PDA

View Full Version : Mtb noob alert: Are susp. forks tuned for rider weight?


AngryScientist
10-03-2018, 08:50 AM
Reading through the other thread on mtb stuff; there are a few mentions of “better” fork. Just curious- does a 135# rider benefit from a different suspension fork than a 220# rider? Do you tune a fork for this variable?

Suspension tech has advanced so much in the world; it seems to my uneducated guess that a very light rider might wind up having to ride an overbuilt fork if it is designed without a weight limit?

Just curious.

gdw
10-03-2018, 09:07 AM
Yes, quality forks are tuned for the rider's weight, riding style, and terrain.

Jaybee
10-03-2018, 09:30 AM
If you are somewhere on the spectrum of normal adult sized and riding a quality fork (and even RockShox/Fox/Manitou/X-fusion mid-tier offerings qualify here), then you should be just fine.

The fork will come with suggested air pressures (or coil, but prob not for this application) based on rider weight and you can adjust from there. Further tuning based on moving the spacers in the air shaft around to get more progressive or more linear response as you move through the travel, and you can also adjust the rebound rate.

Assuming a new rider and a XC-ish application, a Fox32 or Reba will do you just fine. A 135 lb rider wouldn't find these overbuilt, I don't think. A 220lb rider might find either of those forks to be a bit noodly compared to a Fox34 or a Revelation, but that's going to depend a lot on experience, terrain and riding style. The 135 lb rider might find a Fox32 to lack stiffness if he/she is hitting the right terrain hard enough.

Tony
10-03-2018, 09:35 AM
Fox does a good job with fork and shock tuning instructions and videos
https://www.ridefox.com/fox17/help.php?m=bike&id=919

boomforeal
10-03-2018, 09:36 AM
Yes, quality forks can be tuned for the rider's weight, riding style, and terrain.

fixed that for you

often, the better the fork the more adjustable it is

that can be a blessing if you know what you want and how to get it. it can also be really bad if you have no idea what you are doing and start twiddling dials; this is the much more common scenario

the track record of companies trying to short cut the process is mixed: the best example i can think of is fox's ill fated "ctd" system (climb/trail/descend) which provided lots of people with the ability to choose between 3 really poor suspension settings, and which fox tried to improve incrementally, year after year, until it was eventually scrapped

FriarQuade
10-03-2018, 09:39 AM
Spring rate is the big thing you need to dial in for rider weight. Don't forget your gear in this process. After that you will need to set the rebound, something almost all respectable forks have. Then other adjusters as applicable. Something that can help in this process is the ShockWhiz from Quarq. It hooks onto your air spring valve and works with almost any air sprung fork. It can help a novice make sense of all the options you have on a modern fork or shock and really help get you to 95% dialed.

joosttx
10-03-2018, 12:00 PM
Spring rate is the big thing you need to dial in for rider weight. Don't forget your gear in this process. After that you will need to set the rebound, something almost all respectable forks have. Then other adjusters as applicable. Something that can help in this process is the ShockWhiz from Quarq. It hooks onto your air spring valve and works with almost any air sprung fork. It can help a novice make sense of all the options you have on a modern fork or shock and really help get you to 95% dialed.

My wife gave a me shockwiz for my birthday last week. It did help me tune my fork. If you know what you are doing and like fiddling with stuff I don’t think you need it. I prefer to ride, and not fiddle so I glad I have it.

Mikej
10-03-2018, 12:11 PM
No, they are not tuned. You tune it with how much air you put in and which way you turn dials. Most forks are now air / oil. Spring rates would be for forks with springs, not all of them have springs. PUSH INDUSTRIES will valve your fork for specifics to your weight terrain style etc. for $280.

Ken Robb
10-03-2018, 01:01 PM
My 2001 Manitou has spring and air suspension. Since I weighed about 230 lbs. when I bought the bike I had to run quite a bit of air pressure which I feared might lead to early leaks. I called Manitou and had a good discussion with one of their techs. He didn't think I had to worry about leaks but he pointed out that springing by air pressure is progressive with fork travel and that I might be happier with a stiffer spring and less pressure to get a more uniform spring rate throughout the stroke of the fork. They sent me a new spring that did improve the fork for me. I now weigh about 182 lbs. and I'm still happy with the fork with the heavier spring. Obviously I'm not obsessed with having the latest/greatest technology. :banana:

sfscott
10-03-2018, 09:38 PM
Somewhat OT, but has anyone ridden a Fox Live system yet?

WAAAY expensive and only on a WAAAY expensive frame, but I am fascinated by it.

peanutgallery
10-03-2018, 10:35 PM
The higher end forks provide much better damping units, particularly in the smaller chuff... as well as bigger/stuff. Granted, you have to set it up properly. Think a basic Reba versus a charger unit found in a Pike. Huge difference to me

In my experience, an XC fork (100mm or less) is there to take the edge off and setup is relative, 32 mm is fine. Longer travel forks allow you set the proper sag etc so it works better. They also flex more, hence the 34 and 36 mm stanchion tubes. You don't want a 150mm fork with 32mm legs, even if you weigh 110 pounds. Personally, I've found forks with 36mm legs to be too stiff for what I'm doing. To each their own

Setup, most manufacturers provide the basics and you go from there. Specialized has a little web based deal for the new stumpjumper where you enter the model and your physical details and it gives recommended settings (front and rear) along with tire pressures. Personally, I find these a bit harsh. I go a bit soft as it suits what I ride

As far as volume spacers, those are for plebes:) Get an MRP cap. If you go there you have to adjust your air pressure match the change in volume

The key is having fun, the modern mtb has really tamed the woods...and don't buy a used 2001 Manitou in the classifieds:)

Reading through the other thread on mtb stuff; there are a few mentions of “better” fork. Just curious- does a 135# rider benefit from a different suspension fork than a 220# rider? Do you tune a fork for this variable?

Suspension tech has advanced so much in the world; it seems to my uneducated guess that a very light rider might wind up having to ride an overbuilt fork if it is designed without a weight limit?

Just curious.

quehill
10-03-2018, 10:45 PM
Yes and no, every decent suspension fork is adjustable using either air pressure via a shock pump or alternate springs if it's a coil fork. On the other hand, rider weight and riding style should definitely affect the fork you start out with. Fox, for instance makes (in the range from XC to all mountain) 32s, 34s, and 36s with the number being nominal stanchion diameter.

I'm a big guy and I run a Fox 36 on my big bike- a long travel Pole Evolink 29er. I know a little guy who runs a 36 on his hardtail, which is almost certainly silly- he should be on a 34 at most, but the 36 sure looks cool.

I personally think the MRP Loop TR is a great choice for a smaller guy who wants more-than-XC stiffness without sizing up to something like a Pike or a Fox34. If you end up needing 27.5 I have a nice one down in the basement I'd let go for a song. <insert dancing banana>

joosttx
10-03-2018, 11:22 PM
T,

The key is having fun, the modern mtb has really tamed the woods...and don't buy a used 2001 Manitou in the classifieds:)

i have to agree New MTB forks (Fox 34 for example) compared to forks 10 years ago are so much better.