Gravel bike fitting, what’s it all about?

pablo Posts: 3
edited March 2022 in Road buying advice
So all my friends are old and lazy and have succumbed to gravel bikes, they go on adventures, send me pictures of bridleways and gravel tracks (and bivvy sites with fires and beers!) and it all actually looks quite good fun… I flog myself on Zwift and country lanes on my 3T Strada and I can’t help feel they have the better deal…

So I’m sat on looking at options and it’s really quite good because the whole website is fit-centric so I can get the fundamentals sorted because in all honesty, I don’t care about groupsets anymore… I just want a bike that fits, especially if I’m on it all day, day after day. I’ve used data from a previous Retul level 2 fit so I’m confident with the outputs and the geometry data must be from the Manufacturer.

But how should a gravel bike fit, am I looking for something like a mtb fit or a road bike fit? on an mtb, I’m out of the saddle more than a road bike and the gravel bike geometry is a fair bit tighter, should a gravel bike even replicate the road bike fit and I let the geometry of the gravel bike work it all out?!

This is the bike in question, a BMC URS One

The indicative bike fit looks promising, this is the fit data.

My understanding is that I can move me (the blue dot) out to the right a bit with a longer stem and I am still comfortably in the “this will fit” box based on Reach and Stack? There looks like plenty of scope for adjustment.

There is another option, the Orbea Tera MX20 and the fit data is promising too

In my head, being at the bottom/right of the box makes more sense though? I’m loathe to just add a longer stem when the bike is designed to pitch the rider up a bit more. An additional spacer to what the fit data recommends and I’m moving up the box too?

Any thoughts?! And yes I could go and sit on them all but stock and stockists etc etc and Velomatch have real time stock data so when I’m ordering, I know it’s in stock.


  • me-109
    me-109 Posts: 1,915
    Depends how much and what type of off-roading you imagine doing, but a little bit shorter and higher on the front end. You're only talking 10mm or so, not huge amounts.
  • pablo
    pablo Posts: 3
    Thanks, that’s useful, maybe I’m overthinking all but having previously bought a bike that, on paper should fit, I am cautious of getting it wrong and the supply/stock situation isn’t helping!

    Use-wise, I’m thinking it’s mostly fire roads, bridle paths and hard packed loose surface stuff (if the latter description isn’t an oxymoron), eg chalk paths of Wiltshire etc.

    What I don’t want to end up with is a race-orientated cx bike that’s been labelled as a gravel bike, nor something like a Surly that’s just for hauling loads of kit slowly across continents!
  • The fit is, for most riders, going to be more akin to an endurance road bike IMO. I have an open UP and I basically have a 10mm shorter stem on it, and the stack height is around 15mm higher than my race bike. Other than that, bars, saddle height etc. are all the same as my road bike.

    I mainly use mine for similar type of terrain and road surfaces that you mention, anything a bit more technical such as single track or even cx type courses and you notice that the bike really is not cut out for it (well, that has been my experience anyway).
  • joeyhalloran
    joeyhalloran Posts: 1,080
    I'd echo the above, for 'fast' gravel that you're talking about it's essential just like road riding with a few more bumps. If you are comfortable on your current bike for LONG days (if that's what you're planning) then 10-20mm shorter and higher should give you a reasonable 'fit window'. It may be 10mm short and higher is right, it may be 20mm is right but I wouldn't have thought you'd be much outside of that.

    Though also remember some gravel bikes on the MTB end of the spectrum are designed for much shorter stems. For example the new Sonder Camino range each size has been designed around a 50mm stem. The more Road end of the spectrum will be designed around the usual 90-120mm stem sort of length. It may have an impact on handling.
  • pablo
    pablo Posts: 3
    Really useful advice, many thanks. I’m not touring, “fast gravel” sums up the intentions even if my legs might disagree…