Mountain Biking - Can you make a fork stronger?...Mod it?!?!

I am trying to get back into shape. I am overweight and want to drop the pounds again and use the bike like I did last time. I weigh 385 pounds and whatever adjustment on any fork from the bike shop doesn't leave any travel once I get on it. I even tried a double clamp with 170 MM of travel and I sent it downward. I just bought a 2002 Gary Fisher Kaitai. It came with working stock Manitou Magnum fork with 80 MM of travel. My issue is not the travel....it's the stiffness of it. Is there a way to mod it and be more stiff to keep my huge ass in the air? The bike shop already upgraded the living crap out of it before I bought it from them. They put a LX Crank and new BB with a new LX rear derailer and XT front derailer with a XT Front Hub and a LX rear hub. I bought it used for 300 bones. Any help would be great. And yes I do some off road riding. If I lose enough weight, I'm buying a Santa Cruz.

Heavier springs, heavier weight oil, prayer.

Are you talking about making the fork casing stronger to stop flexing in that area? Or are you talking about making the suspension in the fork more resiliant to your current weight?

If you're talking about making the casing stiffer then you could try a couple layers of biodirectional carbon fibre. Rougthen the area with deep cuts from a hacksaw to prevent delamination when cured. Lay the carbon on wet (use epoxy, its stronger ;) ) and then slide some shrinkwrap plastic carefully over the top without disturbing the fibres. Heat up the shrinkwrap with a heat gun til it squeezes tight around the blade of the fork, shrinking from middle to end in order to squeeze excess resin from the job. Leave for 24hrs to allow full cure.
This technique really just creates a seperate casing around the fork. However this casing wont flex as much, esspecially when a ton of layers of carbon is used. You're really just locking up the fork and thus the flex.

I dought however that anyone would wanna scratch up their forks, or soak em in resin and layers of carbon and just generally stuff around with it all. May I suggest solid forks and sealed roads til you lose some weight? :)

you might want to just find a pair of cr250 forx on ebay and figure out how to mount them on your frame

how about this...forget the XC forx...just get yourself on double crown Marzocchi with custom springs...or two springs in each leg

you might want to just find a pair of cr250 forx on ebay and figure out how to mount them on your frame

how about this...forget the XC forx...just get yourself on double crown Marzocchi with custom springs...or two springs in each leg
Umm........

This technique really just creates a seperate casing around the fork. However this casing wont flex as much, esspecially when a ton of layers of carbon is used. You're really just locking up the fork and thus the flex.

I dought however that anyone would wanna scratch up their forks, or soak em in resin and layers of carbon and just generally stuff around with it all. May I suggest solid forks and sealed roads til you lose some weight? :)
Dude, that's not what he's asking and that's the most impractical "mod" I have ever read.


As for the OP, 300+ is waaaay up there. Try to find a friend or a demo/test bike equipped with a freeride/all mountain fork with air springs. Turn the compression all the way up, and max out the reccomended pressure.
If you intend to stick with a coil spring, what can be done to really really stiffen up the fork is to get some cheap elastomers for a rockshox quadra fork (or something similar with a elastomer the shape of a magic marker), and slide the elastomer into the inner coils of the heaviest coil spring available for your fork.
Of course this will void your warranty instantly, but I've done this for a few friends/customers that were heavier riders and they were pleased with the results.

Dude, that's not what he's asking and that's the most impractical "mod" I have ever read.
Hence this precation I wrote.....that you failed to quote;

Or are you talking about making the suspension in the fork more resiliant to your current weight? I wasn't sure what was needed so I tried to answer his question the best I could with the knowledge I have :) . The technique does work......and it works well. I've repaired many a cracked road bike headsets with this technique, and if you rougth up the surface enough, it will never delaminate. I use similar techniques to build CF recumbent frames. Please don't mock what you don't understand :)

If you wanna see what myself and 15 of my friends do with composites in a crummy garage in a field, then you only have to ask ;)