Would this set-up intefere with air port readings?

[wellmt]

Hello all.
I have an iBike stem mounted computer. I have the Garmin mounted (on the new mount) in front of the stem. The Garmin is just about below the air port. The little garmin joystick is about a mm lower that the very bottom of the iBike air port. Will this configuration cause readings in the iBike to be off?




For the record, this a BDop Dashboard Genie Pro. Trying it out on the winter trainer. It's similar in style to the FSA mount, but being made of metal it's rigid and doesn't wobble around. It's also lighter.

Thanks

[cujo]

I do not think so. You could rotate the arm down a few degrees. This would lower the garmin and allow for cleaner aire flow to the IBIKE. I would also coast down and cal ride with the garmin in place for the best readings.

Joey Coddington
DLP

[wellmt]

Thanks. Unfortunately that's a low as I can get it due to clearance for the Garmin. If the mount arm was a few milimetres longer I'd be able to get it lower. If you look carefully the Garmin is butted right up against the stem faceplate.

I originally rode with the Garmin mounted on the bars close to the iBike which I think would actually block wind from one direction (light was mounted on the other side) although it seemed to work OK.

I guess for accuracy I'd better do the set-up again. - I suppose I was hoping not to, since everything seems to be working well. Hopefully it would be more accurate rather than less. I guess turbulence caused by the Garmin is the main concern.

[coachboyd]

Wind is a funny thing. Just by looking at that I would think it would force MORE air into the unit. What you might notice is at slow speeds you are fine, but when going downhill or really pushing it that your wind speed is off. I made a very basic mock up of what will happen with the wind turbulence as it hits the front of the Garmin. On the very front, you will have the wind jump up and then swirl back to the unit. . .this will cause a big mess of air turbulence right around the center of the screen of which air will flow over and right into the windport of the iBike.

Again, this is a very basic mockup of what would happen as the wind hits the front, but the main key is wind speed would not be consistent with wheel speed and that could throw off your results. The wind port is VERY sensitive.


One thing that you MAY want to try, although it would block your view of the Garmin, is to move your iBike to the very front of the stem. The would put it a bit higher than the Garmin and you might have better results.

[cujo]

Try going to the same place, but at the bottom of the faceplate. You would be rotating the arm from 4oclock to almost 6. I hope this makes since. This will effect ease of button access on the garmin. But you should be able to see it and the wind flow would be much smoother.

Joey

[wellmt]

Thanks guys. Joey, can't do it. As the arm moves down it effectively becomes shorter. Basically I'm stuck with this position, I've tried everything. I've managed to get 3 to 4mm gap now between the bottom of the air port opening and the garmin joystick.

I guess like all science I should go and test it, weather permitting.

I'll do the same short loop back to back with the Garmin attached and then not attached. I'll try and include a fast descent too. I won't do any iBike changes and then I'll compare the files and see if there is anything significantly different. Hopefully not, as my aim is to not have the mount & Garmin attached for events, only for training.

Don't really want to move the iBike mount at this stage, as it has been working great so far and I can always fall back to bar mounting the Garmin.

[tlee]

What if you flipped your Dashboard Genie the other direction so that the Garmin is not in front of your stem, but to the right of it?

[wellmt]

Sure, I can reverse the L shape easy enough, but my plan was to have the two computers in a line, otherwise I may as well stick the Garmin back on the handlebar. I just wanted to avoid a contraption like the Topeak extender. Thanks.

[cujo]

What if you fliped the mount and changed sides?


Would that let you get the angle right to place it in the lower position?

It must have a arching bend in it that I can not tell from the photo. With my ergomo I built my own mount with a seat post clamp an some reflector pieces.

Joey

[wellmt]

Thanks for all the suggestions.

Nah, still doesn't work. It's this position or nothing. That mount of yours sounds pretty innovative. I have no idea how big or heavy a Ergomo computer is.

In reality the Garmin/iBike would be better the other way around, but the iBike on a stem mount is really reliable. The bar mounts are relatively expensive and I want to leave the iBike on the bike more than the Garmin.

Still, I'll try the experiment in the next week or two and see if the mounting arrangement in the photos screws the iBike readings up.

[cujo]

Do you need to see what tha garmin is reading?

If you are using it to just "map my ride" Flip it upside down. You will not be ablr to see it but it will still do its thing and you acn still down load the info when you are done.

[wellmt]

Sometimes. I use it a little for navigation, but I was going to start experimenting with the programmable intervals - since I can see the Garmin in the dark. It's main use is of course as a data recorder.

For days when I don't need to see the Garmin - e.g. a cycling event - and just want to record data, I'd just stick it in my back pocket and remove the Genie mount.

[wellmt]

OK I've finally figured out a position that works, doesn't intefere with the iBike and gives me my bar tops back. I've given up with trying to mount the Garmin in front of the iBike and instead have put the Genie mount on so that it faces backwards and away from the stem. The Garmin and the iBike are almost exactly level, the Garmin to the right of the iBike. I thought I'd catch the Garmin on my knees if I was hauling out of the saddle, but I can just about get away with it. I've made a couple of mods to the Genie too. I'll post a picture in the next couple of days.

[namblor]

I saw a rider yesterday that had a Garmin attached to the top tube. Seemed to work perfectly for that person, maybe for you too.

[wellmt]

I saw a rider yesterday that had a Garmin attached to the top tube. Seemed to work perfectly for that person, maybe for you too.

When I read that, I thought what a crazy idea. Then I thought about it a bit more and on my summer bike where I rarely need to see the Garmin except to check a direction occasionally, it'd make perfect sense! Thanks.

[wellmt]

Here is how I finally mounted the Garmin next to the iBike on the Winter training bike. I run a shortish (100mm) stem and 42cm bars so it looks a bit cramped but it seems to work.



It now frees up enough of the bar so that I can use the tops quite happily and doesn't interfere with the iBike. The mount only weighs about 52g and is rock solid.



I chopped the carbon part of the mount down and removed the inside end plug so that the Garmin could get in tight to the iBike mount. The Garmin is a little bit lower that the iBike so I can get to mode button the unit by reaching under the unit. I might experiment with the height a bit more.