Weight Weenies
* FAQ    * Search    * Trending Topics
* Login   * Register
HOME Listings Blog NEW Galleries NEW FAQ Contact About Impressum
It is currently Thu Jun 29, 2017 8:37 am

All times are UTC+01:00





Post new topic  Reply to topic  [ 5 posts ] 
Author Message
PostPosted: Thu May 31, 2012 9:02 pm 
Offline
User avatar

Joined: Tue Mar 20, 2007 5:07 pm
Posts: 232
Location: Palo Alto, CA
Team Trek bike due to arrive shortly. Never had a Trek. Bike is a 6.9 SSL with the Duotrap in the chainstay. I've been told the Duotrap will work as a speed sensor for my SRM system (7900 wireless, PC7) so I don't need the bulky zip-tied pod. Is this true? Do I just pair like normal via the PC7? Oddly, I couldn't find an answer to this question easily online. Thanks, all!


Top
   
Posted: Thu May 31, 2012 9:02 pm 


Top
   
 
PostPosted: Fri Jun 01, 2012 1:46 am 
Offline

Joined: Sat Dec 13, 2003 2:25 am
Posts: 4872
Location: Canada
Yup. I have done that for a friend with one.


Top
   
PostPosted: Mon Aug 27, 2012 1:14 pm 
Offline

Joined: Mon Oct 08, 2007 9:51 pm
Posts: 213
@Geoff.
If i understand correctly, the BB mounted 'sensor' supplied with SRM is in just a magnet that lets the SRM unit transmit cadence.
Since the duotrap also transmits cadence does mean one no longer needs to install the SRM BB pickup ? (With internal cable routing, Di2 battery mounting, etc all going on under the BB shell , installing these SRM BB pickups has me resorting to hot glue and other hacks)


Top
   
PostPosted: Mon Aug 27, 2012 2:35 pm 
Offline

Joined: Mon Dec 28, 2009 8:30 pm
Posts: 5729
Location: Bay Area
You still need the SRM magnet since it trips the reed switch, however, you don't need it for cadence necessarily. The way I understand is that the magnet ALWAYS needs to pass through the sensor pickup on the back of the spider, but you can pair other sensors as secondary cadence/speed sensors. For instance, to use a Garmin speed sensor you have to pair it as a Duotrap, etc.

_________________
Don't take me too seriously. The only person that doesn't hate Froome.
Gramz
Failed Custom Bike


Top
   
PostPosted: Mon Aug 27, 2012 4:39 pm 
Offline

Joined: Sat Dec 13, 2003 2:25 am
Posts: 4872
Location: Canada
The SRM system has three different 'sensors' on the bike (i.e., exclusive of HR):

1. the speed sensor;
2. the cadence sensor; and,
3. the power sensor.

The PowerMeter includes the cadence sensor and the power sensor in its housing, but speed requires a separate wireless transmitter, typically attached to the chainstay with zip-ties. The Duotap negates the requirement for the speed sensor, as it broadcasts speed data in ANT+.

In order to 'activate' the PowerMeter cadence sensor and, as Karsten mentioned, the reed switch for power, the PowerMeter requires a separate magnet positioned within the arc of the reed switch. Personally, I do not recommend using the stock SRM magnet for this purpose, as it is more intrusive than required. Instead, just glue a 1/2"x1/8" rare earth magnet to the chainstay/bottom bracket shell (depending where the reed switch is in relation to the frameset. If I recall, on the Madone, we put it high on the chainstay, as it was flatter there).


Top
   
Display posts from previous:  Sort by  
Post new topic  Reply to topic  [ 5 posts ] 

   Similar Topics   Author   Replies   Views   Last post 
There are no new unread posts for this topic. 1999 Trek 5500 geometry is similar to what current Trek?

in Road

bikebike

5

779

Sat Aug 13, 2016 4:25 pm

AJS914 View the latest post

There are no new unread posts for this topic. bontrager aeolus 3 d3 clincher

in Road

swissphil

7

1103

Tue Nov 01, 2016 6:49 am

spandexboy817 View the latest post

There are no new unread posts for this topic. Attachment(s) New Bontrager xxx carbon saddle

[ Go to page: 1 2 ]

in Road

Stormtrooper

15

1419

Sun May 14, 2017 4:35 am

addictR1 View the latest post

There are no new unread posts for this topic. Bontrager R4 Tubular tyres - views?

in Road

campagowlo

8

558

Mon Apr 17, 2017 7:41 pm

russianbear View the latest post

There are no new unread posts for this topic. Water collecting in Bontrager Aura 5 wheels

in Road

kevina6

11

602

Tue Apr 04, 2017 6:34 pm

Tomstr View the latest post


All times are UTC+01:00


Who is online

Users browsing this forum: arthurf, Baidu [Spider], djcharlou, Google [Bot], Google Adsense [Bot], Hastur, jlmcabral, jo.k, madik, Rogma84, Spessartpantani, Vieuxchnoque, wobbly and 42 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Limited