Notices
Track Cycling: Velodrome Racing and Training Area Looking to enter into the realm of track racing? Want to share your experiences and tactics for riding on a velodrome? The Track Cycling forums is for you! Come in and discuss training/racing, equipment, and current track cycling events.

Which Power Meter?

Old 11-14-18, 08:21 AM
  #1  
FinkFloyd
Member
Thread Starter
 
Join Date: Nov 2017
Posts: 30
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 20 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Which Power Meter?

I hope you won't mind me asking a power meter question. I have decided that I'm going all in on the track stuff and training with a view to starting racing next year. I train with power on the road and on the turbo, so it seems to me that this would be a worthwhile investment for the track bike. My main interest on track is the mass-start stuff; I am not ruling out sprinting but it doesn't hold the same interest for me, and I am not particularly concerned about pursuiting. I've read the previous power meter threads and have drawn the following tentative conclusions:

1. Pedal-based systems (and the Stages crank) aren't ideal for the track due to their accelerometer-based designs.
2. SRM is the gold standard.
3. If I want a crank based system, SRM and Power2Max are really the two choices; the Infocrank does exist but doesn't offer any great advantage over SRM.

My questions are therefore as follows:

1. I see that SRM offer two basic iterations: wired, for use with the PCV system, and wireless (each can come with SRM cranks or Rotor cranks). Is there an advantage to the wired system? If I've understood correctly, it has to do with instantaneous data transfer; is there a different benefit that I'm missing?

2. Using the wired system obviously ties me into the PCV head unit. Does this do everything a more modern head unit does (e.g. syncing wirelessly, etc), and is it really worth the expense of buying a new head unit (I gather the wireless SRM will sync with ANT+) compared with sticking to my Wahoo unit?

3. Is the Power2Max system appreciably inferior in any important respect to the SRM? I note that the Power2Max system comes with a rechargeable battery, which seems to me better than the SRM sealed unit solution.

Thanks in advance for any help.
FinkFloyd is offline  
Old 11-14-18, 10:49 AM
  #2  
carleton
Elitist
 
carleton's Avatar
 
Join Date: Jul 2005
Location: Atlanta, GA
Posts: 15,872
Mentioned: 88 Post(s)
Tagged: 0 Thread(s)
Quoted: 1347 Post(s)
Liked 54 Times in 44 Posts
Hi, FinkFloyd. Have a stroll though this thread. Questions you haven't even thought of are covered there.

https://www.bikeforums.net/track-cyc...computers.html

Feel free to ask questions there. Everything there is still relevant. Track PMs don't change much over the years.

Wireless power meters require maybe 3s to start recording data. Wired, with two reed switches, can start after 1/2 a pedal stroke.

This is because Torque data travels with the Cadence data into the head unit which calculates Power. So, when you have cadence, you have power. No cadence, no power. That being said, only standing start specialists (Tam Sprint, 500M, Kilo, etc...) would want wired. Wireless SRM would probably suit your needs.
carleton is offline  
Old 11-14-18, 02:59 PM
  #3  
FinkFloyd
Member
Thread Starter
 
Join Date: Nov 2017
Posts: 30
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 20 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Thanks - I saw the previous threads but you've largely confirmed what I took from those info-wise. I suspect that one of the Rotor SRMs might be the way to go (not least because it goes with a standard threaded BB rather than Octalink).
FinkFloyd is offline  
Old 11-14-18, 04:42 PM
  #4  
carleton
Elitist
 
carleton's Avatar
 
Join Date: Jul 2005
Location: Atlanta, GA
Posts: 15,872
Mentioned: 88 Post(s)
Tagged: 0 Thread(s)
Quoted: 1347 Post(s)
Liked 54 Times in 44 Posts
Originally Posted by FinkFloyd View Post
Thanks - I saw the previous threads but you've largely confirmed what I took from those info-wise. I suspect that one of the Rotor SRMs might be the way to go (not least because it goes with a standard threaded BB rather than Octalink).
Octalink uses a standard 68mm bottom bracket. It always has.

