What is wrong with my loop for archive pages?

I made a loop for my archive.php pages. The loop need to show the last x posts and add a pagination.

My current loop is like this:

<?php
$style_classes = array('span5 odd', 'span7 even');
$styles_count = count($style_classes);
$style_index = 0;
while ( have_posts() ) : the_post(); ?>

<article id="post-<?php the_ID();?>" class="<?php $k = $style_index % $styles_count; echo "$style_classes[$k]"; $style_index++; ?>">

..Here comes the content of the post..

</article>
<?php endwhile; ?>

<?php numeric_pagination(); ?>

I have a counter for odd and even in the loop to echo the posts on the right way in the framework. The problem is that I cant add a pagination code in the loop.

At the moment when I use this code in my loop:

$wp_query->query('posts_per_page=10'.'&paged='.$paged);

It will forget that it have to show the archive of a category and shows all posts.

This works for a specific blog page or homepage were every post is shown from new to old but it breaks on my archive pages. What am I doing wrong here?

[No bumping, thank you.]