I got a used MKII Birdy Light, whose 56T single chainring I'd like to replace with a double eg. 56/40T.

Using a Litepro derailleur and a B-series Litepro clamp, it look like the fork won't move far enough outward to reach the outer ring.

According to the datasheet, the bottom bracket is a 113mm, TH BB-7420ST.

On a Birdy (Light), has someone successfully replaced the single chainring with a double? What derailleur did you use, and did you have to replace the bottom bracket for a wider one?

Thank you.

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Edit: Another issue is the seat slides down unless I tighten the clamp really hard. Cleaning the seatpost + inside with a clean rag and degreaser didn't help much. Any idea what I could try?
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Edit: One more question: Using this crank puller, I was unable to remove the crank, with the Birdy Light supposedly using a 68x113mm TH Industries BB-7420ST bottom bracket.

Should I try harder, or are there different pullers to match different square taper bottom bracket axles?

https://cimg8.ibsrv.net/gimg/bikefor...07d0316951.png
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Edit: It was the right puller. The cranck was just super tight.

I am unsure about birdy 2 but birdy 3 uses a 68mm BSA threaded bottom bracket.... So either can use a 24mm crank or a 30mm crank depending on the crank spindle.
There are a few options available out there.

I have the front wheel specs.... Let me see if i can find it for u

https://cimg9.ibsrv.net/gimg/bikefor...e9049121b4.jpg
This by any chance what u are looking for ?

New Wheels for Birdy Disc
 

Come on.... it not that hard to get a new set of wheels assuming you dun mind mismatch hubs.....
All you need is a birdy front disc hub which can be found here.....
https://www.cycletaiwan.com/circus-m...-disc-hub.html

For the rear you can choose any 135mm QR hubs out there..... Like DT Swiss 350 , White Industries etc.....

Hi ,

Link as requested....

https://www.dropbox.com/s/1fiyp60u1vd311b/Test.mp4?dl=0

It depends of what type of cassette you want to mount.

For a small wheel bike and without a bigger than usual chainring (60 or 65t that anyway isn't compatible with the new Birdy chain tensionner) a cassette with a smaller cog of 9t or 10t is needed (as mounted by R&M on the Birdy Touring).

The classic Shimano/SRAM freewheel body is limited to 11t as smallest cog.

R&M was using the now discontinued Shimano Capreo 9s system and is now using a Sunrace system (R&M use the 10s one, there is also a 11s)..

Another option that I have chosen is to use the SRAM XDR system.

Dropbox is not safe, can you post it somewhere else ?

For the Birdy disc front hub, there are indeed some options, also Hubsmith and Ridea but not easy to really buy.

This work for you ?

Front disc hubs if u want to buy a set yes it will be expensive.... Hubsmith , Ridea , Bzwheels all have hubs that will work on birdy disc.
However i would recommend getting the front hub and rear hub separately as it is easier to source the rear hub from your local wheel builder then it is to buy the entire set and ship it.
Besides u only need the front hub which u can get online easily and if need be the bearings can be changed to match the rear ones.
However if u insist on matching the hubs then it will be expensive I must.

If you choose to go with SRAM XDR system then Ridea and BZWheels are out for now.... That means u only left with hubsmith.
Alternatively get the front hub online and u can get a better rear hub to build the customs wheels at almost the same costs..
Just Saying

I can buy Ridea and Hubsmith Birdy disc front hub separately.

For the rear hub, as said the problem is to have a freewheel body that accepts a smaller cog with less than 11t. Besides Sunrace and its proprietary body derived from the old Shimano Capreo, there are now SRAM with XD/XDR, Shimano Microspline and Campagnolo N3W

Thanks for the video.

But this Brompton front block adapter for Birdy is not the H&H adapter that I have, see picture below from the website of Bikegang (mine is slightly different from the first picture, it is like the second 3D drawing).

As you can see, the angle of the Brompton block is very different on the two adapters, on your it is much more vertical.

When I turn the fork, it also slightly pushes on the clip but not enough to unlock it and it only happen at a big fork angle that never happens when riding.

https://cimg5.ibsrv.net/gimg/bikefor...ac77e5f28a.jpg

https://cimg6.ibsrv.net/gimg/bikefor...ee8bbd74b5.jpg

I'd like to install a double crankset on a Birdy Light from 2010 (ie. MK II).

But using the current 113mm bottom bracket, I fear the chain will rub against the frame when on the inner ring.

Has someone successfully done that upgrade, and could offer some feedback (bottom bracket, clamp, derailleur, double crankset)?

Thank you.

https://cimg1.ibsrv.net/gimg/bikefor...743483c23b.png

Hey, so recently got my hands on a Birdy MK1. It was cheap and the frame still looks solid no cracks etc, just the seller neglected to tell me the free-hub is dead.

Turns out it is very hard to get a hold of 18inch wheels here in the UK. And finding a replacement hub seems next to impossible (20 year old part out of production I assume)

The Hub in question is a Shimano Nexave FH-T300 Silent Clutch
7 speed cassettes

Not sure what to do here, seems like a simple fix if you know what your doing. Any suggestions would be much appreciated. Can I use a different hub without wheel rebuild, any where I can find parts etc

Thanks

you should look on eBay Kleinanzeigen in Germany there are often Birdy parts like wheels. Some sellers will ship to UK.

