PT SL 2.4 Update

RapDaddyo said:

(4) The data transmission rate is 2x the PT SL (i.e., .63sec vs. 1.26sec).😄

Interesting, thanks for the update. On this point, is memory doubled accordingly? Also, has the torque sampling frequency changed or is it still 60Hz (and hence the aliasing effect still exisits)?

Alex Simmons said:

Interesting, thanks for the update. On this point, is memory doubled accordingly? Also, has the torque sampling frequency changed or is it still 60Hz (and hence the aliasing effect still exisits)?

I'll ask.

RapDaddyo said:

I'll ask.

Thanks. Also I meant to ask - is the receiver in a modified cradle, or part of a new CPU. Hence, can we use existing CPUs with a 2.4 hub (or not)? I guess if the HRM is different then it's a new CPU.

RapDaddyo said:

I just returned from Day 1 of Interbike and met with the Saris folks about the PT SL 2.4. The major bits of new info are as follows.

(1) They addressed the moisture problem with early production units by sealing the electronics with a brush on sealant. It looks sort of like candle wax and it entirely seals the circuit board and related electronics parts. They tested it by removing the CF shell from the hub and rode it around while spraying water at the hub. So, the inside was basically completely exposed to water. They stopped production in June due to the moisture problem but they are now shipping and have had only two units returned from the resumed production run.

(2) They have an optional wireless (2.4 GHz) cadence transmitter that mounts on the chain stay. This provides a completely wireless installation.

(3) The HR receiver is different (2.4 GHz) and the transmitter is coded.

(4) The data transmission rate is 2x the PT SL (i.e., .63sec vs. 1.26sec).

I'm returning to Interbike Thursday and Friday, so if you have any questions let me know and I'll ask.

P.S., Don't go to Interbike unless you just got your bonus and you're looking to spend it all in one place.😄

Thanks for the update!

While you're there (and if it's not too much bother), can you stop by the Polar booth and get info/specs on the CS600 bike computer and the updated wireless power module?

Oh yeah...if the PT computer is a new model, ask Saris why they didn't throw an altitude sensor in there. 🙂

RapDaddyo said:

I just returned from Day 1 of Interbike and met with the Saris folks about the PT SL 2.4. The major bits of new info are as follows.

(1) They addressed the moisture problem with early production units by sealing the electronics with a brush on sealant. It looks sort of like candle wax and it entirely seals the circuit board and related electronics parts. They tested it by removing the CF shell from the hub and rode it around while spraying water at the hub. So, the inside was basically completely exposed to water. They stopped production in June due to the moisture problem but they are now shipping and have had only two units returned from the resumed production run.

(2) They have an optional wireless (2.4 GHz) cadence transmitter that mounts on the chain stay. This provides a completely wireless installation.

(3) The HR receiver is different (2.4 GHz) and the transmitter is coded.

(4) The data transmission rate is 2x the PT SL (i.e., .63sec vs. 1.26sec).

I'm returning to Interbike Thursday and Friday, so if you have any questions let me know and I'll ask.

P.S., Don't go to Interbike unless you just got your bonus and you're looking to spend it all in one place.😄

OK, now I am thinking about getting one now, but what am I supposed to do with my three other PowerTaps wheels that are incompatible with this harness...

Alex Simmons said:

Thanks. Also I meant to ask - is the receiver in a modified cradle, or part of a new CPU. Hence, can we use existing CPUs with a 2.4 hub (or not)? I guess if the HRM is different then it's a new CPU.

The cradle is the same (I didn't take my calipers but it appeared to be identical) and the CPU case appears identical (except for the 2.4 stamped on the top right), but the internals are different -- 2.4 GHz receiver for hub & HR data stream. So, backward compatibility, don't know. Forward compatibility, no way.

Tom Anhalt said:

Thanks for the update!

While you're there (and if it's not too much bother), can you stop by the Polar booth and get info/specs on the CS600 bike computer and the updated wireless power module?

Oh yeah...if the PT computer is a new model, ask Saris why they didn't throw an altitude sensor in there. 🙂

I already did stop by their booth and saw the new unit. It looks pretty slick, completely wireless. The wireless chain pickup has the cadence pickup and the speed pickup is on the left chainstay, also wireless. I'll take my camera tomorrow and post pics. Availability Spring 2007. Cost estimate ~$700 (including the computer).