Needle bearing BB-7700:
https://bike.shimano.com/en-US/produ...0/BB-7700.html

Sealed bearing BB-7710:
https://bike.shimano.com/en-US/produ...0/BB-7710.html

Last edited by carleton; 11-14-18 at 04:45 PM.
carleton is offline  
Old 11-14-18, 04:44 PM
  #5  
FinkFloyd
Member
Thread Starter
 
Join Date: Nov 2017
Posts: 30
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 20 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by carleton View Post
Octalink uses a standard 68mm bottom bracket. It always has.
Really? My bad - I thought from the way that the SRM sales materials drew a distinction between them that Octalink must be something different.
FinkFloyd is offline  
Old 11-14-18, 04:47 PM
  #6  
carleton
Elitist
 
carleton's Avatar
 
Join Date: Jul 2005
Location: Atlanta, GA
Posts: 15,872
Mentioned: 88 Post(s)
Tagged: 0 Thread(s)
Quoted: 1347 Post(s)
Liked 54 Times in 44 Posts
Originally Posted by FinkFloyd View Post
Really? My bad - I thought from the way that the SRM sales materials drew a distinction between them that Octalink must be something different.
Added links above.

Also, you don't need the $100+ Dura Ace BB. You can use a $20 105 Octalink 19.5mm BB as well. I've used that as well as the sealed and unsealed Dura Ace.
carleton is offline  
Old 11-14-18, 04:48 PM
  #7  
carleton
Elitist
 
carleton's Avatar
 
Join Date: Jul 2005
Location: Atlanta, GA
Posts: 15,872
Mentioned: 88 Post(s)
Tagged: 0 Thread(s)
Quoted: 1347 Post(s)
Liked 54 Times in 44 Posts
Click "Service Instructions" in the Shimano websites linked above to get detailed info.
carleton is offline  
Old 11-15-18, 11:05 AM
  #8  
gl98115
Senior Member
 
Join Date: Apr 2014
Posts: 631
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 140 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by FinkFloyd View Post
3. Is the Power2Max system appreciably inferior in any important respect to the SRM? I note that the Power2Max system comes with a rechargeable battery, which seems to me better than the SRM sealed unit solution.
Power2Max currently sells two track power meters in NA. The NG has a rechargeable battery while the NGeco uses replaceable coin cell batteries. Neither use magnets for cadence.

power2max NG
gl98115 is offline  
Old 11-16-18, 02:11 AM
  #9  
Dalai
Senior Member
 
Join Date: Jan 2006
Location: Australia
Posts: 2,160
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 89 Post(s)
Liked 6 Times in 5 Posts
Originally Posted by FinkFloyd View Post
the wired system obviously ties me into the PCV head unit. Does this do everything a more modern head unit does (e.g. syncing wirelessly, etc).
Nothing with the PCV is wireless. PCV is connected to the wiring harness on the frame. Download of data is via a cable with USB to connect to your PC.
Dalai is offline  
Old 11-16-18, 03:08 AM
  #10  
Dalai
Senior Member
 
Join Date: Jan 2006
Location: Australia
Posts: 2,160
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 89 Post(s)
Liked 6 Times in 5 Posts
Also not sure if it matters to you, but the wired track SRM's are not waterproof - not sure about wireless track units as happy with my wired units...

For accuracy and repeatability of data, it is very easy to check the slope of the SRM units yourself with a known weight and then update the crank via the SRM software or PCV. Interestingly PowerMax claim this is unnecessary.

I wouldn't be put off by the battery not being readily replaceable as it lasts a number of years even with regular use.

