I’m considering finally investing some money in a power meter and trying to find the right one for me. I would like a power meter that costs me the least amount of extra time to prep for racing since time is very limited for stuff like that, but it needs to be able to go between my tri bike (with a 10 speed cassette) and my road bike (with a 9 speed cassette) since I alternate frequently. I think that rules out powertap because changing cassettes constantly would be too tedious (I’ve done it before) and I prefer to race with different wheels than I train on so I don’t have to change tires. Also racing with latex tubes I really don’t want to risk frequent changes, seems that would make an eventual failure more likely. So I’m looking at crank based options thinking it might be easy to just change cranks real quick as needed, but that might not go as quickly as it seems. Anyone doing this and have any thoughts?
I have a Stages on a shimano crank arm that i swap between my TT and road bike. It’s a pretty easy swap and only takes me a couple of minutes to do.
I have a crank based power meter and switch it between two bikes multiple times a week during race season. Takes 5 minutes and that is with two bikes that have different BBs. Just invest in a torque wrench.
the powertap freehub body just pops off. So if you buy a 2nd freehub body you can swap cassettes in 2 seconds.
Literally two seconds.
if you pick the right cranks, you can swap cranks pretty quick too though.
I’m considering finally investing some money in a power meter and trying to find the right one for me. I would like a power meter that costs me the least amount of extra time to prep for racing since time is very limited for stuff like that, but it needs to be able to go between my tri bike (with a 10 speed cassette) and my road bike (with a 9 speed cassette) since I alternate frequently. I think that rules out powertap because changing cassettes constantly would be too tedious (I’ve done it before) and I prefer to race with different wheels than I train on so I don’t have to change tires. Also racing with latex tubes I really don’t want to risk frequent changes, seems that would make an eventual failure more likely. So I’m looking at crank based options thinking it might be easy to just change cranks real quick as needed, but that might not go as quickly as it seems. Anyone doing this and have any thoughts?
Yes…at least I used to (before acquiring more PMs). I would easily swap a GXP based Quarq crankset between bikes that both have GXP BBs installed. In fact, there’s a video on Youtube of me doing the swap in just over 1 minute (unpracticed) 
And that was swapping an entire crankset over. With the more recent BB30 version SRAM/Quarq cranksets, the removable side is now the DS instead of the NDS like on the GXP versions. That means swapping the BB30 version between 2 bikes would be even easier if one has a spare NDS crank and axle already in the second bike. It’s literally a one-bolt process.
I have a Power2Max and swap it between bikes all the time. On the order of 5 minutes if I’m putting the non PM crank back on the bike I take the PM crank off of. Less time if I’m swapping and leaving the other bike without a crankset (which is usually what I do).
I’ve thought about the Powertap though just to make it easier.
I have a Quark that I switch between my road bike and my tri bike. Pretty simple operation and allows me power on both bikes.
I swapped for about a year or so. Its easy and not too slow. Got tired of it still and bought the 2nd power meter. then the 3rd. it’s a disease
the powertap freehub body just pops off. So if you buy a 2nd freehub body you can swap cassettes in 2 seconds.
Literally two seconds.
if you pick the right cranks, you can swap cranks pretty quick too though.
Interesting, I didn’t know that. I still think the downside of having to switch tires for races would put me over the top. It isn’t that it takes too long for that alone, it is that I believe frequent changing would increase the margin for error and increase my likelihood of a flat. I race exclusively short course so a flat is devastating.
Thanks for all the responses about changing the cranks! I am thinking of something like power2max and getting the FSA crankset since I already have an FSA bottom bracket. Put the same bb on both bikes and switch cranks at will.
All the time. Super easy. Only question I have is do some of you re-grease everything.
I bought a Quark for my wife. I was switching it between her road and tri bike once a week during race season.
I did get good at it, so we are talking less than 5 min.
Interesting, I didn’t know that. I still think the downside of having to switch tires for races would put me over the top. It isn’t that it takes too long for that alone, it is that I believe frequent changing would increase the margin for error and increase my likelihood of a flat. I race exclusively short course so a flat is devastating.
Perhaps if you learned how to change a flat really quickly it wouldn’t be quite so devastating. You could probably do this by, I don’t know, changing tyres more regularly for practice?
But seriously, changing a tyre takes all of about three minutes versus changing a crank rated by most here at about five and if you take a little longer (say use up the full five minutes instead of three) I’m not sure what you could possibly do wrong that you wouldn’t notice before you racked your bike. If you want a crank based PM then that’s great, you don’t have to come up with some bizarre notion for spending the extra cash.
