Birdy thread
10-03-25 | 02:06 AM
#2576
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Joined: Aug 2011
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From: Paris, France
Will it fit a FH-QC400-HM hub? Is a 9T and the chain as durable? What 9-34T cassette should I get?
If it won't fit, what square taper should I get so it pushes the dual chainring far enough outward to work with the derailleur?
If it won't fit, what square taper should I get so it pushes the dual chainring far enough outward to work with the derailleur?
10-03-25 | 02:58 AM
#2577
Senior Member
Joined: Mar 2018
Posts: 1,976
Likes: 1,970
Will it fit a FH-QC400-HM hub? Is a 9T and the chain as durable? What 9-34T cassette should I get?
If it won't fit, what square taper should I get so it pushes the dual chainring far enough outward to work with the derailleur?
If it won't fit, what square taper should I get so it pushes the dual chainring far enough outward to work with the derailleur?
You can run a Hollowtech MTB bottom bracket, which will add 5mm to the width, you can tune the chain line with spacers.
Last edited by 50PlusCycling; 10-03-25 at 03:04 AM.
10-03-25 | 03:35 AM
#2578
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Joined: Aug 2011
Posts: 2,777
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From: Paris, France
Thanks for the infos. Is the 9T Capreo cassette still sold? If not, what other brands should I look at?
If I go for a dual chainring and a regular 11T cassette instead, any recommendation for an affordable Hollowtech MTB bottom bracket + crankset combo for use with a Birdy?
Using a ruler to measure the current setup (original Driveline BB and a Sora two-speed derailleur), it looks like ~15mm is needed to move the inner ring far enough for the derailleur to work its magic, so a hollowtech MTB might not be good enough
For ~the price of a new hollowtech bottom bracket + crankset (provided there's a combo that would solve this problem), do you know of a lightweight square taper bottom bracket instead of eg. Shimano's BB-UN300 (330g)?
I have a SuperB 8918 tool handy: Will it work to unscrew the hollowtech Driveline BB?
If I go for a dual chainring and a regular 11T cassette instead, any recommendation for an affordable Hollowtech MTB bottom bracket + crankset combo for use with a Birdy?
Using a ruler to measure the current setup (original Driveline BB and a Sora two-speed derailleur), it looks like ~15mm is needed to move the inner ring far enough for the derailleur to work its magic, so a hollowtech MTB might not be good enough
For ~the price of a new hollowtech bottom bracket + crankset (provided there's a combo that would solve this problem), do you know of a lightweight square taper bottom bracket instead of eg. Shimano's BB-UN300 (330g)?
I have a SuperB 8918 tool handy: Will it work to unscrew the hollowtech Driveline BB?
Last edited by Winfried; 10-03-25 at 05:54 AM.
10-03-25 | 06:03 AM
#2579
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Joined: Feb 2017
Posts: 2,551
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Will it fit a FH-QC400-HM hub? Is a 9T and the chain as durable? What 9-34T cassette should I get?
If it won't fit, what square taper should I get so it pushes the dual chainring far enough outward to work with the derailleur?
If it won't fit, what square taper should I get so it pushes the dual chainring far enough outward to work with the derailleur?
The cassette is from Ethirtheen, its the same that Helix is using on the ultralight Helix with Shimano derailleur. The 9-39t might also fit on the Birdy, but I am not sure (cogs up to 36t have been tested), I am astonished that a 40t cog fits on the Birdy 3 without touching the rear swing arm?
Shimano, like Campagnolo, has also now cassettes with a 9t cog, the new 9-45t cassette but its for a Shimano Microspline hub.
Below a video of showing that its possible to mount a Shimano 105 Hollowtech 2 on the Birdy with some tuning.
The Capreo is discontinued since a long time and was using a special hub.
10-03-25 | 08:09 AM
#2580
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Joined: Aug 2011
Posts: 2,777
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From: Paris, France
Having to buy a new hub + 9-34T cassette + bottom bracket + crankset + LHS bolt per the video, and then redo a wheel is not worth it for my need.
So I'll go for a square taper… and the question remains: What spindle length should I get a double-chainring to work? Does someone know the splindle length of the Gen 3 Birdy City so I have an idea?
So I'll go for a square taper… and the question remains: What spindle length should I get a double-chainring to work? Does someone know the splindle length of the Gen 3 Birdy City so I have an idea?
10-03-25 | 10:18 AM
#2581
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Joined: Feb 2017
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There is no need to buy a new crankset and BB, I just mounted a new wheel with an XD compatible hub using the original rim and new spokes (spokes length wasn't the same for the new hub) and the 9-34t cassette using the original Birdy 3 crankset.
