LIMITS Power Meter – Pushing the limits of power meter pricing – Zwift Gear Test

LIMITS power meter was created through an Indigogo funding campaign looking to make the power meter at a price that would make “it possible for everyone to own a power meter”. Have LIMITS managed to create a power meter for the masses? Let’s find out! In a power meter Zwift Gear Test

LIMITS Power Meter – Pushing the limits of power meter pricing

Limits Power meter

I’m sorry, every man and his dog are doing some sort of pun on the LIMITS name when it comes to the reviews of the new power meter company. But perhaps from a marketing perspective, the LIMITS name was not well chosen. You can push limits in a positive sense when looking at price, weight, ease of use, but also push the limits in a negative sense when looking at reliability, accuracy, and durability

Limits Cycling was initially funded successfully via an IndieGoGo campaign, and I think it is only fair to say that this particular power meter has had a troubled birthing. With funding completed in May 2015, there are still backers waiting to receive their units two YEARS later.

Limits Power

So with that in mind, let’s take a look at the LIMITS power meter! Especially from the point of view that if you see one knocking around on eBay at the moment, should you give it a shot?

Device DesignLimits power

When you open the box on the Limits power meter, you see the power meter itself seems a relatively simple affair, but there are a collection of other bits that look a little odd. Inside we’ve the actual power meter made of black plastic, two batteries, washers, (fragile) battery end caps, installation tool and the spacer for the opposite pedal to maintain and equal Q-angle between sides

Limits Power

One of those odd bits is the series of allen key adapters. For reasons known only to Limits, they have used a set of non-standard bolt heads at different locations in the construction of the power meter

Limits power

In installation is not the easiest approach in the world. The BePro pedals, which take a little setting up, realistically take 15-20mins if you are slow. By comparison, you are certainly going to need 45-60mins to get these installed.

Pedal off, Power meter in, careful with the tightening. I understand that the Limits is built to a price point, but the installation seems particularly complicated, and the whole package feels like it has been made at the expense of hitting that price

I think that is reflected by the end caps which felt, for want of a better word fragile. I managed to crack one simply twisting it on with my fingers!

Because the Limits power meter unit goes between the crank and your pedal, it has the effect of increasing your Q-angle.

Now for some people, this might not be an issue at all, heck there is even some debate about the significance of the Q-Angle when it comes to a bike fit. I think it might be reasonable to say if you have “glass knees” or have had issues with bike fits in the past, this might be something to cause you to hold off that eBay bid!

Limits Power Meter Specification

  • Battery: SR44 Silver Oxide – which Limits advises specifically after having reported issues with NiMh batteries – estimated 200hours – I road with the Limits for about 40 hours before taking them off, and did change the batteries to see if signal improved – nope
  • Total Weight: under 100g for both power meter and extension
  • Measurements: Power and Cadence
  • Communications: ANT+ no BLE here!
  • Power Measurement accuracy: +/-2%
  • Water resistance: IPX7 – 1min at 30m
  • Maximum weight of the cyclist: 90kg officially, but has been tested with 150kg rider

Whilst there is no downloadable manual, the Limits does have a trouble shooting section which will be of use to some riders, and is quite useful when upgrading the firmware which is managed with an external app. That in of itself doesn’t sound too bad until you use it. The approach is functional, but it really doesn’t feel end user ready, instead giving the impression of factory configuration software, which has been shipped as the company was not able to develop their own app in time,

Limits Power Meter Test – Zwift Gear Test

Before each ride, Limits advises that you calibrate with the pedal in the 6 O’clock position,

With things in position, a quick claibration can be performed on a Garmin head unit, followed by a 10 minute bed in period on Zwift

I took the power meter off and reinstalled it after the first bed in ride, as the power meter numbers were very out of whack compared to comparison power meters I was using… unfortunately this didn’t really improve matters

However after reinstalling the firmware things seemed to settle down, and give readings more in keeping with my other power meters, meaning it was time to start a formal Zwift Gear Test via Zwift, and Jon’s Mix

But even after the calibration, new batteries and reinstalled firmware the Limits would still give slightly odd reading compared to the 4iiii Precision and the PowerTap C1 chain ring – massively under reading my wattage

But one thing I am aware of from testing power meters is that you need to plug the data into a graph to see what is going on, merely comparing head units can suggest there is a bug, but not actually what is going on.

So after riding the Limits power meter for several rides, and tweaking things as advised in the companies troubleshooting steps, this is the best graph I was able to generate:

Limits Powermeter

Initially, it doesn’t look too bad, however, when you zoom in on the data you can see that there is a different story to tell. At higher wattages, the Limits holds well with the other two power meters, but I’m also seeing considerable drop outs when on the steady state sections, up to four in a minute, and lasting for several seconds at a time

Limits Powermeter

Certainly, in a Zwift race, the drop outs that I’m seeing would rapidly result in your being dropped, and likely not able to get back in the draft, and knowing that is probably due to an issue with your kit is always an unpleasant experience. But what about steady state work?

While there is one drop out at higher power, I tried another test, gradually increasing power, and that seemed to confirm my suspicions that the issues appear to be focused to lower power levels, although I couldn’t find a specific reason for this. Again, as a result, I wouldn’t really want to be relying on this unit for my training data.

Limits Powermeter

Limits has responded to a few points over time regarding a few issues encountered with other riders units as well

Battery Life

LIMITS comments that whilst there are three coin cells which will fit the Limits Power meter, “it is the SR44 batteries, i.e. silver oxide, which should be used; rather than the slightly cheaper LR44/AG13 Alkaline batteries – apart from price, silver oxide batteries have a slightly higher capacity and a voltage, which should eliminate premature low or critical battery warnings.” The company stressed that advertised battery life to be expected with Limits was calculated using silver oxide batteries. Some people might comment that these are not as easily available, but given the power of the internet, should not be a major issue,

Power Data Still Fluctuating

Again thanks to those who have provided their power data as it enables us to compare and analyse your data with ours and draw conclusions. The conclusion was that we needed to adjust a hysteresis value in the firmware. We have subsequently done this and have units under test to determine the impact/improvement. We will update you early next week on the outcome of the testing” – Unfortunately, this hasn’t addressed the issues I have had with drop outs

Battery End Caps

“We are aware that some you have seen split battery end caps, and we are currently working on a solution for this. We’ve asked a number of backers to work with us on the proposed solution to get a broader feedback, and we hope to release a model drawing this week so we can move forward quickly and address this issue.”

 

Limits Powermeter Conclusion

Ultimately the conclusion of this review is “buyer beware“. You still can’t buy the Limits power meter from Limits themselves, but they have delivered on the Indiegogo orders. Part of that is reflected in the fact those original orders are now beginning to filter through to eBay.

Limits

This is the time of year that cyclists tend to be on the lookout for good deals with power meters. In my tests, the Limits power meter has been shown to track reasonably well when you are not getting drop outs from the unit, but from the point of view of racing in Zwift, the drop outs pretty much make the Limits Power meter currently unusable.

Remember, just because a product has a low price, doesn’t mean it’s a good deal! In its current incarnation, I’m going to give the Limits Powermeter 2/5 – I really hope that they can address these issue when they start shipping a final release version, but for the moment, you are better staying clear of the eBay units!

Fingers crossed the final release version will be more successful!

Limits

About James Gill

A runner first, a cyclist second, and when pushed a swimmer. Working as a GP registrar, I found that I went from walking 12miles a day on the hospital corridors to sitting in a chair. Whilst at medical school, I'd run 10km in an evening just for fun, but having lost the general activity required to be a hospital SHO, consciously being active has now become more important - well until I broke myself!