Australian Cycling Forums - Bicycles Network Australia

Posted: **Sun Apr 07, 2013 3:30 pm**

Hi
I am looking at buying a new go fast bike, and the Trek Domane 5.2 has caught my eye. Looking for meaningful reviews online has only produced articles about its new iso-speed decoupler and how it rides.

Looking at videos of the seat post flex has go me wondering if there will be a fatigue failure issue.

Has anyone heard of such failure or any comment on the flexing seat post.
cheers
steve

Posted: **Sun Apr 07, 2013 3:50 pm**

Should it really matter to you if you're buying new and have a lifetime warranty that Trek honours? Isn't that the whole point of buying carbon? That being enjoying carbon qualities and relying on the warranty for any durability issues.

This would be a good question for a secondhand buyer, but by then the "word on the street" should be available by then.

Are you particularly heavy?

Personally I believe it's better to buy a frameset/bike that is less likely to have a warranty issue in the first place, but then I seem to be in the minority these days.

Posted: **Sun Apr 07, 2013 4:00 pm**

No have not heard of failures.

I am curious about the bike too. I was really surprised how much the seat tube flexed when I applied force to a LBS model mid last year. I had suspicions the seat tube's flex may have compromised power delivery to the pedals. However, I doubt Fabian Cancellara would ride one if that was the case. In fact, there's a possibility seat tube flex and resultant saddle movement may enhance power delivery to the pedals. i.e. energy absorbed by the seat tube will be delivered back to the saddle shortly after, potentially enhancing power delivery to the pedal.

Considering Spartacus weighs 82kg and can pump out 450+ watts for 20-30 minutes, after riding 240k (as he did in TdFlanders2013), I have confidence the seat tube and coupling are unlikely to fail....though who knows after 30,000km. I doubt Fabian would race the same bike for more than 5,000k.

Other thoughts I've had are that seat tube flex would have been chosen to be ideal for a particular bodyweight range. The lighter the rider, the less flex and vv. A heavier rider may very well see less life out of the system.

Anyway, kudos to Trek for bringing to market a bike like this.

Posted: **Sun Apr 07, 2013 8:51 pm**

They are an interesting frame. I've not ridden one but personally I'd rather see flex induced by small seat stays than from a pivot point.

You'll start to see round seat posts on the aftermarket soon that'll induce flex without any pivot points or wearable parts - I like that idea but no doubt these would flex less than the Domane.

Anyone looking for more comfort from their bike, the first thing I'd do is install 25mm tyres and drop 10psi from your pressures.

Posted: **Sun Apr 07, 2013 9:56 pm**

Thanks Guys for the thoughts. I am on the heavier side and hence the questions. I was looking for a more relaxed frame and the Domane is trek's offering.

I will try to find out if the Domane has a make rider weight. If anyone knows that would help. Being full bodied at 110kg, its best to do some due diligence first.

I can't believe that Trek would release something that would come back and bite them in claims and lawsuits. They would have had to do their homework before releasing the Domane.

I do like the Domane concept, the other option I am looking at is the Giant Defy.
cheers
steve

Posted: **Sun Apr 07, 2013 10:08 pm**

V17L wrote:I will try to find out if the Domane has a make rider weight. If anyone knows that would help. Being full bodied at 110kg, its best to do some due diligence first.

125Kg

Posted: **Mon Apr 08, 2013 5:52 am**

thanks Nobody

Posted: **Mon Apr 08, 2013 9:15 am**

jacks1071 wrote: install 25mm tyres and drop 10psi from your pressures.

Done. It really can't be overlooked... I've been running 100psi and 110 for a "sprited ride" with 25s. I don't think I could cope with anything more.

Posted: **Mon Apr 08, 2013 10:05 am**

Xplora wrote:
jacks1071 wrote: install 25mm tyres and drop 10psi from your pressures.
Done. It really can't be overlooked... I've been running 100psi and 110 for a "sprited ride" with 25s. I don't think I could cope with anything more.

Mine has 85 & 95. Find the back has too much bounce higher than 95. Probably prefer 80 in the front but 85 is better for standing. More than 85 in front is too rattly on the rougher bits of path. (82Kg, 11.6Kg bike.) At these lowish pressures I prefer latex tubes due to their lower flex losses.