Note I own two wired track SRM's and a mix of wired and wireless road units too, so if you have any specific questions then fire away.
Dalai is offline  
Old 01-09-19, 06:19 AM
  #11  
Ricovonsuave
Junior Member
 
Join Date: Aug 2015
Posts: 10
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Apologies for grave-digging, but if you're still looking at track PMs, Stages did make a DA crank based system which I'd heard some okay reviews of, and for my 2c, I've had good luck with the PowerTap track hub, as has a training buddy of mine. Obviously you don't get to use it when you put a disc wheel on the back for your A races, but for training and geeking out on data purposes it's been good and seems generally accurate - paired with my old Garmin 510 mounted under the saddle, and using GoldenCheetah for analysis. You do have to buy the special White Industries style splined cogs for it, but a 13T and 14T are enough, for most things really... 15T if you want to warm up on it I wish they made a 12T though....
Ricovonsuave is offline  
Old 02-18-19, 09:20 PM
  #12  
DaleG85
Junior Member
 
Join Date: Feb 2019
Posts: 17
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
What are people's opinions on the Verve Track Infocrank? I got a price last night of $1500.

cheers for the help
DaleG85 is offline  
Old 02-19-19, 08:58 AM
  #13  
Morelock
Senior Member
 
Morelock's Avatar
 
Join Date: Dec 2017
Posts: 560
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 251 Post(s)
Liked 29 Times in 21 Posts
The Verve is relatively new (and expensive) so you're probably not going to find a lot of reviews on the track specific model for a while.

It looks pretty good overall, and with British cycling using it (at least some form) it's going to get good feedback going forward. The cadence method seems a bit murky (From the tech document - Proprietary process for accurate cadence measurement, which does not use magnets or accelerometers in order to achieve accuracy and save battery usage ) and the <2sec startup time could turn off a true sprinter... otherwise it looks solid. The crank length options, especially 155 and 160 is appealing.
Morelock is offline  
Old 02-20-19, 07:45 AM
  #14  
DaleG85
Junior Member
 
Join Date: Feb 2019
Posts: 17
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Morelock View Post
The Verve is relatively new (and expensive) so you're probably not going to find a lot of reviews on the track specific model for a while.

It looks pretty good overall, and with British cycling using it (at least some form) it's going to get good feedback going forward. The cadence method seems a bit murky (From the tech document - Proprietary process for accurate cadence measurement, which does not use magnets or accelerometers in order to achieve accuracy and save battery usage ) and the <2sec startup time could turn off a true sprinter... otherwise it looks solid. The crank length options, especially 155 and 160 is appealing.

Thanks Mate,
I had been speaking with them the other day and this is what the salesman told me regarding cadence

"An accelerometer is not how the InfoCrank registers cadence, it works from Torque impulses. It is not necessary but you can choose to use the magnets."
DaleG85 is offline  
Old 02-20-19, 09:29 AM
  #15  
Morelock
Senior Member
 
Morelock's Avatar
 
Join Date: Dec 2017
Posts: 560
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 251 Post(s)
Liked 29 Times in 21 Posts
interesting... obviously over my pay grade on the technical side, but I wonder why the option to have magnets if it's not necessary?
Morelock is offline  
Old 02-20-19, 09:49 AM
  #16  
colnago62
Senior Member
 
Join Date: Aug 2014
Posts: 2,104
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 586 Post(s)
Liked 254 Times in 152 Posts
Cyclops Hammer and Magnus work this way. They will do cadence without a sensor. My feeling is it less accurate and a little laggy.
colnago62 is offline  
Old 02-20-19, 04:02 PM
  #17  
Clythio
Senior Member
 
Join Date: Aug 2016
Posts: 122
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 65 Post(s)
Liked 6 Times in 5 Posts
Originally Posted by Morelock View Post
interesting... obviously over my pay grade on the technical side, but I wonder why the option to have magnets if it's not necessary?
Powertaps work this way too, clocking each 2 torque peaks one pedal turn, and it's pretty good and accurate if you pedal all the time pushing some torque every pedal move, like on a training session interval.
It doesn't have any lag, but it floats a lot out of reality if you soft pedal, if you stop pedaling on a downhill or inside a group, drafting, like we do on a race peloton, which hurts some metrics like average etc, and lay some crazy high spikes on the file. That's the reason I use Powertaps WITH a dedicated cadence sensor (left crank mag attached).
InfoCrank now uses the same principle - torque peaks from one of the cranks, to count crankset revolutions.
Clythio is offline  
Old 02-24-19, 07:46 PM
  #18  
DaleG85
Junior Member
 
