There are specific racks that can be found for use with suspension bikes, I had to find one for my own bike but it was quite a challenge. There’s little choice when it comes to racks designed for suspension bikes and the available options are usually heavier, more difficult to repair, have lower carrying capacities and are more complicated and so more prone to breaking. In the end my front rack has been OK; it’s overcomplicated, very heavy and is incompatible with all but the most diverse pannier mounting systems, yet it’s one of the best I have ever seen for use with front shocks.
So, mounting panniers is more difficult with suspension but not impossible. If you’re undeterred or simply have no choice then read on :)
I can’t find the front rack I use for sale anywhere anymore, but here is a picture of a very similar front rack produced by Zefal, these racks mount to the v-brake attachments, which not all suspension forks have, and use adjustable metal pipe clamps that unfortunately won’t fit onto larger diameter forks; which happen to be the good ones.
The very best front rack for suspension forks I have seen is the Old Man Mountain Sherpa Front Rack which instead of using the pipe clamps such as the Zefal is mounted to a replacement skewer that goes through your front hub. The only major limitations is that it’s still incompatible with many of the best suspension forks, specifically any forks that are ‘disk only’ will not have the v-brake mounts required, some brands such as FOX use their own custom axel designs and so the skewer won’t fit either and this type of rack will only fit onto 26” fork and wheel setups.
All but the very best suspension are pretty useless for touring, the cheap un-dampened ones produced by brands such as Suntour are not worth the extra weight and hassle when they inevitably degrade as mine have, if you feel you really want at least some front suspension I would recommend looking into Fox, RockShox, White Brothers or SRAM as a good starting point – even then only for 26” mountain-bike wheels, as larger ones are huge and will add a great deal of weight. Unfortunately many of these won’t be compatible with any front racks that I know of because they tend not to have v-brake mounts, they are wide in diameter meaning the metal clamps, use to secure the bottom half of the racks, won’t fit around them and some of them use custom axel designs meaning racks like The Old Man Mountain Sherpa will also be incompatible.
As for rear suspension, the only kind I have seen successfully used is the type that mounts to your seat post such as the Topeak beam Rack. these racks are OK for light touring but typically can only carry 15lb and being connected to your seat post means that all the weight must be supported by your rear suspension mechanism which will make it soft and perhaps even sag a little, which will slow you down for sure.
I realise this article sounds like doom and gloom but the point is there are options available and as long as you understand their limitations you should be able to make a good decision; and don’t forget there is always the option of using a trailer!