Example: https://www.ebay-kleinanzeigen.de/s-...53098-217-2865

I think that some of the people who sell Birdy bikes might have some spare parts although not listed on the internet. However, have you tried servicing the freehub? See, for example, and . If that doesn't work then ,if the rim is in good condition, one option is to build a new wheel using the old rim and a new hub. From what I've ready the Silent Clutch freewheel mechanism has been replaced by the standard (clicky) pawl and ratchet freewheel mechanism. What really matters is the distance between the drop-outs. Any hub of the right dimensions will fit the bike and this opens up the opportunity to fit, for example, a 9 speed cassette with a wider gearing range although a new derailleur and shifter will probably be required.

You've therefore got several options: (i) Attempt to service the freehub. (ii) Rebuild the back wheel yourself while keeping the 7 speed gearing;(iii) Rebuild the back wheel using a hub that accommodates a wider range cassette; (iv) Contact a business with known skills in maintaining bikes, preferably Birdys to see if they will do the work. A couple of possibilities are:
https://www.kinetics-online.co.uk/about-us/
https://www.avonvalleycyclery.co.uk/

Pedalkraft has a lot of Birdy spare parts, maybe also old ones !

The rear hub is a standard 135mm OLD hub.

Are there spacers on your bottom bracket? If so, how are they arranged? These photos show that the Birdy Rohloff (white) has no spacer on the left side whereas the Birdy City (blue) with 9 speed derailleur has a spacer on the left side. Both bottom brackets are the same length.
https://cimg9.ibsrv.net/gimg/bikefor...e8a2d00440.jpg
https://cimg0.ibsrv.net/gimg/bikefor...e3a6ec85b2.jpg

No spacer. It's a square taper bottom bracket, so I might be able to add a spacer or replace that BB with a hollow one like above, but before going ahead, I wanted to check if someone had sucessfully installed a double crankset (clamp, BB, derailleur, crankset, shifter).

To know if it will work, you need to measure the chainline.

R&M adapts the chainline of the Birdy according to the rear transmission, its different for the different Birdy with different IGH and Birdy with derailleur.

Greetings from sunny Singapore! I have not done the conversion myself, but a local bike shop has done it on 50/34T using Shimano Claris R2000 Braze-On FD.

Oops I'm not allowed to post links. You can search for the LBS name, Green Basikal on facebook.

What model of Birdy do you have ?

What is the brand of the front derailleur mount used for the conversion ?

You could maybe post some pictures of it.

I have a Birdy GT. Let me clock 10 posts and I can attach pictures of my bike and the link to the double chainring Birdy.

The brand of the front derailleur is Shimano.

I had tried to upload a picture of the Birdy with dual chainring in my album. Can you check if you could see?

​​​​​​

The Birdy GT is a derailleur Birdy, it has the chainline distance of a derailleur bike which is compatible with a front derailleur

There are several bike pictures, b do not see any Birdy picture on the FB page of Green Basika.

See . In particular see

Over here, we have 5 Birdy models (excluding the P40), they are the new classic (with tubular frame), the City, GT, R20 and the Rohloff (all having the same monocoque frame). All the above models only have single front chainring.

The Birdy with internal gear hub like the Birdy Rohloff and the R&M Birdy City have a different value of chainline and it might be more difficult to fit a front derailleur on hem than on Birdy with a rear derailleur like the GT, Standard, Touring...

Thanks for attaching the screenshot! Looks like there are some extensive modifications needed to install a dual chainring.

I will be sending my Birdy for Rohloff conversion by next month, will ask more about the amount of modifications required.

On the Birdy Rohloff, the dropout is different and the chainline too to accommodate the wider chainline of the Rohloff hub (+ of course the rotating grip and dual cables furnished with the Rohloff hub).

I wonder about absorbing the chain slack on a Birdy with a double ring in the front. The somewhat unusual tensioner on Brompton absorbs plenty of slack and I was able to get away with a triple ring in the front without essentially any modifications regarding the slack - I can actually fold the bike with the chain on the smallest ring in the front. However, when I replaced the rear Brompton derailleur with a regular one, like on a Birdy, I ran into problems with the slack for a folded bike. I made a chain catcher, such as one I saw in photos of some Birdys, but it only helped with one ring in the front. Two or more rings were turning into disasters. You could always fold, of course, exclusively with the chain on the largest ring, but it is a hassle.

Just curious, do you guys do a lot of climbs? I find the stock 10-speed with single chainring more than sufficient for my commute. The only mod so far is to upgrade from 52T to 56T Oval.

The titanium Birdy is factory equipped with a 52-36 front and Shimano 105 front and rear derailleur (rear is a RD-5800-GS, front FD-R7000, the frame has a front derailleur mount for a braze-on front derailleur).

It has the current Birdy chain tensioner around the crankset chainring.

Folding is OK whatever the chainring with, as always for BIrdy with a rear derailleur and cassette, the chain on the smallest cog.

Now, the frame geometry of the TI Birdy is different from the Birdy 3 and I do not know if it will also work with a Birdy 3 with double chainring?

About the choice of the front 52-36, with the small wheels of the Birdy, 36t front gives really short gears, I never need the 36t front + 32t rear I have. A 53-39 combination is probably better.

The original gearing of the Ti Birdy (and R20 SP 11) with only a 11-28 cassette is not a good choice (gearing too long for hills on the 28t, too short on flats with the 11t). Its probably the reason why Pacific Cycles mounted a front compact crankset and front derailleur on the Birdy Ti. The 9-32t cassette range of the R&M Birdy touring is a much better choice.

Thanks much for the link. Looks like a wider bottom bracket is indeed required, as a replacement for the original TH BB-7420ST 113mm square taper.

Good call, although I personally don't mind since the smaller ring is only used on very steep hills, and i'm always back on the bigger ring when I need to fold to catch a train, etc.

It depends where you live, and/or if you use the folder for touring (= heavy bike) like I do.