'Correct' size vs size that feels right?

RodeBike

Hi,

After considering my options and requirements, I'm going to buy a Trek Domane AL 5- I'd ideally wanted the ALR frame, but they're not making it anymore.

Anyway, my height, which is just about 6' 1", suggests that I'm supposed to be on a 58 frame, and one bike shop that I'm looking at bikes with is adamant that that's the size I need. Another shop I'm looking at has had me on both and seem to think I'm better off on the 56- they say the height chart doesn't take into account leg vs torso length, which makes a lot of sense to me. The 56 feels far more comfortable to me, but the certainty of the guy in the other shop, along with me being comfortably in the 58 frame according to Trek's sizing, is leaving me with doubts.

Does anyone have any advice/suggestions? This is my second road bike after getting into it 3ish years ago and running a Boardman Road Sport pretty much into the ground, and outgrowing it now from a performance perspective. The AL isn't a massive upgrade necessarily, though it is a fair bit having ridden it a bit, but the SL that I really want is just beyond my budget right now.

Anyway, any thoughts or advice on the sizing would be very welcomed- and not necessarily Trek specific, more the idea of what feels right vs what the guidelines say I should be on.

Cheers.

whyamihere

Buy the one that feels comfortable, ignore the guy who won't look past the size chart.

DeVlaeminck

Were you happy with the Boardman - how does the size of that compare to the Trek ?

RodeBike

whyamihere wrote:

Buy the one that feels comfortable, ignore the guy who won't look past the size chart.

Cheers for the reply, yeah that's my gut feeling alright, but I guess I'm just wondering if there's something I'm missing that I'll only figure out after the fact. Is there, do you reckon? Or is it really just all about comfort?

RodeBike

DeVlaeminck wrote:

Were you happy with the Boardman - how does the size of that compare to the Trek ?

Funny you should ask, the Boardman was way too big from the get go- I bought it without knowing anything about bikes, which basically put me on par with the guy who sold it to me at Halfords

I've spent all my time trying to 'shrink' the bike, with a shorter stem, inline seatpost, compact bars, the whole lot, but it never got there for me. If nothing else I want this bike to fit, even if it isn't a massive upgrade necessarily. It's probably why I'm wary of the bigger bike too.

rokt

Have you compared the geometry of both the 56 and 58 bikes ?

What is the difference in the stack and reach on each size ?

I had the same problem recently. I fell between two sizes, a
52 and a 54. Don’t laugh, but I found a GCN video on YouTube
very useful.

tangerineowl

Agree on the bike that is comfortable to you.

The majority of online size charts still don't take into account inseam for height, which is daft.

My experience has been the same in pretty much every shop I've been into.

joey54321

You could, if funds allow, have a bike fit on a jig first which should definitively tell you. Retail, Trek, Pro off the top of my head all have fancy bike fit tools to not only fit you but also help choose a new bike.

First.Aspect

What length stem does the trek have as standard. When I rent them, they seem to spec 80cm or something stupidly short like that. If so you have ample scope for adjustment if needed later. Finding a fit on a frame that's too large is in my experience next to impossible, but it is much easier the other way around.

DeVlaeminck

The geometry chart for the 2019 Domane suggests there is relatively little difference in the reach between the two sizes - about 3mm from memory - but quite a bit difference is the stack height at the front. It looks like what used to be called sportive geometry - fairly short reach tall front.

If you want a racey position the 56 with a long stem might be better as the 58 is quite tall - if you are actually wanting a taller front end (and it's not massively tall) which the fact you are going for a domane suggests you do then the 58 still has a fairly short reach for your height - 380 - that is by no means a long bike for someone 6'1 unless you are all legs and no torso. I'm just under 6'2 and without sitting on them I'd definitely get a 58 and stick a slammed (no spacers) 12cm stem on it - when I was younger (I'm 50) maybe even a 13cm - I have a relatively longer torso than legs.

edit though when I was younger I'd probably want something with a more aggressive geometry

RodeBike

Thanks for the feedback, guys, much appreciated.

In relation to the geometry, it's something that always confuses me- the advice seems to be that stack and reach are key, but I find that top tube length tends to dictate the overall feel of a bike more than anything. It's 1.3cm shorter on the 56, and the difference in feel of the 'reach' is quite dramatic- I think there's only 1cm difference in stem length between the two of them, 110 vs 100, but the bars on the 58 feel miles away in comparison, and make me lean onto them too much with my weight.

I seem to much prefer a feeling of being closer to the bars than necessarily preferring a stack or 'height' increase, if that makes sense. On the 56, the feeling is of being 'in' the bike if that makes sense, whereas on the 58 I feel like I'm 'ahead of it' with my weight. This is why the reach measurement never seems to equate to feel for me, from the charts there's little or no difference, and the 58 'should' feel better, yet it feels like I'm on a stretched out race machine, which is ridiculous I know! I'm not sure if any of that makes sense, but I think I'm benefitting from trying to put my own words on it all and getting feedback from you guys, so thanks for that.

