questions about PT, Quarq
I am not training w/ power at the moment, but I'm trying to get set up with that for the 2013 season. I was going to go the powertap route, but then started thinking Quarq because:
1. did an online bike fit with Todd from TTbikefit... I made his suggested changes to the bike config, and then he suggested trying shorter cranks to help open up my hip angle a bit... so...
2. that got me thinking that if I am going to go w/ shorter cranks and I still have the gearing that came with my bike (Felt B14 with 52/38 and 25/12 cassette), I should just make the switch to compact gearing, ESPECIALLY since I am considering some hillier races for next year...
So, my question is - if I am going to be messing with the cranks anyway, am I better off going the Quarq route instead of purchasing new cranks/chaingrings up front plus rear powertap/wheel?
I'd really appreciate any advice!
Comments
I have both and they have pro's and cons. The PT is the easiest to move from bike to bike and will even travel well if you have a wheel bag and are renting or borrowing a bike.
The Quarq will also move between bikes, but you need a couple HEX keys. I think I like the Quarq better because it is part of the bike. I just don't think about it and take for granted that it is there. My PT is laced into a deep wheel (Zipp 404 Firecrest) and I don't always want to ride around on those. As a result they stay on my Tri bike and my roadie has the Quarq. It expensive, but a great system none the less....
I have a road bike and a tri bike with similar wheel/cassette setups. So shifting is dialed in. Changes from bike to bike with one hex wrench, park tools set, cheap, and you need these in your garage anyways.
takes about 5 min, at most, to pop the chain off (inwards, resting on the bottom bracket), loosen the hex bold (nondrive side), pop off the crank arm (non drive, then drive side), lube (not every time, only if needed, don't want dry spindle), and then do the same stuff on the next bike (but, in reverse, of course), put the chain on, then go hit your intervals.
That's it...chain off, loosen bolt, pop off the cranks, put on the cranks, tighten bolt, chain on.
Just as clean, if not cleaner, than popping a rear wheel off.
When you sell your bike and move on to another keep your wheels use them on your new bike.
I like being able to run any wheels I want. The Quarq is a very easy swap between bikes (make sure all bikes have the same style bottom brackets). I actually own 2 Quarqs (53/39 and a 50/34) that I swap between 3 different bikes regularly. Piece of cake. Vwith the Qalvin iPhone App I can even recalibrate then if I want to change the chain rings. Finally, Quarq customer service is outstanding.
My issue with swapping the Quarq between bikes is that my P3 and Madone have different bottom bracket set ups. The Madone is BB90...
I also agree about using the heck out of the 404 and run them every time I use my TT bike. Just personal preference that I don't like them on my roadie.
I can use whatever wheels I want at any time, on either bike. I have a speed/cadence sensor on each bike, and have to change my joule to receive the values from whatever bike I'm using that day, but that's pretty easy as well-just switching menu options.
Each has pros and cons, so it's just a matter of preference. I mostly chose quarq because I already had so many sets of wheels that I didn't want to give that flexibility up.
Dino:
What's your other BB? If its GXP then you could still use a Quarq, because they make a BB30-to-GXP adapter. My Specialized Allez E5 is BB30 and my other two bikes are GXP. I have no issues swapping the Quarqs among the three bikes,
In the long run would have been cheaper and would have been more easily adaptable. At this point I feel to deeply invested to switch.
And since I'm on that subject, what type of cranks do y'all have your quarq on? I think the Rotor is the only one that comes in 165s, but would be interested to hear any comments about the different cranksets. The link to the BB adapter was also helpful... I have a Felt B14 with an FSA MegaExo BB... I don't know much about bottom brackets, but do either the GXP or BB30 work with that, or would I def need an adapter?
Another Q - has anyone purchased a used Quarq? Comments on that? Would you not recommend doing that?
All of this makes my head hurt.
I don't THINK GXP and MegaExo are compatible. I run the SRAM S900 cranks with both my Quarqs. They've been solid and I've had no problems.
If you want to harmonize your bottom brackets across your bikes, you can get decent bottom brackets fairly inexpensively. You don't need the $200+ black box GXP with ceramic bearings. 2 brand new SRAM Team BBs (http://www.competitivecyclist.com/za/CCY?PAGE=BUY_PRODUCT_STANDARD&PRODUCT.ID=8175&MODE=) should cost you $80 (talk to your shop about getting the right size and English v. Italian threading)
Never bought a used Quarq
Unfortunately, at the moment the SRAM S9XX cranks only go down to 170mm, but a 165 is supposedly coming soon. If you need smaller than 165 now, the rotor quarq is available in 155, 160, 165.
No matter what BB your bike has, I HIGH recommend getting a GXP or similar design crank, as there are tons of options to convert an oversized BB such as BB30, BB30PF, OSBB, BBRight down to gxp, but you can't put a oversized crank spindle into all standard BBs.
For example, I personally have the SRAM S975 GXP and swap it between all my bikes including a Cannondale with BB30. I simply put $20 wheels manufacturing BB30 to GXP spacers in the BB30 bike and a $30 SRAM GXP BB in all the other bikes and swapping take literally a few minutes. I posted a video of this to the EN forums maybe a year ago.
However, at your desired length of 165 you will have to go with something other than SRAM GXP today since that length is not available. I would look at the Rotor cranks as they come in the shorter crank lengths you are after.
http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&item=230816111911&ssPageName=ADME:B:WNA:US:1123
Madone is BB90 as you said, so you need a BB90 to GXP adapter. You already have this, so nothing you are all set.
P3 uses a standard threaded English BB, so all you need is a English threaded GXP BB. about $30 new from ebay.
Then you can easily swap the S975 from bike to bike by simply loosening the 8mm bolt on the NDS, removing the crank, re-installing in other bike, tighten up the 8mm bolt and you are done.
Your issue is that you have a rotor crank which i believe uses a shimano octalink style BB which is not compatible with a SRAM GXP. Therefore after you put the GXP BB in the P3 you will no longer be able to put the rotor crank in.
Of course since you already have the PT on the P3 then you don't have to do any of this and you are just fine with what you have.
Clear as mud?
Matt et al.
A bit off track.
1) Can't there be chainline problems with putting on adaptors (shifting issues)? The adaptors take an internal bearing and sort of make it external.
2) increased crank friction with adding adaptors (bb30 to gxp, or whatever)? Not a big deal?
thanks.
1) nope, BB30 (etc) are narrower than GXP by about 11mm I believe. So the spacers fill that space and do not move the chainline at all. As long as you get the right spacers no problem at all, and there are tons of spacers out there for the different BB/crank combos.
2) not sure if I can explain this right, but no I am not worried about any extra friction. The wheels manufacturing ones I put in go into the existing bb30 bearings. The same BB30 bearings are what spin, the spacers fit the crank spindle tighly and the crank does not spin instead the spacers, the spacers just turn the bearings exactly how a BB30 spindle would. On a BB30 setup you usually put thin wave washers in between the bearings and crank arm any way, with this adpater you are just putting a bigger washer in the same spot.
here is a description and picture to help: http://wheelsmfg.com/products/bottom-brackets-front-drivetrain/bb-adapters/bb-30-shims-sram.html