Jipe

The hub dynamo in the test are hub dynamo for big wheels that rotate slower than the small wheels of the Birdy (and most folding bikes).

The Shutter Precision dynamo of the Birdy disc is a special type of SD-8, the results of the tests in the link aren't valid for small wheels hub dynamo that have other magnets. Its the only commercially available hub dynamo compatible with the Birdy disc since the SON XS for Birdy disc was discontinued (its actually the same model that was mounted on the Brompton in non disc version, now replaced by the smaller SON XS New).



On my Ti Birdy, I mounted a Velogical rim dynamo on the front wheel. It weight less than any hub dynamo but the power output vs. rotational speed characteristics is very different from a hub dynamo (less power at low speed, up to much more at very high speed).

CEBEP

My setup on Brompton is SON Delix hub I bought as built wheel, SON Edelux II and SON rear light. Total cost was very higher, but I went for the most reliable option which also provides probably best in class optics (Edelux II reflector is designed by B+M), bullet proof construction of everything and least resistance when lights are off. According to my research it’s the best you can get for Brompton.

The interesting thing about Birdy is that R&M paired hub/lights themselves, so we can be sure lights will work with best performance. Another thing to consider is location of light. I’m not sure if Edelux II will fit seamlessly and installing B+M light only to have it fail after a year is something my heart will not take. If Supernova light would’ve had light sensor and automatic switch it would be even better.

Even if the SON hub would’ve still available I’m not sure if it’s logical investment considering that bike already comes with hub, front/rear lights. Still, I wouldn’t definitely recommend SON hub and lights as in my opinion they have best performance and quality in the industry. Worthwhile investment assuming you’d like to pay once.

CEBEP

I emailed Schmidt SON yesterday asking if they ever made black dynamo for Birdy and just received reply that it was only SON klasik polished model which is still available on SJS website. There is no way I’m ever going to install polished dynamo hub on my black Birdy Touring

Jipe

Unless you replaced the fork to have a 100mm OLD, you cannot mount a SON Delux hub dynamo on a Brompton that has a fork with 74mm OLD. Its probably a SON XS or SON XS New (its what I have with also Edelux II and SON rear light).

I saw other comparison tests that show that SP dynamo hub are very good and close to SON. So, I think that replacing the SP SD-8 by a SON XS doesn't bring any noticeable benefit.

For the front light, its different, the SON Edelux II is much better and I like its auto mode with the light sensor that automatically put the light on in tunnels...

For the rear, the BUMM My is very small and powerful.

CEBEP

My bad, it’s SON SX 28. Here is my setup on Brompton. I also used SON rear light (black with white lens) which blends in with rear black rack. The biggest difference between SON and B+M is SON is waterproof.

CEBEP

Wouldn’t this one fit on Birdy?

CEBEP

Unfortunately I’m not home at the moment and can’t measure Edelux II. But if it will fit, then changing front light to Edelux II and along with it adding rear light on the rear rack will probably be the best upgrade of dynamo lights you can get on Birdy. There will also be minimum possible drag on SP dynamo as it will automatically switch itself and rear light off during daytime (no daytime light).

Jipe

No, the problem on the Birdy disc is not the OLD which is the standard 100mm but the position of the disc which isn't standard, its closer to the center of the wheel, at a bigger distance from the dropout.

So, the Birdy disc requires a specific, non standard front hub, with or without dynamo.

CEBEP

I think SP hub is just fine and will be even better if lights will have auto off function.

jackyharuhiko

exactly this. 👍

CEBEP

Here is Edelux II




diameter difference will be +4mm from each side which seems to be alot considering Supernova E3 almost touched the fork.

CEBEP

I’m still thinking of options how to widen the range, do it once to make sure I will have enough range.

Rohloff is not an option as it costs high and not accessible for me as a direct swap kit.

