Some years ago, I got a really good deal on a Jamis Dakar Expert frame. I built it up with some parts that I had sitting around, and others that I bought.

The bike has a Fox Vanilla rear shock/spring, and during my first few rides, I found that it rode better with the pre-load cranked up most of the way. I assumed this was because I was used to riding a hardtail and/or road bike, and once used to the "feeling" I would start to dial the pre-load back.

Shortly after building up the bike, I got married, and my wife was not a fan of off-road riding. So the Jamis sat for a while. But this year, with my wife traveling frequently, I will have many opportunities to ride it.

Last weekend was the first, and also the first time I really put some heavy use on it. Even with the pre-load turned up, it feels "soft" in the back. I checked the coil spring, and it's marked as:

500# 1.6

500 lb spring, with 1.6" of travel. Since they no longer seem to make this shock, no one was able to give me much info on it, nor did they stock replacement springs, so I called Fox directly. The tech told me that for my weight (190 body weight, probably around 205 with gear, camelbak, etc), I should have an 850# spring. So I ordered one.

Since then (which was the other day), I've had a few people tell me that 850# is waaaaay too heavy, and that I should have something more like a 700#. I've found a few online calculators, but they all give me different answers, ranging from 538# to 960# (!).

Does anyone else have a bike with a Fox Vanilla, and if so, what's your weight vs spring rate? I don't want to turn this bike into a hardtail.

Fox has the information you need. Just give them a call and tell them your bike and weight.