Alloy VS Carbon Road bike

[XYGTHO]

Hi all. Looking at getting a new commuter as my old flat bar is about to hit its 10year bday. Also the wife has it on a trainer at the moment so great time to use that as an excuse to buy myself a new bike.

Already have a 160mm dually, and 140mm hardtail. Enjoy riding the hardtail to work but it is slow with 1x10 and fat tyres. My old 15kg flat bar I could hold 28-30km/h so hoping a real roady will make the commute even faster.

I can get the 2016 Giant Defy Advanced 3(Carbon) for $1600. It has 2x10 Shimano Tiagra. OR
I can get the 2016 Giant Defy Disc 1 (Alloy) for $1500. It is 2x11 Shimano 105.

I would also love to do some duathlons (not competitively but to best of my ability). Will commute 20kms a day and might stretch some rides out when time to 30km on way to work with the odd weekend 50+km ride. I will most likely keep the bike as per my last commuter for around 10years if it lasts.

Both the bikes seem to be pretty closely specd except the drive-train. Never had a road bike or carbon bike. I am comfortable working on bikes and doing everything myself (have a torque wrench). After a push either way. Am I better off carbon frame for ride characteristics or alloy and better drive-train.

 

[nakedape]

50/50 call that - on the one hand, carbon goodness and on the other, discs (which can be swapped later for hydraulic). Groupsets can be swapped easier than frames. Which has the better wheelset?

 

[RB 24]

Both good bikes and Giant's warranty is second to none.

I bought myself a few years a go now a boardman slr 9.2 for around 3k. Saw the same bike today for $1600. I love mine and it has been faultless.

It's easy to get caught up with what's hanging off the bike more than what the frame is like. From memory and I am sure duckmeister can chime in the carbon is a composite carbon of a lower grade?

Good luck.

 

[XYGTHO]

50/50 call that - on the one hand, carbon goodness and on the other, discs (which can be swapped later for hydraulic). Groupsets can be swapped easier than frames. Which has the better wheelset?

Both have discs mate. Wheelset I have no idea to be honest not up at all with road wheels. Only just learning about the groupsets. From what I read the new 2x10 tiagra is equal to the old 105?

There is a 2012 Giant Defy 2 alloy for sale locally I can pick up for $600 with about 900kms. It is 2x10 Tiagra but being second hand no warrenty and assume 2012 tiagra would not be equal to the new tiagra?

 

[Trickymac]

go the alu with 105

 

[The Duckmeister]

Get the carbon frame; you can always upgrade the bits down the track.

New Tiagra running gear is actually pretty damn good; although still 10-sp, it draws a lot of heritage from the higher-spec 11-sp. groups, so in some regards is better than previous-generation 105.

It's easy to get caught up with what's hanging off the bike more than what the frame is like. From memory and I am sure duckmeister can chime in the carbon is a composite carbon of a lower grade?

Giant use two grades of carbon in their range (have used a third, lower grade in the past, but not for the last couple of years). The Advanced models use T700 carbon, which is very common throughout the bike industry, and Giant have used it for around 20 years. The Advanced SL models use T800 fibre, which is a higher tensile strength fibre, which means they can use less to still make a stronger frame. Depending on layup, it can make a slightly less forgiving frame. The moulding processes differ slightly between the two levels as well.

 

[KouraKoura]

Just went through the same thing

I just picked up my first ever roady bike to commute on after battling with a harsh "urban" tank for several years. I went for carbon over upspecced components on an alloy. (105 vs Ultegra). reason being, comfort. And I'm glad I did. The commute is much smoother with a carbon frame.

If you're shifting gears and braking a lot, then maybe groupset difference will be more beneficial, but if you're just cruising along at 35-40kph, you'll absolutely notice the difference carbon makes.

 

[scblack]

I own a carbon and an alloy roadie.

I would suggest you buy the carbon frame. The ride quality will be so much better - carbon really makes a BIG difference on a road bike.

Unless you intend to race, the difference between Tiagra and 105 will be minimal for commuting purposes.

 

[Knuckles]

Get the carbon frame; you WILL always upgrade the bits down the track.

You spelt it wrong.

 

[Calvin27]

+1 for discs.

Road components don't wear nearly as much as mtb so if you are waiting for them to wear, it could be a long time.

 

[creaky]

In general, alloy road frames are a pretty jarring ride. You could get a flexy seatpost (e.g. syntace hiflex) but that is another $250 that you would be better putting into the next model up carbon bike anyway.