At this moment I ended up with Shimano hub and 11-36 cassette and while 36t will definitely be enough for me for climbs if 11t will not at some point I can change the chain wheel for something bigger like 54/56t.
y understand is that another option would be CS-RK3 which is direct drive at 2nd gear and will provide - %25 and + %33.3 to the cassette gear. It costs about $130 and is accessible to me. However it seems like it will accept max 9 speed cassette (11-34t) which means derailleur will also have to be changed. It will also add 1.15kg of weight. The question is which cassette does it accept, will it accept Shimano cassettes? As they are the most widely available in Istanbul.

glye

S-A says 8- and 9-speed and 11-34t. But there's no physical hard limit at that point. The hub physically accepts cassettes compatible with the shimano HG, which most cassettes are, and is available all the way up to 12-speed. The 34t max is likely to limit torque on the hub. But this is a limit set with large wheels in mind. Smaller wheels means less torque, so you can go as much bigger as your wheel is smaller, to put it that way. I'm sure your existing cassette and derailer will be fine. (As long as the cassette boss doesn't break, as mine did.)

CEBEP

Thanks glye
Will I need to buy anything else except the hub to rebuild the wheel or do I need to buy anything else like shifter etc? Also how many holes?

glye

That info is right there on the front page, and in the manual. https://www.sturmey-archer.com/en/pr.../cs-rk3-silver

Jipe

This Sturmey Archer hub is an internal gear hub and as all internal gear hub, it will require some torque blocking system, i.e. something that avoid that the hub axle turns wrt. the frame dropouts (its the special parts that R&M add to the Rohloff).

Did you test the Birdy with its 9-32 cassette as it is now ? Is it really too limited ? Or did you already replace the 9-32t 356% cassette with a smaller range 11-36t 327% cassette ?

I would never add such an heavy low efficiency hub to a Birdy !

CEBEP

I’m testing it now, I also test it at 11t cog which seems to be enough for me. Didn’t replace the hub yet as I was waiting for Big Apples which were delivered yesterday. Will most probably move forward with upgrade in 2 weeks. Shimano cassette is 11-32/34/36. Will go for 36 as if I’ll decide to go a tad higher on chainring in the future to make sure I’ll still be able to comfortably climb hills.

Jipe

Again, why to pay spend money to move to a solution that gives a smaller overall gear inch range ? As you can experience, the factory transmission works very well.

If you feel that 52x9 is too long, its better to change the chainring for a smaller one with narrow-wide teeth.

With some patience, you could may be order a XDR hub or complete wheel from Ginkgo in Germany

CEBEP

This XDR hub is not available in Turkey, no warranty and can’t be imported to Turkey because value exceeds $150. Same goes for cassettes, I’m not sure they are available locally either.

CEBEP

Is there a way for me to check and troubleshoot what could he the cause of a noise from the front wheel as I increase the speed?

I think it maybe the brakes and I really hope not the dynamo hub. If it’s disk brakes can I align them myself if the issue is misalignment?

glye

This is included, see "lock-washer" in the manual. This hub doesn't develop much torque, so that simple solution is plenty. Even my Alfine 11 uses just a lock washer / no-turn washer, and isn't moving in the dropouts.

CEBEP, as you'll see in the manual, this hub assumes your frame has a cable housing stop on the chainstay. It doesn't have an arm for this, like Alfine hubs do. This can be a problem. Bolt-on cable housing stops exist, but for round tubes. Attaching one to the Birdy can be tricky. The pictures of the Pacific Birdy Touring 3x8 doesn't show exactly how they have solved it. They may have developed a custom housing stopper part that sits inside the swingarm, by the hole the cable comes out of. https://www.pacific-cycles.com/birdy...DY-Touring-3x8

glye

Do you get it when you increase speed in a straight line? That's a bit worrying, in that case.

I get such a noise only in hard turns, which indicates that the fork/swingarm is flexing. So long as it is only a slight noise it is harmless. And in this case alignment may not help: If I could get it to be silent in hard turns, it might then make noise in a straight line instead.

You can of course check that the caliper is centered over the brake disk. And if the brake disk is bent, you can bend it back (don't use fingers directly, you don't want skin fat on the disk). I use clean tissue paper on the disk when I do this. And of course check that the wheel is properly set in the dropouts and that the quick release is screwed tight.

CEBEP

I checked that yesterday and also couldn’t find any videos ir closeups pictures of how the hub cable housing stops is secured as it seems like the cable goes up to the rear fork and I can see nothing more. Frame has 2 holes to line the cable through but I couldn’t find a clear picture of stop. Assuming frames are all standard there should be a solution but as there is no explanation I could find it’s not worth the experiment for me.

CEBEP

Yes, when going straight. Will check the disk alignment when I’m back home. What about brake calipers,
do they require adjustments/alignment?

fatbikeGM

I was finally able to add photos to my initial post #1885