CEBEP

Many thanks, could you please send pictures of plastic washers that need to be removed if it’s not too much trouble?

CEBEP

As I circled back the thread, in 2020s I came across rear hub and Sunrace cassette discussion on R&M Birdy Touring. First of all I don’t understand much in it at all. What I know is Sunrace cassette provides decent gear range. But as I understand the hub is a weak point and I’m on borrowed time as I’ll start riding it (I’m about 100kgs). Am I right or hub quality improved by now?

If not what are my options for an upgrade for sturdier setup and similar or wider gearing range?

One of the members mentioned switching to Alfine 11 hub which has even wider range. Is this a good setup and what would be required for such mod? I assume rear wheel will need to be rebuild, which spokes will need to be used, derailer, anything else?

jackyharuhiko

Talking about cassette, I also talked to the bike shop yesterday about the options. My Pacific Cycles Birdy 3 is factory equipped with Shimano Sora with 11-32T 9 speed cassette, and the shop recommended me to go to 11 speed cassette but with the lowest and highest gear teeth unchanged. I wonder what is the use of going with more speed without changing the max and min gear ratio? Smoother shifting? There is also a SRAM electronic wireless system but that’s not essential to me.

I don’t know how is the original hubs, I know that the front hub has to be custom made and it’s Birdy-branded, but the back hub is a low end Shimano M475L which I saw some poor reviews online, it also stops quickly in a free spin. Anyway it’s not an issue for me since I changed the wheel set already. This hub has ceramic bearings, and it free spins for a long time, but the improvement to the ride quality is not as strong as changing the tyres and the BB/crankset. But it certainly looks good and the carbon wheels shed about 400g from the weight. Now the whole bike weighs about 11.1kg.

CEBEP

Not aure if you’re still on the forum and I understand it’s an old post. Could you advise what else do I need to know to install an Alfine 11 on Birdy 3? Which spokes did you use to rebuild the wheel and which hub model if you have model number? Also what are these tensioners? Any pictures you have left from the installation showing the process?

I hope to have this info in case rear hub will go bad and I’ll need to consider other options.

thanks.

Winfried

FWIW:
https://kstoerz.com/freespoke/hub/190

glye

Hi! I'm still here, just not very active. It's my Birdy in that picture. I still use it and am happy with the Alfine 11. I sometimes build my own wheels, but in this case I went with a professional builder to save time. So I don't know what spoke lengths are used. Spoke brand and thickness is not important here, just go with a common reputable brand and a normal dimension, not crazy thin ones. You probably wouldn't find super thin spokes in so short lengths anyway.

For Alfine 11 the choices are afaik: a) colour (black or alu), b) number of spoke holes (36 or 32 I think, I use 32 which I recommend on such a small wheel), and c) cable shifted or electronic Di2. I use cable shifted. Electronic costs more and you need to recharge the battery, but some will prefer that given how sensitive the mechanical one is to wrong adjustment. I think my model is SG-S7001-11, but just go with whichever model is current. As you see in the link Winfried posted below your post, the dimensions are the same for all those model versions.

I have the Shimano Alfine chain tensioner CT-S500 which like the hub can be had in black or alu. Many brands will surely work fine. I would recommend one with 2 idler wheels, not 1 like the CT-S510, because 2 gives much better chain management when folding the bike, and also better chain wrap around the rear cog. You could save money by using a regular derailer like the one you already have. Just remove the shifter, and use a few cm long piece of shifter wire that you cut just long enough to position the derailer in the right place for a straight chainline. If the derailer has a shift adjustment barrel, this should be quite easy to set up. Though a dedicated single speed tensioner probably weighs less and may be less sensitive to be damaged. You will need a narrow type chain. 8 or 9 speed is fine. Single speed chains are also fine, possibly better, as long as it's the narrow kind, 3/32" and not the massive 1/8.

You will of course have your own opinion on what the best gearing ratio is. Either the Alfine cog or the front chainring can be replaced to give a ratio you are happy with. You will want a straight chainline for the best chain life. Some Alfine cogs can be flipped to adjust chainline, but if not your best bet is to adjust the chainring with chainring spacers. They are tiny, cheap, easy to use and weigh nothing.

