Made a date with a drillpress wednesday.
 

Gonna make some speedholes in 6061 T-6 bars under the grips, and some in the 4mm wall parts of the chromoly stem. Strong stuff, but heavy.
Won't be so heavy tomorrow thanks to a buddy with lots of bits and the machine. :D

Have fun. I'm a pretty big weight weenie but not sure if I would trust having holes in two components that are responsible for keeping my collar bone in tact.

I've never really fully understood weight weenies (titanium QR skewers and god knows what) but I figured if they can feel the difference then that's good but I think putting holes in components is just taking it too far. :lol: Oh well, at least you'll have fun with the drillpress. :D

The person who has the press is a cyclist and builds steel trusses for stage lighting.
We will discuss the placement and size of the holes.

The heaviest weight\duty is my bars and stem.
Nobody breaks the ends of the bars, the stress isn't there, it's @ the stem clamp. The bars are say 5mm wall. They don't flex, they won't break -ever.
Few holes, maybe up to 1/3 of the metal removed under lock-on grips.

Skip dinner and leave the components alone.

Or maybe get a haircut.

Homer had speedholes in his car. They were sweet from what I can remember

I need more cheeseburgers, I weigh under 150, my bike needs to be around 20lbs -It's say getting up 21+lbs. Feeling heavy again -so we have a date with the drill.

Metal work is fun to me anyway, so is riding a light bike up stuff.
http://www.crystalpyramid.com/DISTRI..._champion.html

Rock on man. I'm interested to see just how much weight you save.

Ahh, but does he engineer them?
OK, you're working on chromoly, that's good. Even if it fails, it shouldn't fail catastrophically - - might bend, but shouldn't snap. I'd be careful about the idea of drilling through the sides of the stem: the sidewalls are the strength for vertical torsional loads. Drilling top-to-bottom might be better.
That may be true, but the bars are a continuous length of seamless, drawn tubing - - made to distribute load over their length. Shortening of this length of this load-absorption could stress the rest of the structure of the bar at the bends and such.
I don't think I'd do any overlap of those holes in the grip area (as your drawing indicates) - - maybe a single spiral so that ther aren't any holes in alignment? Just a thought. Good luck . . . doublecheck your insurance :) .

I can't believe anyone would even consider this (drilling) as an option in this day and age! I'm actually still uncertain as to whether this is a joke or not. But if you are serious, and you'd have to be pretty dim to be serious about this, I would wear full body armor. Unless of course you want to die trailside from septic shock after your stem or handlebar snaps and stabs you in the intestines. I thought this idea died in the late eighties after people started drilling cranks and subsequently severing large arteries when they snapped-and it will. Ok, maybe you just don't know, but a 21lb mountain bike is plenty light enough for any pro racer, so if it's not light enough for you, do something about it and train more. And you proponents of his idea better stop telling him to do it because thats just not right.

I'm all for modifications, being a machinist myself, but that would scare me. There would be jsut as much stress along the whole length of the bar I would think. Just more likely to bend/break at the stem clamp or riser bends. And if the least stressed point was the end of the bar, drilling it would just bring it closer to being the most suseptable point to break. It'll *probably* never break, but who knows. Hope it works though and you don't face plant into your stem someday from the bar snapping. That would suck.

bad idea
pm me when your bars snap, so i can say told you so and laugh at you

Ah, a trials rider. I support your decision.

I'll bring that up. I'm not the smart one about the loads and torsion.

"I don't think I'd do any overlap of those holes in the grip area (as your drawing indicates) - - maybe a single spiral so that ther aren't any holes in alignment? Just a thought. Good luck . . . doublecheck your insurance :) .[/QUOTE]


Good ideas, keeping the holes out of alignment, I was planning to keep them inside the grip collars, the bars have been shortened already =the collars won't be moving.

To my detractors -seen drilled-out lightweight trials rims? -holes in the rims between the spoke nipples.
I'm too cheap to buy, i'll make 'em. Maybe I'll break them.
Maybe I'll go down 500 grams with my drilling. I doubt I'll weigh it, all I have to do is lift the front once to know if it was worth it.
It'll be fun, cost nothing. I'm not telling anybody else to go this route.
I doubt anybody is running such stupidly thick steering. If I worked with CNC machines I'd be doing the same, maybe a little more sophisticated.

I might acid etch designs into my frame next...what? ...the tubes are gonna snap?
I running stuff that's strong -not light.
I'm not hucking, i'm orthotropically challenged.
Gravity is a harsh mistress.

Thanx for your concern though, really!
I am not doing this as a whim.
Some thought is going into the project. Don't go off drilling your lightweight components kids.
I bought heavier thickness of metal with the idea to do this. I've bent 2 pairs of bars already.

And grinding\cutting\shaping metal is a hobby I include with mtbing.
Lil' custom edges, can't buy that.

