steveadorjan

I've been toying with the idea of getting a Brompton for a while, but I simply cannot make up my mind as to which model to go for (apart from the current predicament of what's available at all ). I'm 179 cm tall and my legs are somewhat shorter, so on my regular road and mountain bikes I ride with a saddle height of 71.5 cm (top of the saddle to center of crank set). I'm used to a sportier position (road and mtb) and I was almost sure that the S-type bar would fit me the best (lower bar and increased reach due to the forward angle of the S-stem), whereas the M-bar would put me in a too upright position (i.e. bar grips would be higher than the saddle). However, I have tested both bar types and found the M-bar quite ok (not as sporty as I'm used to, but really not that bad at all). On the other hand, I was surprised that on the S-bar Brompton I found myself in a rather too cramped position: while the lower bar position is certainly closer to my setup on the road and mountain bikes I'm used to, somehow the reach seemed too short (i.e. I felt too hunched) and I was missing the more stretched out forward position from my other bikes. For some reason, I did not feel this so much on the M-bar Brompton, even though it has a shorter reach and higher stack on paper.
Another counterintuitive issue that bugs me: I have read that by placing more weight on the front wheel (i.e. forcing one to lean forward more) the S-bar is better at alleviating the twitchy steering that Bromptons are notorious for. Again, I felt that the M-bar was less twitchy (in spite of having less weight on the front wheel), while the S-bar felt rather nervous. To be honest, I spent far less time on the S-bar and the S-bar test bike I rode had Kojak tires, while the M-bar had the stock Marathon Racers, so that might have been due in part to the slicker Kojaks too. And with a longer test ride, I may have become more used to the S-bar, but I'm not sure.
So, all in all, what's the general consensus about the handlebar choice for average height, sporty riders looking for a ride experience closer to regular bikes? Am I wrong, in fact, and is the S-bar twitchier than the M-bar or the other way around?

linberl

The two bar have different reaches. It's a question of what fits you properly (if at all). With Brompton it is not easy to change out the bar, although a slight riser bar can be subbed for the S bar (there' a company that produces a revision kit). But overall the decision should be based on proper form - does either bar put you in an optimum cycling position with your knees correctly places in relation to KOPS (for you, of course) and you weight balanced well with no excess pressure on your hands? Tires can be swapped if you decide you prefer Racers or Kojaks. But the bikes come with different stems depending on the bars so if you decide wrong, you have to not only replace the bars later but the stem riser as well (and cables). General consensus doesn't mean much, either, as it should be all about YOUR flexibility and comfort, not someone else's. Twitchiness goes away after you've ridden whatever small wheeler you buy for a while.

steveadorjan

Thanks, I'm aware of the difficulties involved in changing from one to another, that's why I want to make sure I get the right one. There was no excess pressure on my hands/wrist with the S-bar (as I've mentioned, I'm used to a sporty setup with low bars on my other bikes). On the contrary, for some reason, the reach seemed shorter with the S-bar even though it should be the other way round according to the geometry figures. I'm really not sure why I had that feeling. Perhaps I should test again the S-bar on a longer ride.
As for the twitchiness, I was expecting the steering of the S-bar to be more stable due to more weight of the front wheel (and what I've read in various Brompton forums), but for some reason the M-bar seemed to make steering less nervous. But this could well have been partly the result of the Kojaks. I was just wondering if people have had the same experience with the S-bar setup (compared to the M-bar)

linberl

Whichever one you get you will adapt quickly and stop noticing any twitchiness so imo that's not an issue. Kojaks don't make a big twitchy, either - I use them on my 16" wheeled Bike Friday pakiT. They grip just fine and ride better than the racers I originally had. The M bar put you more upright and more weight on the rear of the bike which makes the bike more stable overall (why we slide back when going downhill). Since its a pricey proposition, are there shops where you live that will rent you the bike for a full day? Ideal would be to ride each one over the same route. Or maybe a brompton club that you can connect with to spend more time on each style? Also, I am not sure that "weight over the front wheel" is to mean rider weight. I find putting a lowrider front rack and panniers on the wheel itself helps to reduce twitch but that weight is MUCH lower than rider weight; imo rider weight is too high to have much mitigating effect.

steveadorjan

Yes, that's how I rented the M-bar, so I guess I'll rent the S-bar for a day too, though the M-bar was a 6-speed and I actually used it for an extended hilly ride to test climbing ability on 10-15% inclines, and the S-bar is a 2-speed titanium model, so I would not be able to ride the same route (they have no S6 test bike available).
But I appreciate your input about weight over front wheel. I thought that body weight mattered, but what you said makes sense

linberl

Keep in mind the titanium model is also substantially lighter than a 6 speed regular Brommie, and that will make it feel more "nimble" to you as well. That may be part of what you are sensing when you ride. I have 2 bikes and one is barely 19 lbs (my pakiT) and I have a Dahon as my beater bike which is 24lbs and switching to the lighter bike always takes me a few moments to adjust.

12boy

I have only had an Sbar and it doesn't seem as twitchy as my mini velo and similar to my Xootr Swift. I live in windy Wyoming and the Mbar position would be too much drag for me. I have ergon grips and 4 in bar ends and like to bend over when fighting a headwind. However, 4 hard back kibrary books, a 22oz water bottle, a wire cable lock and my 2 lb tool roll in a front bag on the stock front bag mount and it isn't twitchy at all and the ride smooths out too. I am only 5' 7" so that might be a factor....however the pentaclip can give you a little extra set back.

Jipe

I have a S bar Brompton and I am also about 1m79. The S bar fits perfectly.

But you should also look at the saddle position.

The Brompton pentaclip on which the saddle is mounted allow for two positions in height and two positions in length. To have enough distance between the saddle and the handlebar and not being cramped, you need to put the pentaclip behind the seatpost (saddle rearward in the picture below).

With 1m79 and short legs, putting the saddle on the highest position in the pentaclip should allow you to use the standard 520mm seatpost (but this depend also of the saddle height and pedals thickness).

steveadorjan

Oh, this might have had sth. to do with my feeling cramped. On the M-bar I tested (for a day and a half), I adjusted the saddle pretty much according to my road bike setup (almost KOPS, correct saddle height etc.). But I had the S-bar for much shorter and the saddle might have been too forward (I did adjust the saddle height but did not have time for more, as I had to return the bike to the shop quickly). So I guess I should definitely give the S-bar a second chance and make sure the pentaclip is in the correct position. Saddle height was definitely not an issue (as I've mentioned, my saddle height is only 71.5 cm, so I didn't even need to use the telescopic part of the seatpost that all these test bikes were equipped with), though I did have to stop occasionally and re-adjust the M-bar I tested due to slippage (these test bikes might not be maintained that well). But the S-bar then probably needs the pentaclip to face backward to allow for a more rearward saddle.
As for the twitchiness, this could have been exacerbated by the superlight construction and the tires. It's just that I was expecting the bike to be much less twitchy with the S-bar (with more body weight on the front wheel, that is a better weight distribution/balance on the bike itself)