Gravel bike geometry (poll)

  • This topic has 63 replies, 28 voices, and was last updated 1 month ago by  DezB.
Viewing 24 posts - 41 through 64 (of 64 total)
  • Gravel bike geometry (poll)
  • This is a timely thread. I just looked at the 2020 Croix de fer and compared to the 2019 it is an inch lower in stack, an inch shorter wheelbase, it’s gone from 71 HA to 72 and offset has gone from 50mm to 52. Trail is down 9mm to 60 and flop is down 3mm to 18, mechanical trail changed from 65mm to 57mm.
    Not sure it’s really a gravel bike anymore, seems like it’s going towards the old school road, or newer CX bike.
    This thread seems to confirm that.

    Premier Icon jameso
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    ^ looks same to me? Middle sizes are 71.5 HTA, as they always were. 50mm offset fork.

    Premier Icon roverpig
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    Not sure about the exact geo changes and it’s relevant to this thread that geo of the same bike can be quite different in different sizes, but they do seem to be positioning the CdF more as an endurance road bike with the Fugio now more obviously their gravel/adventure offering.

    kerley
    Member

    Linked to the thread, how does a slacker seat tube come into play with handling. Eg 72degree head tube paired with 72.5 seat tube on the space chicken. Most gravel bikes seem to be around 73 seat tube

    It would make no difference to me as I set my saddle in relation to the bottom bracket. A 1 degree change in seat tube would just mean I need either an inline seat post or a set back seat post to get my saddle in the right place.

    Premier Icon thisisnotaspoon
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    Linked to the thread, how does a slacker seat tube come into play with handling. Eg 72degree head tube paired with 72.5 seat tube on the space chicken. Most gravel bikes seem to be around 73 seat tube

    With the shorter wheelbase and longer stem/bars you already have a lot of weight on the front wheel so the ~76 seat angle of modern mtbs is largely useless (and would probably push you too far forward). Contrary to many a rad skilz video on youtube, for sharp corners having your weight over the bb is better than over the bars.

    It would make no difference to me as I set my saddle in relation to the bottom bracket.

    Works to an extent and if you only have one bike and one position. But makes no allowance for a more aero position on a road bike, or a more relaxed position elsewhere. For example my road bike is setup with the classic “knee over pedal spindle” measurement, and it works. But if I get into a tuck my legs hit my ribs as the resulting hip angle is too tight. Moving the saddle forwards and up and adding 20mm to the stem would give a much better position for going fast.

    bluebird
    Member

    My road and my gravel bikes (Cervelo and Scott) have a different head angles depending on the frame size. I’m not sure HA alone tells you much.

    Premier Icon roverpig
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    The thing with this geometry stuff (at least for me) is that it’s fun to geek out over the numbers and try to understand how it all works, but then a bike pops up that pushes your buttons and it all goes out of the window.

    Fifteen years ago now, I rode Etape du Tour, to commemorate turning 40 and to try to convince myself that I wasn’t really getting old. There was a guy on our trip who had this lovely Kona road bike in a two-tone paint job. As a child of the 80s I thought this was the coolest thing ever. Now, I’ve just seen the 2019 Kona Libre in purple and I’m not sure I even care about the geometry any more 🙂

    scotroutes
    Member

    Have you ordered it yet?

    Premier Icon simondbarnes
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    This is a timely thread. I just looked at the 2020 Croix de fer and compared to the 2019 it is an inch lower in stack, an inch shorter wheelbase, it’s gone from 71 HA to 72 and offset has gone from 50mm to 52. Trail is down 9mm to 60 and flop is down 3mm to 18, mechanical trail changed from 65mm to 57mm.
    Not sure it’s really a gravel bike anymore, seems like it’s going towards the old school road, or newer CX bike.

    Where are you getting your numbers from? The frame hasn’t changed.

    longsider
    Member

    I’m loving trying to get my head around this whole bike geometry. Through various searches I’ve just discovered that the 3T exploro in a large is pretty much identical to the large space chicken. The reviews on the way the exploro handles on road and off it seem my kind of ride. fast and fun. I love their mantra “Going nowhere..fast” Admittedly the two bikes won’t ride the exact same due to all the aero work on the exploro but it gives me an idea what I’m about to thrash around on.