Join Date: Feb 2019
Posts: 17
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I noticed yesterday the huub wattbike team run infocranks on the training bikes.
DaleG85 is offline  
Old 02-24-19, 07:54 PM
  #19  
Morelock
Senior Member
 
Morelock's Avatar
 
Join Date: Dec 2017
Posts: 560
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 251 Post(s)
Liked 29 Times in 21 Posts
Originally Posted by Clythio View Post
Powertaps work this way too, clocking each 2 torque peaks one pedal turn, and it's pretty good and accurate if you pedal all the time pushing some torque every pedal move, like on a training session interval.
It doesn't have any lag, but it floats a lot out of reality if you soft pedal, if you stop pedaling on a downhill or inside a group, drafting, like we do on a race peloton, which hurts some metrics like average etc, and lay some crazy high spikes on the file. That's the reason I use Powertaps WITH a dedicated cadence sensor (left crank mag attached).
InfoCrank now uses the same principle - torque peaks from one of the cranks, to count crankset revolutions.

Cool, thanks for the info!
Morelock is offline  
Old 10-21-19, 07:16 PM
  #20  
Clythio
Senior Member
 
Join Date: Aug 2016
Posts: 122
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 65 Post(s)
Liked 6 Times in 5 Posts
Power Analysis Software?

I use WKO3 in order to check my track files.
It allows you to look “into” the file, selecting data by data interval and checking short efforts in detail, in order to analyse, compare, etc
But they don’t sell or even support it any more (if I change computer, they won’t give me a new download/key for it...)

WKO4 and 5 are total mess if you want do to the same - they’re “automated integrated multi metrics tools”, good for long distance guys maybe.

Besides the well known and good Golden Cheetah, any other suggestion of softwares that fit our “detailled” view approach? :-)
Clythio is offline  
Old 10-21-19, 09:37 PM
  #21  
carpediemracing 
Senior Member
 
Join Date: Feb 2007
Location: Tariffville, CT
Posts: 15,181

Bikes: Tsunami Bikes

Mentioned: 35 Post(s)
Tagged: 0 Thread(s)
Quoted: 299 Post(s)
Liked 36 Times in 22 Posts
Originally Posted by FinkFloyd View Post
My questions are therefore as follows:

1. I see that SRM offer two basic iterations: wired, for use with the PCV system, and wireless (each can come with SRM cranks or Rotor cranks). Is there an advantage to the wired system? If I've understood correctly, it has to do with instantaneous data transfer; is there a different benefit that I'm missing?

2. Using the wired system obviously ties me into the PCV head unit. Does this do everything a more modern head unit does (e.g. syncing wirelessly, etc), and is it really worth the expense of buying a new head unit (I gather the wireless SRM will sync with ANT+) compared with sticking to my Wahoo unit?

3. Is the Power2Max system appreciably inferior in any important respect to the SRM? I note that the Power2Max system comes with a rechargeable battery, which seems to me better than the SRM sealed unit solution.

Thanks in advance for any help.
I used the wired SRM (non-track - Cannondale SI models, two of them, and one regular SRM crank) for about 8? years. I upgraded one then the other to wireless (my standard is still wired).

For wired, the disadvantages:
1. You have to use the SRM harness. I found that after a year of use the harness needs to be replaced. Knocking the bike around, moving the pickups just a bit to adjust for different wheels, the odd chain off, etc, will affect the harness.

2. The PCV has very little memory. It's a lot for most purposes, meaning like a crit or even a full day on the track, but it's limited to something like 6 or 8 hours at the finest granularity. I regularly downloaded data after running out of memory in races, which are honestly the only thing I really want to analyze.

