Ewan's Training Log

[Jack Hughes]

Just randomly ride over potholes, that work!

Do you have an idea of how big the other riders you are comparing to are? Strava weight categories might give a clue.

The problem is that you are at the lighter/small end of the spectrum already

[IanM]

Two thoughts:

1, broadly speaking I'm pretty happy with my vectors but only having one powermeter I'm sometimes anxious about their accuracy, and occasionally I get the odd bit of weird data. In particular with this ride I looked at my CP chart for the past few months and decided that 255-260w was a reasonable target for the ride. In the end I spent the entire first leg backing off the power because I was worried about blowing, but I was consistently 20w higher than my target. Either I'm considerably stronger than I'd guessed, or something is fishy. The other thing that leads me to be sceptical is that my power balance was a consistent 55% when it is usually spot on 50% during TTs... Maybe there was something off about the calibration that day.

Yes, I know what you mean. I sometimes wish I hadn't sold my PowerTap wheel now, but at least the static torque test looks easy enough to do, and I hope to get my weight weighed today and try it out later or tomorrow. Re balance - are you frequently swapping the pedals between bikes?

2, I know strava data is pretty rubbish and powermeter accuracy may vary, but I'm fed up of always having a low speed:power ratio compared to other racers. I'm only trying different lengths for now because that is what I have to hand, although I'd like to try a -17 stem to drop my bars c.1cm. I'm not sure if I'll detect the change in stem length, but I've recently been feeling like I'm perched on the front of my pads so it might also be more comfortable too.

It's a shame that Strava doesn't show you the PM brand/model in the same way it does with headunits - then you could immediately discard power values from known unreliable models Maybe you should do the static torque test to make sure your Vectors aren't out?

Did you get much useful data from your testing?

Just randomly ride over potholes, that work!

Yes, my patent pending Pothole Method is clearly the future!

[Jack Hughes]

Yes, my patent pending Pothole Method is clearly the future!

The ManderMethod, a serious rival to the Chung formula?

[IanM]

Yes, my patent pending Pothole Method is clearly the future!

The ManderMethod, a serious rival to the Chung formula?

Undoubtedly. Potential for huge gains! And broken bones.

[Ewan]

Do you have an idea of how big the other riders you are comparing to are?

Not really, I'll have a stalk online to see if I can find weights/photos later.

Re balance - are you frequently swapping the pedals between bikes?

Yes, between the TT bike and road. All have the same length crank but since I'm using a 910t, I'm never sure whether or not it is setting the angles correctly as there is no option for doing this manually! I'll look into the static test.

Did you get much useful data from your testing?

Probably not. I was thwarted by wind and running out of time but I did some runs with an 80mm +/-10º stem and a 105mm +/-10º stem. The longer stem therefore increased real by 25mm and raised stack by 3mm.

This is a picture of the test setup with the short stem. I don't have a long stem pic because I accidentally fitted the wrong stem for the photo.


This is the final data:





The wind made it almost impossible to do anything useful, and given the small number of runs I wouldn't be confident in the results but there is a small hint that the longer stem may be faster... probably enough to warrant another attempt at testing.

[IanM]

Position looks good. Re swapping, are you using a torque wrench (and if so, which crowfoot?), or just tightening up and hoping for the best? I've changed to the latter option as my crowfoot is just a little too wide.

[Ewan]

I should also add that the long stem feels marginally more comfortable. I've changed to a 1x10 setup and the lefthand extension feels very short without the extension... overall, I think the longer stem felt a little better. The only thing I noted was that I sometimes felt like I was slipping forwards on the saddle with the long stem - can anyone remember what this is usually a symptom of?

I googled bot the other riders and I remember seeing Mark at sign on. He's smaller than me and was riding a Giant Trinity with disc Bambino and SRM. No info on the other guy, other than perhaps he won a hillclimb back in 2011.

Re swapping, Yes, I always use the Parktools torque wrench, however I've basically got vector2 so I *think* correct torque is less important now. I can't remember which crowfoot adaptor I use but I had the same clearance issues with the vector1 design where the petal frequently pinched the wrench between the pedal and the pod making it impossible to remove. I partly solved this by filing a small amount off the crowfoot adaptor, but it's no longer an issue with the newer design. I wonder if I sometimes forget to remove the battery cover when I move between bikes and whether this would cause a problem?

[IanM]

Forgetting to remove the cover would definitely cause an issue. It's unlikely you're installing the pods at exactly the same angle each time, so you absolutely have to take the battery cover off for 10 seconds when switching between bikes, so that it prompts the install angle check.

Re torque, I don't think there's a correct torque, rather there's a minimum. Below that and it'll under read (IIRC). Above the minimum and it's fine. That's why (AIUI) it's less important that you use a torque wrench, as long as you make sure it's good and tight. I could tell in the past when I've not done it correctly as the balance would be off. Also, the recommendation that I follow is to do some short sprints after moving them over, and before doing the install angle check. Then after 1 or 2 rides, take the battery cover off again to reset the install angle in case it's shifted slightly as the pedals bed in.

As long as you follow the install (and post install) protocol, the values should be fine. It's just a bloody faff... I'm hoping to be in the market for a new bike later this year - current plan is to spec a Quarq with it and sell the Vectors, so I can get away from the faff.

[Ewan]

P2Max... IIRC I read some reasonably negative reviews about the Quarq on the LFGSS power-meter thread... not sure Xav likes them?

edit: i'm wrong... it's the rotor he didn't like (among others):

AJE98
Does anyone have any experience with the rotor power LT or the new Inpower? Thinking of changing from my stages to one

xavierdisleyxavierdisley in reply to @AJE98
Still a left sided power meter, no point. New cheap Quarq or P2M.

[IanM]

There's a recent TTF thread with almost entirely positive feedback for the Quarqs. CyclePowerMeters seem to recommend them pretty heavily too.