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Birdy thread

Old 04-17-21 | 06:41 AM
  #1526  
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Originally Posted by JRat
I've now tried that braze-on clamp from Amazon UK (B07T4KTZBD) and agree that it won't work. The problem is that the part holding the rear clamp fixing bolt conflicts with the rear triangle. This prevents the clamp from being placed low enough for the braze-on mount to be at the right level (when I tried the clamp on the bike the braze-on mount is 7cm above the top of the chainring, which looks to be too high). I've now placed an order with Bikegang. I note that the specific Birdy braze-on clamps have the clamp tightening screw placed where it doesn't conflict with the rear triangle. I'll send part B07T4KTZBD back to Amazon.
Besides Ridea and Colour Plus finding a front d clamp is really hard due to the 40mm size.
If you are looking for a seatpost clamp I do know 2 options that are avaliable that are not Ridea or C+ that will suit your purpose if you are looking to change it.
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Old 04-17-21 | 10:00 AM
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Originally Posted by Samidare
I wouldnt suggest getting the brompton front block on a birdy though.
If you own one i suggest that you get it removed.
Reason being that if the front blocks moves it will cause the front suspension clip to be loose and will likely cause an accident.
With regards to the rear rack. Any reason why an easy wheel which is lighter cant be use ?
I have two Birdy with a Brompton front block.

A titanium Birdy on which the bloc is directly attached on the head tube with two bolts with two hole drilled into the very thick and strong head tube. The block sits on the head tube bottom reinforcement for the semi-integrated headset. It cannot move down.

A Birdy III with the H&H Brompton front block adapter. The adapter is strong enough to avoid any risk that the block moves down.

You can use any Brompton easy wheel with a M6 bolt on the Birdy. The only thing you must care is to check that you can still attach rear pannier far enough rear to avoid to touch the pannier with the heel of your foot.
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Old 04-18-21 | 08:49 AM
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Originally Posted by Jipe
I have two Birdy with a Brompton front block.

A titanium Birdy on which the bloc is directly attached on the head tube with two bolts with two hole drilled into the very thick and strong head tube. The block sits on the head tube bottom reinforcement for the semi-integrated headset. It cannot move down.

A Birdy III with the H&H Brompton front block adapter. The adapter is strong enough to avoid any risk that the block moves down.

You can use any Brompton easy wheel with a M6 bolt on the Birdy. The only thing you must care is to check that you can still attach rear pannier far enough rear to avoid to touch the pannier with the heel of your foot.
Well in any case maybe what i said was wrong but the H&H Brompton block adapter will cause the front suspension clip to move down.
I am just telling you that there is a risk. I cant post the video as i am a new to the forum.
I can show you the video if you are interested.
My friend got injured while cycling and had to remove that adapter.
If you look at your front block and move it towards the clip you will see that the bottom part does hit the clip.
Now imagine if that happen when you are cycling it would be painful to say the least.


Secondly why are you using a Brompton easy wheel when there are so many other version out there in the market.
Easy Wheel and Rear Rack, Do you not know about them that why you are using the brompton version ?

In case you are wondering I am from Singapore and I used to own a b3 disc version but have sold it off and now am using a P40.
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Old 04-18-21 | 10:25 AM
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I have a Birdy III with the H&H front block adapter and it didn't move down, even with the front bag heavily loaded.

Yes, please publish the video if you can or send me a message with a link to i if you cannot.

For the easy wheel, when i wrote "Brompton easy wheel" I was meaning any easy wheel for Brompton with a M6 bolt, not made/sold by Brompton.