The Tiagra worries me a bit more than it would comparing 105 vs Ultegra but I have no experience on Tiagra gear in the last few years so it could have come closer in performance to the 'top three' groupsets, not sure.

Can you squeeze your budget and/or the dealer pricing to 105 carbon at all ?

 

[andrew9]

A solid mid-weight Alloy frame, like that Defy, would be my choice for commuting, but I thrash my commuters. I like the fact that locks and hitting the bike going through doors won't hurt it.

I have generally used refurbished 1980's steel road bikes for commuting though, but I also have a 9kg+ alloy "winter training" roadbike. Occasionally I like riding it more than my carbon Addict, I like the "hard" road feel sometimes.
That being said, if I only had one proper roadbike, it would be carbon.

2x11 105 is a very nice groupset, proper close ratios, and shifts better than old 2x10 105. I love it.
2014 era Tiagra has clunky and heavy front derailleur shifting, my wife has it, works fine though. The new Tiagra might be better, it looks cool.

I like the looks of the cheapest Defy the most, without the dropped seatstays of the other models

 

[The Duckmeister]

The Tiagra worries me a bit more than it would comparing 105 vs Ultegra but I have no experience on Tiagra gear in the last few years so it could have come closer in performance to the 'top three' groupsets, not sure.

Your worry is unfounded, plus you basically admit you don't know what you're talking about.... 4600 (2012-15) Tiagra shifters are cosmetically tweaked 7800 Dura-Ace units, and actually better than the "superior" 5700/6700/7900 series shifters. The rest is just material differences to bring it down to budget. As I said previously, the new 4700 series draws a lot from the 11-sp. groups, so is still a really respectable component set.

 

[mtb101]

warning, warning .... I'm seeing cable disc brakes on defy 3.

there's a BIG difference between hydraulic discs and mechanical discs.

hydraulic similar to mtb, mechanical about same level as sticking foot in rear wheel to slow down. and then try adjusting the crappy things rrrarrrr.

 

[XYGTHO]

+1 for discs.

Road components don't wear nearly as much as mtb so if you are waiting for them to wear, it could be a long time.

Thanks all. Reason for getting one to commute on so Im not wearing out my mtb, chain, caassette, fork etc.
Sounds like Carbon is the go. Don't think it will get any upgrades. Those $$ are kept for the mtb.

 

[XYGTHO]

warning, warning .... I'm seeing cable disc brakes on defy 3.

there's a BIG difference between hydraulic discs and mechanical discs.

hydraulic similar to mtb, mechanical about same level as sticking foot in rear wheel to slow down. and then try adjusting the crappy things rrrarrrr.

hydros would be great but out of my price bracket. I started mtb on mech discs riding the local downhill on a hardtail being a newb and no idea. I think for a road bike it will be fine? Local shop has the alloy 1 disc in store and the carbon 3 so might ride them both to see how they feel shifting, road vibration etc. I think the best thing is you don't have to touch the brakes to take the wheel off! And if I get a wobble it won't rub on the pads.

 

[creaky]

Your worry is unfounded, plus you basically admit you don't know what you're talking about....

Ahh, that's why I said "not sure" at the end of that sentence so that the OP could seek a more informed opinion on current Tiagra from a wise gentleman such as yourself.

 

[Calvin27]

Thanks all. Reason for getting one to commute on so Im not wearing out my mtb, chain, caassette, fork etc.
Sounds like Carbon is the go. Don't think it will get any upgrades. Those $$ are kept for the mtb.

No wait, you misunderstood. I was gunning for the alloy bike! If you are riding in the wet, disc for sure, even if they are cable.

 

[Duane]

Can you squeeze your budget and/or the dealer pricing to 105 carbon at all ?

The Defy 3 Advanced is part of the factory sale, the next model is not so there is close to 1K jump.

warning, warning .... I'm seeing cable disc brakes on defy 3.

there's a BIG difference between hydraulic discs and mechanical discs.

They are all cable at that price point in "name" brands anyway.
I agree which is why I'm spending more on a hydro equipped gravel grinder although I'm assured by owners and industry types that a well maintained cable setup is ample for road use with skinny tires and small contact patch. I have no experience with road or cable discs.

 

[SF Trailboy]

If you really want to play the game get this and then a china carbon frame down the track perhaps?

https://www.bicyclesonline.com.au/2016-polygon-bend-rv-gravel-cyclocross-disc-bike

Only Sub $2000 hydro bike I know of.

Really dissapointed that I only just bought a Avanti Giro, when I came across this!