Posted: **Mon Apr 08, 2013 12:24 pm**

I'm super lazy, so while my tyres often get down to 80-85psi I just don't pump them up enough to let myself run them at 80psi... it goes to 100 and then fades over a couple weeks LOL

Posted: **Mon Apr 08, 2013 12:56 pm**

Nobody wrote:
Xplora wrote:
jacks1071 wrote: install 25mm tyres and drop 10psi from your pressures.
Done. It really can't be overlooked... I've been running 100psi and 110 for a "sprited ride" with 25s. I don't think I could cope with anything more.
Mine has 85 & 95. Find the back has too much bounce higher than 95. Probably prefer 80 in the front but 85 is better for standing. More than 85 in front is too rattly on the rougher bits of path. (82Kg, 11.6Kg bike.) At these lowish pressures I prefer latex tubes due to their lower flex losses.

So many people over-inflate their tyres and its the best way to introduce some comfort.

Posted: **Mon Apr 08, 2013 6:36 pm**

V17L wrote:Thanks Guys for the thoughts. I am on the heavier side and hence the questions. I was looking for a more relaxed frame and the Domane is trek's offering.

I will try to find out if the Domane has a make rider weight. If anyone knows that would help. Being full bodied at 110kg, its best to do some due diligence first.

I can't believe that Trek would release something that would come back and bite them in claims and lawsuits. They would have had to do their homework before releasing the Domane.

I do like the Domane concept, the other option I am looking at is the Giant Defy.
cheers
steve

Trek I believe have always warranted their stuff to ~120kgs and 135kgs depending on whether it was a pure sporting road bike, or anything else - ie 110kg rider will be under their warranty limit for any adult bike they make.

However I'll add that I have broken 2 trek frames at 92kgs - one detected prior to failure, and one detected after, though the way it broke happened not to spill me (glanced back and saw my rear wheel had lost lateral support after a big crack sound), ie I do not have a great deal of faith in their ability to engineer stuff that doesn't break, without putting their customers through some trial and error with stuff breaking - and imo when you buy a trek, you are buying the warranty. I've also cracked a bontrager select rim (detected before total failure), though I don't believe they are currently flogging too many wheels with paired spokes, so they might be a little more durable vs that failure mode these days.

it is possible to make cf flexible without it fatiguing, however bear in mind that seatpost failures can result in being stabbed in the backside by the stump, and/or falling onto the rear wheel, which in the case of a roadbike will actually tear you a new one, out of your current one.

Posted: **Tue Apr 09, 2013 12:07 pm**

Hi V17L,

My wife recently purchased a Domane 5.9 (Di2) and loves it (just the usual issue of not having enough time to ride it more).

She has lower back issues, which was a major contributing factor to this choice and she says the bike extremely comfortable, especially on the rougher roads/paths. Much more noticable than on her old carbon Bianchi C2C It is better on her back and she doesn't feel as fatigued after a ride. You can see a little movement on the seat post but its not a huge movement or ungainly and hasn't reflected any decreased performance (Its seems to have worked ok for Fabian over the last few weeks as well).

They come standard with 25mm tyres but even if they different , I'm with Jacks (Dion) that this size tyre is the way to go, even on your current bike.

A great bike and I am even thinking of getting one myself (I'm 105kg).

Cheers

Posted: **Tue Apr 09, 2013 8:37 pm**

Hi Bianchi,
It is a great looking bike, and I am very tempted.

I think I will have a few more sleeps before I decide. If I do, I would love the 5.9, (very jealous of your wife), but my budget would stretch to a 5.2.

I think the best answer is to go to the lbs and do a test ride.

cheers
steve

Posted: **Tue Apr 09, 2013 9:21 pm**

Hi V17L

Bought a 5.2 about a month ago rode a Giant Defy Advanced 0 also found it really comfortable don't even notice the flex so much when riding it but a very smooth ride and very happy with my purchase

Good luck

Posted: **Tue Apr 09, 2013 10:06 pm**

Hi Wags
I know it is off topic, but I a curious, as the defy was also another I was looking at. As you have ridden both of them, what was the difference, ride, fit, look, equipment, that swung it to the Domane.

Hi Bianchi, same question re when your wife purchased the 5.9, had she rode anything else, and what swayed her for the 5.9
cheers
steve

Posted: **Tue Apr 09, 2013 10:44 pm**

The Defy has DI2 but I felt more comfortable on the Trek was much smoother in the rear and liked the look -Giant I thought was a little boring but would have been happy with either

Posted: **Wed Apr 10, 2013 11:15 am**

Hi Steve,

We did all the research etc reading reviews etc.

Our ride home from work has a really rough stretch of about half kilometer (actually, it's pretty ordinary for most of the way but this section is brutal) and this was only about 4km from the bike shop so when she tested the Domane we headed straight there. It was a case of OMGosh, and when combined with the general comfort and the electronic shifting, she had made her mind up.