The only limitation is if you want to put a rear pannier on the rear rack and have relatively big feet. Then to avoid to hit the pannier with the heels, you need to put the pannier very much to the rear, and easy wheels above 45mm in diameter do not allow to put the pannier at the rear end of the rear expedition rack.
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Old 04-21-21 | 02:11 PM
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The Ridea front derailleur clamp was delivered today so I did an trial fit of the clamp and the Shimano FD-5700 derailleur. This revealed that the chainrings need to be moved out by several millimetres to be within the range of derailleur cage movement. Close scrutiny of the bottom bracket area revealed that there are spacers (2mm + 0.5mm?) on the non-drive size where the BB screws into the frame. If they can be moved to the drive side then that should shift the cranks across by 2.5mm which might just be sufficient. However, to try that shift that I'll have to get an external BB tool. I don't think my feet will notice the lateral shift in the cranks.
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Old 04-23-21 | 09:32 AM
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Hello, I would be grateful of feedback on the following: I have a mk3 Birdy using the Nexus 8 gear hub. However, even on first gear, it is difficult to climb steep hills. I read some threads that it is possible to replace the front chain ring. Could anyone make a recommendation on the replacement chain ring? Thank you for your help
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Old 04-23-21 | 10:02 AM
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Originally Posted by OMurchu
Hello, I would be grateful of feedback on the following: I have a mk3 Birdy using the Nexus 8 gear hub. However, even on first gear, it is difficult to climb steep hills. I read some threads that it is possible to replace the front chain ring. Could anyone make a recommendation on the replacement chain ring? Thank you for your help
Rather than disturb the chainring with its associated chain guards how about using a bigger sprocket on the hub? The supplied sprocket is 16T so an 18T sprocket reduces the gearing by about 12% which is roughly the difference between the Nexus 8 gears (excepting the 18% gap between 2nd and 1st gears) and would put the new top gear where 7th gear is currently. You might also need a new and longer chain (9 speed) but it would be worth trying the larger sprocket with the chain already on the bike. A new sprocket and chain will be no more expensive than a new chainring. An 18T sprocket on the hub gives about the same gearing reduction as fitting a 46T chainring. You could fit an even bigger sprocket if you want even lower gearing but remember that what you gain at the bottom you lose at the top.

I've got an ongoing project to try and fit dual chainrings and a front derailleur on a Birdy 3 with Nexus 8 hub in order to widen the gearing range but keep finding new obstacles.
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Old 04-25-21 | 06:07 AM
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Feedback to JRat

Thank you for your response on my question re: Gearing / Chain Ring / Nexus Gear Hub. I really appreciate it. I will go with your recommendation, and I will send photos and feedback once I have it completed. Thanks again
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Old 04-25-21 | 03:20 PM
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Adding front derailleur and having two chainrings that extend the gearing range is the best option because increasing the sprocket will reduce the upper range.

Some pictures of a factory two double chainring Birdy 2 race.






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Old 04-28-21 | 02:11 PM
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I have abandoned my project to put a front derailleur on the Birdy City. Getting the bottom bracket unscrewed to enable moving spacers from left to right side was proving to challenging as it's not just the matter of having the right tool but also holding the tool in place while applying sufficient force.I didn't want to make a mess of the bike only to verify that moving the spacers isn't enough to shift the chainline enough to suit the derailleur's range of movement. I wonder if Birdies built with a front derailleur are fitted with a longer crank axle in order to get the chainline further out.

I've therefore decided that the Birdy City will have to be rehomed who doesn't want to tackle big hills and have got a Birdy Rohloff on order (I was offered an attractive discount on a new one which helped make the decision). I'll be interested to compare the crank axle length on the two bikes as the Rohloff hub has a wider chainline than the Nexus hub.

Another pending project, to fit ergotec AHS handlebars to a Birdy so I have more variety in hand and body positions, will wait for the Birdy Rohloff which should be early next week.
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Old 04-28-21 | 04:57 PM
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Bikes: Trek 730 (quad), 720 & 830, Bike Friday NWT, Brompton M36R & M6R, Dahon HAT060 & HT060, ...

Originally Posted by JRat
Getting the bottom bracket unscrewed to enable moving spacers from left to right side was proving to challenging as it's not just the matter of having the right tool but also holding the tool in place while applying sufficient force.I didn't want to make a mess of the bike only to verify that moving the spacers isn't enough to shift the chainline enough to suit the derailleur's range of movement. I wonder if Birdies built with a front derailleur are fitted with a longer crank axle in order to get the chainline further out.
You need to bolt the tool to the BB spindle, to keep it in place. This VAR tool comes with all provisions there and for other you need to take care of this yourself.


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Old 04-29-21 | 01:53 AM
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Birdy are equipped with external bearings !

I am curious to know if R&M adapted the chainline for the Rohloff Birdy compared to the Nexus 8 Birdy.

Replacing your Nexus 8 Birdy by a Rohloff Birdy is of course a radical solution and change, the Rohloff hub is a completely different category of hub than a Nexus 8 !

Last edited by Jipe; 04-29-21 at 07:05 AM.
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Old 05-02-21 | 07:26 PM
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Hi guys. I have a birdy GT and have recently installed a bigger chainring. For next upgrade for speed I am looking to change the cassette to <11t to either sram force or 3t bailout which both requires xdr drivers.

