cynergy

hi folks,

i've recently got back into riding and have been bike commuting regularly. i use an older trek 520 (v brakes) in good weather, and a trek fx aluminum hybrid with disc brakes in bad/wet weather. i ride 8 to 13 miles each way, and am interested in buying/building a lightweight bike to be used for light commuting (no bags or racks or fenders needed) and for fitness. it's pretty hilly where i live (NH) and i have bad knees (switched from jogging to riding because of the knees) so I'd like to equip the bike with a subcompact 2-ring crankset to keep the required torque down on the steep grades.

disc brakes are nice, but i also don't mind using traditional side pull brakes on this bike.

i've been looking at the Specialized Sirrus pro carbon fiber bike... it has a compact 48/32 crankset and a carbon fiber frame.

i have also been looking at a Specialized Roubaix carbon bike, and i would swap out the front crank (if it's possible) with a 48/32 crankset or similar (maybe even more compact).

Would it make more sense to go with the Sirrus Pro and ride it as is, or should i consider buying a road bike, and try and swap out the front crankset with something more compact? Would I have problems with using such a small chainring set with the front derailleurs for a typical road bike? On the carbon bikes, can i slide the derailleur up or down enough to provide proper clearance for the chain ring?

Also, would it be easier to assemble my own steel-framed bike? i am comfortable doing basic bike mechanics and have a decent bike work stand, etc.. would this be a much more expensive route than buying a pre made factory bike and then swapping out the crank set? with a steel frame bike, it seems like I could more easily adjust the front derailleur height, position, etc..

thanks in advance!

cynergyou

PaulRivers

It's almost always more expensive to build up a bike from parts than it is to buy the bike complete.

I like the full carbon sirrus, my brother has one, but if you really want the lightweight "feel" my opinion is you need to go to the regular road bikes. Nothing felt lighter to me than a full carbon roubaix.

The other questions about gearing would be best answered by your bike shop. I don't know that switching gearing will really change much but I can't answer that question myself.

On a sidenote, I personally got tired of never having space to store stuff on my "fast" bike and ended up going back to having a rear rack and bag. Carrying a lock, carrying a different shirt for the ride home when it was colder, carrying snacks for a longer ride, it was annoying to not be able to bring any of that stuff. Also, you mentioned commuting, I take it you can keep the bike inside at work or something like that? I don't like to leave an expensive bike locked up outside.

cynergy

Hi PaulRivers,

Thanks for the reply. I am going to see if any LBS's have the roubaix and the Sirrus in stock for me to check out.

I can keep the bike inside (and I even sometimes bring it up to my work area if i forget my bike lock) so that's a benefit of my current workplace. I would probably use a backpack if i need to carry anything while riding the faster bike.

i will ask my LBS about installing a compact crankset.

Thanks again for the feedback!

Cynergyou

joejack951

Do you need/want fenders or the option for a rear rack? Rear racks can be grafted onto just about any frame but having dedicated mounts for one yields a much nicer install. Same for fenders.

fietsbob

OEM factories produce many brands ..

My local shop sells Trek ... FX is their fitness bike range.. Top of the line is Carbon Fiber..

puma1552

I love the Sirrus (own one), but I personally feel that the current Pro Carbon at $2500 (note the 2019s will go up on Specialized's site literally any day now) is just not a lot of bike for the money, considering you can buy an Ultegra/105 mix carbon road bike for that price. The Pro Carbon has slinked down in components every year the last three years (as well as price, it was $2800 a couple years ago), and it seems hard to justify at the current price considering what else you can get.

I realize you aren't shopping Tarmacs, but just to drive the point home, even from the same manufacturer, this is way more bike for $100 less (yes they skimp out on the cranks, Specialized usually does):

https://www.specialized.com/us/en/me...=239623-129048

I also personally think there's a price point beyond which (say $800-$1000) that a hybrid just doesn't make a lot of sense.