SRM info needed

[labratmatt]

I'm looking at getting an SRM and have a couple of questions for experienced SRM folks:

1. Do all SRMs come with the data cable used to connect to the computer? It seems that a lot of the used ones I've seen on ebay and elsewhere don't include that cable. This of course make me wonder if only certain SRMs work with the cable.

2. Is there a big difference between the old Powercontrol IV head unit and the new Powercontrol V head unit. It looks like the display is better. Did anything else change?

[Too Tall]

All SRMs can d/l data to your PC.
Diff. between PCIV and PCV are not huge. I've owned both. The PCV has a more durable display that is marginally brighte also the new unit is smaller. None are big deals.

[labratmatt]

All SRMs can d/l data to your PC.
Diff. between PCIV and PCV are not huge. I've owned both. The PCV has a more durable display that is marginally brighte also the new unit is smaller. None are big deals.

That's what I was looking for. Thanks for the quick reply, TT.

A quick follow up question:

I guess SRM doesn't usually include the USB/Serial cable (that is used to download data from the Powercontrol to the computer) when they sell a new SRM? Seems odd.

Thanks again.

[John H.]

They include everything. If it is an old unit it may not be USB, but they have always included a download cable. They are inexpensive to buy if you need to get one.
Also PCIV vs. PCV- the IV works fine but has no value whatsoever. When the battery dies- SRM will upgrade to a PCV for about $500- they will not put another battery in a PCIV. Keep that in mind when shopping for a used unit.

[J.Greene]

They include everything. If it is an old unit it may not be USB, but they have always included a download cable. They are inexpensive to buy if you need to get one.
Also PCIV vs. PCV- the IV works fine but has no value whatsoever. When the battery dies- SRM will upgrade to a PCV for about $500- they will not put another battery in a PCIV. Keep that in mind when shopping for a used unit.

considering the battery issue, what's a good price for a used pro model?

JG

[labratmatt]

Excellent info. Thanks, guys.

[11.4]

Yes. To clarify (I have both track and road SRM), a new one comes with the USB Prolific cable, your choice of front or rear mount cable (the difference is in where the speed pickup goes), mounting hardware, PC-V, and powermeter cranks (with rings on road units, without on track).

Usually the cable is attached with zip ties and most cables on used setups could be reused but people seem not to. They are quite durable. There's a new version of the cable with a different power pickup, but the sensitivity is a good bit lower and sensitivity is already an issue with some setups. I'd recommend sticking with the older one and improvising on mounting. There's usually a certain amount of experimenting in how you mount all the hardware and wire on a carbon frame or on aero bars, some carbon drop bars, etc. There are some examples of solutions at www.competitivecyclist.com (which they sell, of course) but each bike tends to have its own particular needs. A classic steel frame is easy, an aluminum frame usually isn't too hard, but carbon frames get tough and aero monocoque frames are downright demanding. Note that you can't use a standard SRM on the new Trek Madone with the wider bottom bracket -- you have to deal with SRM on a converted one with a MTB-based power assembly (come to think of it, that means a compact Dura Ace SRM should actually work on the new Madone -- anybody tried it?).

SRM in Denver has fabulous service. Sometimes it's hard to get through to them, but keep calling. Both Leslie and Amy can answer any question you have and offer the best customer service in the industry.

[Too Tall]

considering the battery issue, what's a good price for a used pro model?

JG
I've had several guys tell me they were able to snag them in good condition from auction for $1600 to $1800 for pro models complete.

Yep, all of what 11.4 said. Cables and hardware are very durable. Hot glue guns are my friend :)

[J.Greene]

I've had several guys tell me they were able to snag them in good condition from auction for $1600 to $1800 for pro models complete.

Yep, all of what 11.4 said. Cables and hardware are very durable. Hot glue guns are my friend :)

Thanks TT. I have a buddy selling me his and it looks like I'm getting a very good price.

Is there anybody out there who wants to trade for some 175 crankarms? I need 170's and would like to make such a deal.

JG

[John H.]

A good proice for a pro with a PCIV is whatever they go for in the used market for a PCV- less $500. That is what it will cost to get another powercontrol when it dies.

[nm87710]

Thanks TT. I have a buddy selling me his and it looks like I'm getting a very good price.

Is there anybody out there who wants to trade for some 175 crankarms? I need 170's and would like to make such a deal.

JG

You probably already know this but just in case...When changing crank arms you need to also recalibrate the PM offset.

[gregclimbs]

<disclaimer> I am a coach and a srm dealer (as well as powertap etc)</disclaimer>

to answer your questions...

1) yes, all cables are included in new srms (download and bike wire harness as well as charger). the newer style has a serial to usb converter built in (but is still there and requires a driver be installed).

the newer integrated d/l cable is NOT PCIV compatible and will BSOD your PC, so get a serial cable and usb-serial adaptor.

I know, I have 3 srms with 2x PCV (one with the coded polar chip <newer> and one without) and 1xPCIV. I know they will continue to support to some degree the PCIV because mine has torque analysis, external stop and online capabilities and those do not fit in the PCV package.