Does the stock wheel allow me to install a xdr driver or do i need to rebuild a new wheel for this?
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Old 05-03-21 | 02:06 AM
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You need to rebuild a new wheel with a new hub and (most probably due to a different length) new spokes.
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Old 05-03-21 | 12:47 PM
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Hey, has anyone here re-laced their 3rd gen Birdy disc front wheel? If so, do you have the measurements of the front disc hub by chance?
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Old 05-03-21 | 04:35 PM
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The only Birdy disc front hub measurements I have is for the front dynamo hub. For the wheel set I made, I used Hubsmith Birdy disc front hub with straight pull spokes (I couldn't find the same front hub as mounted by Riese & Müller).
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Old 05-08-21 | 03:46 PM
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Originally Posted by Jipe
Birdy are equipped with external bearings !

I am curious to know if R&M adapted the chainline for the Rohloff Birdy compared to the Nexus 8 Birdy.

Replacing your Nexus 8 Birdy by a Rohloff Birdy is of course a radical solution and change, the Rohloff hub is a completely different category of hub than a Nexus 8 !
I can confirm that the chainring offset is different between the two bikes as they should be as the Nexus hub has a smaller chainline offset than the Rohloff hub. The crank length appears to be the same (measured by tape and not calipers) but the Rohloff Birdy doesn't have the spacers on the left side of the bottom bracket. I assume they are on the right side but it's difficult to see as that bike has the extra chain tensioner that's clamped to the bottom bracket.

I'm planning, when the weather is amenable for bike fiddling, to try fitting the derailleur clamp and derailleur onto the Rohloff birdy to find out, as a matter of curiosity, if it will fit OK with the bottom bracket and cranks shifted to the right.

I'm well aware that the Nexus and Rohloff hub gears are somewhat different, both in performance and price. The new Birdy is my third bike with Rohloff gears (but I must rehome one of the others as it hasn't been used for nearly a year). The Nexus hub has the disadvantage (apart from the smaller gearing range) of the twist shifter turning in the opposite direction to the Rohloff shift so, when I tried the Nexus Birdy, I kept shifting gears in the opposite direction to what I wanted.

The Rohloff Birdy has been both up and down the worst hill on my local cycling circuits. We got up the hill with a couple of gears to spare but 40mph (>60kmph) going down was, I felt, plenty fast enough as the steering was feeling a little twitchy and lacks the inherent gyroscopic stability of a full-sized wheel. I didn't try going up that hill with the Nexus Birdy as I knew that I would run out of gears.
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Old 05-09-21 | 05:31 AM
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Thanks for the interesting information.

On a Birdy 3 Touring with 10s derailleur, there is a 1mm spacer on the left side.

Like on your bike, I cannot see if there is a spacer or not on the right side due to the chain tensioner clamped on the bottom bracket.



Last edited by Jipe; 05-10-21 at 09:45 AM.
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Old 05-16-21 | 08:24 AM
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I'm still under the 10 post limit to be able to post photos.

I have my Birdy Rohloff ready for action with the Humpert Ergotec AHS handlebars which provide extra comfort on longer rides by allowing different hand and body positions (photo fotthcoming when I've got enough posts). However, it's necessary to slacken the clamp and rotate thees bars to the vertical position to get a compact fold. The bottle cages are fixed by SKS bottle cage mounts which have adjustable straps and quick release latches so easy to remove for transport. I've also got a pair of Carradice front pannier which fit nicely onto the front rack and there's also the option of a bag on the rear rack.

I did some measurements of the bottom brackets and cranks on both the Birdy City and the Birdy Rohloff. Both cranks are 139mm across the ends. The chainline on the Birdy City (blue bike) is 47.1mm (measured by calipers between centre of chainring to the far side of the 40mm dia seat tube then subtract 20mm to get the centreline) whereas the chainline on the Birdy Rohloff is 50.8mm. This is significantly less than the 57mm recommended by Rohloff for the 13T sprocket on a splined carrier but that's another issue. There might be small errors in my measurements due to estimating the centre of the chainring axis.

I also did a trial fitting of the front derailleur on the Birdy Rohloff.The larger chainring is just within the limit of the cage when in the inner position. However, I did not spend time fitting the smaller chainring to see how it would line up. It might just work but I'm not going to spend time investigating.
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Old 05-16-21 | 10:24 AM
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I measure also about 51mm on the Birdy Touring 10s pictured above.

This distance is to the middle of the chain place on the single chainring (which is not a correct measurement for a double chainring setup, the distance must be measured to the middle of the two chainrings).

It seems to me that the crankset mounted on the Birdy Touring is actually made for a double chainring setup, I see the place to put the inner chainring.

I measure also about 51mm on my Birdy titanium factory equipped with a compact 52-36 crankset and a braze-on Shimano 105 front derailleur.