10-15-25 | 03:51 AM
#2583
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Joined: Aug 2011
Posts: 2,777
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From: Paris, France
Even with a 122mm square taper BB and a compact double derailleur, on the smaller ring, the chain rubs against the inner side of the cage. Thanks to its plastic insert, the noise is less annoying with a Triaga derailleur than a Sora (→ metal to metal), but still.
I've seen people use a triple crankset, with ou without the external ring: Would the internal ring sit further outward than with a double? For the shifter, should I use a double or triple?
--
Edit: With two, 2mm spacers for a grand total of 122+4=126mm, the chain still rubs slightly against the cage. A riding test is required to see if that's good enough. So it looks like going for a 125mm BB is a better option.
Edit: With 3+2=5mm worth of spacers for a total of 122+5=127mm, it works perfect on the bikestand. So either get a 127mm BB, or a 125mm with spacers for the flexibility.
Out of curiosity, how does that Shimano BB "for Chain Guard Installation" differ from the plain version?
Edit: On the BB-UN300-K, "drive side has a flange while non drive side is straight and has a lock nut to take up any variations in BB width." (source)
I've seen people use a triple crankset, with ou without the external ring: Would the internal ring sit further outward than with a double? For the shifter, should I use a double or triple?
--
Edit: With two, 2mm spacers for a grand total of 122+4=126mm, the chain still rubs slightly against the cage. A riding test is required to see if that's good enough. So it looks like going for a 125mm BB is a better option.
Edit: With 3+2=5mm worth of spacers for a total of 122+5=127mm, it works perfect on the bikestand. So either get a 127mm BB, or a 125mm with spacers for the flexibility.
Out of curiosity, how does that Shimano BB "for Chain Guard Installation" differ from the plain version?
Edit: On the BB-UN300-K, "drive side has a flange while non drive side is straight and has a lock nut to take up any variations in BB width." (source)
Last edited by Winfried; 10-15-25 at 07:24 AM.
10-15-25 | 06:10 AM
#2584
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Joined: Aug 2011
Posts: 2,777
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From: Paris, France
And I need to install/change the housings for the two derailleurs.
How to do you stick them through the frame and catch them through the opening in the front?
Edit: Mission accomplished with the help of a piece of string to keep the existing housings (rear brake + light) out of the way as much as possible, and a light + tweezer to reach and pull the new housing out. 👍It can then be used to run the second housing (front or rear derailleur) through.
Edit: Because the bend is very tight to route the front derailleur housing before it enters the clamp from below, you'll need to add a flexible noodle (for lack of a better term):
How to do you stick them through the frame and catch them through the opening in the front?
Edit: Mission accomplished with the help of a piece of string to keep the existing housings (rear brake + light) out of the way as much as possible, and a light + tweezer to reach and pull the new housing out. 👍It can then be used to run the second housing (front or rear derailleur) through.
Edit: Because the bend is very tight to route the front derailleur housing before it enters the clamp from below, you'll need to add a flexible noodle (for lack of a better term):
Last edited by Winfried; 10-17-25 at 02:31 AM.
10-20-25 | 11:04 AM
#2586
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Joined: Feb 2017
Posts: 2,551
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No, none of these 3rd party tensionners works 100% like the one of Pacific Cycles.
For the housing+cables inside the frame, I never had to do it on the Birdy 3 but its usually a mess on all bikes with internal cables!
For the housing+cables inside the frame, I never had to do it on the Birdy 3 but its usually a mess on all bikes with internal cables!
10-27-25 | 11:28 AM
#2587
Senior Member
Joined: Aug 2011
Posts: 2,777
Likes: 142
From: Paris, France
Turns out I had the Litepro chain tensioner handy and gave it a try: It works perfectly to keep the chain tensioned while folding.
And to keep it from falling inwards when unfolding, either use a narrow-wide chainring, or a plain chainring and Birdy's chain protector:
And to keep it from falling inwards when unfolding, either use a narrow-wide chainring, or a plain chainring and Birdy's chain protector:
Last edited by Winfried; 10-27-25 at 11:31 AM.
10-31-25 | 07:38 AM
#2589
Senior Member
Joined: Aug 2011
Posts: 2,777
Likes: 142
From: Paris, France
On a Gen3 Birdy, I don't use panniers so would like to replace its Expedition rack with a low rider rear rack, which would have the extra benefit of not interfering with the front derailleur's arm if left on the big ring when folding.
Does someone know if PC's official rack can be found in Europe, and if not, if there are valid alternatives with a way to roll the bike folded?
https://shop.mightyvelo.com/collecti...ar-front-racks
Does someone know if PC's official rack can be found in Europe, and if not, if there are valid alternatives with a way to roll the bike folded?
https://shop.mightyvelo.com/collecti...ar-front-racks
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Last edited by Winfried; 10-31-25 at 07:56 AM.
