Water in the rear subframe

[Philip]

Has anyone figured out yet where to drill a hole to allow all that water to drain?

I washed my bike last weekend. At the track today, not dusty, not muddy, perfect. The bike is still clean, but the rear subframe looks like it has been through a mudhole. The water came out and picked up all the dust.

I also do not want to be carrying that water around.

 

[Fod]

Fill the cavity with helium balloons!

I would just go crazy with the speed/drain holes. Warranty won't matter either way from the looks of it

 

[gprix1]

Interesting. Looks like drilling a couple of small drain holes may become a common mod.

 

[Philip]

Who wants to go first?

 

[Philip]

@Mark911 -- Have you drilled holes there already?

 

[rayivers]

If it were my bike I'd take off the black plastic mud guard / shock protector, and if there's a chamber in the upper subframe plastic (which I think may be inside that V-shaped area below the front tip of the black 'Future of Fast' graphic), I'd drill one small hole into the rear of it from the wheel side & see what happens. If it doesn't work, either try another spot or just put the black plastic back, no harm no foul.

 

[Fog 25]

I think you would have to Swiss cheese it with all the individual chambers in the subframe. You would be better to try and seal the subframe.

 

[Mark911]

I noticed this the first week I had my bike. I mentioned it to Alta back when but apparently their using the same revision plastic on the new bikes. There's several weep holes throughout the various cavities, none seem to work very well. I just cleaned the transition between the rear fender and the lower mud shield (the black thing) and taped over it with black duct tape. That's where most of the water enters while riding or washing. There's a big gap for the rear tail light harness as well. I still end up removing the subsection between washes and let it drain so it doesn't make a mess as you pointed out.

I also noted that the cooling system overflow hose just dumps all over the battery pack and it'll make a mess also. I added a much longer hose and routed it down to the bottom of the bike. The newer bikes have a pressurized system so the overflow circuit might be different.

 

[Judaslefourbe]

I also noted that the cooling system overflow hose just dumps all over the battery pack and it'll make a mess also. I added a much longer hose and routed it down to the bottom of the bike. The newer bikes have a pressurized system so the overflow circuit might be different.

You are correct. We validated that the cooling system can be pressurized, even on older models. Feel free to plug the overflow hose so it stops puking everywhere.
One less maintenance item!

 

[Philip]

Here is how to check if your coolant system is already plugged up:
https://altaownersforum.com/threads/plug-your-coolant-overflow-hose.194/

 

[Philip]

I have decided to tackle the filthy rear subframe problem on my new bike.

This is where the water puddles after every pressure washing:


All the large cavities have drain holes at the bottom. But none of the small ones do.

The water and the dirt seem to collect mostly in the outer layer of these "pockets", whereas the inner pockets are mostly clean, and presumably not as full of water:




The small pockets in the rear seem to be either well-drained or very small to contain large amounts of water. Many of them were relatively clean, which led me to a conclusion that the water that spews on my freshly washed subframe mostly comes from the large outer pockets along the sides.

The water must be entering though this joint between the subframe and the rear fender (see the red outline).

In order to drain all the pockets at the bottom, I'd have to drill 50 holes (see red X marks)!


I didn't like the idea of adding all these holes.

So, here is what I did. Here are my tools: a torch, a piece of steel wire, and an electric drill with a thin bit.


I heated up the wire and poked a hole in the separator wall at the bottom of each pocket, making it drain into another pocket or sometimes outside:


Some holes I was able to drill with the electric drill:




I tested how the water drains, and I am glad I did because many of the holes created with the hot wire became almost closed when I was removing the wire that was still hot. I had to re-do those holes until they were draining.

That's pretty much it. I will let you know how it works in practice.

On my other bike I will try taping over that crack between the subframe and the fender with a narrow scotch tape. I am curious which of the two bikes will be cleaner and look nicer the day after the wash.