Jipe

For the behavior of a bike on rough surfaces and bad roads (cobbles, potholes...), what is important is the relative overall wheel diameter difference, some values:
- Road bike 28x622 about 678mm
- X11 28x451 about 507mm, 25% smaller than a road bike wheel.
- 20' with wide tires 50x406 about 506mm, same as X11.
- 20" with ultra low rolling resistance Greenspeed Scorcher 40x406 about 486mm, only 4% smaller than X11.
- Birdy R20 with 32x406 about 470mm only 7% smaller than X11.
- Birdy with wide tires 50x355 about 455mm 10% smaller than X11.
- T-line with ultra low rolling resistance Greenspeed Scorcher 40x349 about 429mm 15% smaller than X11.
- Brompton with standard tires 35x349 about 419mm 17% smaller than X11.

Conclusion: the relative wheel diameter difference between the X11 and a road bike is significantly bigger (47%) than the relative wheel diameter difference between the X11 and the standard Brompton wheel diameter. With a wheel diameter 25% smaller, the X11 wheels won't behave like a road bike wheels.

There is no wheel diameter difference between the X11 and an ETRTO406 with 50mm wide tires.

The wheel diameter difference between the X11 and the Birdy either in ETRTO355 with wide tire or ETRTO406 with max width possible on the Birdy is pretty small, 10% or less.

I am pretty sure than any fast ETRTO406 bike (Tyrell, Moulton...) with race ultra low rolling resistance tires (like the Greenspeed Scorcher), even if the overall diameter is 4% smaller, will be faster than the X11 with its factory mounted Schwalbe One 28x451 which are road training tires, no race tires.

Sentinel1

No bike is actually FAST Jipe. The rider is the motor. A seasoned Pro on a cheap £200 folder would beat any of us on any supposed fast bike. What a quality bike has over a cheap and cheerful bike is EFFICIENCY. Meaning less watts have to be wasted to both get it up to speed and keep it there. To that effect in the folding bike world. The Tern X RANGE are as fast as they get.

Where the X11 is superior to its smaller brothers. Is road handling. And a more stable smoother ride. Especially downhill. I could go just as fast on the X10 and X18 as the X11. But I didn't feel as stable shooting down hill at 35mph. On the X11 nothing phases you. Uphill downhill it is the KING of folders period. Might be MATCHED but never surpassed. It' is perfection personified.

davidhunternyc

Yes, I only rode the T-Line for a 1/2 hour and I definitely felt every bump in the road with a vengeance. Going over cobbles I thought the skinny wheel could slip in between and cause me to fall. I was weary of pot holes and cracks. I normally ride a kick scooter and I worry about this too but it's odd that I felt the same on a $6K bike. Your comparison between the T-Line and Verge X11 corresponds to my thoughts. I'm also considering a Helix Ultralight.

Sentinel1

i hear you. Don't know the Helix. I will have to do some homework. But the X11 is a helluva bike. You feel like you own the road on that bike. It's so efficient sometimes I think I'm on an electric bike. It can coast at speed for over A 100 metres in the right conditions. And it's incredible on hills. Which is the number one reason I bought it.

davidhunternyc

I need help from all you bike experts again. As I've said, my shortlist includes: 1) Brompton T-Line 2) Tern Verge X11 3) Helix Ultralight

I did test ride and Brompton T-Line and loved it. I still have yet to test ride a Helix as they are more difficult to come by. Today, however, I tested a customized Tern Verge X11. In a word, "WOW!" I've never ridden a bike so fast. I've also never ridden a bike with an electronic shifter. Welcome to the 21st century.

Buying a bike is a trepidatious decision. I know nothing about bikes and I'm here to learn.

Like I said, I checked out a used Tern Verge X11. Honestly, I don't care that it's used. I think Terns are kind of ugly anyway. They are engineering machines to do one thing... go fast! The one I rode today blew my mind. It seemed twice as fast as the Brompton T-Line but here's why. It's fully customized. You guys know this stuff. I don't but the parts on this bike are expensive. It has 12 speeds and uses an electronic shifter too which blew my mind. Here's the rundown on this bike:

We put the bike on a scale and it weighs 21 pounds.

Tern Verge X11 - Upgraded Carbon Wheels with Dt180 Hubs that fit a 12 Speed SRAM Casette $1000 Sram Force Axs Groupset 12 Speed $1100 SRAM Red Crankset With Ceramic Speed Bottom Bracket $950 SRAM Xtr brakes $550 Carbon Bar And Seatpost $300 S-Works Saddle Carbon $325.