Woofer said:

OK, now I am thinking about getting one now, but what am I supposed to do with my three other PowerTaps wheels that are incompatible with this harness...

There's a solution, but I can't disclose details. Stay tuned.

How's the iBike II look?

frenchyge said:

How's the iBike II look?

I walked by their booth but didn't stop and ask Qs. Will spend some time there tomorrow.

Alex Simmons said:

has the torque sampling frequency changed or is it still 60Hz (and hence the aliasing effect still exisits)?

Actually, it's not the rate at which the data that are sampled that causes the aliasing...it's how the data are handled after they are collected. Specifically, because power is calculated every X seconds (instead of every Y pedal strokes), more often than not the resultant power value is based on a non-integer number of crank revolutions. Changing either the sampling frequency or the time interval over which power is calculated doesn't address this issue.

acoggan said:

Actually, it's not the rate at which the data that are sampled that causes the aliasing...it's how the data are handled after they are collected. Specifically, because power is calculated every X seconds (instead of every Y pedal strokes), more often than not the resultant power value is based on a non-integer number of crank revolutions. Changing either the sampling frequency or the time interval over which power is calculated doesn't address this issue.

You're right of course.... 😉

RapDaddyo said:

The cradle is the same (I didn't take my calipers but it appeared to be identical) and the CPU case appears identical (except for the 2.4 stamped on the top right), but the internals are different -- 2.4 GHz receiver for hub & HR data stream. So, backward compatibility, don't know. Forward compatibility, no way.

Well that sounds like the cradle is simply a handlebar/stem mount now as all data is fed wirelessly directly to the CPU. Is that right? I though maybe the cradle was the receiver and that then fed the CPU the data via the pins on back of the CPU.

RapDaddyo said:

I already did stop by their booth and saw the new unit. It looks pretty slick, completely wireless. The wireless chain pickup has the cadence pickup and the speed pickup is on the left chainstay, also wireless. I'll take my camera tomorrow and post pics. Availability Spring 2007. Cost estimate ~$700 (including the computer).

Thanks! Did they have any info about the recording rate, memory, etc.? Any idea what a spare power module and speed sensor would cost? I saw somewhere that the computer alone was ~$400, so I'm thinking the sensors would be ~$200 or less???

Tom Anhalt said:

Thanks! Did they have any info about the recording rate, memory, etc.? Any idea what a spare power module and speed sensor would cost? I saw somewhere that the computer alone was ~$400, so I'm thinking the sensors would be ~$200 or less???

I'll ask. Also, the rep wasn't quoting the price as something set in stone yet. It was more like, "We're hoping to keep it to around $700 for the complete package, including the computer."

One more thing I learned at Interbike today. Neither Zipp nor HED are anywhere close to having a disc wheel with a PT hub (i.e., not this model year). The only other folks who might be working on it is Bontrager. They aren't at Interbike (because Trek isn't here), but there may be a couple of Bontrager folks lurking about. I'll try to track one down. If not, I'll get an update on their plans when I meet with them on another matter.

RapDaddyo said:

The cradle is the same (I didn't take my calipers but it appeared to be identical) and the CPU case appears identical (except for the 2.4 stamped on the top right), but the internals are different -- 2.4 GHz receiver for hub & HR data stream. So, backward compatibility, don't know. Forward compatibility, no way.

with the new 2.4 hub you need the new handlebar computer. i don't know if the new computer will work with the old SL hub, but i'm guessing it won't.

ric

ric_stern/RST said:

with the new 2.4 hub you need the new handlebar computer. i don't know if the new computer will work with the old SL hub, but i'm guessing it won't.

ric

I also doubt it, but I'll ask. They would have had to provide for both wireless data capture and through the contact pins on the mount. I'll confirm whether the new computer is backward compatible with the SL or earlier hubs.

Alex Simmons said:

Interesting, thanks for the update. On this point, is memory doubled accordingly? Also, has the torque sampling frequency changed or is it still 60Hz (and hence the aliasing effect still exisits)?

Memory is 15 hrs at the shortest recording interval (.63sec). Torque sampling frequency has not changed.