    So, case in point, Mason seem to get a lot of positive reviews, but the Bokeh looks pretty racy on paper. At the other end of the spectrum, Genesis is a company that I know and have tended to like their stuff over the years. I also quite like steel, so their Fugio 30 looks nice. But it’s pretty slack at 70.5

    I owned a fugio, and now own a racier G2. The fugio was by far the more fun bike offroad, especially on twisty singletrack. You do notice the slack front end on the tarmac though. I changed wheelsets out to 700c and fitted 37mm tyres which helped the road feel, without sacrificing too much of the offroad fun factor.
    If its any kind of a recommendation, I am thinking about going back to a fugio now that they have slimmed it down a little and have GRX. I just had more fun on it.

    fasthaggis
    Member

    Fifteen years ago now, I rode Etape du Tour

    Limoges > Saint-Flour ?
    That was a long day 😉

    lovely Kona road bike in a two-tone paint job

    I bought one of those a while ago because :-
    A)I wanted a Kona (actually a Dedacciai Scuro) road bike.
    and
    B) I am also a childish person of the 80s
    Picked a size that usually fits me and built it up,never gave the geo a thought.
    Still ride it a lot and it is indeed lovely.
    kona
    Not sure I could ever love that Kona Libre though.

    Premier Icon thisisnotaspoon
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    Admittedly the two bikes won’t ride the exact same due to all the aero work on the exploro but it gives me an idea what I’m about to thrash around on.

    The aero is definitely a case of marketing over reality. I’m sure that quantitatively it’s faster if you control the variables. But in the real world a skinsuit saves more seconds than a frame, several times over. No one wears a skinsuit. So it’s fast, but only as fast as you can survive without any spares in your jersey pockets. Otherwise it’s like the age old “you could save more weight/drag by having a poo”.

    My gravel bikes usually have something approximating a NACA aerofoil of mud and dirt on the back of the seatube anyway. How does that compare to a Kamm tail?

    Premier Icon roverpig
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    Limoges > Saint-Flour ?
    That was a long day 😉

    You’re not kidding. I’m still getting over it 🙂 The climb up Puy Mary near the end still gives me nightmares.

    Not sure I could ever love that Kona Libre though.

    Each to their own 🙂

    Premier Icon roverpig
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    If its any kind of a recommendation, I am thinking about going back to a fugio”

    Thanks, that is interesting to hear. Although I’m currently lusting over the purple Kona the Fugio still ticks a lot of boxes for me. I’ve always enjoyed steel bikes and the move to 725 plus that orange fade paint job works for me too.

    Thanks, that is interesting to hear. Although I’m currently lusting over the purple Kona the Fugio still ticks a lot of boxes for me. I’ve always enjoyed steel bikes and the move to 725 plus that orange fade paint job works for me too.

    Yep I`m very, very tempted. Like I say, they have sorted the bug bears I had with the original, better tyre clearance, slimmed it down a little. Unfortunately it still has the annoying allen bolt that you need to remove to get the rear wheel off, but that’s not a game changer on its own. There are better value options out there, bombtrack hook ext, and the Norco Search XR which is insanely good value imho but I know the Fugio is going to ride well and fit me like a glove.

    Premier Icon jameso
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    “you could save more weight/drag by having a poo”.

    Drag..? Mind boggles / trying not to.

    Where are you getting your numbers from? The frame hasn’t changed.

    https://www.freewheel.co.uk/genesis-2020-croix-de-fer-frameset-vargn2006

    Since it’s Genesis’ own site, I assumed they had it right.

    Premier Icon jameso
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    ^

    Chainstay 405mm 407mm 407mm 410mm 410mm

    No chance that’s the CdF geo – someone’s uploaded the road bike specs to the Freewheel site. Genesis site looks right. Madison own both companies but different staff etc.

    Premier Icon simondbarnes
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    Since it’s Genesis’ own site, I assumed they had it right.

    Those numbers are different to the ones on https://www.genesisbikes.co.uk/bike/croix-de-fer-fs-2020

    Mister P
    Member

    I shall go have a word with the Freewheel web gang now. Thanks for the heads up.

    No chance that’s the CdF geo –

    I did wonder. I assumed they had read the reviews that said it was comfortable and competent but not thrilling and decided to go for thrilling.
    Would have made an interesting Gravel bike 😵

    Also tell the freewheel gang the price is £299 for about the next hour or so..

    Premier Icon BadlyWiredDog
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    I was told by someone who should know that all bike frame geometries are actually identical. They just change the numbers on the spec sheets and sit back laughing at bike testers and forum geeks as they adjust their perceptions to suit the numbers.

    Bit like the Suzuki GSX-R1100 back in the day which had about 60 clicks of adjustment for every aspect of its suspension front and rear, of which, it transpired only around five made any real difference. Funny how none of the mags clocked that, probably because even the five that did owt were wrong anyway.

    Premier Icon DezB
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    D

    ooh, I looked it up
    HA 70.5
    SA 74
    Reach 382
    Stack 584

    er, still D

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