ancker

So I have a 2008 Trek 1.2 triple with an 8 speed cassette and 32 spoke rear wheel. I'm thinking about getting a PowerTap Hub with part of my tax return. I'm also planning on upgrading to a Trek 2.x around Christmas 2011. The 2.x has a 10-speed cassette and if I understand correctly, a 24 spoke rear wheel. I plan on keeping the 1.2 as a backup and mostly riding the 2.x so it's more important for me to be able to use the powertap on the 2.x when I get it.

My question is what I should do in the meantime with the PowerTap. I'm considering buying the 24H PowerTap Elite+ and a Bontrager SSR/Race (the Trek 2.x stock wheel) and have my LBS move my current 8-speed cassette to it, then swap cassettes when I get the new bike. Can I even do that? Can different speed cassettes be swapped? I have no problems riding with a mismatched rear wheel on the 1.2 (assuming a 700x25c front with a 700x23c rear won't be a problem.)

I don't want to put the PowerTap in my current wheel because it has 32 spokes and the 2.x wheels are 24 and then they'd be incompatible. I also don't want to use my current 1.2 wheel on the 2.x when I get it.

Do those of you with PowerTaps just always buy the same spoke count rear wheel? Obviously you don't buy a new PowerTap for each bike. Or maybe you do, but I can't. I have around a $1200 MAX budget. So $850 for the PowerTap Elite+ and $350 for the rear wheel/tire/tube.

Comments? Suggestions? Should I just wait on the PowerTap until I get the 2.x?

echappist

standard response is to contact your neighbor to the north by the name of PSIMET, and at your budget, you can buy a lot more than just a Elite+ from him.

A few things to clarify:
-Chances are, you won't be able to use your wheels with the powertap hub. When you build a ptap wheel, you have the option to select how many spokes you want, etc. Now you may be able to have a wheelbuilder to strip down the wheel to just the rims and build from there, but you certainly won't be able to reuse the spokes. In some cases, the rim won't be compatible with ptap hubs.
-If your shimano hub can accommodate 10 speeds, it should be able to accommodate 8 speeds. I've done it.

grwoolf

Reach out to psimet (popular guy around here that builds wheels) or wheelbuilder.com and they can work through options much better than using a Bontrager wheel for much less $. You should be able to get a ptap elite on a nice training rim with a Garmin 500 for under $1,000.

ericm979

Don't get a 24h Powertap hub. Their flange spacing is not optimal and makes for weak wheels. Get at least a 28h. 32h if you want to use the wheel all the time and you're not a lightweight.

And get it built up with a new rim, not a used one. The labor to disassemble the old wheel and reuse the rim will be as much as a new rim costs, and it'll still be a used rim. Rims are consumeables.
I suggest a Kinlin XR-270 rim if you're light and easy on wheels, or an XR-300 if you want something a bit sturdier for all of 10g more.

MegaTom

As long as you're sticking with Shimano or SRAM for your next bike, the wheel & cassette will be interchangeable between bikes. And ditto above about PSIMET/Wheelbuilder; you can get a much better wheel than what that Bontrager rim will give you for about the same price.

JTGraphics

I have to agree send an email to PSIMET he's building me a SL+ powertap with Kinlin XR-270 rim now price is very good the PowerTap Elite+ should be well with in your price range.

achoo

I've built my own PowerTap wheel, and I'll echo what ericm979 said: do NOT try to skimp on the spoke count. The PowerTap hub geometry can make for a weak wheel. I'm no expert wheel builder by any stretch, but I think the problem is that it needs a much higher difference in drive-side and non-drive side tension than a more normal hub. So don't try to get a lightweight rim, either, because it has to be sturdy enough to handle that tension differential.

And you probably want to ride it a lot, too, for training. So you want it to last.

In other words, a PowerTap wheel that's built to last is going to be heavy. There's no way around that.

