2.4 PT Dropouts

Perhaps I jinxed myself. Ride number 2 wasn't as successful. As a FYI, the ride was a consistent 3-5% grade, until minute 40, when i turned around - notice speed line on chart.
It all started out good, with Watts being reported on the CPU. Then, I tried to zero the torque and it showed -0. So I reset to 0 and continued riding, within a minute of my restart, the power numbers faded quickly 200, 140, 75, 15, and then hovered under 25. I thought I may have displaying Torque on the CPU, tried the same rezero process, and it would read normal numbers, then quickly faded to under 25.

Also, notice the power spikes between minutes 7 and 40, those were after I pulled over and tried to reset the torque.

I checked my MAX and AVG power on the CPU and noticed that the AVG numbers were dropping continuously, like it was actually averaging the under 25 Watts into my ride numbers. Then I tried to see if I could get the MAX Watts to increase and it registered a higher number. The transmission icon was on continously.

Got home and downloaded the file and it showed accurate numbers for the first 7 minutes of the ride (this is when I tried to zero torque) and then everything was much lower.

I did a torque test and the default number is reading 538 - obviously higher than the desired 512.

Jesse - you out there.....any ideals? Anyone else seen anything similar?

Thanks
Chris

 

After blasting Saris on this forum, I was at the end of my rope. However, I sent back my malfunctioning 2.4 and the replacement works like a charm. Did a 100 miler with 9000 feet of climbing on Saturday, not one data drop. Did an easy 60 miler on Sunday, not one data drop.

Although I still think there is a better way to handle these problems, I am encouraged that the product actually works as advertised when you get a good one!

 

I spoke with Saris yesterday and we went through a more thorough process of resetting the torque values to 0 and "testing" the torque offset - which was at 511, which is spot on. Only had a chance to do a round the block test and it seemed to be picking up the power readings accurately again (not under valuing them).
Saris and I concluded that I somehow wasn't resetting the torque properly - resulting in lower power ratings.
I'll continue to monitor and advise.

 

That is great to hear ... unfortunately, we get a skewed perspective on these things from the forum... Yet, perhaps you should your new hub back to SARIS so they can see what it is that is right about this new functioning hub, rather than seeing what is wrong with the failing ones. I wish they could reproduce it on all the hubs that go out and I would have bought one myself.

 

Ever since Saris walked me through the zero torque process, the 2.4 has worked flawlessly, no drops or other issues. As Jesse previously suggested, I think there were a few of them that had some issues that they've addressed.

 

For zeroing torque, I select the Watts (top) line of the display, hold the Select button down until the 'Watts' flashes, hold the Select button down for 6 seconds and hit the Select button one more time to get back to normal mode.

What more does, "...a more thorough process of resetting the torque values to 0 ..." involve? - TF

 

Well, my interpretation from the PT manual was to just press and depress the select button (instead of holding it down for x number of seconds, 6 as you suggested). The Saris rep had me hold it down for ~10 seconds - "watts still flashing" and then depress once more to set it (flashing stops).
I have since zeroed by holding the button for 10 seconds instead of just depressing and it has been working fine.

 

Saris needs to write up a new manual....the one they have is just plain awful!
I too have had problems with power reading low, and will try setting the torque correctly now that I know how.

 

I'm seeing a very similar problem with frequent dropouts on a 2.4 SL (*really* annoying when you're doing intervals around a velodrome and it cuts out ... ). Random times, more frequent but not only around town. This is a 28 hole job shipped to Australia via Trek Aust (the Australian distributor). I replaced all the batteries with new ones, no difference. Was the lot that was shipped to Australia one of the first ones that had possible quality control issues? I'm not sure where the serial No. is on the hub to check it, any tips? (it's going back under warranty, it's defective!).

For what it's worth, there's a second problem with these hubs. I bought the unit to lend out to riders I coach, and need to be able to swap cassettes quickly and easily - thus the 2.4 ... perfect... right? 5 mins to swap between bikes and no wires to break.

Except that it has an alloy freehub body (Shimano) and when run with an Ultegra 10sp cassette, the cassette rings dig in and have to be pried out (and often damaged in the process). Many AL alloy hubs have this problem with 10sp (which is why Shimano's 10sp dura ace freehub body is different, it's the only Al alloy freehub Shimano do, and it's got deeper splines to reduce/eliminate dig in). I'm hoping that there's a steel freehub (the hub came from some manufacturer, is there a steel one I can swap in? 15 grams, who cares? I want the thing to last more than 1500km) or that there's a 10sp specific freehub body I can get for it so it doesn't keep getting jammed up. As above, both Shimano (dura ace alloy freehub) and Campag alloy hubs don't have this problem, it's only other manufacturers that insist on using Al alloy freehub bodies that are not designed to work properly with Shimano 10sp.


American Classic have ack'd the problem and supply little radial shims for their Al alloy freehubs so they last with 10sp. Is any such thing in the pipe from Saris, or any solution?

 

anyone else still having issues with their 2.4 PT?

i just purchased mine at the end of april (not sure when my wheelguy got this 2.4 in stock). did a 4 hour ride today with 10 drop offs. anyone with any advice? ill try out the zeroing out the torque for 10 seconds tomorrow.

another issue.. within the first week with the wheel, the computer displayed "lo batt", so i replaced it with the replacement battery it came with. after one ride, its again displaying "lo batt".

any ideas?

 

Mine's on its way back to the US for testing/replacement. They aparently aren't interested in fixing the problem with the freehub though.

 

did you they ask you to go through the whole changing the batteries on the computer and the hub before they accepted the computer back from you?

im guessing im going to try changing the hub batteries today. nothing to lose.

 

No, because I'd already done that.

 

replaced my hub batteries this morning and went out for a ride.

nothing else was turned on, with the exception of the pt 2.4, and i still managed to drop about 6 times in the span of 45 minutes.

i turned on my garmin edge 305 for the last 15 minutes and dropped about 5 times.

i guess ill have to reach customer support. thanks for the replies.

 

I noticed that most of the posts regarding this subject were prior to mid April of this year. I tried to order a 2.4 in April and the back order dates were extremely long and undetermined. A friend just received his today after being on back order for about 2 months. I am curious to know if Saris has ultimately fixed the problem at this point and is now shipping a product they are more confident in, or am I still running a moderately high risk of receiving a product that still has the issues noted throughout this post.

 

I have a repaired 2.4 and, after about a month, I have not had a single dropout. It has worked flawlessly. Assuming you can guarantee that you get one of the new units, I doubt you would have any problems.

One note: when I first received the unit back, I saw what I thought were dropouts when viewing the data in Cyclingpeaks. Then I figured out that the time in CP continues when stopped. This can make it appear like you have lost the signal for a while.

 

Thanks for the info. I have the SL now and will prob wait another month before I order the 2.4 just in case there are additional bugs to work out.

 

Somebody know more about the backlog of the Powertap SL 2.4?
7 weeks ago I ordered a Zipp 404 with an SL 2.4 hub. But I still haven't one and my LBS told me he doesn't know how long it will take because the Zipp importeur hasn't any hubs.

 

Yeah I have an account here in Oz and I know our distributor isnt getting a shipment on SL2.4 at present. He refuses to even talk 'ETA'. lol

 

My friend just received his on a Zipp 303. The LBS told him the week before they had no idea on ETA either. Then, out of no where, his wheel shows up laced up with the 2.4. Hopefully this means that the issue is getting resolved and new units are now being received by the distributors.