Giant Defy 3 (2010) vs Trek Domane AL2

General cycling advice ( NOT technical ! )
Big-Bird
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Giant Defy 3 (2010) vs Trek Domane AL2

Postby Big-Bird » 14 Aug 2017, 6:48pm

Hi All, I am new to this site so please forgive me if posted this question in the wrong section.

I am looking at getting myself a new bike having previously owned a 2010 Giant Defy 3. One of the bikes I am looking at is the Trek Domane AL2.

Just wondering if anyone has experience of these 2 bikes and how they compare in real life. With the Defy I never really got the most out of it as found it too twitchy which when combined with the poor road surfaces (covered in loose chippings and potholes) it was a recipe for disaster so gave up with it. As a result I am looking for a less race inspired road bike.

I have now moved to the chilterns and finding my current hybrid is now holding me back (Carrera Parva) which I will keep for a bit of mixed riding along with my commute.

Thanks in advance for any help or advice and please feel free to suggest other bikes up to around £600

Wynne71
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Re: Giant Defy 3 (2010) vs Trek Domane AL2

Postby Wynne71 » 14 Aug 2017, 8:01pm

Hi.
I'm new here as well, am moving from a Giant hybrid to a road bike soon.
I've gone for a Merida Ride 300 as a road bike, a decent compromise between speed, comfort and handling from what I've read. Only been on a turbo with the ones in the bike shop, but I got the impression it was a good balance.
Slightly longer head post (probably used the wrong technical term there...) giving the rider a more upright position, impacting upon the feel of the bike.
The Ride 100 is priced around 649 but sure the 2015 model could be had for way below 600.
Possibly worth a look.

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Paulatic
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Re: Giant Defy 3 (2010) vs Trek Domane AL2

Postby Paulatic » 14 Aug 2017, 8:37pm

I own a Domane. It was originally aluminium but is now CF. viewtopic.php?f=5&t=92411&hilit=Domane&start=60

Not an uncommon problem viewtopic.php?f=5&t=100707&hilit=Domane

I thought the geometry was similar to the Defy?

I do enjoy riding the Domane though it is a lovely ride.

Presently though I am mostly riding a Merida race lite
Reasons : it's got a triple
It was so cheap (£100) I can afford to wear it out.
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531colin
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Re: Giant Defy 3 (2010) vs Trek Domane AL2

Postby 531colin » 14 Aug 2017, 8:59pm

Big-Bird wrote:............ I am looking for a less race inspired road bike.........


Hi big bird, and welcome to the forum.
Whats needed to compare the "twitchyness" of 2 bikes is the frame geometry table. I can't find that for the Domane AL2, or anything much like it.....and my computer has a hissy fit when it hits Trek's website, which doesn't help.
The steering "feel" of a bike is largely determined by the geometry of the front end......head angle and fork offset, also called rake. https://en.wikipedia.org/wiki/Bicycle_and_motorcycle_geometry.
Virtually all "road" bikes are more or less copies of actual bikes that actual world-class athletes use to race on.....thats a fashion-inspired (largely male) thing, and it makes the bikes into a less-than-relaxing ride for us ordinary mortals with ordinary reflexes....I can find myself in the ditch if my attention wavers for a second.....and I would much rather be looking at the view than staring at the tarmac.
So, now for the numbers........
Fork offset or rake is almost always 45mm, thats sort of the "racing standard" that eg. carbon forks tend to be made to.
Head angle.....combined with a 45mm offset, 73 degrees will see me in the ditch PDQ. 72 degrees is Ok, but I prefer 71.5 deg. (Yup, small differences)
There is a "fiddle" that most manufacturers employ, where they use a shallower head angle on the smallest bikes (some down to 71 deg.) and a steep angle (73.5) on the big bikes. This might work to your advantage, but maybe not if you are a big tall bird.

Don't buy a bike without a proper test ride, on proper roads. Riding a turbo tells you nothing. You might find "cross" or "gravel" or many other strange "types" of bike have more forgiving handling.
Happy hunting!

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Paulatic
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Re: Giant Defy 3 (2010) vs Trek Domane AL2

Postby Paulatic » 15 Aug 2017, 9:03am

The Domane has a head angle of between 71 and 72.1 depending on size.
https://www.trekbikes.com/us/en_US/bike ... 0000-2018/

The Defy has a head angle of 72 to 72.5
https://www.giant-bicycles.com/gb/defy-3-2016

So from Colin's observations the Domane will be a more relaxed ride. It's certainly a ride, to me, which gives loads of confidence on descents and tricky surfaces.
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531colin
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Re: Giant Defy 3 (2010) vs Trek Domane AL2

Postby 531colin » 15 Aug 2017, 8:42pm

Paulatic wrote:The Domane has a head angle of between 71 and 72.1 depending on size.
https://www.trekbikes.com/us/en_US/bike ... 0-2018/....