Again, my bars are 1/2 cm thick walls.
My stem is the same bolt\faceplate threadless ones everyone uses that are aluminium.
Mines chromoly steel...and hard!

I misunderstood earlier - only a Chromo stem. Lightening holes in 6061 T-6 bars? Yowza! That IS courting catastrophic failure.
Ah, but the whole discussion makes me wax nostalgic about roadsters on the dry lake beds and green/black duotone pages in Rod & Custom magazine.

http://www.hotrodsonline.com/cf/oh/c...lides/0130.jpg

EDIT>> How 'bout doing the hole-thing to a set of light chromoly bars instead? (like the old Bontager Crowbars) Then you've got the maleability going for you if things do go south on you.

You bought heavier parts so you can drill them to make them lighter....yea you you've put a lot of thought into this....haha

Guys, he said his handlebars were 5mm thick heated treated aluminum and his stem is 4mm CHROMOLY. :eek::eek: First of all, those are massively robust pieces so I don't doubt they could withstand a few holes. However, couldn't you find some much, much lighter parts that are still strong enough? Seriously, I can see an adult male gorilla doing a 40 foot drop with these and not putting a scratch on them. lol

To the naysayers - jeff's bars really are stupid thick - he posted a pic here a while back. I really do think they can take it, especially considering his weight and riding style.

I personally think the weight savings will be miniscule, but he's already admitted this endeavor is more for entertainment purposes than anything else, and that's cool by me.

The thread title scares me more than anything.

dosen't matter how thick they are. There are too many factors to worry about. Do you have a degree in stress anylasis or structural engineering? Didn't think so, leave the parts alone.

Hey...it's not without discussion. Dminor has given me points that will help in design.
C'mon...do you play with your shocks outside the design parameters? -with frames\loads on tubes\welds.
When's the last time I said I busted? I bust bolts..eh?

Weight =no spring.
Waiting 'till spring. Dig?
I'm gonna do whatever I do on a chromo frame -sorry, it'll get trashed too fast if Alu.
The weight\strength issue underlies everything.

Other stuff is welding a disc mount to the rigid fork and removing the old bosses. ;)
Don't wait for photo's...be a while.

Not my bike, so I'm interested to hear how it went. I'm also not about to drill holes in my $90 stem and handlebars.

this is a worse idea than drilling your parts. disc on a fork not meant to take it when designed is not a good idea. unless you are having it done free or very cheap, a decent rigid disc for can be had pretty d@mn cheap. if you do have it done, at least use a good front skewer to help stiffen things up.

yeah, it may be all about the technical fun aspect for you, but that, and drilling parts into things is generally not good. see: the drillium fad in 70-80s road racing.

but, i'm sure the designers of you components took into account that someone might want to drill holes in said components during their designing phase......

stuff does brake. stating they won't is only courting disaster. i've seen many, many broken unmodified parts that where claimed "unbreakable" at one point.

not trying to be an ass or anythng jeff, but there are better ways to save a miniscule amount of weight on a bike without compromising structual integrity. and it's all stuff that wouldn't cost much cash. if you keep drilling and shaving, stuff *will* break on you eventually, even at your weight.

i'm saying this as i broke a frame in half, one i thought unbreakable. and yes, it was very high quality steel. even though it (gasp!) wasn't ritchey tubing.
:rolleyes:

I would bore the bars from the end.. make the inside bigger. Also, drill the stem top to bottom. go for it, i love drilling things out.

Methinks we have a few people getting a little too whacked out about this whole thing. For the most part, we're talking steel here, folks. That's welding (or brazing). That's the beauty of steel - - it's something the shade tree fabricator can touch without a degree in metallurgy. In that advent of compact MIG rigs, you don't even have to be a the Wizard of Oz with the TIG torch (but it doesn't hurt :) ) Haven't any of you more timid types ever fabricated your own parts? We aren't talking nuclear physics here - - this is bicycles. Blacksmiths built 'em before Orvile and Wilbur made one fly. I know so many people who are afraid to fix anything on a bike - - they'll replace it and junk the old piece - - because they've been brainwashed into thinking these little machines are more complicated than they are. Now aluminum is a little different animal, but if it's steel and it fell off, shucks, weld it back on and ride! [rant over].

Come on there Mr. Machinist, more stress are towards center lines. Tarnt that the physicalosophy?
Back to the Bridgeport for you :(

yes, i've done all sorts of mods to parts of my rides. but i've stopped short of drilling holes in direct weight and load bearing areas, that weren't designed with holes meant to be in those particular areas......

yes, it's steel. steel can still break. it just *tends* to do it less catastrophically than carbon or aluminum. doesn't mean it doesn't happen from time to time though.

it's not the material i question, it's the engineering of what he wants to do.