DougG

My frame has a third bottle mount under the front side of the downtube. Why, I have no idea, since it's fairly useless with the derailleur cables crossing and passing right over that area. In fact, I just discovered that the FD cable actually wraps over or around one of the protruding screw heads and rubs against it. This might be why my FD seems to go in and out of adjustment frequently!

I can't just remove the screws since that would leave holes in the tubes. So here is my idea: I'll cut off the shanks of the screws, thread them into the downtube with some strong loctite or epoxy, then grind down anything that protrudes.

Does this sound like a good way to do this, or is there an even easier way to plug up these holes smoothly? It's an aluminum frame, BTW.

Camel

NOt a good idea IMHO.

My Waterford seemed at first glance to have similar interferance with the third cage/bolts and cables. No actual problems though.

You might try crossing the cables on the down tube (hard for me to explain), but easy to do when you change cables.

Put a cage there-one with a little offset from the tube, rather than flush.

--Why I'd say not to "plug" those holes:

You might want the third cage (I find it handy for heavier items like tools, or powders inside a .5L nalgene).

You might accidentally damage the frame.

You might want to sell the frame.

Supertick

Why not just reverse the cables. My Cannondale came assembled the same as yours and I just reversed the cables. Works fine now.

DougG

I don't understand what you mean. My RD cable goes from the right shifter to the left cable stop, and the FD cable from the left shifter to right cable stop. The cables then cross in an "X" near the bottom of the downtube because that's the way they have to pass thru the guide under the BB.

By "reverse" do you mean keep the cables on the left and right sides so they do not cross? I had thought about that but understand that it can cause some rubbing problems against the headtube when turning the bars.

It would solve the cage mount and crossover problems, however.

Supertick

Yes that is what I mean. Right to right and left to left. There is no rubbing on my bike and I just did a 3150 mile tour without any problems. When I mounted the third water bottle cage I placed a small presta stem washer under each of the two screws to keep them from rubbing. That way the cables do not cross and the cage is above the cables.

Camel

Superstick's explanation is what I meant to say...

Good luck!

Rowan

Very sound advice. And if cable rub is a possibility on the headtube, obtain some self-adhesive Velcro spots and stick the soft ones on the tube under the cables.

HillRider

Your "cross the cables" installation is sometimes done to keep the housing from rubbing on the headtube when the bars are turned a lot but it's unnecessarilly fussy and the cables housing length can be adjusted to prevent it anyway.

dvs cycles

Pull the screws and use some plastic plugs that are available at most hardware stores.
Could even put some silicone sealant in the holes too. Why do something not reversible?

c_m_shooter

I would plug the holes. You can get set screws from the hardware store that don't have a visible head. They just install with an allen wrench. Use red loctite so they don't fall into your frame.

JanMM

socket set screws

mtnbiker4791

hardware store will also have nylon screws (plastic) that will be 5x1 screws with a flat blade button head that will fit in there good giving you a good seal and not protrude away from the tube much.

nitropowered

Red loctite would make it impossible to remove the set screws. you would strip out the screws. Maybe if it was a 5 or 6mm head, red would be ok.

Use blue loctite

dvs cycles

I plugged all unused holes on my tandem with plastic plugs from the hardware store. Just get the right size and it leaves a nice clean flat final result.
You can even paint them to match if needed.

cascade168

A couple of things that no one else seems to have mentioned ...

What kind of screw/bolt is in the hole now? If it's a "socket head" type, then you should probably try replacing it with a low profile "button head" type. See this page for reference:

https://www.boltdepot.com/metric-socket-products.aspx

Also, assuming you now have button head screws, then the use of cable donuts should also help. Besides preventing the cable from scraping on the paint, they are also very useful for avoiding obstructions.

Donuts here:

https://biketoolsetc.com/index.cgi?id...ing&tc=O-Rings

dobber

A bit of warmed beeswax is sufficient and easy.

dobber

Agreed. The little bit of rub can be alleviated by a piece of clear tape underneath.

teamcompi

Its a goofy thing to do, if you do not want a bottle cage there, plug the hole with a plastic plug, I am sure your LBS has them, a lot of frames have the little black plastic plugs over the rack mounts. If you wish to put a bottle there and leave the cable the same more or less....strip the liner from some cable casing, place over the cables in question, space out the bottle cage using some plastic washers, or any other sort of spacer, 3-5 mm is lots and install the cage. Plastic washers are available at home depot, but any "thickish" washer will work.

dvs cycles

Some clear framesaver tape would solve the hole problem too. Just tape over them.

BigBlueToe

I bought a bike that had the cables crossing when I bought it. I was troubled, having never seen that before. However, a little research and I discovered that it was no big deal.

If the crossing cables is a problem, simply reverse them - switch cable stops. I have certain rides I take where water is not easy to find. On a hot day, having a third bottle holder is a good thing. You can also use it for other things.