There are two small tricks worth being aware of, when it comes to the shift cable routing, if you choose the cable shifted version (if Di2, I have no idea). You route the shift cable through the frame, same as the original one. You can in fact use the same cable and housing as you already have mounted, unless they are worn out, because with Alfine you'll be shortening them. The Alfine hub has an arm that the cable housing attaches to. This arm should be positioned close to the hole on the underside of the middle of the right chainstay. The hub has coloured anti-rotation washers, specifically for left and right, which force the arm to be in a certain position. As I recall, I had to swap left and right to get the right position for the Birdy. Pull the cable housing out of the hole, and cut it down to the right length to attach to the arm.

Second: In this position, the chain would very slightly rub the Alfine arm, which isn't good. But as it happens, the chainstay has a threaded hole right next to the one used by the mudguard stay, which is in the perfect position to screw in a short bolt from the inside of the stay, so the head of the bolt pulls the Alfine arm outwards, away from the chain, just 1 mm or so is all you need. You could bend the arm a little instead, but the bolt solution is more precise. This has been working perfectly ever since. I can take a picture if you'd like.

Finally, Alfine 11 adjustment. Yes, as many people say, it is finicky. But when you get it right, it works very well. Start with the description in the manual, where you shift to 6th gear and adjust it so that two yellow dots align. But if you get skipping gears then, you adjust it a little bit in either direction until you find the sweet spot. This is for me a point where the yellow dots are 1-2 mm apart.

Be prepared for the oil change, the first should be done after 1000 km, then more rarely after that. It's very easy to do by following the clear instructions you get with the oil change kit. Or you could hand it to your local bike shop, but do make sure they know what they're doing. If they just squirt grease in there like a common 3-speed hub would have, they might ruin it.

Alfine 8 is cheaper, easier to adjust, and more solid, from what I read. If you can live with the smaller range, go for that. But for me I needed the range of the 11-speed, and I am happy with it. If I was buying today, I would consider the Di2 option, especially if it is possible to hook the battery up to my hub dynamo somehow. But all in all it's a great Birdy setup. Happy rides!

CEBEP

Hi glye amd many thanks for taking time and such detailed reply!

Yes, pictures will be very welcome.
Do you think Di2 version with electronic shifting will fit just fine or there is a risk of something not fitting correct? As far as I head electronic shifting is better in a way that it will shift correctly 100% of the times.

Thanks.

CEBEP

I also heard that Alfine 11 slowly leak oil, did you have such experience?

Jipe

Te folded size of the Brompton and Birdy and several other folding bikes depend of the mounting of the saddle.

The size given by Brompton is very optimistic, its with the saddle mounted on a position that minimize the folded size, i.e. pentaclip in front of the seat-pillar, saddle advanced to the front as much as possible and mounted on the lowest position on the pentaclip, a configuration that only fits for short people. Then, the folded bike fits into the airline size without any case around it, in a soft bag snug around the folded bike.

Of course, its with the standard seat-pillar that fits only for people up to about 1m75 and less when the saddle is mounted on the lower position of the pentaclip. People above about 1m75, need a longer seat-pillar that increase the height of the folded Brompton.

With an average cyclist, the folded Brompton is bigger and its the reason why all cases made to carry the folded Brompton are too big to fit in the airline limit. The folded Brompton without any dismounting doesn't fit in any airline compliant case. Its also the reason why the Chubby is bigger.

And its the same for the Birdy, the size given by Pacific Cycles is for short people, the bigger one given by Riese & Müller for taller people.

My comparison picture show clearly that for both bikes the saddle position has a major impact on the overall folded size. Removing the saddle+seat-pillar greatly reduces the folded size.


Last point, how often do most people fly with their folding bike?

In the daily life (putting the folded bike in a caddy during shopping, carrying the folded bike in public transportation, taking the folded bike inside shop, cinema, hospitals, elevators, storing the folded bike under a desk...), the little difference in folded size between the Brompton and Birdy doesn't really matter.

About the Sunrace hub and cassette mounted on the Birdy Touring: I never experienced problem with it, it shifts very well with a Shimano derailleur and it has been realiable for me.

But, its a proprietary solution, the hub accepts only the Sunrace special cassette and this cassette can only be mounted on a Sunrace hub (and maybe the now discontinued Shimano Capreo that R&M was using before the Sunrace solution). These Sunrace components are pretty difficult to buy if not from a R&M dealer (that must most of the time order it).

On my Ti Birdy, Pacific Cycles mounted a standard Shimano rear hub with a 11s 11-28t cassette (both Shimano 105), the range is quite short and the longest ratio too short (front chainring is a FSA SLK-light compact 52-36).

I therefore looked for another solution and moved to a new rear wheel with an XDR body rear hub and Ethirteen made 11s 9-32t cassette (the previous generation Shimano Ultegra RD-R6800 derailleur I have is limited to 32t max).

