QUESTION - "Ideal" Endurance Bike Geometry

Hey CT.

Looking for some help here. I am in the market for a new road build, and am leaning towards a more endurance-oriented geometry. I’m coming off a Tarmac SL7…it was a great ride, but the aggressive geo wasn’t for me. Too long, low and responsive.

After reflecting, I am thinking more and more that an endurance-esque geo would be suitable for my riding style. I would like to maintain some of the road bike “fun-factor”, yet land on a bike which is more comfortable, planted and less twitchy. It will remain on pavé only…I have a gravel bike, so this new one is intended for the road.

While this is definitely a subjective questions, I am curious as to what your “ideal” road endurance geometry might look like? Specifically, what are your thoughts on:

  1. HTA - 72 vs. 73?
  2. Stack & reach?
  3. Trail - where should it land for stable, yet fun, handling dynamics?
  4. Front-center - I don’t want to be riding a tractor :slight_smile:
  5. Wheelbase

Thanks for your help!

If I wanted to build a more relaxed bike I’d go with

HTA: 73 degrees
STA: 73 degrees
Rake: 45mm
Chainstay: 41cm
BB drop: 7cm

This is going to be very much person/size dependent.

For me, I’d be looking for a stack in the low-mid 550s, with a reach in the low 380s. STA just shy of 74 degrees. Chainstays - the shortest that would allow me comfortably to run 30s.

Unless it’s way out there, tyre size and stem length will have as big an effect on handling as trail, but c.45 is going to be fine.

Front center matters more if you’re going to be riding a small bike, as toe overlap can be an issue. Ditto a gravel bike. If you’re riding a size >54 on a road bike, I shouldn’t worry about it.

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Stack and reach are completely size dependent, and to a large extent wheelbase is as well.

HTA: 72
STA: 73.5
Trail: 60 ~ish (depending on offset, say 59-61)
Offset: 50 ~ish (depending on trail, say 48-52)
BB Drop: 80 ~ish (say 78-82)
Chainstays: 420 ~ish
Wheelbase: 1005-1015

Should make a stable and planted bike, comfortable on rough roads or cobbles and probably even a bit of ‘all-road’ type riding.

I would try a few variations and at the distances you plan to ride. Then go get fitted. There is no ideal. The avg power you want to push decides bike position - essentially, more upright or less upright. This then decides the rest - what kind of saddle, more racing geo or more touring geo. Last and perhaps even more important, consider the overall bike flex. You don’t want too soft nor too stiff for your intended use. Think skis, golf clubs, tennis rackets, etc. Most modern bikes, I’ve found, are too stiff. This is mostly because CF bike/fork that flexes more introduces reliability and safety issues.

Nearly everything you just said is completely inaccurate. :roll_eyes:

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There can be no “ideal” geometry since it implies that all riders are the same height, same weight, have the same inseam, same arm length, ride the same roads, are physiologically the same (in terms of pain and endurance thresholds, for example)–which they are not.

That, and there are a whole lot of other variables which are important in determining whether a bike seems comfortable and stable to the rider, such as the materials the frame is made from, the shapes and thicknesses of the tubes and joints, and so forth.

Likely what works for one individual would not work all that great, or at least not be a perfect match, for the next. I would not rely on a magic recipe of geometric numbers to influence what bike suited me best, when it is based, at most, on the law of averages, which often times is built on very weak (anecdotal, one-off or a few odd) foundations.

That would result in the opposite of a relaxed bike….a good stable race bike, maybe but not what OP is looking for. BB is high and no mention of trail, which is a (if not the) critical element of how a bike handles. 43mm offset is more standard for a 73* HTA

Much better direction. Reasonable trail (maybe a touch long), good BB drop and long-ish wheelbase. Not certain about the offset number, though….would need to make sure it produces the desired trail number. It is counter-intuitive, but more offset leads to less trail.

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