3. Brings me to the download - it's a proprietary cable, USB on one end, fine, but the other end is a very hard-to-plug-in plug. I think it's meant to be almost waterproof, but it's hard enough to plug in, and delicate (it sticks out at a 90 deg angle). I've broken a couple download cables.

4. Battery is really easy to replace in a PCV, much easier than the crank/spider. The readily available battery is a bit lower capacity than the stock one, but if you leave it plugged in most of the time it's okay. Battery replacement in the spider is tricky to get right but possible. I send my crank back to SRM now because it's easier, and I have two SRMs partially because of this (I also have two almost identical bikes, both could be "primary bike", so that I don't miss anything due to a weird failure on one bike.

5. I used the (wired) BB pick up for the spider, much better than the chain stay mounted one. The latter can get knocked off kilter pretty easily, wire is fragile. The BB one is tougher, wire is easier to secure, and it's less likely to get knocked askew.

Wireless...

I upgraded mine about 2 years ago. I have the PC7, not the latest PC8. It doesn't hold as much data , there's some other stuff, but I was working within a budget and the PC7 seems good enough. My main goal was Ant+ compatibility so I could use my SRM to feed power data to Zwift, instead of using ZPower for "public" and SRM power "for real". I was being handicapped about 50w at lower power (200w SRM would register 150w ZPower) and 100+w at sprint power (1100w would register as 950-1000w Zpower).

1. Pickups - there's a magnet by the BB, but no wire so there is very little to move the magnet (no snagging the wire by accident). I use an Ant+ wheel speed pick up (don't use external Ant+ cadence, you must get cadence off the BB pick up else power doesn't get calculated - I didn't send my "broken" crank and PC7 back to Colorado to learn this, really, I didn't). Much simpler, no wires.

2. Memory. I read somewhere you could do the whole Tour before downloading data off the PC7. I haven't done the Tour but I've done 30 or 40 hours of riding before downloading data, and the memory is nowhere near full (1/3 full?). It's quite refreshing coming off of the "download 2x a week" PCV.

3. Download is very easy. Regular USB cable, both ends, it's the regular small USB end that goes into the PC7, not the microUSB. It takes longer to download than the PC5 but you're downloading a month or two of data. Data transfer speed is obviously limited (I think the PC8 is faster?).

4. PC7 battery is so good that I plug in maybe 2x a year? 3x a year? I plug in to download, leave it plugged in until next ride, then I'm good for months.

Also...

If you have a wired SRM, the nice folks in Colorado will upgrade you to a wireless for some very reasonable amount. One Cannondale SI was upgradeable (I think they replaced the circuitboard?), I think it was $450?, and $200 for a refurb PC7. Great investment. The second one I happen to send in around Black Friday, I simply bought a new Cannondale SI spider outright for about $600?, plus another refurb PC7.

Hm, maybe it's time to send in the regular SRM to get that upgraded. Well, I'd rather get some other stuff so maybe that'll wait.
__________________
"...during the Lance years, being fit became the No. 1 thing. Totally the only thing. It’s a big part of what we do, but fitness is not the only thing. There’s skills, there’s tactics … there’s all kinds of stuff..." Tim Johnson
carpediemracing is offline  
Old 10-22-19, 03:42 PM
  #22  
Voodoo76
Blast from the Past
 
Voodoo76's Avatar
 
Join Date: Mar 2005
Location: Schertz TX
Posts: 3,151

Bikes: Felt FR1, Ridley Excal, CAAD10, CAAD12, Felt DA, Dolan

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 190 Post(s)
Liked 33 Times in 27 Posts
I had a P2Max track. There was one significant issue if you are looking at sprint data (accelerations, etc). There is a significant lag (2 to 3 sec) in the recorded cadence. My guess is related to averaging and use of an accelerometer rather than a magnet/reed switch.