When the cassette of my Birdy Touring had to be replaced, I did the same on my Birdy Touring that has now an 11s 9-34t Ethirteen cassette and Shimano Ultegra RD-R8000 derailleur. I hesitated between this solution and a SRAM Force Etap AXS 12s and 10-36 cassette but since it is a daily used utility bike, I preferred a mechanical rear derailleur.

Schwinnsta

A few points and a few questions. First, the Brompton telescopic seat post pretty much solves most suitcase problems. You can remove the inner post and saddle and keep all your saddle settings. You also get to keep seatpost bung. When I was working, I am now retired, I had to at times fly with little notice, so I set the Brompton up to pack in under two minutes. Mostly I used a B&W hard case. A couple of times I had problems on arrival with the way Homeland Security repacked my bike, so I went a Vincita Case. It was a tight fit with B&W case.

Does the Birdy lock up together as one piece in the folded position like the Brompton? Can you use the Birdy in shopping cart mode like I do with the Brompton? I have posted pics of this before. I did have to mod my rack though to facilitate this. When you say Riese and Muller size is larger, is their model actually larger? I did not understand this.

Jipe

Yes, the Birdy lock up in one piece when folded. The way the front wheel folds is totally different of the Brompton, so people used to fold the Brompton need to learn how to quickly fold the front wheel of the Birdy, once done its very easy o do, the folded front wheel is locked by the folded stem (the rear is very similar, folding on the rear suspension axle, rear locked by the seatpost pushed down).

For the shopping cart mode, its more or less like the Brompton: a naked bike without any mudguard or rear rack doesn't roll (like the former E Brompton that doesn't really roll folded).

You need to add some rack or/and easy wheels to make it roll folded.

R&M rack roll folded but not like the former R Brompton that rolls on 4 easy wheels, it has only two easy wheels to pull it.

There are third party rack with 4 easy wheels.

For the folded size, the bike is the same, its just that the saddle is mounted differently by R&M = for tall people and that the R&M Birdy come with mudguards from factory. Just like the Brompton, where the R (mudguard+rear rack) is bigger (higher) folded than the E, the Birdy with rear mudguard is also higher folded.

Its very easy to remove the seatpost+saddle (its a quick release lever like the extension of the Brompton telescopic seatpost, no tools needed) from the Birdy to make it smaller folded and the Birdy seatpost is long enough to fit for tall people, there is no optional longer and telescopic seatpost that both make the folded Brompton higher folded.

I have the BW case, its too big for airlines rules and its too small for a Brompton with 600mm seatpost and saddle on the top position of the pentaclip.

Now, I never said that the folded Birdy is as small as the Brompton, but very close, so close that the slightly bigger fold isn't a problem in daily life and the BIrdy is much faster and comfortable than the Brompton. Its also more versatile for luggage transport with now the possibility to use a Brompton front bag, front low rider pannier and rear full size rear pannier (even for people with big feet).

CEBEP

Thanks foe the info. Do I understand you correctly in a way that XDR body rear hub and Ethirteen made 11s 9-32t cassette will be a direct swap? Or is it a must to change the deraileur too? Can the same spokes be used to rebuild the wheel?

Will this setup will offer similar gear range and values to the Sunrace which comes on R&M and with this setup the cassette will be easier to source when replacing is needed?

Sorry for so many questions but I understand almost nothing in hubs and cassettes.

glye

I'll post pictures in a bit. I think the Di2 hub will fit fine, but you'll have to study pictures/manuals and decide what you think, unless you find someone who's already done it. You'll also need to attach the battery somehow. There's a seat tube model which could be a problem on a folding bike, and an external model that I'm sure could be mounted somewhere, with zipties. Someone did it on a Brompton, you can see details there:
https://www.kinetics-online.co.uk/fo...peed-brompton/

No, I haven't seen any leaks. It doesn't get oily on the outside, and when I changed the oil I pulled about as much out as I put into it. (Some say that for long term storage the bike should be standing up, not lying on the side, to avoid leaks. Most people would do that anyway.)

jackyharuhiko

I saw people installing SRAM Rival eTap electronic shifter with 12 speed cassette on a Dahon K3 Plus. So I think it should be okay to install on a Birdy.

glye

eTap / Di2 cassette shifting should be fine afaik. But Alfine Di2 is another story. After a close look I have my doubts about Alfine Di2 on a Birdy. I would not buy unless I could find accurate dimensions of the motor unit. It might not fit under the curve of the Birdy chainstay/dropout, see photo. The motor unit seems to have a bigger diameter than the hub flanges, almost as far out as the locknut. That would be a problem.


