I just installed some VO porteur bars on my Nishiki with a 70(?)mm stem since that is what I had on hand and find the handling to be squirrely and the cockpit to be a bit crammed. Any guidelines to determine the length of the stem that I need?

I've got a 100mm on my Pug with the VO Porteur bar and it seems to handle just fine. Not sure what to say about guideline, but it has proper proportion to my eye and works fine for me atmo.


P1010515 by Sallad Rialb, on Flickr

I found something similar when I went from drop bars, on my Motobecane Grand Jubilee, to Mustache bars, fitted with Barcons. The front end felt unusually light and almost unstable. I did get used to the difference but I am wondering if stem length might have something to do with it?

This is the stem, original to the handlebars. The stem reach is 65mm, as I recall...


And this is the stem holding the same bars as fitted to my Motobecane...

Randyjawa

I wanted to send you a PM, but don't have enough posts, yet. I just recently bought a 1975 motobecane grand record. I like how you have your grand jubilee set up - can you tell me what size tires you are running and what type/size fenders? Also how do you like your mustache bars? Did you ever change out the stem? I am considering going with the less aggressive porteur bar, or nitto randoneur bars.
Thanks!

I have a set on a Trek Multitrack hybrid errand bike. I like the bars, but for me they were too long, so I took off about an inch. I think the stem I'm using is 90, but what someone else uses on a frame with different geometry probably isn't going to be useful info.

There's an ideal seat-to-handlebar distance for each style bar, but it takes some time to determine. It is likely that with bars that sweep back so much that you'll want a longer stem to keep the bar from being too close to your body.

You may want to make estimates by taking your best-fitting bike and measuring it. Of course, different styles of bars imply different riding styles and positions, so there's no exact science to it.

I've built up a few bikes with porteurs for myself and for friends. I find a longer stem works better if the bars are lower than the seat, and a shorter stem for when the bars are higher. But overall, I don't think it makes much difference.

As no glider mentioned, it really comes down to the saddle to bars distance. With a long top tube, you'll need a shorter stem, and vice versa. That said, I have these bars on a French bike with 59cm top tube and 80cm stem, and it works fine. The bars are lower than the saddle. I could stand having a longer stem, maybe 100-110mm, but what I have is fine. It only feels cramped if I try to make a really sharp turn, like a U-turn at low speed.

This is the view from the cockpit:



And this is my riding position, which you can sort of make out from this angle:

The shorter the stem the lighter/quicker/more responsive/'unstable"/etc the steering/handling will feel, given all other factors are equal. Picture a 1' rod on a pivot point; if you move the bar 1/2" (on the end opposite the pivot) it moves the bar close to the pivot less than if you moved that same 1/2" on a 2" rod on the same pivot. If you go from a 140mm stem to a 60mm stem it will definitely take some getting used to(again, all else being the same).

Brian

also realize that these types of bars place your hands aft of the headtube making for the effect of a negative length stem

I switched from drops to porteur bars and I added 30mm to the stem length, and I may need to add more. I like a decently aggressive position, but drop bars never worked for my hands.

That's one of the nice things about the porteur bar - you can wrap the whole thing and can have a couple different hand positions. Now if someone would just make a combined inverse brake level / bar end shift pod, I'd be in business.

southpaw, Is that cork/shellac bartape on your bars? Looks great