FWIW, I had my first attempt at a PowerTap wheel with a lighter-weight rim fail on my when I was descending a 12% grade that I was doing hill repeats on. At the bottom, when I was braking to stop, about three spokes pulled right through the rim. I think the heat from braking from 45 mph while still on the hill (either that or go out into traffic...) softened the metal just enough to cause it to fail at that time. I rebuilt the wheel with a sturdier rim and haven't had any wheel issues since.

Just last week my PowerTap did go out of calibration, so it's on its way back to Saris. That's another thing to be aware of - they can and do go out of calibration. Recalibration is covered by warranty, but I don't recall offhand how long the warranty is. I did ask Saris how much a recalibration costs out-of-warranty, and the figure I was quoted was about $350.

echappist

this ain't a powertap, and the company is new, but i suggest you check them out

The quoted price include a Value Added Tax of 19%, which residents of the U.S. do not need to pay.

ancker

For more info I'm 5'6" and 155lbs/70kg so I'm mid range. I will be getting a Garmin Edge 500 next week, so ANT+ is a must.

I plan to use this wheel/powertap both inside and out. I'm not currently racing and don't have any immediate plans to serious compete. I do intend to enter a crit or two and see how I stack up at our local "open to literally anyone" weekly Time Trial this summer. My goal for this year is to train train train and maybe enter a few serious races next year for fun. My Trek 1.2 is ~21lbs so I doubt I'll notice a few hundred grams on a sturdier wheel.

Thanks for the tips towards PSImet for a complete wheel. I thought of that but assumed I couldn't afford it.

(Side note: I was only considering 24H as that's the stock number of spokes in the Trek 2.x rear wheels. I have no personal opinion other than not wanting it to explode on me and/or need replacing often.)

grwoolf

If you have not gotten them already, you should think about getting the books "training and racing with a powermeter" and Friels "cyclist training bible". Based on your goals, I think you'll find the powermeter to be a very effective tool in combination with the info in those books. The Friel book sort of caters to hard-core racers and doesn't specifically focus on power-based training, but I picked up a lot of good information and applied it to a less structured training approach that works for me.

jsutkeepspining

Jesus thats amazing if its quality. Anyone have one?

echappist

+1. It's just a fancy gadget if you don't utilize it to its full potential.
Just came out. The main drawback is you have no idea what the torque is.

Psimet2001 

*cough*

My only drawback is that being in IL you'd have to pay tax, but you'd have to do that anyway at your LBS. How central in IL? If you know some Wild Card racers - ask them about me.

My take - and trying to add something that doesn't sound like a commercial:

I often build using customer's existing rims. The rim in general isn't that much of an expensive part of the assembly but does have a lot to do with the overall strength of the final wheel. I would hardly ever re-use spokes under any circumstance. Usually the wrong length and most people don't get that but outside of that it's just not a good idea.

ancker

Have the bible but haven't picked up the powermeter book as I don't have a powermeter yet. I have been reading Carmichael's "Time Crunched Cyclist" and it seems to fit a lot closer to what I
can commit on the training side of things. I'm thinking a powermeter is going to help me get the most out of such a small amount of training.


Yup. I'm in Champaign/Urbana. I'll ask around. I'll send you a PM or email from your website in a few days to get a quote.
Bummer on IL sales tax but as they say, 'there are only two things you can be certain of in life, first is death, the other is taxes'.

ericm979

Read the power meter book before you get the power meter. If you don't finish it thinking of all the cool things you can do with the data, then the power meter will be a waste. You just won't be using it to its potential. There's nothing wrong with that. Not everyone is a data-driven dweeb. Some of the guys I ride with don't even use a bike computer and that doesn't keep them from being fast.

Speaking as a long time power meter user, if you're not racing I wouldn't bother with the power meter.

echappist

qft

ancker

I fully understand this point of view. Though reading through the "Time Crunched Cyclist" I'm convinced that I need to power to ensure I'm getting an effective workout each time I hop on the bike to "Train". Whether I'm racing or not I'm still trying to get a good workout on the bike with the end goal of being super fit. I'm hoping a fortunate side effect of that is also going to be getting fast.

