jdogg111

question for the folding bike afficianos here.sub 20 lb road bikes are everywhere, some folks even have sub 15 lb models, my question is why aren't there sub 20 lb folders on the market, besides the ones you have to drop 3 or 4 Gs on. Zizzos liberate, for a decent price is the lightest I've seen at 23 lbs.maybe I'm just not looking hard enough, but I'd be interested to know the reason be it parts, build, strength, etc.thanks.

linberl

Bike Friday will make folders under 20lbs, no problem. You'll pay for the lighter weight at a premium, if they use triple butted cromo and titanium in the build. But you can get their Pocket Rocket Pro drop bar folder very light. For an upright, you can get the pakiT down to 15lbs. Lighter weight = more money.

jfouellette

You can also buy a frame and build it yourself with light weight components.

base2 

My guess is that for how folders get used weight just isn't that big of a design consideration so long as the final weight isn't too egregious to lift onto the bus.

Think about how much weight mattered for that 1-2mile ride to the bus stop & that mile from the bus stop to your destination. What is that? Maybe 2 sub 10 minute rides, twice per day?

It's not like many folders are designed to be high performance, drop bar, aero racing machines in the first place. The upright posture is moreorless a necessary design requirement derived from the absence of a top tube. That pretty much precludes high performance high speed racing as an intended use case.

(Obviously, there is a such thing as drop bar folders. But, you won't be seeing them in your local crit.)

tcs

What's the build spec on that?

tcs

LOL! Light, cheap, strong: pick two!

linberl

Bike Friday's advanced bike builder is down right now but if you go and look up the pakit in advanced view, you will see all the configuraitons. Start at the high end price to see the lightest builds.

CliffordK

I've seen carbon fiber folding bike frames for sale from time to time.

T1000 Carbon Fiber Folding Bike Disc Brake Frame/fork 20inch BSA Bottom Bracket $669

20inch T1000 Carbon Folding Bike Frame Disc Brake Foldable Bike Carbon Frame BSA $947



With some hunting, one can find lightweight carbon wheels and rims. And everything else to get the bike built up.

Carbon Fiber likely does well with the monocoque frame design, although the hinge would be a challenge.

Pinigis 

Be careful when comparing manufacturers' weight claims. Some try to fool with small print that says the weight "does not include pedals or saddle", and some just outright lie.

hihi2u2

Best route, alot of time, folders comes with heavy and outdated components by default.

This guy loss 3Kg on a Brompton. Bringing the weight to 8.9kg (which is sub 20lb). https://m.youtube.com/watch?v=rz24HOdUctA&t=625s

pinholecam

Carbon folding bikes... as far as the ones I have seen, the joint is not only still metal, but it also has to start early before the actual joint, so there is substantial chunk of metal, meaning that the weight saved isn't that fantastic.

Relatively mid priced with room to become light are the Tyrell FX and Dahon Dash series of mini-velos.

The Bike Friday Pocket Rocket Super Pro is triple butted steel w/ Ti seatpost. I got mine down to 8.5kg (with pedals). If can go lower with a carbon fork and seatpost.
However, it is a very expensive option.

My custom Ti breakaway 700c bike is 7.8kg (includes pedals ), so customizing one for 20" wheels might get it to be lighter.

Fentuz

to answer the OP question (answered in other subjects), folders require frame strengthening due to the hinge mechanisms, the more hinges, arguably the heavier. So the frameset is limiting. Now, yes, there are lighter weight frame but they are low volume so expensive and expensive = less sales so vicious circle.
Then the folders are supposed to be "economical"; unlike race bike or high end MTB, there are less people willing to spend loads of cash on folder so, the manufacturer do not assembled them which top of the range groupset (few Sram Red or Shimano Duraace etc.)
Then, the manufacturer have to mix and match things to give a 20" similar range/gearinch to a 27.5" or 29".

So, if you considered the budget gravel/road bike, aluminium frame fitted with similar groupset, the weight or 20" is pretty similar 10-12kg.

If OP wants a 8-9kg bike, OP will have to start from a lighter frame and then fit premium groupset, descent wheels like Dahon/Tern Kinetix pro (Chinese carbon don't seem to be super light) and fit light weight seatpost and faster basically, weight winny game and this is very custom and pricey.

I my experience, the sweet spot for [weight vs price vs part availability vs low maintenance] is 9.5 to 10.5kg. It is easily achievable when starting from a 12-13kg std commuter bike.