I always liked the look of classic drillium brake levers, but having the brake cable exit the top of the lever is not a classic feature I miss. I really want some drillium levers with aero routing, but as far as I know, no one makes/made such a thing.

I was thinking of buying a set of new Tectro Campy knock-offs, and doing the ventilation job on them myself. I have access to a proper machine shop drill press and lathe. I'm actually considering riding these things. What do you all think? Suicidal? I'd especially like to hear from engineers.

I think it's suicidal only if you MEAN to hurt yourself

That said, I would think that even and consistent spacing would be the hard part. There are some vented aero levers though, look for Dia-Compe Aero Grand Compe:

A jig to get it done properly would be necessary, make that and you're basically done. Hard part'll be making it

Nice! I'll bet those cost a fortune when/if they turn up on eBay.

Where do you think I got the pic... hint hint...

EDIT: They're cheaper than MOST brifters...how's that

Drillium would require a drill press and a mill, not a lathe.

Tooling is the key to success. Designing and fabricating the tooling is MUCH harder than detailing the parts.

Be careful drilling brake levers and other safety-related items. You don't want a catastrophic lever failure right when you need the lever the most (a panic stop).

The mill would be used for the chamfering? Now that I think about it, I don't want slots, just holes. Actually, the shop has a mill, and a five axis CNC machine that I don't know how to use. I wonder if the machine could be programmed to make the holes?

you dont need a drill press but it makes things a lot easier. as long as you don't go overboard with the holes you have nothing to worry about really

You need to make a set of jigs/fixtures to hold the complex shaped part without allowing it to move and thus marring it. The VMC could be programmed to do the job of course.

Alternatively you could use soft jaws and some kind of rag/leather/etc. and hand do it very carefully. Layout the pattern and center punch the holes then use a centering drill which will give you a nice hole plus an angled chamfer of larger size around it.

Probably easier to buy a set of levers unless you have the skills/tools/extra time or just like fabricating stuff (I do).

Yup, I like fabricating stuff as well. I also want aero routing and a campy style quick release -- I've never seen originals like that.

I didn't even know it till I bought an old pair but most late 80s Modolo levers have routing for the top of the hood and for internal aero routing.
Cheaper than tooling unless you have the time and material. Just skip ove the "rare" wording.

https://cgi.ebay.com/Mavic-410-Brake-...item41515f48a5

They do, but you need the part that allows you to do that and they don't all come with it, and you need to drill your handlebars and route the cable/housing through them at the bends where the levers are mounted and at the tops where the cable/housing exits.

vjp

A mill would typically be used for making or deepening slots/grooves/veins in crank arms, seat posts, brake arms, etc. Slots are typically used for infilling with paint. The countour of the bottom of the slot is determined by the profile of the cutter head. (flat, round, oval, ...). A mill can be used to make holes, too, round or elongated, flat-bottomed or round bottomed. The side walls can be square, tapered, or whatever - it's all in the cuter profile(s) you have.

A drill press can be used like a mill if it's fitted with an end mill (the cutting bit) and equipped with a sliding machinist's vice (typically hand cranked). These vices are relatively inexpensive (under $100), as are the carbide bits (under $50). Just go slowly (low feed rate and shallow depth of cut). Don't forget to use liberal amounts of cutting oil.

Where is DrilliumDude when you need him?

Here's my own set of Diacompe AGCs presently on my 84 Peugeot PSV:

They're stamped with the perforations and not really "drillium" but they are very light. The original silicone (instead of latex) hoods also have lasted all these years with no signs of aging and rotting. Highly recommend these for classic buildups if you want light weight, lasting quality and looks.

If you want real light wieght but not fussy on quality, these CLB aero levers could work for you:


Again, not really "drillium" but stamped with perforations, this time at the back of the lever arms.
Not the cleanest finished levers, but passable.

Hmm. That's interesting. What are the relative advantages of silicone and latex (and gum rubber???) for this application? I had never thought of their being made of different materials.

We used a cnc mill way back in the day to do chain rings. You could program it and it would come out perfect every time. I don't like to do drillium on derailleurs or brake calipers or hubs because they are engineered to their limits already. For a one time use like a world championship or something, I'd give it a shot. I think brake lever s can be successfully drilled, but the weight saved is really insignificant.

I got a funny story about this nonsence: a guy in work saw us drilling chainrings and asked us why we were doing it. After we explained the cosmetic, and weight reduction reasons he seemed to have a glimmer of understanding. Weeks later, I run into him, and he has black tape all over his (really cheap) bike. He had drilled 7/8 th inch holes through the frame, down tube, seat tube, and top tube. He drilled the ashtabula crankset up through the end of the arms, right through the pedal threaded ends! He drilled the brakes, the seat post, everything. He thought we would make fun of him so he covered all the holes with black vinyl tape!
The tape probably weighed more than the metal re removed.

Silicone has much much longer life than latex rubber. that's why silicone material is used for exterior caulking on buildings. They also stand up to heat and light, tons better than latex rubber, that is why all halogen car headlight bulb gaskets (O rings) are now made from the stuff.
Not 100% sure the AGC hoods are silicone, but that's the only explanation I can think of why the original white hoods on mine had not dried up and cracked after over 20 years on the bike in all kinds of environement.

Chombi

This is the fixture (with a lever installed and ready to drill) that Frank Spivey used to make drillium brake levers back before you could get them drilled from the factory:


More info of Spivey and drillium here: https://www.velo-retro.com/peterjohnson.html

^^^That is unbelievably cool.

Silicone is about as environmentally stable as anything man-made. Latex, also known as gum rubber, is almost the exact opposite. It is damaged by UV and ozone (smog).

Silicone can stretch at least 100% before breaking (actually, elongation is up in the 200 to 400% range). However, silicone is notch sensitive, so if it is nicked, it will break long before it gets to the 100% elongation. If you use the silicone in compression, notch sensitivty is less of a concern.

You can add fillers, such as fibers, to improve the properties.

This might help:

https://www.raydobbins.com/molteni_re...lling_ring.htm

https://www.raydobbins.com/molteni_re...ing_levers.htm

Thanks for the link!

Thank you for the links!

Campag super record levers where drilled while the aluminum was a Flat sheet,
then it was put into the punch press, and shaped into the part.

The D-C AGC and the CLB appear to have done the same.