FarHorizon

Obviously not from front to back, but from side to side? The majority of steel forks out there, like this one:



...are overbuilt to the point of lunacy.

By staggering the holes between the inside & outside of the fork, you could eliminate weight without compromising structural integrity?

Of course, after doing the "swiss-cheese" mod, you couldn't put abnormal stress on the thing, nor could you use it in the rain. But with a drain hole at the bottom...

What say youse, fellow BikeForum dwellers?

desconhecido 

"Can heavy steel forks be drilled?"

I don't know why not. They don't take away your driver's license for doing something like that, do they? Maybe lose your driller's license, though.

I'm curious if it would make different whistling sounds depending on how fast you ride. Perhaps you could drill the holes at slightly different angles and in slightly different sizes and get it to play "The William Tell Overture" by varying your speed and shimmy. I'd pay to see that.

FarHorizon

Talent is where you find it! LOL

LesterOfPuppets

I dunno if it would be worth the trouble. But it could be done. Hopefully with a drill press. I'd hate to be drilling more than a couple holes by hand.

If you have lots of money and don't need U-brake studs you could just buy a 20" carbon race fork and be under 2 lbs.

FarHorizon

I thought of that too, but this is a 26" wheel bike. Haven't found such a fork yet (or even an aluminum one, for that matter). What I COULD do is to replace the fork with a 700c carbon fork AND lightweight wheel. Leave the back a 26".

This would decrease the bike's effective head tube angle (from, like 73 degrees to probably 69), increase the trail by a large amount, and make the bike feel like it was on rails for stability.

Probably safer & easier than drilling the fork...

LesterOfPuppets

More details on project are needed.

From the photo provided I figured a 20" was needed.

Do you want a light fork or just a holey fork?

FarHorizon

A light fork is the goal... The bike is a 26" design, and I plan to leave the rear alone. If I could find a 26" carbon cyclocross fork, it would be sweet, but so far as I can tell, nobody makes one. The only lightweight components available are for 700c road bikes.

I have no objection to modifying the original fork, though (which is like the photo, but 26"),

LesterOfPuppets

Have you weighed the fork? Measured the ATC (axle to crown)? What make/model/year is the bike? Do you need any specific brake mounts? Steerer size? Threadless or threaded?

If you want disc, MRP has a really light fork available in a 445 ATC, which would work well on a MTB frame designed for 80mm travel forks.

MRP Rock Solid Rigid Carbon Fork > Components > Forks > Rigid Forks | Jenson USA

LesterOfPuppets

If current fork is a real porker, like 5 lbs, and you want cantis or Vees, you can get below 3 pounds pretty cheaply. Gotta paint it yourself, though.

Rigid 26" Steel Fork 1 1/8" Threadless Unpainted (100127956) at CambriaBike.com

FarHorizon

Thanks, @LesterOfPuppets - I'll check it out.

cale

I suppose the question becomes, "Do you want to be the guinea pig for a DIY-drilled fork?"

randallr

I've worked in the bike industry. Any frame members or components on the bike forward of your knees (also the seatpost) are considered safety critical because if they fail you are crashing fast and hard. My experience is cycling companies test these components pretty carefully for ultimate strength and fatigue resistance. Drilling out these components would not be advisable, it would be a lot cheaper to go the direction you're considering and buy something lighter. Drilling opens the door to fatigue and corrosion.

desconhecido 

But, people would stop laughing at you for not using clip in pedals.

LesterOfPuppets

Salsa like to put lots of holes in their forks. Unfortunately there was a recall, but they're still putting holes in the redesign. They probably don't save weight after brazing in that threaded boss, though.

FarHorizon

As it turns out, the stock fork isn't so bad. With a lightweight front wheel & tire, I can live with it. Should I ever want other, I'll just go to a 700c front wheel+ fork & see what that does to the steering. And as for YOU, @desconhecido - Why would I ever WANT them to stop laughing? Life's no fun without laughter!

RaleighSport

What about that nashbar carbon mtb fork? IIRC it's about 2lbs... buuutt it has posts, and a disc tab.

surreal

You know there are plenty of CF rigid forks available, right?

LesterOfPuppets

A lot of old, rigid 26" MTB forks fit 700c with a caliper, if you're dying to get a road wheel on there. With some forks you can unscrew the canti posts, for a cleaner look.

Here's a 395mm 26" MTB fork with a road wheel in it. 1999 Shimano RSX long reach brake caliper doing stopping duty, clearing 32mm knobbies, no problemo.

LesterOfPuppets

Also, if you have crappy OEM knobbies, you can probably save a pound per wheel by replacing them with these. Mine weighed about 330g apiece. They wear kinda quick but I don't care cuzza the lightness.

Kenda Klimax Lite XC Tire 26x1.95 | Fast L3R compound | 345g

FarHorizon

The V-brakes currently on there probably weigh less than a road-caliper style brake. The current tire is a 26 x 2.10 Schwalbe street tire. I have, in the spare parts bin, a 26" deep-v wheel that is much narrower, & I plan to put a 1.25" lightweight on there instead. I need to clean & repack the bearings, but other than that, the wheel's like new. I'll post a photo when done.

desconhecido 

True that.

LesterOfPuppets

So what's the make/model/year of the bike? What kind of Alt Bike are you making out of it?

FarHorizon

It's an Electra Townie coaster brake. Aluminum frame, but steel fork. The bike is remarkably light except for the seat, the fork, and the wheels. The seat I can easily replace, the fork may not be so bad as I thought, and once I replace the front wheel & rear tire, plus stripping off extraneous stuff (fenders, lights, reflectors), I'm curious to see how light the bike can go. I could also put a fixed-gear rear wheel on the thing, but I'd feel inclined to have a rear brake then, and that would destroy the weight savings. If I put the 700c carbon fork on the front with a lightweight wheel & tire, the thing would be odd-looking but VERY stable to ride. Tilting the whole bike back with the larger front wheel would change the head-tube angle considerably and provide significantly more trail. The steering should be easily "hands-free" with stability to burn.

I also have a 110 BCD crank & chainwheel that I could throw on, but I need to check the original chainwheel - if it's steel, then maybe just change the ring. If it's already aluminum, then nothing to be gained by tampering with it.

Just checked - the chainwheel's steel. Time to throw on a lighter crank!

LesterOfPuppets

I wouldn't guess the front end would rise any with a road fork. A 375 atc fork with 700c wheel and 23mm tires would probably drop the front end an inch or so.

I'm just eyeballing the electra fork at 410 atc, so that estimate above should be considered a WAG.

Would have to know exact ATC of Electra fork to nail down a number.

FarHorizon

Just for kicks, I pulled the front wheel off my wife's 26" bike and the front wheel off the Townie. Since her bike has 26x1 ⅜ tires, and the Townie has 26 x 1.9 or 2.1 (I don't remember which), her wheel was much lighter than mine. I swapped them (and will need to adjust the brakes on both, since they're slightly different "26-inch" size wheels).

I'm happy with the change and since she doesn't ride her bike often, it should be OK until I get the deep-v 26" wheel ready. It needs a bearing cleaning, lube, & adjustment, a new rim strip, and a tube & tire. The rim WILL take 1.25 tires, so that's what I'll use.

Has anyone tried the "butterfly" bolts for threaded wheel axles? The first pair I tried (being aluminum, and not well made) stripped before I could even get them tightened. Does anyone make good ones with steel inserts?