Gravel vs road bike saddle position

[hannawald]

Hi, I am a newbie to gravel. Do you have the same saddle position on road and gravel? Or you sit slightly more forward vs bottom bracket on gravel bike as is usual on mtb? It seems to me that many road bikes have 15-20mm offset seatposts while their gravel siblings with longer reach in the same size are also equipped with 0 to 5mm offset seatposts. (Seat tube angle is usually similar) Maybe the center of ballance is placed more forward on gravel hence you are supposed to sit more forward?

[CasualRider]

if you're comfortable on your road bike, transfer your fit to your gravel bike. Do not look at gravel bike size, look at actual measurements of reach and stack. Seatpost offset is not that important. What is important is for your saddle to be in the same position in relation to BB as on your road bike.

Most gravel bikes have longer reach so you can run shorter stems. I still don't really understand the idea behind it.

[jayjay]

Most gravel bikes have longer reach so you can run shorter stems. I still don't really understand the idea behind it.

It's for a longer wheelbase and a "more stable ride"

[hannawald]

if you're comfortable on your road bike, transfer your fit to your gravel bike. Do not look at gravel bike size, look at actual measurements of reach and stack. Seatpost offset is not that important. What is important is for your saddle to be in the same position in relation to BB as on your road bike.

Most gravel bikes have longer reach so you can run shorter stems. I still don't really understand the idea behind it.

OK, I was hoping I can compensate longer reach with different saddle position. I know you set your saddle position first then adjust reach via stem but I was hoping there is some difference road/gravel as is with mtb steeper seat tube angles/zero offset seatposts.

I don´t get why many modern racing gravel bikes have zero offset seatposts and road bikes are usually supplied with 15-20mm offset seatposts.

[voicycle]

My preference is to match saddle position relative to BB, then raise the stack and shorten the reach to the handlebars at roughly a 1:1 ratio. 10mm for my gravel race bike and 20mm for my bikepacking and winter bike.

I bought my first gravel race bike too small because I wanted to match my road fit, then learned by lots of trial and error that the same fit just won't work for me for both disciplines. It's not so much about my riding position but about the fact that I'm using my arms for suspension more on the gravel bike. So my riding position is actually very similar but I need the bars just that bit closer so I have more range to let them move around under me.

Bikepacking/winter bike was a custom build based on what I learned with the gravel race bike. On that one the extra stack and shorter reach is about fatigue/posture as well as extra clothing and reduced flexibility in the cold or after multiple days riding. If I were going to raise the stack much more than this I wouldn't want to keep bringing the reach in at the same rate though. I think I read somewhere that 2:1 is a more normal ratio so I might try to match that. [EDIT: I just got curious enough to stick my MTB into my geometry spreadsheet for the first time and it looks like my stack is +47mm compared to my road bike but the reach is still equivalent to my bikepacking bike - I had to make some guesses to account for bars/hoods/width/hand position, but I'm pretty sure the functional reach is very close. Also means it's not far off of 2:1 compared to my road bike.]

Shorter stems are supposed to give more direct steering control which is generally a good thing when moving off road, but it can also make things feel twitchy if you make too big a change from what you're used to. In order for me to feel like I can move pretty freely from bike to bike without anything ever feeling unfamiliar I like to have my gravel bike stems 10mm shorter than my road bike. That's what I'm looking for on my next gravel race bike: -10mm ideally, but if the geometry chart doesn't allow for that then I'd rather size down and have the same stem length as my road bike than size up and have -20mm. For my bikepacking bike I'd probably want the opposite: -10mm ideal stem length or size up and use a -20mm.

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I think there is a biomechanical / bikefit principle that says you can move your saddle further behind the BB as you relax your fit, but in my experience as long as you're planning to ride all the bikes in a similar way then saddle position relative to BB should remain consistent. Engine works the same so keep that part of your position fixed. Adjustments are just to allow you to wrestle with your cockpit a bit more efficiently and/or account for extra fatigue from the riding surface or increased riding duration.

[hannawald]

Ok, thanks all. I will probably try to copy my road bike saddle position. I was influenced by Trek Checkmate, Ridley ASTR RS etc which use low/zero offset seatpost but then I realised BMC Kaius and Cervelo Aspero use offset seatpost so I can't derive anything from that.
And Trek started to use zero offset seatposts on their Madone while Emondas use to have 20mm offset seatposts, they also used very long reach bars (100mm or so) and then shortened to 80mm reach bars while stem length remained the same so they are very liberal with what components they put on bikes...

[jdms2k]

My road and gravel saddles are the same height from pedal to the saddle and same distance from behind the bottom bracket. They have different reach and drop

[la85]

My road and gravel saddles are the same height from pedal to the saddle and same distance from behind the bottom bracket. They have different reach and drop

Same!

[Lelandjt]

if you're comfortable on your road bike, transfer your fit to your gravel bike. Do not look at gravel bike size, look at actual measurements of reach and stack. Seatpost offset is not that important. What is important is for your saddle to be in the same position in relation to BB as on your road bike.

Most gravel bikes have longer reach so you can run shorter stems. I still don't really understand the idea behind it.

I don´t get why many modern racing gravel bikes have zero offset seatposts and road bikes are usually supplied with 15-20mm offset seatposts.

I don't get why so many road riders still have their saddles so far back. My guess is those are the people who haven't tried a more forward position yet.

[Kubackjeee]

On my gravel bike I like to sit more on the back of the saddle, saddle height also little lower then on my road bike. That gives me better control on bumpy terrain and helps preventing saddle sores. Reach is -1 less and stack about 1 cm higher

[hannawald]

On my gravel bike I like to sit more on the back of the saddle, saddle height also little lower then on my road bike. That gives me better control on bumpy terrain and helps preventing saddle sores. Reach is -1 less and stack about 1 cm higher

You almost copy the position of ex pro Nathan Haas:) I have listened to a podcast with him and he said his saddle is 5-7mm further back, 1cm lower and bars are 1cm higher. He said it was better for terrain control, he can lighten the front of the bike on bumpy terrain.
He also commented front positions on a road bike - it gives slightly more power for short term efforts but utilise muscles which consumes too much glykogen and that is not good for 5hour efforts.

[hannawald]

Btw hard for me to have 1cm less reach as my road bikes used to have 100mm stem at 56 size. Gravel frames have usually 1cm more reach than racing road frames. I will have to make it work for me with the same reach:)

[Kubackjeee]

Btw hard for me to have 1cm less reach as my road bikes used to have 100mm stem at 56 size. Gravel frames have usually 1cm more reach than racing road frames. I will have to make it work for me with the same reach:)

But on the other hands gravel bikes often have 71 degree ht as opposed to 73 in road bikes. So they're designed to use with shorter stems like 70-80mm. I have 71ht and 110 stem and it definitely would work better with shorter stem. Steering is definitely on a slow side with my combo.

[spud]

Btw hard for me to have 1cm less reach as my road bikes used to have 100mm stem at 56 size. Gravel frames have usually 1cm more reach than racing road frames. I will have to make it work for me with the same reach:)

But on the other hands gravel bikes often have 71 degree ht as opposed to 73 in road bikes. So they're designed to use with shorter stems like 70-80mm. I have 71ht and 110 stem and it definitely would work better with shorter stem. Steering is definitely on a slow side with my combo.

true, but there's also the contribution of trail. If that figure is kept managable, the longer stem won't be too much of a detriment during normal riding/steering. But I def don't like longer stems when it comes time to loft the front wheel to clear obstacles - unsettling how easy it is to have the bars go oblique to direction of travel.