I think I've decided...(kind of long-ish)

[Cataboo]

It could be the tires or the hubs on your aurora. I don't know what the trek 520 has on it stock. It could be the seat tube angle, crank length something like that. It could be that you're not using the gearing as efficiently, the aurora has larger gears, so are you hanging out in bigger gears and not spinning as efficiently as you do on your 520?

I don't think you should buy a surly long haul trucker without test riding one - because I don't imagine that it's going to be faster than the aurora.

I haven't really ridden an aurora much - I test rode Zen's around a parking lot once, and it seemed like a really nice ride. But I can't say that it felt slower than my surly pacer.

[MartianDestiny]

Do they both have the same tire on them? If not switch the tires and see what happens.

Geo plays a part, any weight difference in the wheelsets might (rotating weight is what you feel more than overall bike weight), a difference in your position (if you aren't at optimal efficiency and are closer on one bike than the other you may be noticing a power difference), some would claim build type (some bikes are built "stiff" and take all that power to your back tire and some are built softer which can be more comfortable but may loose you power from pedals to wheel in flex).

Lots of science crap goes into that unfortunately. Pinning down exactly why would be difficult.

[moderncyclista]

Well. I've got alot to think about and possibly research - but I'm giving the Aurora six months - I want to get some more use out of it. Catriona: Yeah, I think I mash gears on the Aurora but spin on the 520 now that I think about it. Also, yeah I think it would be slow and steady on the LHT (which it is built for.) I've just had some say it's the "bike to get." I like to find what fits. MartianDestiny: They don't have the same tires. The 520 has Race Lite Hardcase 32's and the Aurora has some Vittoria (spelling is prob. bad sorry) Randonneurs 32's. I do think the Aurora flexes quite a bit. The other bike seeming stiffer. You gals have helped me peg what I do and don't like in a bike in general. It seems silly. I've been riding for years but never really thought about why I liked some bikes and disliked others. I'm going to give it some thought and do some more research. Thanks for the advice on all counts ladies. You're wonderful.

[Cataboo]

No worries. At least we're not doing what my bf says to me - It's all in your head.

But I've definitely had "slow" wheels and "slow" tires. Repacking the hubs with grease helped the slow wheels a bit. Banishing slow tires also helped. If the aurora's not as stiff, that's possibly why I thought it was a very smooth ride (but I rode around a parking lot for 5 mins maybe)

I climb better on my titanium road bike with a compact double than I do on my carbon bike with a triple. I don't have much of a clue why.

[moderncyclista]

Okay. I've talked to my LBS. I'm gonna either trade/sell the Aurora (in the next few months - I've got til' August or September til' the new models are announced right?) and buy a new model year 520. I'd be okay with buying another 2009/2010 model too, so that's a choice as well (I just thought I'd look less cheesy with two diff. color 520's. As far as I can tell from Bike Pedia.com they change the color of the fivetwenty approx. every two years) I like having a back up bike and really I know I adore the 520. So, that's where I'm at for now. Unless, I change my mind. *grins*

Again, you gals help and suggestions were infinitely eye opening and thought provoking. (((((*hugs all around*)))))

[bikerHen]

Just asking . . . why do you want two of the same bike? My two main bikes are about as different as two bikes can get. Slow, heavy Surly LHT and fast sleek full carbon Ruby. Two very different ride but I love them both. If I were getting another bike I would definitely get something different.

Something like the Surly Pacer, I don't need but can't stop lusting after. bikerHen

[moderncyclista]

bikerHen: because I want one as it is, with slick race-lite tires for touring and another I'm going to customize a lil' bit with maybe cyclo-cross style brake levers, knobbier tires, etc (studded tires for winter) what-ever tickles my fancy. I just like the geometry of the 520. Out of all of the bikes I've owned - is really perfect for me. *for me being the operative words* I know some might say - get a race bike - etc. I am short-legged but long torsoed. Touring bikes work for me because of this. Most bikes I can stand over - but the top tube is too short. If the top-tube length is correct, then I can't stand over it. So, some might say - wow - go custom, well - I don't have that kind of cash. I would love to have a bike built to my specs. Love it - but alas - I don't make that kind of scratch. I know a few people who own two of a bike they love. I've had one bike in the shop before -and had to ride a back-up bike: I usually prefer one over the other - so why not the same bike? I don't want them to be twins so a different model year would be good. It works for me, but everybody is different. The other bike I was debating was the LHT - I like my bikes - sturdy, durable, and fast enough to be fun. ;D We're all different. Celebrate the difference. I used to own a mountain bike and I hated it. Weird, huh? I'm a loveable weird, I promise.

[bikerHen]

Well when you explain, it makes sense. Same frame, two different bikes. I was thinking more like two identical bikes. Couldn't quite wrap my mind around that. bikerHen