Thanks for sharing, thats useful info. Hows the spring locking mechanism holding up? Does it look like it will need replacing or tightening in time?

The lock mechanism is holding up fine. It's a very simple design and it appears to be very robust. There will be no adjustments needed to keep it working as it should for a very long time. The only possible failure I can anticipate would be the fracture of the torsion spring, but I would expect that would be a very rare event which would only happen after many thousands of lock/unlock operations. I also think the lock would still operate in the event of spring failure, although vibration might cause the shaft to rotate to the unlock position with no spring pressure to hold it in place.

Any new bike deliveries since the recall on the front fork?

Thanks so much for posting this. It was a reall help. If I have any complaint with Helix, it is the lack of support/instructions for basic maintenance.

I just got mine. I ordered with a stated April delivery date. I was going to post a picture of the weld, but looks like I can't post pictures until I have ten posts. Shoot me a private message if you want pictures of the weld (or the rest of it). It looks exactly like the previously posted before/after pic to my amateur eyes.

Which model did you buy?

Standard

https://cimg4.ibsrv.net/gimg/bikefor...4a831e2ac8.jpg
https://cimg5.ibsrv.net/gimg/bikefor...cb423524ac.jpg
https://cimg6.ibsrv.net/gimg/bikefor...10f7c91e7b.jpg
https://cimg7.ibsrv.net/gimg/bikefor...224b376b47.jpg

This Donnelly MXP tire 32x507 is really a low pressure tire, only 1.7-3.1bar for a 32mm wide tire is very low especially for a tire which isn't tubeless.

Interesting. For the sake of "reasonable" comfort with this tire, what pressure do you suggest that helix owners run? (1.7bar seems awfully low to someone coming from skinny road bike tires.)

Custom Helix Tubelito tube? I would not have thought that the Helix company could obtain a custom order for an inner tube not likely to have a very large market in that size.

Custom dog walker Helix accessory? Nice!

Custom Dog? Very nice!

Bym, what is your impression of the Donnelly MXP + Tubolito combination for riding on paved roads/trails?

I've read so many mixed Tubelito reviews citing leaks encountered immediately on first use, and difficulties encountered getting Tubelito patches to hold. I wonder if those reviews can be attributed to "growing pains", and if the (perhaps newly minted) Helix branded Tubelitos are more reliable. Any insight?

I do not know for the Helix Tubolito but I bought two ETRTO406 Tubolito's for my Moulton.

These two were one after the other replaced for free by Tubolito due to leaks around the valve.

One of the replacement had a puncture that I could locate and I applied a special patch from Tubolito (Tubolito cannot be patched with classic butyl inner tube patches and glue). The patch didn't last very long, after one month or so, I had small leaks around the patch. I replaced it with a second new patch and the same problem occurred after a short time of use. My conclusion from this is the the very expensive Tubolito's cannot be repaired after a puncture.

The fourth, last Tubolito had a slow leak and I couldn't locate the place of the leakage (the Tubolito's cannot be inflated at high pressure without being mounted into a tire, the low pressure at which it is possible to inflate a Tubolito alone didn't allow me to locate the place of the leakage).

This was the end of my Tubolito experience, at about 30€ piece, I didn't wanted to invest more

For the Donnelly tires, because they are mounted with inner tube and not tubeless, I am afraid that at these very low pressure and because the tire is quite narrow, there will easily be puncture by pinching of the inner tube between the tire and the rim wall.

FWIW: Recognizing that their previous patches did not work well at all, Tubolito fairly recently released a new patch kit which contains a separate tube of glue.

Thanks for the information.

But this doesn't solve the problem of finding the puncture if its a small one that generate a slow leak.

Also, as you can read in my post, at lest two of my four tubolito's I had problems at the welding of the valve on the inner tube itself.

Actually of the four, I had only one real identified puncture.

I appreciate your reminder about valve tube connection leaks and about slow leaks. I'd read about these issues elsewhere but had forgotten. :(

Slow leaks can occur within the valve, which can be tricky to locate unless you place the wheel in water before touching the valve.

Slow leaks occurred at the place where the valve is sealed on the tube itself.

The way it is done is that there is a big round hole in the inner tube and the valve has a round piece of the same material as the inner tube at its foot which is glued or soldered to the inner tube.

The leak appear at this soldering.

Note that due to the very low pressure allowed in the inner tube when not mounted into a tire, its very difficult to locate any slow leak because at such a low pressure the leak is very very small, much smaller than what it is at the normal tire pressure of several bar.

A leak occurring perhaps more frequently when the o-ring is positioned incorrectly outside the rim rather than inside where it would somewhat isolate the "weld" from the metal at the rim's valve home.

The round hole for the valve is bigger than this O-ring, its not the weld that touch the valve hole in the rim.

The material used for the inner tube isn't really elastic like Butyl for the classic inner tubes.

The deformations of the Tubolito due to pressure become easily permanent (for instance, the small cups of the rim tape cause small permanent bumps on the Tubolito, its also he reason why the Tubolito cannot be inflated at pressure above the ambient pressure without tire: it behaves like a chewing-gum). I guess that something similar could happen at the rim valve hole and the O-ring is there to prevent that ?

But Tubelito represents advancing technology... and that must always be seen as being good... isn't it?

truthfully, I am somewhat concerned about relying onTubelito tubes for the bike I've ordered, but might as well try them.

1. Is the tuberous tube still leaking?
Answer Not leaking yet, keeping the wind for a long time

2. How good is Donnelly MXP on a variety of surfaces (concrete/asphalt/trails and dirt roads)?
Answer I am satisfied with off-road and on-road riding

3 No comments on parts if your bike is an ultralight model?
Answer I personally upgraded most of the parts to titanium.

Actually, the Tubolito aren't bad. They have advantages: much smaller to carry them, much less weight.

But some claims aren't true: they aren't puncture proof as claimed.

And there were problems (hopefully some problems are fixed:
- reliability (leaks at the valve/inner tube welding, hopefully solved. They must solve it to become a sustainable business, in my case, they sold 2 Tubolito's and had to replace both of them due to welding issues, what cost them a lot of money, replacement innertubes + shipment cost + handling costs).
- puncture repair patches weren't reliable in the long term (hopefully solved).
- identifying were is the leakage for slow leaks. I think this cannot be solved because finding slow leaks require inflating the innertube at high pression and the material used doesn't allow to inflate the Tubolito at high pressure without a tire.

Note that Schwalbe now offer a new innertube that seems similar to Tubolito (haven't tried them because it doesn't exist in the size I need).

The puncture repair issue is important because the Tubolito remain very expensive, replacing a classic inner tube costing 4-5€ at each puncture isn't a major issue, replacing a Tubolito costing 25-30€ is more a problem.

I have spotted this one some years ago and I think the material is definitely the attractive part.

Riser bar and/or adjustable stem
 

For those who have a Helix folding bike, what is greatest amount that you've been able to raise its handlebar by means of a riser bar or adjustable stem without changing cables?