I’ve just tried a flat bar on my bike in place of a 1″ rise low riser. Initially it feels wrong, just too low I guess and it’s giving me a tiny niggle of lower back pain; since the stem’s at it’s highest point I can’t raise it slightly. After riding for a while though I get used to the new position and the lower back niggles seem to subside; I even seem to be able to go a little bit faster (aerodynamics perhaps).

I can of course switch back to low risers but I was wondering whether it might be worth persevering with the flat bar and new position. For general riding (most of mine’s on the road with the occassional off-road excursion) what are the advantages & disadvantages of various bar heights, is it just a case of balancing personal comfort and efficiancy? With various bar and stem combinations there’s a huge amount of possible variation and that, along with the body’s ability to adjust to new positions it’s not easy to know when you’ve got the best option for yourself.

Stick with what you have for a while. Changing height and length will move your weight around, chaniging distribution between front and back wheel and also arms/seat, and make it harder / easier to slide back when going downhill. If you ride mostly on road then you’ll probably want a more road style position, ie long and low, aerodynamics are important on the road. there’s no perfect setup if you do different types of riding, it’s all a balance. Also the seat may have something to do with you back problems, fore/aft position and tilt.

More to fiddle with!

Flat and very low rise bars are popular at the moment but the reason they have become so is largely being driven by DH racers wanting to get their front ends as low as possible in order to get the front end to grip more. This increase in grip comes from having a lower centre of gravity and more weight over the front wheel as the low rise/flat bar pulls you down lower of the front wheel.

Riser bars became popular at a time when forks weren’t typically 200mm in travel and consequently the front end of a bike was significantly lower. At that point, there was a desire to raise the riding position in order to make it easier to ride down steeper terrain. On some of the courses in this year’s World Cup, the terrain has been so steep (for example Champery) that pro-DHers have been reverting back to higher rise bars.

You’ll notice that all of this comment has been centred around downhill rather than trail riding. Typically what becomes popular with pro-DH racers also becomes fashionable with trail riders. To some extent your bar height will make a difference on a trail bike, say if you’re running 150mm or more. But for 145mm trail bikes and less, the height of your bars tends to be primarily determined by comfort and not performance.

I use a zero rise 50mm thomson, a 5mm spacer between it and the headset and low rise monkey bars (685mm), it seems spot on 🙂 (with marzocchi 66’s on an Orange Subzero)

My bar height is totally dictated by comfort, been an old fart its correspondingly high to save my back.

i tend to put my bars as low as possible and then bring them up to the point where the bike handles sensibly. that is where they stay. I don’t know if that is helpful…

why did you try the flat bar in the first place? i am slightly confused.

my bars are at about the same height as my saddle. Slightly lower on my summer season as the slackness makes it want to wheelie on climbs more so i dropped the bars a little. Set for comfort mainly, and then tweaked for handling.

is their a rule of thumb like saddle height? My mmmbop bars feel a touch too low but on steep uphills the front end wanders already so am loath to lift them any higher.
If i move the bars up and then the seat forwards a touch would that sort the wandering front end?

The front end wandering is more a function of the head tube angle; the Mmmmmmmmmmmmmmmmmmmmmmmbop has a very slack angle which will cause it to be harder to control at low speeds.

that’s what happens with my summer season. I dropped the bars a touch compared to my normal inbred and it helped loads. Is now just a case of perching right on the nose of the saddle on steep climbs 🙂

Well, I wanted a nice new Thomson stem in 80mm and Thomson only do this in OS, so I had to ditch my 25.4 low risers (I could shim them I suppose) and thought I’d try a flat bar (partly so I wouldn’t get laughed at on here for having stubby barends on risers 😳 ). The things is the old stem had a few degrees rise, the Thomson doesn’t so although I’ve moved the stem up the steerer it still feels a bit low. I think I’ll try some low risers again and see how I get on (the barends will be going on them too!).