I’ve seen it written about by various people, but does anybody have any idea roughly how much going from a typical riser bar to a typical flat bar is effectively going to shorten the reach of the stem at all?

Ideally would like to work out before hand the new stem length I’d need to compensate rather than going down the trial and error route…

Stems don’t magically change in length by fitting new bars.

Queue a spew of utter bollocks filling this thread.

From what I’ve seen of bars it varies hugely. With a medium or high riser you have quite a lot of adjustment in effective stem length from a relatively small amount of tilt fore and aft.

Can you work it out from this website?

Eh?? If anything a flat bar (if actually flat) would extend the reach. You can get flat bars with various amounts of sweep so just get one that allows you to angle it to get the same amount of up- and back-sweep as your riser and the same width. Then the only difference is in the vertical rise

helpful1 doesn’t understand how steering works but keeps manufacturers selling fractionally longer or shorter stems…

Oh… I understand way better than you Chief.

So only buy one stem per bike.

Stems don’t magically change in length by fitting new bars.

Queue a spew of utter bollocks filling this thread.

Strong 1st reply… Chapeau sir! 😕

From what I’ve seen of bars it varies hugely. With a medium or high riser you have quite a lot of adjustment in effective stem length from a relatively small amount of tilt fore and aft.

Quite… And bars are designed to be angled forwards ever so slightly to achieve the stated up-sweep normally (though again depends on the bar). For argument’s sake, would be going from a 750mm bar with 20mm rise to a 750mm flat, similar back sweep on both.

Can you work it out from this website?

Sadly not, as that doesn’t take into account for handlebar shape at all. Useful tool in its own right though to be fair!

I think I see what you mean now. You’re saying that because the bar has a rise you can rotate it in the stem clamp so instead of all the rise being in the vertical direction some of this ‘rise’ can can be in the horizontal.

I think it would depend on your current setup. Looking side-on at your bars/stem, do you have the ‘rise’ part of the bars tilting forwards or backwards ?

Let’s say you’ve got the rise vertical. For a flat bar of equivalent sweep (i.e. same stated angle), I don’t think the overall reach would be noticeably shorter. If you imagine the arc that your outstretched arms form, equivalent sweep flat and riser bars would both fall very closely along the line of that arc.

Are you just wanting to lower the front end ?

You can effectively “shorten a stem” by rolling a set of risers backward. This will also effectively change the rise, backsweep, and upsweep of the bar.

Most flat bars now have the clamp area of the bar eccentrically offset so there will be some degree of adjustability, just not as dramatic as a riser.

What bar you need, what stem you need, to acheive your desired outcome will be down to trial and error. There’s too many variables between “typical” components.

Otherwise known as **** knows.