Don't know if they have fixed that in the current generation.
Voodoo76 is offline  
Old 10-22-19, 08:43 PM
  #23  
carleton
Elitist
 
carleton's Avatar
 
Join Date: Jul 2005
Location: Atlanta, GA
Posts: 15,872
Mentioned: 88 Post(s)
Tagged: 0 Thread(s)
Quoted: 1347 Post(s)
Liked 54 Times in 44 Posts
Originally Posted by Voodoo76 View Post
I had a P2Max track. There was one significant issue if you are looking at sprint data (accelerations, etc). There is a significant lag (2 to 3 sec) in the recorded cadence. My guess is related to averaging and use of an accelerometer rather than a magnet/reed switch.

Don't know if they have fixed that in the current generation.
Cadence is needed to calculate Power. If Cadence is late, Power will be, too.

The Wired SRM PC5 was great for standing starts because it could be equipped with TWO reed switches. Meaning it got cadence readings every HALF pedal stroke. You need 2 readings to calculate the time between readings (rate). Using a PC5, you could get 2 readings in 1 rotation of the crank...thus making Cadence available for the Power calculation faster than any other system...twice as fast as even a PC5 system with a single reed switch.

SRM stopped putting 2 reed switches on their SRMs back in like 2011 or 2012. They also removed that "Two Reed Switch" option in their software.
carleton is offline  
Old 10-23-19, 05:57 AM
  #24  
Voodoo76
Blast from the Past
 
Voodoo76's Avatar
 
Join Date: Mar 2005
Location: Schertz TX
Posts: 3,151

Bikes: Felt FR1, Ridley Excal, CAAD10, CAAD12, Felt DA, Dolan

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 190 Post(s)
Liked 33 Times in 27 Posts
Originally Posted by carleton View Post
Cadence is needed to calculate Power. If Cadence is late, Power will be, too.

The Wired SRM PC5 was great for standing starts because it could be equipped with TWO reed switches. Meaning it got cadence readings every HALF pedal stroke. You need 2 readings to calculate the time between readings (rate). Using a PC5, you could get 2 readings in 1 rotation of the crank...thus making Cadence available for the Power calculation faster than any other system...twice as fast as even a PC5 system with a single reed switch.

SRM stopped putting 2 reed switches on their SRMs back in like 2011 or 2012. They also removed that "Two Reed Switch" option in their software.
The earlier road Quarqs, ones that required a magnet, had multiple switches (as I recall 4). They primarily used that to verify direction of crank rotation, you could zero the meter by pedaling backwards.

This is a potential advantage for wheel based systems like Power tap. Update frequency for wheel rotation speed as the "v" in the power equation is 3 to 3.5 times the crank "v" for typical gearing.
Voodoo76 is offline  
Old 10-23-19, 06:10 AM
  #25  
carleton
Elitist
 
carleton's Avatar
 
Join Date: Jul 2005
Location: Atlanta, GA
Posts: 15,872
Mentioned: 88 Post(s)
Tagged: 0 Thread(s)
Quoted: 1347 Post(s)
Liked 54 Times in 44 Posts
Originally Posted by Voodoo76 View Post
The earlier road Quarqs, ones that required a magnet, had multiple switches (as I recall 4). They primarily used that to verify direction of crank rotation, you could zero the meter by pedaling backwards.

This is a potential advantage for wheel based systems like Power tap. Update frequency for wheel rotation speed as the "v" in the power equation is 3 to 3.5 times the crank "v" for typical gearing.
True, but the downside of wheel-based systems is that they are very far down on the kinetic chain. Power meters are supposed to measure what the body is doing, so ideally you'd want the meter close to the body to get the best readings. Without actually being on the body, the closest we can hope for is a shoe power meter, next best would be cleat, then pedal platform, then pedal spindle (LOOK, PowerTap), then crank arm, then chainring spider (SRM), chainring, chain, cog, rear hub (PowerTap). Some power is lost as friction at every step listed.

BUT, on the other hand, the rear hub is very close to where the power is applied to the ground. So, it could be argued that it's in a great position to measure what really matters: How much power was produced that made it through the bike and into the tire that propelled the bike.
carleton is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.