CEBEP

Just received a reply from Efneo. 1st gear is direct drive with no efficiency loss. I believe my 36t cog should be enough for hills which I will test first of course. If not and I’ll need even lower then 38t will make sense. Then most likely the second gear will be used most of the time which will be less efficient. But if my 52t will do fine on hills do you think the 52t first gear will make sense as it’s a direct drive with no efficiency loss? Apparently Efneo will accept any 130BCD chainring. Then second gear can be used (74t equivalent) if 11t smallest cog will not be enough.

They also advised that it can achieve chainline from 42mm to 46mm which I assume is within chain line distance of Birdy?

I will obviously start considering this if after extensive use the 11t smallest cog will not be enough.

glye

Thudbusters are nice. Suspension stems exist also. Another option for a comfortable ride on the Helix could be to rebuild the wheels in 406 / 20" size. Then you have tons of tires to choose from, and can likely go to bigger tyre widths like 50 mm or more, only limited by the frame and fork (perhaps Helix can estimate the limits). But if you want mudguards you will likely have to use the original ones since they are specially made for this bike.

Jipe

No, its the opposite, the Schlumpf exists since much longer than Efneo and is sold by many bicycle shops.

Now, personally, I wouldn't use any of both on the Birdy, the 9-32 or 9-34 cassette solution is much better, it has a better efficiency and weight less (FYI., I have a Schlumpf High Speed Drive on another bike).

For Helix, there is also a big question-mark about what will happen now that they announced that they won't be able to provide the many remaining Kickstarter and pre-ordered bikes and if they have to refund many backers and pre-orders that do not want to add money to buy an Helix at the full price

glye

If 2x up front is enough for you, then 52t physical ring will work, and you get the direct drive efficiency as you say. The 3rd speed would not be very usable in that case. You could of course use any size chainring between 52t and 38t. The direct drive efficiency is most useful when going up hill, when you need all the help you can get. On the flats and especially down hill it matters less - unless you are competing.

Chainline - I'm not sure. Sheldon Brown says the common standards are road double 43.5 mm, road triple 45, and MTB triple 47.5 - 50. The road standards are likely assuming 130 mm OLD hubs, while the Birdy uses the MTB standard (and now also road?) 135 mm hub spacing. That could mean 47.5 is the ideal, and the Efneo 46 mm is a little narrow. I'm not sure though. Efneo should be able to advise.
https://sheldonbrown.com/chainline-multi.html

Did you tell them you have a Birdy? I see it is not listed as compatible on https://www.efneo.com/gearbox/gtro-for-folding/
The Efneo has a reaction arm that must rest against the frame. It could maybe interfere with the seat tube when folding the Birdy. Efneo should know.

CEBEP

glye thanks for advise about the arm resting on frame. Yes, I did inform them about model of bicycle but they didn’t say anything certain about the chainline, only range.
I don’t think it will be safe for me to experiment as I have almost no knowledge in this area and no one implemented it successfully.

glye

Beware that both Schlumpf and Hammerschmidt require you to modify your Birdy frame: https://www.biketinker.com/2010/bike...-double-fixed/
For Efneo and Patterson this is not required (but I don't know if they will fit the Birdy).

Jipe

The ATS Sclumpf speed drive for the Brompton doesn't require a chamfer of the bottom bracket box. I also don't know if it will fit the Birdy.

glye

Nice to have the ATS option! Schlumpf is well regarded quality. Efneo is less common, but it has been around a while by now. It got a very good review in road.cc in 2017.
https://road.cc/content/review/22779...-front-gearbox

I am considering it for another bike, but there the lack of any option between 28t and 38t is a bit of a problem.

CEBEP

I checked some pictures and it looks like the R&M Birdy Touring once folded rear on the rear rack wheels from one side and the rear fender/mudguard from the other. Is it normal that it rear on the rear fender when put on the floor?

glye

You mean "rest on the rear fender"? Yes, that's normal. And this is why the stay for the rear fender is very thick, and there is a pad on the top of the stay/fender connection to hold the weight and avoid scratching the fender.

The front fender may also touch the ground, and it has a similar pad. But it will not take as much weight, so the front fender stays are normal thickness.

jackyharuhiko

Mine didn’t come with fenders but I installed a set of “easy wheels” to support the bike and for rolling when it’s folded.



