RWS Modification Question

Post Reply
Norm
Posts: 99
Joined: Sat Feb 02, 2008 7:56 am

RWS Modification Question

Post by Norm »

Is there anything magical about the tubing used in the RWS?

I'm currently running the stock RWS on my TT bike with the intake taped in place on my bar about 2/3's the way to the brake lever. While this is an OK position and I'm getting clean air there, I'd like to experiment with a more compact installation that places the intake beneath and forward of my stem. The main problem preventing me from making that happen is that the RWS tubing kinks in the bends.

I'm considering going down to my local hardware store to see if I can find a rigid alternative -- something like coper tubing that I can bend without kinking.

What kinds of things should I consider while shopping for materials and doing the install? Is inside diameter important? Do I need to avoid bends of a small diameter? Is the intake scoop necessary? Are there any considerations other than getting the air intake into clean air?

This isn't urgent, I'm just tinkering with my setup. If it fails, my current setup with the stock RWS is perfectly fine.
User avatar
lorduintah
Posts: 642
Joined: Fri Jan 11, 2008 9:37 am
Location: Plymouth, MN

Re: RWS Modification Question

Post by lorduintah »

I would look for TYGON® tubing. It is clear and plastic, but can be found in different wall thicknesses, which would prevent the collapse issue.

It is also easy to cut to length and as flexible as any other rubber. You might have to look at Scientific Supply or Pool supply web sites, not sure if many hardware stores will carry a variety, if any at all.

Tom
Norm
Posts: 99
Joined: Sat Feb 02, 2008 7:56 am

Re: RWS Modification Question

Post by Norm »

OK, here's experiment #1:
IMG_0323.jpg
IMG_0323.jpg (63.49 KiB) Viewed 21260 times
I found some 1/4" OD copper tubing at Home Depot, which fits nicely in the 1/4" ID plastic tubing of the stock RWS. I cut a 16" segment of the tubing and bent it into an S shape with 2.25" diameter arcs, being careful to leave enough of a backward run so I can zip tie it to the stem. The idea is to have a rigid straight tube sitting between the stem and the front wheel right inline with the bike body. Here's what it looks like on the bike:
IMG_0326.jpg
IMG_0326.jpg (86.22 KiB) Viewed 21253 times
Before I permanently install it, I'll wrap it in black electrical tape to make it a little less noticeable. Even with the black tape, I think it will look a little strange hanging out down there. What do you aero / wind scaling / wind offset gurus think?
coachboyd
Posts: 527
Joined: Thu Mar 27, 2008 7:01 pm
Contact:

Re: RWS Modification Question

Post by coachboyd »

I like that!

I think if you somehow fastened it to the front of your stem you would also have a good connection to the iBike wind port. I also don't think you need the tube extending out as far by your wheel.

As long as you do your cal ride with that RWS in place, you will get good data.
Looking at it, you may not even need to have it swoop back towards the head tube, just make it shaped like an elephant's trunk.

I may swing on down to the hardware store and experiment with something like this as well.
Boyd Johnson
http://www.boydcycling.com - high performance carbon wheels and accessories
rruff
Posts: 445
Joined: Wed Apr 23, 2008 10:48 am

Re: RWS Modification Question

Post by rruff »

Looks good to me. Is the tube supported anywhere? Also, I'd use aluminum tubing... weighs ~1/3 as much. And I wouldn't cover it with tape.
NCH1
Posts: 100
Joined: Mon Dec 28, 2009 12:33 am
Location: Sydney, Australia

Re: RWS Modification Question

Post by NCH1 »

I'm thinking of putting something together like this, great idea!, but with aluminium as rruff suggested. Does anyone have any thoughts on giving the pipe some stability, besides the use of cable ties?- I'm pretty sure there is going to be some bouncing around and therefore likely to affect the wind scaling and accuracy of readings.

Thanks

Nik
gerrard
Posts: 50
Joined: Mon Dec 27, 2010 3:22 am

Re: RWS Modification Question

Post by gerrard »

Any reason for having the big bend in the tube rather than just running it up the inside of an aerobar and having it stick out the front a bit further?

Are the end pieces on RWS anything special or can I pick up something similar at a hardware store to use instead?

Gerrard
NCH1
Posts: 100
Joined: Mon Dec 28, 2009 12:33 am
Location: Sydney, Australia

Re: RWS Modification Question

Post by NCH1 »

Yeah, I'm thinking of something like that. Possibly a a short S-bend, Z-bend or installation as per existing RWS installation under the aero wing, but with aluminium. I might also see If I have an old bicycle pump hose attachment and experiment with the rubber insert. There is still the issue though of afixing the RWS. If it is too elaborate it will be unstable whilst in motion, not to mention the difficulties posed in dismounting the unit to download ride data.

