to, if only because I know I'm going to be out in all weathers, and no matter how fast I run, at some point, I'm going to be on a hill when the weather turns nasty. At that point, I'm going to want something heavy duty enough to be able to cope. 

To be honest, the stuff I take on the hill isn't all that much more heavy than the serious lightweight fanatic's stuff, however, a few grams here and there does end up making a fair amount of difference to the end heft of a bumbag, and I'm sure that if I shaved a few grams off my kit I might, just might run a little bit faster.

That being said, I'm just as likely to run faster if I train harder - and that costs less. 

a light zip

Having dabbled with pertex, and been blown about quite a lot with it on, I tend to gravitate towards slightly heavier fabric options in terms of waterproofness here- eVent being a favourite. Not, I must hasten to add,
because it keeps me dry. I don't think anything will keep you dry in the world of fellrunning, except staying in the car and driving directly to the pub. 

However, when you're on an exposed ridge with rain lashing down on you, I found that pertex flaps about horrendously, and when wet, basically presents no barrier to the wind whatsoever, and you end up miserable and cold, no matter how much money you spent on your jacket. Something that slight bit thicker gives you that slight bit more added protection, and although you aren't necessarily dry, you are significantly more comfortable than your mate, who is in pertex. And that's what it is all about.

a cheap zip

Zip quality - as mentioned just further up is also worth looking at. If you're using a zip, you're likely to be

a) running, probably quite hard and 

b) in some pretty crap weather. 

Then is not the time to be faffing with zips for ventilation, weather protection or getting some food. Zips are a big place to save grams for technical clothing manufacturers, and they can get it severely wrong. A really decent jacket can be rendered useless by a rubbish quality zip. Check it when you buy it. 

Little things. 

However, all of this might be a moot point if you are sitting there thinking... "how much does all this cost?!" in which case, you are the right person for the final catagory here - 

Cheap is right. 

The pair of waterproof trousers I use for putting in my short race bag, the ones I know I am never going to use, cost me a tenner and weigh as little as a pair costing 10 times that much. Sometimes, cheap is right. 

waterproof trousers - for a tenner. 

I have to admit though, I am willing to go cheap if I am literally, never, ever, ever going to wear the gear. If the weather looks like I might actually have to put on waterproof trousers, the expensive ones go in the bag.
The cheap ones are for kit requirement only. 

That being said, you can probably get a waterproof and taped jacket, made from plastic from decathlon for £20. The trousers are definitely a tenner, and the bags they sell are pretty cheap, but of decent quality.

Personally, I'd rather spend a bit more on gear that I am going to be comfortable in, no matter what the weather decides to throw at me, and will last me for a good few years, however, for some, the inexpensive option is right. 

So take your pick. I'd love to be able to afford a set of crazy expensive lightweight gear for racing with, and then have a set of decent gear for when I know I'm going to use it. However, reality dictates that I go with functional and versatile.