11-01-25 | 04:17 AM
#2590
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Joined: Aug 2011
Posts: 2,777
Likes: 142
From: Paris, France
If someone in the audience owns a Touring powered by a CS-RK3 hybrid hub, could you…
1. Confirm the derailleur cable housing is just one piece, running straight from the shifter to the derailleur, unlike the hub housing which has three parts and, in the rear frame, relies on the welded housing stop next to the v-brake noodle in the middle
2. Show a picture of what PC used as housing stop at the other end, provided the cable doesn't just run straight from that housing stop to the "indicator chain"
?
1. Confirm the derailleur cable housing is just one piece, running straight from the shifter to the derailleur, unlike the hub housing which has three parts and, in the rear frame, relies on the welded housing stop next to the v-brake noodle in the middle
2. Show a picture of what PC used as housing stop at the other end, provided the cable doesn't just run straight from that housing stop to the "indicator chain"
?
11-01-25 | 07:07 AM
#2591
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Joined: Feb 2017
Posts: 2,551
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On the R&M Birdy Touring with only a 10s derailleur (now 11s on mine), the derailleur housing in in three parts and uses the bottom openings of both the main frame and rear swing arm. At the opening of the rear swing arm there is a special housing stiffer and made of a kind of spring that prevent the housing to bend and make a loop, instead of sliding inside the main frame, when unfolding the rear swing arm (Pacific Cycles didn't put this special housing on the Titanium Birdy and sometimes the derailleur housing makes a loop when unfolding the rear swing arm).
Are you sure that on the Pacific Cycles Birdy Touring with SA 3s rear IGH hub+derailleur, the bottom cable+housing is for the 3s of the IGH hub and not for the derailleur like on the R&M Birdy Touring?
Are you sure that on the Pacific Cycles Birdy Touring with SA 3s rear IGH hub+derailleur, the bottom cable+housing is for the 3s of the IGH hub and not for the derailleur like on the R&M Birdy Touring?
11-04-25 | 05:43 AM
#2592
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Joined: Aug 2011
Posts: 2,777
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From: Paris, France
11-04-25 | 10:00 AM
#2593
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Joined: Feb 2017
Posts: 2,551
Likes: 575
As explained and shown on the picture I posted, on the R&M Birdy 3 Touring the derailleur cable+housing uses the bottom output opening of the main frame, the bottom input of the swing arm and comes out from the same output opening as the derailleur cable+housing of the picture you posted.
Since I changed the derailleur to an 11s Ultegra, I had to remove and replace the derailleur cable and I discovered that the housing coming from the shifter stops at the special rigid, spring like housing connected to the rear swing arm that goes to a stop inside the front end of the swing arm and the short housing from the rear output of the swing arm to the derailleur goes to another stop inside the rear of the swing arm.
Since there is a stop inside the rear end of the swing arm, I do not understand how a one piece housing could go thru the swing arm and come out from the same hole of which the short housing+cable comes out on my Birdy?
Some times ago, you already asked how the cable+housing for the rear SA IGH is going thru the rear swing arm and to answer your question, I inserted a cable from the top front input of the swing arm of my Birdy and this cable went out om the bottom more or less in the in the middle of the swing arm just like the cable+housing of the IGH of your picture.
Since I changed the derailleur to an 11s Ultegra, I had to remove and replace the derailleur cable and I discovered that the housing coming from the shifter stops at the special rigid, spring like housing connected to the rear swing arm that goes to a stop inside the front end of the swing arm and the short housing from the rear output of the swing arm to the derailleur goes to another stop inside the rear of the swing arm.
Since there is a stop inside the rear end of the swing arm, I do not understand how a one piece housing could go thru the swing arm and come out from the same hole of which the short housing+cable comes out on my Birdy?
Some times ago, you already asked how the cable+housing for the rear SA IGH is going thru the rear swing arm and to answer your question, I inserted a cable from the top front input of the swing arm of my Birdy and this cable went out om the bottom more or less in the in the middle of the swing arm just like the cable+housing of the IGH of your picture.
11-12-25 | 09:15 AM
#2594
Newbie
Joined: Apr 2022
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Birdy thread
11-13-25 | 05:13 AM
#2595
Senior Member
Joined: Aug 2011
Posts: 2,777
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From: Paris, France
Last edited by Winfried; 11-13-25 at 05:34 AM.
11-13-25 | 06:41 AM
#2596
Senior Member
Joined: Aug 2011
Posts: 2,777
Likes: 142
From: Paris, France