So she only rode the one bike but she pretty much knew it was for her. Another major factor that added to her decision was the bike shop owner is also an accredited coach and is very pedantic in relation to bike fitting. They did the whole lot (pedals, changed handlebars & stem, position etc) which was really good.

Cheers

Travis

Posted: **Wed Apr 10, 2013 11:31 pm**

Hi Travis
Just wondered which shop you bought your Domane from

Thanks Jerry

Posted: **Thu Apr 11, 2013 10:18 am**

Hi Jerry,

Riders Choice in Leederville.

We dealt with Gary Suckling for the purchase and fit and the follow up service (my wife needed a longer seat mast) by Phil has been great. Both very proffessional.

On our experience, I would recommend them.

Posted: **Thu Apr 11, 2013 2:34 pm**

Thanks for that travis.
Cheers Jerry

Posted: **Thu Apr 11, 2013 3:28 pm**

This video is telling.
http://www.youtube.com/watch?v=gP6hgLc6Flg" onclick="window.open(this.href);return false;

It highlights how resonance can develop between seat post flex and cadence - see 17sec and 42sec.
Whether this benefits comfort, blood flow, and power transmission from muscles to pedals I don't know. I think it could go either way.
Fabian Cancellara riding a Domane is different to Joe Average middle aged overweight guy. The latter will tend to sit with more weight on the saddle, and be less synched at higher cadences.

I think Trek would do well to publish power and comfort data for recreational cyclists at various cadences and bodyweights while riding the Domane vs a Madone.

Posted: **Thu Apr 11, 2013 4:30 pm**

zero wrote:
it is possible to make cf flexible without it fatiguing, however bear in mind that seatpost failures can result in being stabbed in the backside by the stump, and/or falling onto the rear wheel, which in the case of a roadbike will actually tear you a new one, out of your current one.

[/quote]

I already gave myself a new one thanks to a skiing accident.

It has since been repaired

Posted: **Thu Apr 11, 2013 4:36 pm**

winstonw wrote:This video is telling.
http://www.youtube.com/watch?v=gP6hgLc6Flg" onclick="window.open(this.href);return false;

It highlights how resonance can develop between seat post flex and cadence - see 17sec and 42sec.
Whether this benefits comfort, blood flow, and power transmission from muscles to pedals I don't know. I think it could go either way.
Fabian Cancellara riding a Domane is different to Joe Average middle aged overweight guy. The latter will tend to sit with more weight on the saddle, and be less synched at higher cadences.

Thanks for posting.
It doesn't seem to work as I thought it would. Seems that most of the flex is in the post/mast and the coupling just acts a pivot. You could probably get a similar result with a Thudbuster ST or a Canyon carbon/basalt seatpost or similar. Which also has the advantage of changing to a stiffer post if you feel the necessity to do so.

winstonw wrote:I think Trek would do well to publish power and comfort data for recreational cyclists at various cadences and bodyweights while riding the Domane vs a Madone.

Probably in their customer's interests, but not in Trek's who is trying to push Domane as a unique bike. If the results favor Madone (probably small but likely) then the customer could just buy any stiffer carbon bike, rather than just the Madone.

I think the only advantage of the Damone is a lighter version of inserting a bit of flex into the bike experience. When compared with the Canyon seatpost and another carbon frame, it may not even be that. It is probably slightly faster than running 25s at lower pressures, or pushing a Brooks with a steel seatpost up a hill (both of which I do) but this only matters if you are racing. If not, then there are cheaper options.

Posted: **Thu Apr 11, 2013 9:28 pm**

winstonw wrote:This video is telling.
http://www.youtube.com/watch?v=gP6hgLc6Flg" onclick="window.open(this.href);return false;

It highlights how resonance can develop between seat post flex and cadence - see 17sec and 42sec.
Whether this benefits comfort, blood flow, and power transmission from muscles to pedals I don't know. I think it could go either way.
Fabian Cancellara riding a Domane is different to Joe Average middle aged overweight guy. The latter will tend to sit with more weight on the saddle, and be less synched at higher cadences.

I think Trek would do well to publish power and comfort data for recreational cyclists at various cadences and bodyweights while riding the Domane vs a Madone.

It'd be interesting for someone to do some independant research on the concept of introducing more flex into road frames and if that actually reduced fatigue which in turn resulted in more performance.

From the video it really doesn't look like a very efficient concept, for cobbles I'm sure it'd be awesome but as bad as our roads are they are hardly cobbles...

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