(p.s. the easy wheels seller sent me the wrong color. I ordered black…. They are sending me the correct one.)

Jipe

Yes, the rear fender stay is very thick. There are two reasons for that.

First as Glye says, because the folded bike rest on it.

But the stay is also used to hold the bottom of the rear pannier with the hook of the rear pannier.

The folding rear rack is a very clever design and there are few folding bikes that allow to use big rear pannier without hitting them with the heels while pedaling..

On my Ti Birdy, I have Ridea easy wheels similar to he one of jackyharuhiko and a Ridea rear mudguard (unfortunately, the Ti Birdy doesn't accept the folding rear rack). The Ridea rear mudguard is crap, its a piece of thin aluminum that break after a couple of months of use, I had to reinforce it with a titanium plate.

CEBEP

Jipe I heard that since the rear rack is suspended, the rear panniers tear off and scratch fender connection as rear suspension constantly moves.

glye

I like the big size of those! I have the folding rack, which is good but the wheels are very small. They can catch on tiny steps/cracks, which might damage the rack. I guess it would be easy enough to find something bigger, I just need to measure for fit.

Jipe

Indeed, the rear pannier hook induce some wear on the rear mudguard stays but they are very strong, so its purely cosmetics (a part is now naked aluminum instead of black and polished).

Yes, the original easy wheels are small and thick, they prevent to mount some rear pannier. Their axle is an M6 bold like for the Brompton.

I mounted bigger 60mm, thinner third party easy wheels for Brompton bought on Amazon.de they allow to use Vaude Road Master Roll-it Waxed lightweight big rear pannier.

CEBEP

€22? These cost $4.82 a pair on Aliexpress, delivery to Turkey is $5.09

Jipe

Yes, and you have to wait for months for the delivery while with Amazon they are delivered the next day !

You must also be careful because there are several models very similar but not identical.

CEBEP

It’s simply not true. You’re probably mixing things up with Aliexpress few years ago. Nowadays they deliver within a 7-10 days to Turkey. Should be about the same delivery time to EU if they send it from China. But most sellers already have warehouses in EU with options to ship from there. Should be even faster.

Up until now I don’t remember receiving anything different from Aliexpress but what I’ve ordered. If it’s Litepro it would be Litepro which you will receive. And your amazon listing reads exactly that.

Of course nobody can stop you to pay x4 times the price if you want.

CEBEP

Assuming Birdy can be converted to Rohloff hub after purchase, can the Rohloff hub be ordered separately as a kit for Birdy? If yes in which exactly configuration and where it can be ordered?

Jipe

You can easily build a Rohloff wheel or have it built by several online shops in Germany.

But to mount a Rohloff on a Birdy as done on a factory built Birdy Rohloff, R&M and Pacific Cycles use some specific parts that can only be ordered from them.

About the easy wheels, the link you gave says: estimated delivery to Belgium Aug 1st. Its one month but my experience is that the estimation is not reliable, the actual delivery time is unpredictable because orders of several customers are grouped for shipment and then the shipment is awaiting for an affordable shipment opportunity.

The problem of long delivery of items coming from China (not only Aliexpress) is a consequence of covid and the huge increase of shipment costs.

CEBEP

Just arrived home and unpacked the bike to give it a quick test ride. Everything seems normal and I found Supernova light to be surprisingly good for street riding. Will not be replacing it. I removed low rider from the front fork which could probably block the light so light is unobstructed. Definitely not as good as Edelux II but pretty good for already preinstalled light.

CEBEP

Could anybody suggest the size/length of the bolt keeping rear rack wheel in place? It was bend probably on the airplane and I need to order replacement.

2_i 

To replace the bolt you need to take it out. Can you do it? Do you need to straighten it out, at least partially, before progressing? By eye it looks like M6.

CEBEP

yes, I can take it out. It’s bent at the connection point to the rack, so it unscrews just fine. After removing not sure if I can straighten it without damaging the thread.

glye

Since you have already taken it out, that's easy. Measure the length (minus the head) and the diameter (outer part of the thread, i.e. the smallest hole the bolt will fit through) rounded up to whole millimeters. If that diameter is 6 mm, it's an M6 bolt. 5 mm = M5. Kindly post the numbers here, I'm also interested.

If any part of the bolt is non-threaded, that's also worth measuring.