mountain bike use

[rid-rider]

does anyone have any experience with the ibike on the trails??? A guy I ride with is interested in purchasing one for his mountain bike. Wasnt sure if it would be the right power product given the abuse mountain bikes take. Was wondering if the constant bumps & jumps would interfere with calculations and if it would mess the ibike up. Seems to me there are some sensitive sophistaced measuring devisces inside that little box that could be rattled lose with a mountain bike. Any feedback?

[coachboyd]

I know that there are some people who have used it on the mountain bike. If you are riding trails that have consistency between ground surface, then you can get reasonable results.

If you are doing really technical trails, and switching between mud, grass, gravel, and road, then the differences in crr is going to be tough for the iBike to handle.

We have some pretty technical trails around here that I like to ride, but I haven't put my iBike on yet for it.

[Morocco Mole]

In my opinion the iBike is perfectly adequate for tracking TSS on the mountain bike, but it is not that accurate if you want to do specific intervals or fine grain analysis of how you generate power. I am lucky enough to now have access to a Powertap ANT+ Disc Hub so I can compare both devices. The thing I find is that although the iBike's power seems to jump around a lot more, my average power for the "whole" ride is usually withing a couple of watts. I ride some pretty rough trails so I really think this is to be expected, especially when you factor in bike suspension it must be very difficult for the ibike to calculate power. You would have better results if you rode more tarmac, fire trails, smooth single track etc

As I do all my power interval training on the road bike, as long as I get a good idea of training stress on the MTB I'm a happy. Also, I haven't had any issues with durability etc, I swap between bikes all the time and everything seems normal on the Roadie. I would recommend a stem mount as that position will protect the iBike more in the event of a crash.

[GWPOS]

I agree with Morrocco Mole. I started using the IBike on my training mtb and my racing mtb. It works great on the climbs and flats. I use it when racing as well with the stem mount as mentioned and have no problems with data. The only time it gets really off is when I go down some technical singletrack with switchbacks, then I have to wait for 5 min. for the unit to recalculate tilt again. I really like training with power and just recently did my second FTP test after training with it for about 11-12 weeks and had a 31 watt increase in my FTP. Have your friend give it a shot. There are people on the forums who can help to get it dialed in for a mtb , which was the only tricky thing I went through.

[MultiRider]

I, too, am using my iBike on my mtb. In general, it seems a bit low to me, so I probably need to adjust the CRR. My average power for extended climbs and for the race as a whole is lower than I achieve on my road, TT, and cyclocross bikes.

The primary challenges are CRR and tilt. If calibrated for hardpack, it reads low for soft conditions. And when the fork dives, it reads low. Fork dive is typically pretty brief and doesn't significantly affect average power, but it sure robs me of peak power. There are rides where I know I totally hammered it on certain sections but it was through rocks or over water bars and the fork sucked up some of the tilt and, therefore, power.

All in all, though, I'm very pleased to have a power meter on my mtb.

I asked John Hamman about the possibility of stuff rattling loose and he said it is not an issue at all. Just don't crash on it. Which applies to road, too.

[Morocco Mole]

I agree with MultiRider, I think we may have been estimating CRR too low for MTB use, most of my rides have been significantly lower on the MTB. I finally got a good 3 hour ride on the MTB on the weekend, with a Powertap MTB Disc Hub for comparison. Post ride I played around with my profile to try and establish an accurate match. Now this was 100% on fire roads, slightly damp and plenty of climbing, but not technical. What I found was that the best CRR was around .016 . I was expecting it might be about 0.009 - 0.010 but even that seems to low. If I go the other way and make CDA any higher I get really inaccurate results especially when climbing and pedaling downhill. Will try and post the file tonight so anyway can have a play with it.

[jazclrint]

I just ordered a wireless speed sensor for my Mt. Bike. When I set-up the profile (#2) should I just change the CRR to .016 as I set-up the profile as a good place to start?

[GWPOS]

Morocco Mole, what is your fric numbers when you set it at .016? Just kind of curious. Mine seems pretty accurate, but at times I am not sure.