Folding Bikes - Brompton comfort factor

I've never ridden a Brompton and I'm curious about a few things. I never hear anyone mention the rear suspension, never hear complaints about it being too this or that, or wanting to get rid of it, etc.. A lot of Downtube Mini owners seem to want to get rid of the rear suspension and substitute fat tyres. How does the Brompton suspension perform?

Looking at the design it appears it suits the upright leisure riding position better than a racing posture due to the narrow tyres and lack of front suspension. I'm running 2" Big Apples on my 20" folder and I still find the ride too harsh. How do Brompton owners get around this problem, particularly those who have the S-type model (what are the fattest tyres that can be fitted?)?.

Most people find the rear suspension fine for day to day use, though some find it too soft and reduce this inherant softness by either clamping a hose clamp around the rubber suspension boss to reduce it's available compression, or to fit another harder (semi-compatable) bushing from the Birdy bike line of spare parts (Available in 3 or 4 varying degrees of hardness, coded by the colour of the elastomer they're made from).

The main problem one can sometimes encounter with the standard setup is a degree of 'kangarooing' when cycling at certain higher cadences as the frequency of pedalling transmits through the frame and hinge. It's not too pleasant but can usually be kerbed by slowing or freewheeling. Harder suspension blocks reduce (But don't entirely eliminate) this phenomina.

Another popular upgrade for the front forks is to fit a Pantour supsension hub to the front (a hub with a small degree of 'give' surrounding the axle), or in the case of the best known Brompton 3rd-party modifier Steve Parry a part that converts the stem post to accept an inverted and modified suspension seat-post that provides a degree of damping between the bars and the forks. Both fixes aren't suspension in the sense you might find on a 20" or bigger bike but both do a lot to reduce the vibration and subsequent fatigue one can find in the wrists on longer or bumpier rides.

I think though - that if 2" Big Apples on a 20" are too harsh for you now that you may find the Brompton a little unsuited for comfort needs unless you go in with an open wallet to add things like a Pantour hub and/or Thudbuster seatpost to the bike, as wider plush tyres aren't really available beyond the sorts of things you find on kids bikes, and that there isn't exactly a huge amount of space to fit larger than standard tyres at the back unless you want to sacrifice mudguards (fenders).

LittlePixel's had far more seat time on the Brompton than I have, as I've been borrowing my wife's recently acquired Brompton only for the past month or so. But I can add a few comments from my brief experience.

With the long riser to the handlebars, the rider is in the leisure-position, as you say, and if the bike has been fitted with the tall gull-wing bars, it can be very leisurely indeed. As a result of the high hand position, the rider's weight is shifted back with little weight resting on the bars, and this makes for a comfortable pootling ride with no need for fat tires, in my experience.

However, if your personal geometry (the reach of your arms and your torso length) or modifications cause your riding position to be less leisurely (e.g. an Aberhallo stem adapter and lower bars) then more weight will be resting on the bars. How much weight is shifted forward would depend, of course, on the individual rider's geometry. Even so, the springiness of the long riser would absorb much harshness; the ride would be more comfortable for the wrists, arms, and shoulders than that of a bike with a short relatively inflexible stem-riser.

Regards
T

I've just located a pic of the Parry stem mod LittlePixel mentioned:

http://www.foldsoc.co.uk/sprep2.html

It's a cool idea, though I'd imagine there'd be plenty of sticktion. - A thudbuster ST version?

There are a choice of handlebars and of saddle and these more direct affect the comfort. The M-bars is upright and would tend to focus more on the saddle choice (recommend Brooks). There are now a choice of standard or stiffer suspension blocks, you can begin with the standard block and replace with stiffer if you are bouncing too much, although you have a degree of adjustment possibility with how tight you have the bolt.

The S-bar reduces rear load but increases load on hands and I found harsh, tried Pantour but it was too fiddly so have the Ergon grips, tuned to right angle and its comfy now.

I have often done 60 miles on my M-bar, and have done 100+ miles on my S-bar - the lower position lending itself to longer faster rides.

There is also the P-bars, I have not ridden.

I'm running 2" Big Apples on my 20" folder and I still find the ride too harsh.

What pressure are you using? I run mine at the min of 30 psi per sheldon brown (http://www.sheldonbrown.com/tires.html#pressure) and it's like riding on air...because it is riding on air :p .

The roads are pretty terrible in much of London and at this time of year it's often hard to see potholes.

I think the meter might be inaccurate in my pump as my tyres feel pretty hard at 30 psi. Whatever the PSI, I have them very soft.

I've never ridden a Brompton and I'm curious about a few things. I never hear anyone mention the rear suspension, never hear complaints about it being too this or that, or wanting to get rid of it, etc.. A lot of Downtube Mini owners seem to want to get rid of the rear suspension and substitute fat tyres. How does the Brompton suspension perform?

Looking at the design it appears it suits the upright leisure riding position better than a racing posture due to the narrow tyres and lack of front suspension. I'm running 2" Big Apples on my 20" folder and I still find the ride too harsh. How do Brompton owners get around this problem, particularly those who have the S-type model (what are the fattest tyres that can be fitted?)?.

To better understand the Brompton's unique rubber cone suspension is to examine one of it's predessesors's ones. The classic 1960s Mini Cooper shares this same system:

"....The Mini also had an unusual suspension system that used rubber cones instead of conventional springs in order to save space. This lead to a rather raw and bumpy ride - but this very rigidity, together with specially designed 10-inch diameter wheels pushed out to the corners of the car, gave the Mini its famous go-kart-like handling....."

from:

http://www.duttondirect.com/history/view/make:mini (http://www.duttondirect.com/history/view/make:mini)

For the fans of this classic car (like me), the Brompton offers this same sensation in it's little "Mini-Me" versions of the now very rare sight of these unique cars in Southern California. This was one of the strongest reasons why I purchased my own Brompton in the first place. I really miss the classic Minis my father and my Ex had.

........, and that there isn't exactly a huge amount of space to fit larger than standard tyres at the back unless you want to sacrifice mudguards (fenders).

Can you expand on that please? Isn't the tyre size (from rim bead to "depth" of tyre) limit imposed by the bracing strut across the rear triangle?

Yes - what I meant was if you wanted to try fatter tyres on the 349 rim - ie some nice pink nobbly ones off a little girl's bike :) then it might be too 'tall' to fit in triangle as the lower bracing in the chainstays could get in the way - at least if you tried this with fenders.

Brompton's suspension can be a bit disconcerting when you first try it out, but it quickly grows on you. I have had no problems with it riding here in NYC, and we do have some bumpy roads in here. My Brompton has the 'green' Brompton tires that I pump up hard, and until recently had the M type handlebars which I switched with a mountain bike riser bar which I think gives it the same stance as the S-type model. I am quite comfortable with this setup, my road bike rides harsher but then again it has thinner wheels.

I have to say, watching that Gadget Show video posted on another thread I'm really liking the style of the bike. If I were to buy one second-hand I could always sell at no loss if I didn't want to keep it. What should I be looking for with second-hand Bromptons; have there been any particular developments in recent years that make it worth getting one post-that year?

You're probably best off getting one made after 2003 - they changed the design to lengthen the wheelbase slightly, which makes it more like a normal bike. The stretch from the seat to the bars is the same (to within 5mm) on my Brompton as on my hybrid. I tried a Dahon Vitesse and kept hitting my knees on the bars, it felt like a kiddy bike.

http://www.brompton.co.uk/content.asp?p=189&l=1