I've already noticed that in the 6 months I've been seriously riding that I can't rely on my HR tell me whether I'm actually accomplishing anything on the bike. I don't think I have enough seat time to adequately estimate my PRE yet either.

While I'm likely not going to use the powermeter to its (or my) full potential, I think it's going to help me accomplish my goals better than just winging it every time I hop on to "train".

Disclaimer: I'm a data dweeb. I really like being able to see progress via data. I feel like I'm faster/fitter than 6 months ago but other than my workout average speed being a few mph higher (which I know can be caused by shorter warmup/cooldown) I can't really see anything.

grwoolf

I'd agree 100% about reading the book and needing to be data driven, but disagree that you need to race to see significant benefit from a powermeter. If you are a goal-oriented person that wants to take a measured approach to reach specific cycling goals, I think a powermeter is a smart purchase. I've only had my PT for a year, but I feel strongly that it's help me exceed the cycling goals I set for 2010.

I plan to try my hand in racing this year to see if I like it, but regardless of specific goals, I feel the PT is a valuable tool if you are serious about getting faster and stronger on the bike. For me, I feel like it's a better purchase than a nice set of wheels (everyone I ride with seems to have nice wheels, so to each their own). Just to add, one man's social group ride is another man's race (sprints to the city limit signs and KOM points are kind of silly, but can get pretty competitive).

rbart4506

I bought a PSIMET PT and started the book...Got half way through the book and put it down...Gave my head a shake and got a coach to let him do the number crunching....

echappist

also, there are alternatives between the extremes of time crunched and friel's plans. Most of us in the racing forum don't think highly of the Carmichael plan because it essentially leads you to crash cycles (and if we don't want to be as charitable, it is almost like doing three bouts of overreaching a year). Carmichael is correct in saying that his high intensity stuff will give you very quick results, but he is coy in telling you that this is an ephemeral gain. If all you have is 6 hours a week, the middle ground would be to do a lot of SST to bolster your threshold power. After 3-4 months of doing this, you can start adding in VO2 max and anaerobic workouts to sharpen your top end.

One other thing is that the testing protocol in Carmichael is useless as the assumption is that the anaerobic contribution for the time period he chooses (8') should not vary much from person to person. In reality, the contribution from anaerobic work capacity varies greatly from person to person, and eight minutes is not enough to minimize its effect on your lactate threshold power readings, even if you do two sets of them. It's much better to follow the Coogan method of testing, which entails a test with a large anaerobic component (5' test), followed by 10 min rest, and then doing something that is largely aerobic (20' test).

jrobe

It is definitely foolish to buy a PT without first reading and thoroughly studying "the book." It is only $16 and you can have it from Amazon in a few days.

Then it isn't so much a question as to whether you are a "data-dweeb" or not. It is a question of if you are willing to do the suffering intervals to make it worthwhile. For many people (in fact probably most people), intense interval training takes the fun out of cycling. There is no sense buying a PT unless you enjoy doing intense interval training (it doesn't matter if you race or not).

Smallguy

Do you have any experience with these or know someone who is having good luck with them ?

rbart4506

You don't need to buy the book to figure out if you like to do intense interval training...

You need to buy the book if you are going to try and properly train with a power meter on your own. If you are planning on, or already have, a coach then you don't need to buy and read the book. My wife hasn't even looked at the book, but trains with her power meter as hard as the next guy/girl. She/we have a coach to do all the number crunching stuff and to motivate us to reach for the next level...

I must admit the PT is probably the best cycling equipment investment we have made...To the point we are planning on buying a second wheel so we each have a race wheel and a training wheel. That way we also have a backup just in case...

ancker

I'm not sure I agree with this. I expect I will make great gains with a powermeter solely by the fact that I can be certain I'm putting in exactly the same effort for each interval in a workout. Basing on HR and/or PRE alone isn't going to do that.

echappist

Smallguy, it just came out in December, so i'm not sure. The biggest drawback is that you won't know when your unit is off in calibration. I wouldn't touch it for another 6 months. Also, you have to mail it back to Germany for calibration

if anyone is looking for a racing tubular with powertap, i recommend you go here.