Alfine Di2, note large motor unit


Alfine 11 / Birdy closeup, rear


Alfine 11 / Birdy closeup, side

My "arm pulling patent" isn't quite as I remembered it. The bolt goes in from the outside, and I use a flanged nut to pull on the arm.

glye

I have broken 3 of those weak Sunrace cassette hub bodies, on two different hubs. Same failure on all of them: The body cracks and splits at the pivot point of one of the pawls, where the material is very thin. Then it locks up and becomes a fixed gear hub, so to speak. If you stop pedaling you may destroy the derailer as well. I don't know if they have improved. I hear they work well for some riders, but I recommend avoiding it, for any heavy and/or strong/"aggressive" rider.

By the way, I had the occasional pedal to ground strike in turns. I swapped out the standard red suspension elastomer with the harder green one. That turned out to be a better fit for me, and could be for you as well. Especially if you ride with luggage.


Cracked Sunrace cassette hub body

Schwinnsta

Thanks for the info. I notice on your Brompton that you have about an inch above the wheel and frame in the folded position in your picture above. On mine, in the folded position the bottom of the top tube contacts the wheel and so does the bottom tube as well. I am not sure why yours isn't doing that, but it could decrease your folded size.

I don't doubt that Birdy is more comfortable since it can take Big Apple 18 x 50 (it would be nice if Brompton could make a model that could), I just question if I would have problems with bobbing like I do with Moultons.

Another question: Measured from the ground, how high is the handlebar at max extension vertically. I seldom see this in stats for folders. It seems manufactures like to take the max height of riders from the seat post max and assume you will be comfortable with the drop.

CEBEP

Maybe this will help, at the bottom of the page:

https://www.cyclinguk.org/cycle/bike...-folding-bikes

Schwinnsta

I don't see it there. Why don't you tell me. Thx

CEBEP

Brompton S2L




Birdy World Sport

Schwinnsta

Where is the vertical distance from the ground to the handlebar shown? If you can figure it out from this, cool. Tell me I can not.

CEBEP

I don’t have a Birdy to measure, maybe someone will.

Jipe

I have also two Moulton with the leading link front suspension.

If I had to rate the suspensions of the Birdy vs. the one of the Moulton, I would say that the rear cone suspension with the bottom bracket being part of the rear triangle of the Mouton is better than the one of the Birdy while the front suspension of the Birdy is better than the lading link of the Moulton.

The stem of the Birdy 3 is adjustable in height, there are 5 holes/positions, I never put it at its maximum extension, mine is at the lowest position on the Birdy Touring which is higher than the fixed stem of the Ti Birdy. This lowest position is at about 96cm from the ground and the highest hole 9cm higher, so the highest position should be at about 105cm from the ground. Note that I have a sport 21 degree stem, I do not know if the height is the same on the 10 degree comfort stem ?

On the Ti Birdy that had an 11s derailleur, it was a direct swap, there was even no need to readjust the derailleur (the hub is a Hope RS4). On the Birdy Touring that has a 10s derailleur, since all these Ethirteen cassettes are 11s, the derailleur and its shifter must also be changed.

The hub flank have a different diameter, so the spokes must be changed to have the right length.

glye

Some problems with this question: The Birdy comes with a choice of different handleposts, which will likely have different max heights. I'll assume the Sport 21, which I have and it actually seems to be the only one on offer right now at R&M (don't know about Pacific). Second, since it's a suspended bike, the height from the ground will vary with the weight you put on it, and what elastomers you choose. Even with tyre size and pressure. From the ergonomics point of view I think the vertical distance between bottom bracket and bars might be more useful, but that's harder to measure. Anyway, I'll assume unloaded height. (Reminds me of "The Airspeed Velocity of an Unladen Swallow" ("What do you mean, an African or European Swallow?"))

So on my Mark 3 R&M Birdy (unloaded), with Sport 21 handlepost at max extension, and Schwalbe Marathon (not Plus) 44-355 tyres at whatever pressure they're currently at, the distance from the ground to the center of the bars is ca. 103,5 cm.

Of course you could replace the standard flat bars with riser bars and get considerably higher. The diameter is the common 31,8 mm.
I hope it's useful.

jackyharuhiko

I don’t really prefer those easy wheels. I found that the Birdy can be rolled even when completely folded, on the rear wheel.