Quarq PM self install?
Looked in archives amd didn't see, so sorry if this has been discussed previously. In process of buying a used Quarq PM. How difficult is it for a semi handy guy like myself to installing myself or should I leave this to my LBS?
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1. Make sure the used Quarq fits your bike. The whole GXP vs BB30 thing. Although a GXP Quarq can be fit into BB30 with the proper adapter for your bike. BB30 cannot fit into GXP.
2. Is your BB threaded or press fit? There will be some wrenching required and you'll need the proper tool either way. You'd definitely need a bottom bracket tool to remove and install the old and new crank if it's a threaded BB. Press fit may or may not require a bearing press tool. Some bikes are easier to install press fit bearings than others. My Trek Speed Concept required the use of a bearing press tool... which I did not own.
3. Going from one manufacturer of cranks to another might require an adapter of some sort to work. This is usually true with a press fit BB. Let's say for example that your bike currently has Shimano cranks. Let's say the Quarq is a SRAM crank. They use different bearing kits. That won't be an issue with a threaded BB.
If the Quarq you buy already has the same BB that your bike has (press-fit or threaded), any caveman can do it... If your bike has any threaded BB and you buy a GXP Quarq, then it's also very easy to swap out the BB and install the crank. If you have a press-fit BB and you need a "different" press-fit BB to make the thing work, then my opinion is to let the LBS do it because it won't be worth it to buy the tools necessary (unless you want to use the wheels manufacturing adapter that needs no tools)...
What kind of bike or bikes do you have? Do you already know what BB's they have? Which kind of Quarq are you leaning towards?
http://www.ebay.com/itm/SRAM-TruVative-GXP-Sealed-External-Bottom-Bracket-68-73mm-Road-Mountain-Bike-/360607293177?pt=US_Bottom_Brackets&hash=item53f5de9ef9
or
http://www.amazon.com/SRAM-GXP-Team-Bottom-Bracket/dp/B008H61H6A
I bought a wrench for this, but it's not absolutely necessary if you have a large pipe wrench. I don't even bother with a torque wrench. Just make it very tight, but not crazy tight. There are usually little arrows to show which direction to turn to tighten or loosen. I think the one side is a left handed thread if I remember correctly.
http://www.ebay.com/itm/Bikehand-External-Bearing-Bottom-Bracket-Bike-Tool-fit-BBT-19-GXP-Outboard-Handl-/290916389343?pt=LH_DefaultDomain_0&hash=item43bbf7d1df
or
http://www.amazon.com/Park-Tool-removing-16-notch-external/dp/B000VX5FJ2/ref=sr_1_11?s=sporting-goods&ie=UTF8&qid=1369930651&sr=1-11&keywords=bottom+bracket+wrench
Park Tools has great resources on their webpage for all things maintenance... http://www.parktool.com/blog/repair-help/external-bearing-crank-systems-hollowtech-ii-megaexo-giga-x-pipe-x-type-campagnolo-ultra-torque
My personal advice is to get a Compact and to probably go shorter on the crank length than what originally came on your P2.
consider going shorter cranks perhaps.
i am 6-6. i use 170 mm cranks on tri bike. allows seat to get up and helped me get more aero.
But, since you are buying a fresh new set of cranks anyways, you may as well get exactly what you want. There is some info in the wiki about this topic, and if you search the forums there are some other threads about it. I wrote the following up for another friend and just also shared it with another EN'er via PM... so here it is for you...
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I'm 6'-1" with a 32" inseam. I switched to a 170mm crank 2 yrs ago and have been happy. 2.5 mm doesn't sound like much, but it allows you to raise your seat height by 2.5mm and your top foot is also 2.5mm lower. So you effectively create an extra 0.5 cm or room before your knee hits into your chest when you pedal. So if you are more flexible now, you can lower your bars by that same 0.5cm. so for the same "feeling" while you pedal you have effectively created an extra 1.0cm of drop. This is a lot if you're trying to be more aero over 112 miles. I have found that it also makes it a little easier to pedal with a higher cadence because the 172.5 has a circumference that is ~1.57cm bigger. So for the same effective RPM, say 90, your foot must travel 141cm more per minute with a 172.5 than with a 170. Said a different way, for the same exact foot speed, you will be at 91.13 RPMs (170mm) vs 90.0 RPMs (172.5). Again, this all seems like minutia, but this means for the same net average power over time, the force generated by each revolution of your pedals is ~1.25% less with the shorter crank. These effects will all be magnified if you went to a 165 or a 167.5mm. There will obviously be a point at which going shorter will be detrimental as some people simply can't spin at Lance type RPMs efficiently. But it seems to me like the old standard of 172.5 cranks are simply an artifact of old manufacturing standards and not so much because they make sense anymore.
As a former Mechanical Engineer and BioEngineer (and now hack triathlete), I think most triathletes would benefit from using a shorter crank length and a compact crank But this is an expense most people don't even think about. It's certainly more important if you are buying a new crankset anyways as different length cranksets generally cost the same... It's even more important if you are flexible or are looking for an aero advantage and/or are looking to get every tiny advantage you can to save your legs for the run.
The same is not necessarily true for roadies. They likely want a longer crank arm for maximum torque and speed during the sprint finish and you are already much more upright so your knees hitting your chest is no nearly as big of an issue as in the TT position.
Side note, moving your seat all the way forward will also create similar effects by allowing you to raise your seat slightly and opening up your hip angle a bit.
Have you looked on Craigslist for one Brad? I've seen a few from time to time. If you use searchtempest, you can search by distance from your location and find more results quicker.
Jamie
@John- I did see that one but i currently have 172.5 cranks..I'm unsure about changing. The ones I missed on were a perfect fit and barely used. I just got outbid. Still looking!
Thx guys