Most of this stuff is a foreign language to me. Does all of it make this bike better than a stock Tern Verge X11? For instance I asked what the "red" things were near the crank, like the BSA Shimano Red Coated "something," retailing for $480. Of all the upgrades, can you all break it down and tell me what's good or not?

The bike was a little beaten up, as can be expected with a used folding bike. I would give the condition a 7 out of 10, but what do I know. I checked the hinge and it folded and unfolded well. Because the forks were upgraded there isn't a magnet on the fork to connect to the magnet on the rear triangle. The rear magnet is there but it's useless. I wonder if it can be removed. It does fold, of course, but it doesn't stay folded without a strap. It swings open and there's no way to wheel it around.

As I've said, it's ugly. I don't like the looks at all but it's a speed demon. The fold is awful. Because it's used, is there something that's broken or likely to break soon? I don't know. With 2 out of 3 bikes tested, I'm really excited to try out the Helix. I'm thinking that the Helix might be a great middle ground between the T-Line and this custom X11 in terms of speed and foldability. The parts on the Helix can be upgraded too but that's another story.

Duragrouch

Uh... double-posting essentially the same thing, especially with photos, can annoy the forum moderators. It's repetitively redundant (itself a repetitively redundant statement... small joke). Not so much if you are answering the same question on different threads for different people, that's being helpful. Just asking the same question in multiple places, especially within one subgroup like Folding Bikes.

I hope you can ride the Helix soon to help you decide. Deep research is not at all overdoing it, not for a purchase of this cost.

Sentinel1

That X11 has been messed with too much that's why it's not as goodlooking as it should be. This is what A sexy X11 looks like. You don't mess with perfection. Whoever owns that X11 messed with the aesthetic beauty of the bike as soon as they took the Kinetix pro X wheelset off. And the Sram X sync chain ring. And sram crankset. Plus the X11 looks better in Silver.

The Tern Verge X11. One folder to rule them ALL..

Duragrouch

Not saying this just to be disagreable, but I like the stealth dark gray, understated, in fact it's the first X11/Mu style that I've found attractive. Just a touch of red at the BB, like Brompton has done on one of their designer special editions, I like that too. Doesn't say "bling" to me, just a nice accent, like a great tie on an otherwise dark suit.

Fentuz

Once again, more rubbish from sentinel….


this black x11 has been properly modified by a roady. While some parts may be older than others, it is coherent and clean.
no crap all over the handlebar for example.

so, it is fitted with SRam Red wireless with is top of the range roady stuff (like dura-ace di2). The crankset is the older red 130bcd with was the lightest one on the market (very thought after by hill climber).
the ceramic speed BB is again a roady mod to save some watts and weight.
the shimano discs are known to be the lightest on the market too.
light weight carbon wheel for added stiffness and less weight
dt swiss hubs which are amongst the best in term of quality, weight and smoothness (again, less watt waste)
light weight saddle.

Basically this is a very well upgraded bike in the view to make faster and lighter regardless cost. Now, was the x11 the best donor bike, no as all the x11 specific components were removed and upgraded. A P9 would have been a better starting point as cheaper to acquire.
if the mods were done over a period of time as a continuous improvement project, thats different.


note1: i have been looking into doing exactly the same type of build with a dahon MU sl but ride brake orientated obviously.

note2: i noticed that @Sentinel1 ride on a litepro seatpost and yet post the following:
interesting that a rider that weighs between 85 and 92kg and do things the right way ride on a seatpost limited to 80kg max load per manufacturer instructions…

Sentinel1

That seat post has alot more tolerance than 176lbs (80KG). They pull in their safety measures well under the actual tensile strength of the product. Been riding on that seat post for over 3 years. No problems. Plus I'm 5 8". So less of the seat post is exposed. A 6 2" rider would be a different story maybe.

Jipe

The Verge is the model that had the biggest problem of broken frames, it was not some isolated bad welded frames, the recall cover bikes produced during more than 4 year (January 2012 to April 2016), the max weight limit on the seatpost is not only due to seatpost limitation but also to the frame seat tube, overloading it also overload the frame.

Overloading a frame known being subject to cracking is a non sense!

Sentinel1

The Tern verges I own and have owned. All take up to 105--110kg of weight. The heaviest Ive ever been is 94kg. Which is 11kg (22lbs) withing that limit. And again. After 11 years riding the X10 and 7 years riding the X11. If there was anything wrong with the frames. I think it would have shown itself by now don't you? Just saying.

