No not this:

But BB height.

Looking at using larger wheels in a 26” frame that currently has a BB height of 300mm

Options for wheels are:

650b+ wheels
650b wheels with 40mm tyres

For those interested this is the frame details:

There is oodles and oodles of clearance for both options but both will raise the BB height and as its a rigid set up its never going to change.

As a side thought would a 15mm change in fork length (shortening) – again rigid – have much effect on the BB height? I appreciate it will quicken handling.

All help much appreciated 🙂

How high is too high?

personal preference and intended use.

but 300mm isn’t that high to start with, so you have some leeway. Give it a go and find out, experimentation is half the fun and will give you a better understaindng of the limits as well 😉

650B with 40mm tyres will likely be pretty damn close to 26x2in+ anyway.

FWIW, you can get used to a lot of ‘sub-optimal’ setups quite easily, only you will be able to say when it’s gone too far for you.

Thanks Amedias.

The rear will fit a 29+ wheel again with clearance but that increases the BB height by 40+mm – Looked awesome though 😆

but 300mm isn’t that high to start with

Is it not?

300mm is a nice BB height for many things. Lower is good for bermy stuff, higher is good for techy pedally stuff.

If I recall correctly my Soul was at 335mm, my Spitfire is at 342mm and my Bird was 295mm and now 305mm – all unsagged. Sagged that makes them about 326, 307 and 296.

15mm change at the fork is about 5mm at the BB.

but 300mm isn’t that high to start with

Is it not?[/quote]

no not really, it’s a sensible middle ground kinda height, very adaptable to tyre/wheel changes in fact.

Don’t have exact measurements to hand but I know my bikes vary (currently and over the years) between ~10.5in and ~13.5inch, which is what 265mm to 350mm?

There can often be ~30 variation between models/brands of the same kind of bike so unless you were at the extreme end and thinking of going further in the wrong direction I wouldn’t be overly worried.

Also, think about tyre size, people have run anything from 1.8in to 2.4inch tyres on the same bike, that’s ~15mm just from a tyre change on the same wheels, so a bit more leeway in either direction isn’t a big deal.

Add to that the fact that a smooth trails/moorland wanderer will get away with a lower BB than someone who regularly has to pedal up and along deep rocky/rutted type trails and you can see that ‘optimum’ height isn’t a static thing

People get far too hung up on BB height, especially on HT/rigid bikes, unless you’re talking right at the extremes of height, extremes of terrain, or extremes of performance then it’s into the realms of insignificance.

I say crack on with your experiment (whatever it is) and have some fun 😉

I say crack on with your experiment (whatever it is) and have some fun

“gravel bike” natürlich 😳