Bicycle Mechanics - tapping holes in frame

hi ,any reason why i cant drill through and tap straight into my steel frame to provide bottle cage mounts ?(rather than getting the bosses brazed on ),any advice appreciated !

Yes, there is a reason that is not a good idea.

The frame is thin. You will not be able to create enough threads to get the required strength, even in Cr-Mo. Forget Al or carbon composite.

Even on a fairly low end cromo bike the tube walls will only be 0.9mm thick where the bottle bosses would be. A high end race bike might be 0.4mm.

hi ,any reason why i cant drill through and tap straight into my steel frame to provide bottle cage mounts ?(rather than getting the bosses brazed on ),any advice appreciated !

All you need are these (http://www.imperialinc.com/items.asp?item=0088420)!

There is a tool needed as well, but it works great and they're easily replaced if you strip one.:thumb:

Would Riv-Nuts (http://www.jensonusa.com/store/product/TL401J59-Marson+5Mm+Riv-Nut+Zinc+Plated+Steel.aspx?sc=FRGL) work in this instance, or would the steel still be too thin to prevent the rivnut from pulling through under load?

Either way, the best thing would probably be to have a framebuilder do the work.

On the Park Tool site they show you you can use a wheel skewer and axle as the rivnut tool.

http://www.parktool.com/repair/printhowto.asp?id=147

I think rivnuts are more commonly used on aluminum frames though.

Rivnuts won't pull through even thin steel tubing walls, particularly with the low force a water bottle and cage put on them.

thanks for the help. just looking for a cheap solution.it's just my old fixie but it does need a bottle. i like the riv-nuts but dont like the price of the tool! i guess i'd never use it again so maybe the answer is to get my mate dave to braze them on for me.
so; does this mean a respray due to heating the steel and paint?what doyu think are there other options?

You can buy a cage that straps on, and no holes or brazing needed.

^^Yep, or if you're really really cheap you can use 4-6 zip ties to hold a standard one on. If not, riv nuts work well. Brazing is even better, just drilling through is not.

And yes, the brazing or silver soldering will ruin the paint for a good inch or more around the point you put the brazeons.

Go and re-read the part above that relates to using a QR skewer as an improptu rivnut setting tool. No need to buy the actual tool.

thanks for the help. just looking for a cheap solution.it's just my old fixie but it does need a bottle. i like the riv-nuts but dont like the price of the tool! i guess i'd never use it again so maybe the answer is to get my mate dave to braze them on for me.
so; does this mean a respray due to heating the steel and paint?what doyu think are there other options?

You can make your own tool with a bolt and a couple of nuts and a washer or 2. About $1.00 at the hardware store.

On the Park Tool site they show you you can use a wheel skewer and axle as the rivnut tool.

http://www.parktool.com/repair/printhowto.asp?id=147

I think rivnuts are more commonly used on aluminum frames though.

This is probably the most useful link i've seen all year on bikeforums.

^^Yep, or if you're really really cheap you can use 4-6 zip ties to hold a standard one on. If not, riv nuts work well. Brazing is even better, just drilling through is not.

I don't know if I'd trust zip ties, but back before bikes commonly had water-bottle braze-ons (and dinosaurs roamed the Earth), we'd attach them with hose clamps. Perhaps not the best for paint, but we never lost a bottle cage!

Some of the aftermarket bottle-cages even had small 1/4" wide clamps that look like small hose-clamps!

When using the zip-tie method, put a layer of 3M mounting tape (exterior grade) on the cage before putting it to the frame tube. Make sure it's exactly where you want it, as it's very difficult to reposition once stuck. This is basically the same stuff that is used to affix car emblems and such. That bottle cage won't go anywhere. The zip-ties are then for a little added strength.

Wallbike has the Klikfix Bottlefix for $11 it's a cheap and elegant solution
http://www.wallbike.com/klickfix/bottlefix.html

just thought id post that i have successfully used the park tool link to riv nut my bottle cage on.
thanks for all the posts
i made a tool using a standard skewer, some 12mm steel tubing and a couple of washers, and used the aluminium riv nuts.
worked like a dream !

I use these (http://www.lowes.com/lowes/lkn?action=productDetail&productId=93124-53540-01HMCGF&lpage=none) with a piece of old tube to protect the frame. It's not too inelegant for me and works well.

http://www.twofish.biz/bike.html

When using the zip-tie method, put a layer of 3M mounting tape (exterior grade) on the cage before putting it to the frame tube. Make sure it's exactly where you want it, as it's very difficult to reposition once stuck. This is basically the same stuff that is used to affix car emblems and such. That bottle cage won't go anywhere. The zip-ties are then for a little added strength.

+1 This is by far the easy and non destructive way to go! The cage on
my old columbia is stuck on just this way without mishap for several years.

Try these from Lickbike (http://www.lickbike.com):

http://www.lickbike.com/lickimages/3242.gif

just thought id post that i have successfully used the park tool link to riv nut my bottle cage on.
thanks for all the posts
i made a tool using a standard skewer, some 12mm steel tubing and a couple of washers, and used the aluminium riv nuts.
worked like a dream !
Congratulations. That Park method is a winner for sure, at least with aluminum Riv-Nuts. Takes a whopping amount of hand strength to do stainless ones that way.
I do have a Riv-Nut intallation tool, but I've tried Park's method and it works well.

When I saw this thread with the Park method I used it to tighten a friend's bottle mounts on his Cannondale. Worked like a charm.

Drilled the frame to add a cage on the seat-tube. Found these

http://www.mcmaster.com/param/images/rivets/93495a130_search.gif (http://www.mcmaster.com/param/asp/psearch.asp?FAM=rivets&FT_5722=240073&FT_518=52165&FT_5822=240994&session=desc=Rivet%20Nuts;rivets,518=52165,5722=240073;5822=240994)
Rubber-Insulated Rivet Nuts (http://www.mcmaster.com/param/asp/psearch.asp?FAM=rivets&FT_5722=240073&FT_518=52165&FT_5822=240994&session=desc=Rivet%20Nuts;rivets,518=52165,5722=240073;5822=240994)

Also known as well nuts and well-nut threaded inserts. Great for fastening metal to plastic, damping vibration, and sealing out moisture. Can be installed with a screwdriver.


at Sears Hardware as a alternative to standard Rivet-Nuts.
I tried the Velcro type before but could not get it tight enough to stay in place.

I don't know if I'd trust zip ties, but back before bikes commonly had water-bottle braze-ons (and dinosaurs roamed the Earth), we'd attach them with hose clamps. Perhaps not the best for paint, but we never lost a bottle cage!

Like these from Velo-Orange (http://www.velo-orange.com/bocacl.html).