Plus I always inspect ANY bike I'm intending to ride for damage. I don't just jump on a bike and take off. I can assure you that in the cases where some frames did break. It just didn't happen. It was damage that had built up over time and was unnoticed by the owner. Thats all I have to say on this matter. And will not address it again.

jdogg111

so, can tires actually make that much of a difference in energy needed to achieve same mph . For instance, will I have to use more exertion with a set of generic 20 x 1.95 tires than a set of these big apple I read so much about, same size. Does air pressure factor in? Or is this more of a factor for elite riding as compared to say, casual greenway strolls. Side note, what are the best lightweight 20 inch tires, in your opinion? Ample size of 20 x 1.5 or wider. I have a set of panaracer minit 20 x 1.25 that I honestly thought would roll better than they did. Better than the factory tires but still not worth the extra money they cost. That's why I ask if a certain tire is just that much better to be like, wow. These roll so easily. Even on my full size bikes, I've never really noticed a big difference, but I've also never ran a set of premium tires either, as my rides are more for exercise and enjoyment than anything else and I couldn't justify 50 bucks a tire. On the folder tho I'd be willing to spend a bit more for a smoother more enjoyable ride. Bike in question isn't a fancy high dollar folder, just a zizzo liberte. Thanks for any input on this, interesting subject.

Sentinel1

You could give VEE speedsters 20X1.5 a try. I've found them to be an excellent tyre for a mix of speed all weather grip. And even light off road riding. They wear well too. They are produced for BMX bikes. But are an excellent alround tyre. And not too expensive. I paid 38 British pounds for my last set.

Jipe

If you mean ETRTO406 for 20", the best trade off currently are the Continental Contact Urban, there are 3 width available, 32x406, 42x406 and 50x406:
- low rolling resistance.
- pretty high puncture resistance.
- long lasting, wear slow.
- low weight.
- cheap.

Their only weak point is their relatively thin, supple side wall but this contribute to their low rolling resistance (at normal to high temperature, as low as the race, expensive and fragile Schwalbe Pro-one).

Fentuz

yes, after 5000 k, mine were not worn out however the side wall were very cracked. May be because i run them @50 psi on 32c.
i got the same with cross king 50-584 when I run them @ 20 psi or below

Ron Damon

The discontinued Schwalbe Marathon Supreme 42-406

Duragrouch

It depends on the nature of the riding surface. Very smooth paving, slender, higher pressure tires with inherently low flex and rolling resistance, will be more efficient. With small irregularities in the surface, larger, lower pressure tires actually have less rolling resistance, because their lower pressure allows them to more easily "absorb" those small irregularities (let's say, a small pebble), whereas a higher pressure tire has to raise the tire as a whole (and possibly also part of the bike and rider, and thus raise more mass) to overcome the obstacle. I cannot recall where I read this, it may have been Bicycle Quarterly, they've done some good tire tests, they had a whole article questioning whether larger tires were slower, and in many cases, they were not. Aerodynamic drag, both frontal area, and especially matching tire width with rim width for a good aero match on the sides, rotating inertia due to tire weight, are all factors as well. The above is just based on rolling resistance itself.

john m flores 

FYI, I just managed to mount a set of 2.4" Odyssey Path Pro tires on my Liberté. They just squeeze between the chain stays, although you have to deflate them when installing or removing the wheel from the bike.

I'm still experimenting with tire pressures but initial impressions are that they absorb small bumps and ripples better than stock 1.75" tires.

The new setup doesn't seem any harder or easier to pedal than the old setup, but it's good to know that I can try other, larger tires on the Zizzo, like the Schwalble Marathon 365 or the Super Moto X, both of which roll better than the Odyssey Path Pros.

Jipe

Continental has excellent fast new tires with very high puncture protection that exists in 50x406-2.00x20, 55x406-2.2x20 and 62x406-2.5x20 called eContact Plus they are much better than the Super Moto X.

Schwalbe has the Big Apple, Big Ben and Big Ben Plus but max width is 55x406-2.2x20. I also prefer the Big Ben Plus than the relatively fragile Super Moto X.

roguewave

Still looking for the right folder, I’d own an X11 “IF” I could find one to buy in my area (TX).

Got up this morning and thought, heck with it, I’m gonna go buy one….nope, none around.

Sentinel1

Seek out a second hand DAHON MU SL. It's even greater than the X11. I've been in ecstacy riding mine for the last two weeks. Fit it out with VEE SPEEDSTER white wall 1.5 tires. And you will have the coolest looking folder on the planet. And man it owns any hill. THE NEW KING OF FOLDERS.

roguewave

Ordered a Brompton last year from REI, I returned it because I was not liking the way it locked together…it was cheesey.

i just checked out the new line of Brompton….

T Line Explore - 12 Speed, $5850 bucks

john m flores 

What do you want to do with a folder? Multi-modal commuting? Airline travel? Local errands? Fitness riding?

roguewave

General Travel and boat travel …