Nik
User avatar
racerfern
Posts: 1356
Joined: Fri Jan 11, 2008 12:47 am
Location: Baldwin, NY
Contact:

Re: RWS Modification Question

Post by racerfern »

@Norm
It's OK if the original RWS tubing kinks at the bends as long as you're not at the point of complete restriction. Just set it up and blow gently on the intake end, you'll see the iBike wind react immediately.

Also, with the big "S" you have can you zip tie it to the headtube? That will give a lot of stability.

Like rruff said, aluminum is key.
Fernando
User avatar
andrep
Posts: 44
Joined: Wed Jan 09, 2013 9:21 am

Re: RWS Modification Question

Post by andrep »

Hi,

I created my own RWS-System and like to ask you some questions about it (have a look at the pictures below)

1. Why don´t you offer a special tool to install the RWS (for example between the handlebars ... )
2. How much influence on wind scaling etc have LITTLE changes of the RWS (for example if the front comes 1 cm more out of the aluminum pipe)? Should I fix it so that it can´t move forward or backward?
3. If I put my handlebar-bottle on the bars, the tubeline is changing a little bit - has it an influence on wind scaling or the measurement?
4. The pipe can move 3-4 mm up or down - is it a to
4. Any thoughts?
IMG_1284.gif
IMG_1284.gif (464.78 KiB) Viewed 19173 times
Attachments
IMG_1286.gif
IMG_1286.gif (462 KiB) Viewed 19183 times
IMG_1285.gif
IMG_1285.gif (421.64 KiB) Viewed 19176 times
User avatar
andrep
Posts: 44
Joined: Wed Jan 09, 2013 9:21 am

Re: RWS Modification Question

Post by andrep »

Thoughts on my post above? ...
TriBike
Posts: 70
Joined: Sat Jul 02, 2011 9:27 am

Re: RWS Modification Question

Post by TriBike »

[quote="andrep"]Hi,

I created my own RWS-System and like to ask you some questions about it (have a look at the pictures below)

1. Why don´t you offer a special tool to install the RWS (for example between the handlebars ... )

Not every rider would benefit from this, some, such as myself, do not have the space in between the bars to use such a device... There are plenty of modified RWS Setups out there from our users, different strokes for different folks. Find what works best for you and run with it.

2. How much influence on wind scaling etc have LITTLE changes of the RWS (for example if the front comes 1 cm more out of the aluminum pipe)? Should I fix it so that it can´t move forward or backward?

I believe that there can be an influence, quantifying the change it would have on wind scaling would probably be dependent on the amount of movement etc. and that alone is what makes me want to tell you to be sure that your "intake end" of the RWS has little to no movement in any direction. I also find that black electrical tape works as a better fastener than zip ties.

3. If I put my handlebar-bottle on the bars, the tubeline is changing a little bit - has it an influence on wind scaling or the measurement? Again, little to no movement would be the best option. Also, be sure that the bottle is not squeezing on the tube, which will block the air pressure, and potentially cause erroneous readings.
4. The pipe can move 3-4 mm up or down - is it a to

I think that is too much movement personally.


4. Any thoughts?

Here are a few photos of my personal setup, I find that the RWS Intake works for me best, under the base bar of the handlebars. You can see in the actual race photo (just near my right knee in the photo) that there is nothing impeding the flow of "Clean Air" to the RWS, and nothing Pinching the hose to prevent proper air pressure. Also, you can see that a tube in the center of the Aero Bars would not work for my particular setup. Using a RWS often times requires a bit of imagination and testing.
Attachments
photo copy 2.JPG
photo copy 2.JPG (30.76 KiB) Viewed 19052 times
photo copy.JPG
photo copy.JPG (92.15 KiB) Viewed 19054 times
photo.JPG
photo.JPG (135.17 KiB) Viewed 19047 times
User avatar
andrep
Posts: 44
Joined: Wed Jan 09, 2013 9:21 am

Re: RWS Modification Question

Post by andrep »

Thank you "TriBike" - helfpfull answers and I will fix my RWS as best as possible.

And yes - you are right - my solution isn´t the best for everyone .. and yours not for me, because I have my "bottle" between the handlebars and so there is no chance to catch the side wind ... Thanks!
Post Reply