stevegor

Would a black leather jacket, jeans and Doc Martins do?

BTW, my Kawasaki ZR7 is quickly than any of your folders

niggle

and the Kawasaki has only got 17" wheels, so I rest the small wheel case

stevegor

pibach

I don't think these are the reasons. In fact the Marathon Racers are among fastest tires - you can pump them pretty hard. Also more gears have almost no impact, see single speed racers. You can ride the Mu P8 in quite streamlined position. Its a bit Graham O'Brien like ;-)

yes, the single piece main tube design of the swift might be stiffer. And if you have a very strong stroke, the flex of the Mu frame can absorb some energy. But this won't be much.
BTW, the last Smithfield Nocturne has been won by a Dahon MU SL rider. Second Airnimal. Then Swift. These bikes are all three fast. The Mu SL is a tiny bit faster than my MTB with slicks (don't have a full size racing bike to compare). But I feel quite a difference in speed between my Mu SL and my Mu XL Sport. I attribute it mostly to the gear hub and the wheelset, plus the stiffer handlepost on the Mu Sl (non telescoping). Also the pedals are important. Lastly the Pantour hub allows for better front traction and thus slightly faster cornering.

StuAff

Think you meant Graham Obree Peter Good points though...

noteon 

How'd you get 20 speeds on a Swift? I've got 24 with a Sram Dual Drive, but I can't figure out a 20-speed.

niggle

As Sheldon Brown pointed out, the issue of frame flex 'absorbing' energy is a red herring: the energy does not get absorbed, it is fed back into the drive system as the flexed bit straightens out again (mechanical memory and all that, otherwise the frame part concerned would become permanently bent).

niggle

10 speed block with two chain rings? Or Schlumpf drive? My Pacific Reach has gone from stock 8 speed to 16 speed by adding a second chain ring etc.

Kaito

53/39 rings on the front & 12-25 10spd cassette on the rear. Works great!
I was really wanting a dual drive for the simplicity, but the double ringed front was the easier, lighter route. Gear inch range isn't "huge", but the gearing/cadence for riding the in the sweet-spot is great!
Tuned the front derailer once, and no chain jump issues since.

noteon 

Aha--I forgot they can have derailleurs in the front now.

Kaito

Yup, as an option.
The FD mount even has a pulley/wire to change the cable-pull from top, to bottom, since the cable can't be run from underneath the BB on the Swift.

somersetflyer

Its interesting that you mention a Moulton, most of these rides are with a friend who has just recently purchased a moulton, he is certainly quicker uphill and also has the edge downhill, I think the slightly larger wheels and better suspension my help but on the flat we are evenly matched, Fitness is a contributory factor also keep swapping from a recumbent may not help.

somersetflyer

I have replaced the stock tyres with Marathon Plus, I think that there is a slight trade off on speed, but so far no puntures

somersetflyer

I will need to check the chainring, it was the standard that come with the bike, I am still undecided whether the Rolhoff is as good as people make it out to be, yes there is a very good range of gears, but I cannot help but feel that there is greater resistance in the 1-7 gears, maybe after a few more miles on it, it will loosen up

ShinyBiker

Still waiting on the answer from the OP on whether he has problems going uphill or downhill...

Downhillwuss

Unless conditions are exactly the same on exactly the same route, surely this 'faster' business is all a bit of an illusion?

Yesterday I cycled to work 30 seconds faster than today. Same bike though... 'Feels faster' is probably as accurate as it gets.

msincredible

IMO the biggest disadvantage of small wheels is clearance when riding off-road.

JCFlack

"Faster" can be objectively measured but you're right that if you are comparing average speeds, you have to run the same route under the same conditions, only varying one factor at a time. The varying factor might be the bike, the rider, the time of day ... whatever you want to compare. You probably have to run each test several times to account for variables you couldn't control. Like, why were you 30 seconds faster? Maybe on the slower run, you had to slow for a pedestrian who wasn't there the second time. Or maybe you were tired. Or maybe 30 seconds is such a short time that it is just random. That's why statisticians have methodologies for figuring out if a difference of 30 seconds is significant.

itsajustme

People talk about frame flex absorbing energy on folders, but I wonder, does the handlebar or seatube really intercept any useful forces? You don't pedal with your butt or very efficiently with your arms, so why would anything need to be stiff except the bottom bracket? And wouldn't the bottom bracket be stiffer on a folder due to the lower top tube?

Just a thought.

Bull****. Suppose you want to put a heavy package up on a shelf, except you have to keep lifting because the shelf keeps sagging because it's too flexible. Is the energy fed back into the "drive system"? Nope.

Another word for "memory" is hysteresis and the reason it's associated with losses is because unless your power source is in perfect sync with the memory delay your own force comes back to fight you, which increases the losses inside the source as it has to work harder to achieve the same output.

Think about it. It's like rowing a boat with a friend, except he's pushing when you're pulling. It's not a red herring, Sheldon Brown just prematurely declared aok after he missed the "leak".

pibach

When climbing or accelerating I go out-of-saddle. The handlepost/bar flex becomes an issue.

Furthermore my Dahon has the central hinge. Don't know how well it transmits torsional forces, but a slight loss might be attributed to it (but I would not expect this to be more than 1%).

itsajustme

Yeah, but even out-of-saddle what percentage of total force is really coming from your arms? Or, to put it in another way, in the worst case scenario it can't be worse than riding in saddle, which some claim is more efficient anyway.

Moreover, I would not expect loses due to flexure of the central hinge to be more than 0.01% because I just can't see that part bearing/transmitting more than 1% of the useful forces. There's a video online somewhere of man riding a bicycle whose front and back halves are connected by springs instead of tubes and, except for the difficultly of controlling a bike with a changing wheelbase, he seems to move along just fine.

Of course, it also depends on technique. For example, if you ride pushing down on both pedals simultaneously you'll be lacking efficiency on any bike without rotor cranks.

pibach

I am testing my bike for a single speed conversion. And then you get into situations where arms contribute significantly. Periodically going out-of-saddle - that's what single speed efficiency is about. Stiff handlepost is a requirement.

niggle

I don't get how this analogy helps your argument at all: the shelf sags under the package's weight, then what? You have to keep lifting it? For what reason? Because you want the shelf to stay level? If you are lifting it the shelf becomes irrelevant as what we have is you holding up a heavy package, but the shelf returns to its original shape due to mechanical memory (unless it is permanently deformed) and as it does so it moves upwards, in the same direction as you originally applied the lifting force....

Thinking about it and I do not see that the energy changes direction as you describe: if you push hard on the pedal frame flex may allow the rear wheel to move closer to the bottom bracket, slightly. Then the mechanical memory of the frame straightens out again, pushing the rear wheel back, which pushes the bike forwards. Ok not fed back through the drive system exactly (my bu115hit not Sheldon's), but definitely not pushing against the direction of travel, so no, I do not agree with you and Sheldon remains a god