50PlusCycling

That's definitely odd. Birdies are popular in Japan, but in the clubs here I have not yet seen or heard of a similar breakage. The only common breakage here is in the front fork assembly where it is boiled to the steering tube, and this is usually caused by collisions or improper tightening of the bolts.

glye

It may have something to do with the average weight of Japanese vs. German people. (No offence etc, I'm heavy myself.)

berlinonaut

The front fork is a well known issue, there have been mentions of the issue in Germany as well. The maintenance plan in the manual from Riese and Müller requires since 2006 the replacement every 3 years or 20.000km, whatever happens earlier. So they know that this is a weak point of the bike. This makes the Birdy a pretty expensive bike as these parts are not cheap. Possibly most people do not care about the scheduled replacement. Is this topic mentioned in the manual of the Pacific Cycle Birdys as well?

R+M do however not mention the rear fork in their maintenance plan. I have no ideas how many Birdys have been sold over the years (and even less how many of them have been ridden more than just occasionally) but would assume at least a couple of thousand. 3 reports are not much so I'd assume it is not a huge, generic problem (but maybe still a generic weakness of the construction). On the other hand: If you are affected in the wrong moment that does not help. I'd assume that these breakages do not happen spontanously but rather a crack builds up over time and probably start on the lower part of the arm on the chain side. Over time the crack develops further from there until the swing arm chain side breaks and then instantly the other side as well. At least that's what I could imagine - plain speculation. So it is possibly a good idea to have a look at this area from time to time, especially on the chain side and if there is something nasty to take appropriate action.

glye

That is scary. A bike that requires regular replacement of a core frame part isn't very confidence inspiring. The manual of my Euro Birdy from 2018 says:
- Replace front swingarm "at least every 20.0000 km"
- Replace stem and steerer "after a crash or 10.000 km or 3 years (whichever comes first)"
- Replace handlebars "after a crash or 10.000 km or 3 years (whichever comes first)"

If the Birdy was my main bike, I'd have to replace core parts nearly every year!

berlinonaut

Jup, the follow-up cost were one of the reasons why I lost interest in getting a Birdy a couple of years ago.

timo888 

https://www.ndt.net/search/docs.php3?id=15232&content=1

I haven't ever used it, but maybe local bike shops could offer a "frame review" service that would be better than eyeballing.

timo888 

Anyone know the hardness (durometer measure) of the foam insert in the Birdy front spring?

secret_squirrel

timo888 

I bought a second-hand BD-1 a while back. Can't seem to get the left-rear brake-shoe aligned parallel to the rim. It toes in towards the front of the bike, and I can't see how it would be otherwise, given the angle of the rear triangle. Am I missing something?

secret_squirrel

secret_squirrel

In other news all the parts I needed arrived to convert my 10 speed Mk3 Touring to 11 speed, whilst retaining the high speed 9t cog. More to come unless anyone has posted about this before. Have 2 cassettes a 36-9 which is super wide range and a 32-9 which is the same range as the 10speed touring but with an extra close ratio.

Is anyone interested in the story once it's built?

glye

I am! Also interested in how you plan to do it. My Birdy has the 9-32t 10-speed cassette originally, am considering the 9-36t 11-speed for a more usable range.

Which derailer are you going to use? My concern is that the cassettes are MTB-spaced, and 11-speed MTB derailers all seem to be so long that they may rub the tire, since 11-speed MTB cassettes are dished so that the biggest cog is further inboards than the biggest of a 10-speed.

SRAM has a CX 11-speed derailer "Force CX1" which is nicely short, but it's rated for 32t max, and 21t chain wrap. B-screw may allow the 36t cog, but stretching it to 27t chain wrap seems a bit much. And you'd have to use road shifters, or an adapter.

On the other hand, the MTB 11-speed derailers are designed for 40-50t big cogs now, so they may be riding too low for good shifting on 36t max. And the Birdy prefers to have the chain on the short side, for better chain wrap when folding. Short chain means extra large distance between cassette and derailer, due to offset pulleys. It would be interesting to mount the short cage from the CX1 on an MTB derailer body, if that fits. But it's an expensive bet.

Annoying that Sunrace who makes these 9t cassettes, don't seem to make a derailer that's designed for them, and the small wheels they're meant for.

cogarch

I would love to hear about your switch to Maguras. Which ones did you use? Did you have to make any modifications? And how did you manage the circuitous route of the front brake hose? Thanks.

timo888 

Thanks. I took the block off and replaced it carefully with the dome-shaped washers and this time the toe-in wasn't so pronounced. I'm not sure what minor misalignment the first time was causing such an extreme effect.

secret_squirrel

Magura's have come as standard fit on Birdy's models before - particularly in Germany which is the home country for both - so they fit pretty easily as long as you dont try to put the brake boosters on as well. I have a decent collection of retro bikes so I was able to get hold of some old HS22's in classic fluoro yellow.


My old birdy was an original Birdy Blue (3x7 sachs dual drive - pre-Sram), and the rear brake routing on the early models left lots to be desired which promoted the Magura's in the first place, that model also had simple metal oval loops to route all the cables so there were no cable bosses to drill out for the hoses, and because maguras can pivot through a wide range of angles and have fairly short blocks they actually fitted easier than the V's they replaced.


