iBike and suspension?

[clip]

How iBike reacts if you use it with a full suspension bike? The bike don't stay in the same level (tilt) all the time, for example in the uphill rear suspension compresses and front end extends, and in downhill the situation is opposite. Does iBike give bigger and steeper hills in this case?

I know iBike is designed to a normal road bike use, but I'd like to know this before I buy one. I'm not going to use it in real rough off-road riding, but perhaps with my suspension bike I can ride more lumpy routes using iBike than with a full rigid bike, right?

How about if I make a suspended handle bar mount for iBike, which is well damped so it won't make any excessive up-and-down movement all the time but filters most of the shaking away? How sensitive the iBike is for a low amplitude "suspension" movement (some centimeters)?

[travispape]

How iBike reacts if you use it with a full suspension bike? The bike don't stay in the same level (tilt) all the time, for example in the uphill rear suspension compresses and front end extends, and in downhill the situation is opposite. Does iBike give bigger and steeper hills in this case?

I know iBike is designed to a normal road bike use, but I'd like to know this before I buy one. I'm not going to use it in real rough off-road riding, but perhaps with my suspension bike I can ride more lumpy routes using iBike than with a full rigid bike, right?

How about if I make a suspended handle bar mount for iBike, which is well damped so it won't make any excessive up-and-down movement all the time but filters most of the shaking away? How sensitive the iBike is for a low amplitude "suspension" movement (some centimeters)?

Clip,

I'm the iBike2 developer, used to be primarily a MTB rider with a full suspention bike, and have an interest to dig into the questions that you are bringing up. You would think that I could come up with some detailed answers for you and some data to back it up; however, I don't have much. I'm just so very slammed with other priorities--it's tragic really for someone who still loves MTB riding so much. Tragic I say!

Here are a couple of screenshots from a MTB ride that I did with a borrowed bike (a Gary Fisher FSB) in the Colorado front range back last September. I didn't do anything like a good job trying to get a good calibration before I did this ride, and I think it underreported power as a result. I simply threw on the iBike with a wired speed sensor only, did the tilt cal and wind offset cal, tried to do a coastdown on a gravel parking lot to get something close to the right numbers loss numbers. Friends were waiting, the wind was blowing, and I had to turn corners during the coastdown attempt, so it is definitely low-quality.

However, despite all that the ride data looks good. Here's what the ride looked like:

MTB ride

mtb ride.png (42.75 KiB) Viewed 3863 times

Some things that stand out:

* I think that overall the power is too low based on what I remember from the ride, but I think that can be explained by the rush job for the coastdown. This was back before I had coded up the new procedure where you do a 4 mile ride in addition to the coast-downs.
* The slope data looks very reasonable. This is ride data that came straight out of the iBike without attaching a profile, so it is pretty good that the average slope for this out-and-back came out so close to zero. This is very promising to my mind.

And here's a view of the slope & elevation data (BTW, for the very observant, I had to do a developer trick to be able to see this since I don't have a profile attached):

MTB tilt

mtb tilt.png (43.09 KiB) Viewed 3861 times

What this is showing is that I didn't get any areas of high vibration. It is also showing that the unprocessed slope data coming out of the iBike is very reasonable. The full suspension did not cause anything like a big problem. Maybe not even a little of a problem?

I should mention that I did do another MTB ride on the same bike on a rougher trail where I did manage to get a couple of high-vibration areas; however, it looks like it might be possible that vibration on a FSB MTB is actually less of a problem than on a road bike on rough roads. Maybe Steve Davidson could chime in, but I think this is due to the fact that it is the higher-frequency vibrations that cause the problems. The suspension would filter out that high-freqency stuff pretty well. (And by the way, I think there is reason to think that it is mostly the front suspension that matters--you might not even need a full-suspension MTB to get good off-road results.)

By the way, I just don't remember much about the Gary Fisher that I was riding other than the fact that it seemed to be a couple of notches higher than the entry level bike you would find in the bike shop--maybe a $1600 bike. FSB with disk brakes.

Now that people are upgrading to wireless mounts, I'm hoping that others will take the time to put their old wired mounts on their mountain bikes to try it out. I'm very interested in doing it myself, but just haven't had the time. It is surprising to me that we haven't seen more data from customers also. (If you have some, post it!) But based on the very very little data I've generated myself, I'm not seeing anything that would indicate the iBike would have any big problems giving useful results on a FSB MTB, even on rough single track.

I can't promise you wouldn't run into trouble on your bike--it would be nice if other customers who have tried their iBike on their MTB would chime in!

Travis

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Travis, thank you very much for a fast answer! And actually your answer was more promising than I waited.
Coastdown calibration may be a challenge in MTB use, especially when riding in variable terrain.

There is only one way to find out how fine the iBike works in my use. Let's visit in iBike Store... the product looks so promising. Weather is still quite cold here in Finland (today about zero degrees of Celsius), so the battery life will be quite short. Fortunately spring is coming .

One question: is it possible to export iBike data to another format (*.txt ?), that can be used for example in MS Excel? I have an old version of FRWD sport computer (gps "datalogger", http://www.frwd.fi/ ), and like that text format export possibility to make individual graphics in Excel.

[racerfern]

@ Travis:

WOW. I am impressed at how good the data looked. I expected to see a mish mosh of up and downs. I may have to buy a mount for my MTB.

@ clip:

The iBike2 saves downloaded data in .csv format as default. After downloading with iBike2, the files open perfectly in Excel independent of the iBike2 software.

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...The iBike2 saves downloaded data in .csv format as default. After downloading with iBike2, the files open perfectly in Excel independent of the iBike2 software.

That's a good news. I just sent an iBike order, I can hardly wait to get mine .