I have a Quark with GPX.
A road bike with Gpx bb.
A Cannondale Slice with BB30 bb.
I got hold of BB30 to Gpx adaptor (wheels) for my Cannondale.
I switch a a lot between bikes. All I need is an 8mm hex wrench.
I might not do it in 1 min, but 5 min and both bikes get changed.
I do it 2x/wk to get 1 ride in on the TT.
Little stupid non-issue-really things you’ll have to deal with:
Grease the tidbits every few rides or it gets tough to pull.
Don’t place in haste, missing one of the spacers/covers is a great way to gunk up your BB.
Get the torque right or you’ll be SAGing back or losing Ws
Compromise with chainrings. I like a standard on the TT, but am not as much of a man on the road bike. So I spin a mid-compact.
And the most annoying thing,
The crank will always be on the wrong bike in the morning.
I figure it’s 5 minutes of annoyance per week to save $1500. Eventually, I’d be better off with 2 PMs, but my time isn’t as valuable these days.
I have got a srm 9000 DA… I haven’t switched it between my 11 speed race bike and 10 speed wet weather bike because I read that it is best to match the chain with the crank… So I’m not sure whether it will be good if you get a crank spider type PM to switch between a 10 and 9 speed chain… Hopefully someone chimes in on that with more experience…
Have got a few mates that switch their stages between bikes frequently… Though then there is the issue that a lot of people prefer a slightly longer crank on their road bike as opposed to their TT bike.
Good luck mate
I swapped for about a year or so. Its easy and not too slow. Got tired of it still and bought the 2nd power meter. then the 3rd. it’s a disease
That’s funny…mainly cuz it’s true 
Nope. Got the Quarq for my tri bike, then when I got a road bike a few years later I picked up a Power2Max for it.
I am actually fairly quick at changing tires, last time I did a full IM I got something like 10 flats in training leading up to the race, including 3 on one ride once (learned that one flat kit isn’t enough). But as I said I only race short course now and I don’t care how fast you are, when you are racing for a sprint or olympic distance national or world championship a flat tire is devastating.
And as I said before, the time isn’t really the issue, I could easily change the tire as quickly as I can change a crank (though I will not keep a different crank on the unused bike so it would probably be closer to 2-3 minutes), my biggest concern is that frequent removal and replacement would increase my likelihood of flatting my latex tubes, you have to be a little more careful when you install latex.
And lastly there is one more step I forgot about, and that is removal and replacement of the disc cover. Again, probably takes 10 minutes (I tape mine on) but the reason I ride my road bike is to ride with roadies so I would have to remove and replace it several times a season, that would be a royal pain. I simply don’t have time in my life anymore to spend 10-20 minutes prepping my bike for a ride any more, if I have an hour workout planned I’ve probably only got 65 minutes of available time to get it in.
I swap my Quark Riken about once a week between my road & tri bike. My particular configuration takes a bit longer than some because I have two different bottom bracket standards (BSA & BB86) and I have to install and remove a wave washer and gasket on the drive side each time I swap. Also the non-drive side has a gasket that is loose and doesn’t like to stay in place during the swap. I also like to make sure everything is clean and well lubed so I often wipe the gaskets and relube the crank. So for me the swap usually runs about five minutes. It’s definitely very doable but certainly not as quick as swapping a wheel. Would be easier if both bikes had the same BB standard.
BTW the Riken is rock solid, just works, no problems at all. Data seems very consistent and reliable as far as I can tell (although take that with a grain of salt as I’m not a super-geek like Tom A.). Recently when I swapped cranks my magnet got caught on the chain and fell off. So I downloaded the latest firmware (which I can do directly using my Samsung S5) and voila, no magnet needed. Took less time than re-gluing the magnet. Nice to have a new feature added to a crank I’d had for almost a year!
Changing a tire with a latex tube, with care so you don’t risk flatting, is going to take as long or longer than a crank.
Perhaps if you learned how to change a flat really quickly it wouldn’t be quite so devastating. You could probably do this by, I don’t know, changing tyres more regularly for practice?
But seriously, changing a tyre takes all of about three minutes versus changing a crank rated by most here at about five and if you take a little longer (say use up the full five minutes instead of three) I’m not sure what you could possibly do wrong that you wouldn’t notice before you racked your bike. If you want a crank based PM then that’s great, you don’t have to come up with some bizarre notion for spending the extra cash.