I hate not replying individually, it seems 'rude' somehow, but I really appreciate the effort from you all as I hash this out.

DeVlaeminck

Did they have a few more spacers under the bars on the 56? That might make it feel shorter as the steerer angles towards the rider so the longer it is the closer the bars are. If the 56 feels right with a 10cm stem then that's probably the way to go though as you could easily add a couple of cm there without issue if you decided you wanted it longer and if you ask them to leave a couple of cm of spacers above the stem until you've owned it for a while then you've also got the option to make it a bit taller too if you decide it needs it.

RodeBike

DeVlaeminck wrote:

Did they have a few more spacers under the bars on the 56? That might make it feel shorter as the steerer angles towards the rider so the longer it is the closer the bars are. If the 56 feels right with a 10cm stem then that's probably the way to go though as you could easily add a couple of cm there without issue if you decided you wanted it longer and if you ask them to leave a couple of cm of spacers above the stem until you've owned it for a while then you've also got the option to make it a bit taller too if you decide it needs it.

It did have a few spacers, but nothing noticeably excessive from memory. I do like that idea of having a bit of a longer steerer tube to mess around with the height- is that something that I could order in a stock bike sort of purchase, do you reckon? I must ask them that.

svetty

If you are used to a poorly fitting bike a properly fitting bike might well not feel comfortable to you. If you lack core strength and flexibility you are better working on this and buying the bike which fits.

manoirdelourde

Have you put your measurements into a bike fit calculator? Might be worth a try.
Something like this:
https://pedalforce.com/online/bikefit.php

RodeBike

manoirdelourde wrote:

Have you put your measurements into a bike fit calculator? Might be worth a try.
Something like this:
https://pedalforce.com/online/bikefit.php

Nice one, I'll give that a go.

RodeBike

Svetty wrote:

If you are used to a poorly fitting bike a properly fitting bike might well not feel comfortable to you. If you lack core strength and flexibility you are better working on this and buying the bike which fits.

Interesting point, you could well be right.

On that note as an update on this thread, I just got back from the bike shop there and the owner, who's very experienced with fitting, is adamant that I'm a 58, it's not even close to him. He does a full bike fit before you take the bike home, and said that if it's not perfect for me he'd happily replace it with a 56- but he's totally confident that it's the right size. Long story short, I ordered the 58. I'm happy with the decision in the end, and credit to them it's a nice guarantee to be sitting on if it doesn't work out.

Thanks to everyone for the input, much appreciated.

redvision

The bike sizing charts are just an indicator. They are not individual, whereas a bike fit is.

My first two bikes were 56cm frames as I ordered online and used the manufacturer size guide. For my height and reach it should have been the correct size and both felt comfortable but I was getting some lower back pain. Physio suggested i go for a proper bike fit and i was advised to go for a smaller frame but with a longer stem.

Go with the advice of a respected, experienced bike fitter.

RodeBike

redvision wrote:

The bike sizing charts are just an indicator. They are not individual, whereas a bike fit is.

My first two bikes were 56cm frames as I ordered online and used the manufacturer size guide. For my height and reach it should have been the correct size and both felt comfortable but I was getting some lower back pain. Physio suggested i go for a proper bike fit and i was advised to go for a smaller frame but with a longer stem.

Go with the advice of a respected, experienced bike fitter.

Yeah, that sums up what I'm gonna do, good advice.

crescent

The Domane is a strange beast - lovely bike but weird sizing. My mate has a bog standard small Domane (51-52) and it fits me very well even though I would normally be a medium 54cm. I've also hired a 54 Domane which felt perfect too. I genuinely felt negligible difference between them. Go with what feels right.

RodeBike

Does anyone have a Domane 58cm, in any frame material? The geometry is the same, but I've got a measurement question to ask if you could? The centre of the cap of the steerer tube to the seat tube(front or centre), horizontal... what's the distance? Hard to believe bike companies don't list this...

thiscocks

Get the 56. Worst case its better to have a frame slightly too small than too big as you can adjust with stems ect..

thiscocks

RodeBike wrote:

Does anyone have a Domane 58cm, in any frame material? The geometry is the same, but I've got a measurement question to ask if you could? The centre of the cap of the steerer tube to the seat tube(front or centre), horizontal... what's the distance? Hard to believe bike companies don't list this...

That will be the top tube measurement. Its normally measured from the centre of the head tube to the centre of the seat tube.

RodeBike

thiscocks wrote:

RodeBike wrote:

Does anyone have a Domane 58cm, in any frame material? The geometry is the same, but I've got a measurement question to ask if you could? The centre of the cap of the steerer tube to the seat tube(front or centre), horizontal... what's the distance? Hard to believe bike companies don't list this...