The front was a similar story, and was basically an external run of the way the hoses run today on the current model, although from memory it was on the Left hand leg not the right hand leg. Basically the hose ran down the left hand leg via cable ties, then I used a cable tie through the hollow pivot bolt to create a tight-ish guide loop to allow enough freedom in the fork fold but to keep it out of the way in normal riding. I used hope braided hoses rather than the black oem magura ones, and after about 4 years all that had worn from rubbing during folding and transport was the clear outer. The braiding was untouched.


Magura's are amazing brakes - nearest you will get to discs with a rim brake.


Hope this helps!

secret_squirrel

** 11 Speed modding update **

Started this over the weekend and it didnt go too well. Firstly the 9-32 cassette turned out to be the standard birdy 10 speed version due to a labelling error at the shop. So on went the 9-36T one. The good news it that fitting the cassettes is trivial if you have the Capreo lock ring tool and chain whip. The 11 speed cassettes come with a 1.85mm spacer which is usually used for converting 11 speed freehub bodies for 10 speed cassettes, there was certainly no room to include the spacer on the Birdy hubs. I wonder if its for spacing out the fractionally longer road hub bodies? Any guesses?

So second bad news of the day - I bought too short a 11 speed chain - a 114link kmc one. The standard touring has a 115 link chain, and going from 32t to 36t at the back probably requires one more to make 116 in today. Oddly enough I noticed for the first time that my original birdy chain already had 2 speed links in, which assuming 1 was fitted in the factory then suggests another was fitted later, given my birdy was bought new I suspect its because I ordered the chain ring upgrade.

Fitted an SLX trigger shifter and got a rough n ready set of shifting going with the original Deore Trekking rear mech. So the good news is with more time to fiddle I could probably keep the 10 speed rear mech if I was willing to settle for non-quite precise shifting. More mech experimentation to follow.
*
Last bad news of the day I have a 56T chainring and with it and the 36T sprocket at the back in "Big-Big" the chain rubs the near the top of the suspension pivot at the start of the swing arm this will lead to friction and a broken swing arm which is a bad thing! There is a little triangle shape where the swing arm flares out slightly wider and the chain was rubbing there. I will try to upload a photo later.

*Not really big-big as there is only 1 ring at the front.

Fortunately I have several cunning plans.... tune in in the next couple of days for part 3.

GTA

My old BIRDY ROHLOFF is still strong and working perfectly...

cogarch

Definitely! Many thanks for that.

benedictpayot

Any Classic owner tried changing their tires to Schwalbe Black Jack? The stock tire width is 1.5 and the black jack is 1.9. Do I need to change my inner tubes as well? This is my first time changing the stock tires of a bike so yeah. Also, how's the performance on road / off road/ Many thanks!

rhenning

Stock inner tube will work. Roger

cogarch

I've now replaced the front brake with an HS22 (will sort out the rear tomorrow). The cable/hose routing was much easier than I anticipated and I was delighted to find that the latest design of the booster mounting plate will fit without fouling the suspension. Just took it out for a test drive -- immensely satisfying: like night and day! Thanks for your encouragement.

I was all set to post a picture of the installation but apparently the forum won't let me post one until I've submitted 10 posts. :-|

secret_squirrel

glye

Thanks secret_squirrel, looking forwards to the pictures. So you see no risk of it rubbing the rim or tire?
You're using the GS / medium length, right?
What's your tire width?
Did you also verify that the front hub axle doesn't hit the mech body when folding?

If you also tried the 9-36 cassette, I'm curious what sort of chainline you have to give the front chainring to avoid rubbing the chainstay. Seems to me the Birdy wasn't really designed for external gearing at all, the way that chainstay is shaped...

secret_squirrel

glye

I've done the 11-speed mod now. 9-36t cassette, SRAM NX 1x11 derailer, and SRAM NX gripshift. The derailer is long enough to reach down past the 40 mm tyre, but there's just enough clearance to avoid rubbing. It's a bit shorter than the original XT 10-speed derailer, so there's more ground clearance. I had to space out the 45t Litepro chainring 1 mm more to clear the chainstay. The chainring is aligned more or less with the 8th gear, so the chainline is very bad in 1st gear, but I don't hear any noise when riding it. Shifting is great.

I had to route the shift cable out through the hole on the underside of the swingarm, which I guess exists for the Alfine edition. The fold is unaffected.


SRAM NX 1. gear by gunnsteinlye, on Flickr


SRAM NX 11. gear by gunnsteinlye, on Flickr

First gear, 45-36, gives me 1.74 meters, just about enough to climb hills with a touring load. 11th gear is 6.96 meters, enough to ride about 40 km/h. More range would be nice, but that would require a setup that is either more expensive, more complicated to fix on tour, or heavier (or all the above). I think it will be good enough as is.

R & M, please redesign the rear swingarm so a more sensible chainline is possible!


Birdy in Porsgrunn by gunnsteinlye, on Flickr