2) there are advantages to the PCIV over the PCV. the PCV is more readable and has larger/better display of the main numbers.

the PCIV did two things the PCV cannot do.

a) display all six fields simultaniously:

power/cadence/speed/distance/time/hr

the pcv alternates one of the fields (time/distance) on a user specified interval.

b) the PCIV can be set to average the screen data at a user specified interval (different from it's recording rate).

the PCV is preset from the factory (5s I believe) and it is not changable.

I hope that helps... lemme know if you have any other questions.

:D

g

[J.Greene]

You probably already know this but just in case...When changing crank arms you need to also recalibrate the PM offset.

Does that invlove anything that is not able to be done at home?

thanks,
JG

[gregclimbs]

no i didn;t, but I'm sure I will

thanks,
JG

and be real careful and use a torque wrench... those torx bolts are easy to break (and the torque spec is pretty high). typically, the head shears off!

:D

g

[labratmatt]

Thanks again. Great info from everyone especially, gregclimbs.

[gregclimbs]

Does that invlove anything that is not able to be done at home?

thanks,
JG

just some weights (measured on a scale, not just gym weights and believe the numbers), some time and a spreadsheet.

the wattage list has the spreadsheat posted in their docs section. it is wise to use more than one weight to verify. and if you search, you will find the protocol (which is also in the srm manual - online as well).

also good to test any older meter... the older ones had some drift problems a long time ago (where the straingauge glue was hardening post factory calibration, thusly throwing off the cal). that has been resolved and I haven't seen much drift lately from factory to customer.

g

[J.Greene]

Greg, TT or others

I can't find any mention of this online or on the srm site. In the manual, it is not included in the instructions for changing crank arms. Where can I find other online references?

JG

just some weights (measured on a scale, not just gym weights and believe the numbers), some time and a spreadsheet.

the wattage list has the spreadsheat posted in their docs section. it is wise to use more than one weight to verify. and if you search, you will find the protocol (which is also in the srm manual - online as well).

also good to test any older meter... the older ones had some drift problems a long time ago (where the straingauge glue was hardening post factory calibration, thusly throwing off the cal). that has been resolved and I haven't seen much drift lately from factory to customer.

g

[gregclimbs]

Greg, TT or others

I can't find any mention of this online or on the srm site. In the manual, it is not included in the instructions for changing crank arms. Where can I find other online references?

JG

seems that it accidentally got cut out of the newest manual - shoot me (via pm) you email and I can forward an older copy of it with the how-to.

g

[11.4]

Here's the calibration protocol. That's what you wanted, isn't it?

http://www.srm.de/Online_Manual/SRM_English_Manual/PMCalibrate.htm

Also, SRM has been adding some additional interesting features:

First was the coded Polar chip.

More recently that have offered on-line monitoring, so you can have your SRM connected to a computer while you're riding rollers or a trainer, set your workout regimen, and watch your workout develop real-time. The same port can be used to support telemetry if you can set up the rest of the equipment. I was able to connect the PC-V so modified on my track bike to a smartphone via a mini-USB adapter and ship the data to a computer trackside with SRMWin running. It certainly gives you the ability to coach track events, I'll say that much.

The newest option is to have two reed switches installed in the cranks. This was developed for the Aussie track team and gives shorter sampling intervals, faster recording, etc.

[J.Greene]

sweet, thanks, cool!

JG

Here's the calibration protocol. That's what you wanted, isn't it?

http://www.srm.de/Online_Manual/SRM_English_Manual/PMCalibrate.htm

Also, SRM has been adding some additional interesting features:

First was the coded Polar chip.

More recently that have offered on-line monitoring, so you can have your SRM connected to a computer while you're riding rollers or a trainer, set your workout regimen, and watch your workout develop real-time. The same port can be used to support telemetry if you can set up the rest of the equipment. I was able to connect the PC-V so modified on my track bike to a smartphone via a mini-USB adapter and ship the data to a computer trackside with SRMWin running. It certainly gives you the ability to coach track events, I'll say that much.

The newest option is to have two reed switches installed in the cranks. This was developed for the Aussie track team and gives shorter sampling intervals, faster recording, etc.

[gregclimbs]

Also, SRM has been adding some additional interesting features:

First was the coded Polar chip.

That has been out for over a year and is std on all pcv's. You can upgrade older non-polar (evidenced by the lack of a "c" fo "coded" at the end of serial number) for $150.



More recently that have offered on-line monitoring, so you can have your SRM connected to a computer while you're riding rollers or a trainer, set your workout regimen, and watch your workout develop real-time. The same port can be used to support telemetry if you can set up the rest of the equipment. I was able to connect the PC-V so modified on my track bike to a smartphone via a mini-USB adapter and ship the data to a computer trackside with SRMWin running. It certainly gives you the ability to coach track events, I'll say that much.

The newest option is to have two reed switches installed in the cranks. This was developed for the Aussie track team and gives shorter sampling intervals, faster recording, etc.

The online is an old option, I have it on my pciv (also with torque analysis and the discontinued external stop button. But it has recently become an option in the pcv. I use my online a lot (even in conjuction with my computrainer) as it helps keep you honest and on target.

The telemetry kit (sounds like you hacked your own) is also available commercially as well, but if memory serves retail is close to $3k.

Also, additional reed switches has also been optional for a while as well (and documented in the ta manual).

:)

Hth

G