That will be the top tube measurement. Its normally measured from the centre of the head tube to the centre of the seat tube.

It probably sounds overly analytical, but I was curious about the measurement further up than the top tube- with the different angles of the head tube and seat tube, the distance would be slightly different than the top tube measurement.

RodeBike

thiscocks wrote:

Get the 56. Worst case its better to have a frame slightly too small than too big as you can adjust with stems ect..

I kinda have a feeling I'll end up getting the 56 alright- but seeing as he'll change it after the fact, I may as well see how the 58 feels.

thiscocks

RodeBike wrote:

thiscocks wrote:

RodeBike wrote:

Does anyone have a Domane 58cm, in any frame material? The geometry is the same, but I've got a measurement question to ask if you could? The centre of the cap of the steerer tube to the seat tube(front or centre), horizontal... what's the distance? Hard to believe bike companies don't list this...

That will be the top tube measurement. Its normally measured from the centre of the head tube to the centre of the seat tube.

It probably sounds overly analytical, but I was curious about the measurement further up than the top tube- with the different angles of the head tube and seat tube, the distance would be slightly different than the top tube measurement.

No I think this measurement would be too similar to the tt one. Also with people having different stem heights it wouldn't be very useful. Manufacturers which have sloping top tube designs state the actual and virtual top tube lengths to make sizing easier.

RodeBike

thiscocks wrote:

No I think this measurement would be too similar to the tt one. Also with people having different stem heights it wouldn't be very useful. Manufacturers which have sloping top tube designs state the actual and virtual top tube lengths to make sizing easier.

Yeah, you're most likely right. I think I was being overly analytical after a few tasty IPAs.

Klaus B

Looking around I saw:
-fairlight bikes makes 2 different bikes for each size they sell, 1 for people with short legs and long torso that has slightly longer top tube but short head tube and short seat tube. The other one is for people with long legs/short torso, that comes with short top tube but long head and seat tube.
-most companies nowadays advise that if someone is between sizes to go for the smaller (Ribble and kinesis the lasts that I've look at)
My general opinion is that if you try a bike just sitting on it in a bike shop and it feels alright this does not mean is the right size for you. Only after miles of riding it you can come to some conclusions.
I remember zullo (a famous Italian frame builder) saying that modern race bikes lack balance. He complains that with all this trend to go for a bike smaller than someone should go and than put long/superlong stems to have a racy geometry, the bike become unbalaced, that it make a certain sense to me.
After all that consider that we're all different, and only with a bespoke build you can have the bike you want, so at the end of the day shopping for something not design specifically for you it's a matter of compromises.

RodeBike

Klaus B wrote:

Looking around I saw:
-fairlight bikes makes 2 different bikes for each size they sell, 1 for people with short legs and long torso that has slightly longer top tube but short head tube and short seat tube. The other one is for people with long legs/short torso, that comes with short top tube but long head and seat tube.
-most companies nowadays advise that if someone is between sizes to go for the smaller (Ribble and kinesis the lasts that I've look at)
My general opinion is that if you try a bike just sitting on it in a bike shop and it feels alright this does not mean is the right size for you. Only after miles of riding it you can come to some conclusions.
I remember zullo (a famous Italian frame builder) saying that modern race bikes lack balance. He complains that with all this trend to go for a bike smaller than someone should go and than put long/superlong stems to have a racy geometry, the bike become unbalaced, that it make a certain sense to me.
After all that consider that we're all different, and only with a bespoke build you can have the bike you want, so at the end of the day shopping for something not design specifically for you it's a matter of compromises.

Very good points, thanks for that. Your point about sitting on it in a bike shop seems spot on too- I was in jeans and street boots now that I think of it, and that feeling of being stretched may well have come from being restricted by that, as opposed to the bike itself. The numbers suggest that it's spot on for me, and a good bit smaller than the bike I'm replacing, so fingers crossed- I'll find out this week anyway.

Your last point about compromises was also spot on, and interestingly was a thought I'd had only an hour ago- getting this bike alone was a compromise of sorts, as I'd been looking at the SL5, but couldn't really justify the money at the minute. It's like anything in life really, making the best of things.

Thanks for the thoughts.

Klaus B

Fingers crossed from here as well.
I'm quite obsessed with bike sizes, never happy..long torso and short legs here. But I remember my old trek emonda sl4 carbon tiagra 2015, and well fallowing the trek size chart I found myself really good despite the fact that before buying it I was concerned that I should have taken the smaller size. Than I sold it just because I needed I bike with mudguards.. shame I should have taken it, great bike, I definitely recommend trek for it's quality ride.

Klaus B

Please post a picture and impressions after the first rides