Nope, my PC locks straight up as soon as Trek's website appears.....could you copy and paste the Geo. table onto here?

Hmmmm, I can view the Giant website, but i'm not clever enough to post the Geo. table...... :(

Brucey
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Re: Giant Defy 3 (2010) vs Trek Domane AL2

Postby Brucey » 15 Aug 2017, 8:47pm

is this right?

Image

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531colin
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Re: Giant Defy 3 (2010) vs Trek Domane AL2

Postby 531colin » 15 Aug 2017, 9:09pm

Interesting fork offsets given, 48 and 53mm, both longer offset than the "standard" 45mm, yet the trail looks long to me, for those angles.
Anybody competent to punch it into a bike CAD? (eg https://www.bikecad.ca/

videoman
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Re: Giant Defy 3 (2010) vs Trek Domane AL2

Postby videoman » 15 Aug 2017, 9:25pm

I purchased a new Trek Domane 2 in April 2015 and have been very pleased with it and use it for club riding. I find it comfortable and very stable on long fast descents and would have no problem recommending one if this is the type of bike your after.

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Paulatic
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Re: Giant Defy 3 (2010) vs Trek Domane AL2

Postby Paulatic » 15 Aug 2017, 9:35pm

531colin wrote:Interesting fork offsets given, 48 and 53mm, both longer offset than the "standard" 45mm, yet the trail looks long to me, for those angles.
Anybody competent to punch it into a bike CAD? (eg https://www.bikecad.ca/

Could the position of the dropouts account for it?
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531colin
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Re: Giant Defy 3 (2010) vs Trek Domane AL2

Postby 531colin » 15 Aug 2017, 9:44pm

Image

Image from my Wiki. link above.
Take a line through the headset centre. The perpendicular distance from the wheel axle centre to this line is the offset (or rake).....irrespective of the shape of the fork......straight, single curve, double curve, it makes no difference to the mechanics of where the wheel is relative to the headset axis.

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TrevA
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Re: Giant Defy 3 (2010) vs Trek Domane AL2

Postby TrevA » 16 Aug 2017, 12:44pm

videoman wrote:I purchased a new Trek Domane 2 in April 2015 and have been very pleased with it and use it for club riding. I find it comfortable and very stable on long fast descents and would have no problem recommending one if this is the type of bike your after.


Yes, I've had mine for 5 years now and it's a nice bike to ride. I've probably done 15-20,000 miles on it. I did have a frame break after 3 years, but it was replaced under warranty with no issues.
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Brucey
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Re: Giant Defy 3 (2010) vs Trek Domane AL2

Postby Brucey » 16 Aug 2017, 2:18pm

531colin wrote:Interesting fork offsets given, 48 and 53mm, both longer offset than the "standard" 45mm, yet the trail looks long to me, for those angles.
Anybody competent to punch it into a bike CAD? (eg https://www.bikecad.ca/


seems to tally OK with the trail table in

http://johnforester.com/Articles/BicycleEng/Kvale%20Geometry.pdf

but that is for 680mm dia wheels, which would be about right for a 28mm tyre on a 622mm rim.

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531colin
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Re: Giant Defy 3 (2010) vs Trek Domane AL2

Postby 531colin » 16 Aug 2017, 9:33pm

Brucey wrote:
531colin wrote:Interesting fork offsets given, 48 and 53mm, both longer offset than the "standard" 45mm, yet the trail looks long to me, for those angles.
Anybody competent to punch it into a bike CAD? (eg https://www.bikecad.ca/


seems to tally OK with the trail table in

http://johnforester.com/Articles/BicycleEng/Kvale%20Geometry.pdf

but that is for 680mm dia wheels, which would be about right for a 28mm tyre on a 622mm rim.

cheers


Yes, fair enough. According to the same table, the one I'm used to (45mm offset 71.5 degree head) gives 66mm trail
We are only talking about the difference between 45 and 48 or 53mm offset.

Brucey
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Re: Giant Defy 3 (2010) vs Trek Domane AL2

Postby Brucey » 16 Aug 2017, 11:07pm

but none of the Trek head angles is 71.5 degrees...several are 71.3 degrees though; with 53mm offset they say 59mm trail.

@71.5 degrees the table says
45mm offset gives 65mm trail
50mm gives 60mm
55mm gives 54mm

so 53mm offset gives around 56 or 57mm trail

at this point in the table an extra half a degree decreases the trail by about 3mm. So -0.2degrees will be about +1.2mm

so ~57.2 to 58.2mm trail @680mm dia, 53mm offset, 71.3 deg head angle according to the table.

which is (within rounding errors and assumed wheel diameter differences) pretty close to 59mm, I think?

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