So if the Ridea front derailleur clamp is well dimensioned, it should be possible to mount a front derailleur and second inner chainring on the Birdy Touring.
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Old 05-17-21 | 03:21 PM
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Most chainring spiders are made such that one chainring can be fitted on the inside and another on the outside with the spacing correct for a front derailleur). The Shimano Nexus hub has a relatively narrow chainline (the shift mechanism is between the sprocket and the drop-out) which explains why the cranks and chainring are moved to the left.
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Old 05-19-21 | 08:56 AM
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Originally Posted by OMurchu
Thank you for your response on my question re: Gearing / Chain Ring / Nexus Gear Hub. I really appreciate it. I will go with your recommendation, and I will send photos and feedback once I have it completed. Thanks again
I completed the following:
Back sprocket: changed the 16T to 19T
Chain: the original chain was too tight, so I installed a new KMC X11 chain.

Outcome: Absolutely great! For the routes that I am riding (city / hard gravel / hills) the lower gear ratios as a result of the 19T sprocket make a huge difference, I can now use the full gear range of the Nexus 8. Thank you all again for your help on this!
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Old 05-24-21 | 11:39 AM
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Originally Posted by OMurchu
I completed the following:
Back sprocket: changed the 16T to 19T
Chain: the original chain was too tight, so I installed a new KMC X11 chain.

Outcome: Absolutely great! For the routes that I am riding (city / hard gravel / hills) the lower gear ratios as a result of the 19T sprocket make a huge difference, I can now use the full gear range of the Nexus 8. Thank you all again for your help on this!
Thanks for the update. The original chain might have felt tight due to the springing of the chain tensioner but, if you've left some slackness in the new chain then check that it doesn't come off when the bike is folded.
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Old 05-24-21 | 04:03 PM
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Originally Posted by JRat
Most chainring spiders are made such that one chainring can be fitted on the inside and another on the outside with the spacing correct for a front derailleur). The Shimano Nexus hub has a relatively narrow chainline (the shift mechanism is between the sprocket and the drop-out) which explains why the cranks and chainring are moved to the left.
Yes, most spiders are made for two chainrings but the Birdy is supposed to be a single chainring bike. On the Brompton, also single chainring, the spider is made to accept only one chainring.

Alfine are the same, for the same reason, also narrow chainline hubs.

The total opposite to the Rohloff that has a wide chainline (the original application considered by Rohloff was MTB but the hub was never a success for that purpose and found its market in high end everyday and travel bikes).
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Old 05-31-21 | 02:11 AM
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Originally Posted by JRat
I have abandoned my project to put a front derailleur on the Birdy City. Getting the bottom bracket unscrewed to enable moving spacers from left to right side was proving to challenging as it's not just the matter of having the right tool but also holding the tool in place while applying sufficient force.I didn't want to make a mess of the bike only to verify that moving the spacers isn't enough to shift the chainline enough to suit the derailleur's range of movement. I wonder if Birdies built with a front derailleur are fitted with a longer crank axle in order to get the chainline further out.

I've therefore decided that the Birdy City will have to be rehomed who doesn't want to tackle big hills and have got a Birdy Rohloff on order (I was offered an attractive discount on a new one which helped make the decision). I'll be interested to compare the crank axle length on the two bikes as the Rohloff hub has a wider chainline than the Nexus hub.

Another pending project, to fit ergotec AHS handlebars to a Birdy so I have more variety in hand and body positions, will wait for the Birdy Rohloff which should be early next week.
Birdy City (9SP STD) and Classic came with a square taper crankset which is not suitable for direct double chainring upgrade. Birdy Touring, 10SP Sport, GT and Rohloff have a wider chainline is because it's using the hollow crankset that provides a wider chainline. Many of my friends including myself have been using our hollow crank Birdys to do double chainring setup. That's the cheapest way to get a double chainring setup on Birdys.

The chain will scratch the rear fork when we use the square taper crank to do double chainring setup.

Also, Birdy with these BSA BB usually have 1x2mm spacer installed on the non-drive side and 2x2mm spacers on the drive side. That provides enough space for the 2nd smaller chainring t be installed. Funny enough the expensive Ti 2019 didn't have a single piece of spacer installed on the BB. That causes the chain to rub against the FD on Front-Small plus Rear-Large combination. I have no idea what was Pacific Cycles thinking in making such a low level mistake on a premium bike, or is it that they are taking customers for granted because we all paid to pre-order the bike?

Last edited by BabyCowHK; 05-31-21 at 02:50 AM.
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