Right. So there must be some differences in frame dimensions among the Birdy's: R&M, Pacific, and Bianchi, and over time. Speculation: R&M could have made the suspension hinge slightly wider, to reduce sideways flex and hinge wear.

Anyway. Here are some shots from my ride on Constitution Day, on Sunday:

https://cimg2.ibsrv.net/gimg/bikefor...331a6e4632.jpg
Constitution Day ride


https://cimg6.ibsrv.net/gimg/bikefor...37291983ce.jpg
Svarstad, Norway

As far as I know, all frames from the same generation are the same, whatever the brand and made by Pacific Cycles.

R&M receives the frames and assemble the bikes with a different choice of components than Pacific Cycles. R&M also discontinued the Birdy World models.

For Bianchi, just a guess, but I think they are also assembled by Pacific Cycles because its only sold in Asia ??

The only frame which is really very different is the titanium Birdy designed, made and sold only by Pacific Cycles (there were 3 generations).

But there were several generation of frames.

I do not know to what generation the Bianchi belongs but its transmission is very different, its a 8s Sram PG-850 11-30T.

My Fretta has a monocoque frame, it runs Ultegra hubs and DT spokes with Alexi 20" rims, a Dura Ace 7800 crankset, and a XTR 11 speed cassette and rear derailleur. It was originally equipped with Shimano Alivio components.

So you actually changed all transmission components wrt. the original equipment !

You now have an MTB transmission with a road crankest, any chainline problems ?

Do you have a double chainring or single on your Dura Ace crankset ? How big is it ?

No chain line issues, no rubbing, though there is some noise from chain deflection when running the lowest gear. I had run a double on the front, but switched back to a single with a 53 tooth ring. Everything was bolt-on, no modifications were necessary. The Dura Ace 7800 does not have enough Q factor to run a front derailleur on my particular frame, so it needed to be moved out a bit. I found the extra chain ring and components to be redundant, so I returned it to a 1x11 drive line, and am happy with it.

Hi, first post ;)

I bought a 2nd hand (mk1 or classic)Birdy in dark blue last month, replaced the saddle with a Specialized “The Cup Gel”(as they sold out of the expedition gel saddle)
And pumped the Maxxis Birdy tyres to 90psi and went to town on it, 40kph ect.

as well as it rolls I had to change out the tyres, seamed really limited to either the 3 from
schwalbe, or a few from BMX websites...

I ordered a pair of Big Apples and some matching 5a inner-tubes and then waited over a week and finally got them yesterday and installed them today myself. At 42psi (they rated for 30-70psi)

ive had a quick 30min 7k ride tonight and they’re fantastic! Rolls really smooth and compliments the limited suspension(shock absorbing) the bike has.

if anything it’s making me want to try out the wider, 2.2/2.3/2.4inch BMX offerings in 18inch/355 (I really wanted a neon pair of “fireballs” but sold out...)

has anyone here got any joy from BMX tyres on their Birdy?

when I installed the front big apple tyre, I removed the fender-mudguard and even then the fork had a small protruding moulded screw nub in the wheelwell that rubbed on the Big Apple tyre bang in the middle of the tread so I had to put a spacer between the fork and pumped up tyre and then adjust the quick release lugs to sit in the forks sprockets a touch towards the ground as so not to have the tread reach the forks wheelwell nub!!

back wheel was fine, I also removed the fender-mudguard as it is summer after all :)

Looks like they could easily take 2.2” wheels or 2.3” after I installed the 2.0” big apples, heck maybe even a pair of 2.4”s ;)

regarding suspension, I have the stock medium red PU elastomer, it’s seams ok and not “aged” as I was expecting considering it’s a 2nd hand mk1 style.

but I am itching to upgrade to the multi-s rear shocks, as the interior picture I’ve seen online showing the mini spring and two PU units seam on the money for me, or is the u-design/Urbane Design “adjustable” rear shock better?

Anyways better stop now before I carry on, any advice would be appreciated a lot :)

can I get a link please?

as I can’t seam to find their website online.

Welcome!

Nice! Schwalbe is among the very best, and Big Apple is really good at what it does. I don't know, but I would expect BMX tyres to be a bit stiffer and heavier. They are supposed to take a lot of abuse, and the thread often goes far down the sides.

I am happy with the elastomers, though I replaced the rear red with a green (harder) as I thought there was too much sag, pedals hit the ground too easily in turns. It's good now. When I pulled off the red one, I noticed it was already bent slightly towards ground, after only 1500 km or so. I could perhaps have gained a bit of ground clearance by rotating it 180 degrees. That's something to consider for you since yours is 2nd hand, perhaps you could "renew" it that way. No tools required, just twist it.

yes, I saw how easy it is to rotate it, but my red unit seams to be in good shape, no compression on the underside at all which surprised me as PU normally ages after a decade ect, maybe the seller I bought it off kept the bike in a dark cool garage ;)

on the maxxis birdy 1.50” tyres the elastomer didn’t sag that much but I noticed yesterday that on the 2.0” Big Apples that I felt it sagging much more!

i could get the green PU as I’m sure it would make a big difference, but really want that Multi-S shock, esp if the blue/gold is still obtainable to match my dark blue frame.

Yes, if they can take abuse I was thinking that would be ideal, I don’t mind it being a bit heavy, and the small range of 18” wheels I saw on sourcebmx website (I cant post links yet) most of them had similar grip/tread pattern like the Big Apples.

one has caught my eye, Cult Dehart Slicks, which are semi slick down the middle, so am thinking they could handle roads better than the aggressive bmx tyres out there

That one is nearly slick on the sides too, should roll well if you can fit it. I like all the colour options you can get for bmx.

Multi-S rear is harder that the red PU.

If you are interested, I do not use my set of Multi-S suspension. Contact me by private mail

great.

i would of replied sooner it’s just this forum only let’s be have 5posts over 24h period and couldn’t reply to the PM until I had 10posts...

Edit.

I've mounted a 60t successfully with the pacific cycles tensioner. It just BARELY clears... but useable!

Hi fellow birdy owners!

When folding in the front wheel, how close to the rear wheelset does it actually go?

Currently, my front wheel QR nut hits the Rear derailleur (currently using XTR midcage) --> Is this normal?
Anyone have pics of how close your front wheel folds in to the rear?


Assuming i had NO rear derailleur, I'd probably be able to fold it in another 5-10cm.

Thanks!

My bike came with a Deore XT derailleur and the frontt nut would shove the derailleur out of the way when closed. Caused some wear on the casing but didn't seem to be a problem otherwise. I currently have a current gen 105 derailleur on the bike and there is no interference.

Yes, this is a consequence of the design. My Touring with Deore Trekking derailer had this problem. I could improve on it by carefully positioning the front wheel in the optimal position. It also depends on the QR skewer, I used one from PitLock that is absolutely minimal on one end, nearly flat: https://www.pitlock.de/en/shop/quick...en/set-01.html

Now I don't have a derailer, and the shimano chain tensioner doesn't have this problem. I guess it folds a bit closer, I can take some pictures. Either way, you have to beware of this interference when transporting the folded bike. If you avoid touching the derailer, it will hit something else instead. Hub, spokes, or frame. Vibration can cause damage or at least ugly marks. Some foam/rubber in a strategic location can help.

Currently the limiting factors for my fold is the front tyre (good, that's a soft buffer)...

https://live.staticflickr.com/65535/...f066389d_c.jpg
IMG_20200619_112648767 by gunnsteinlye, on Flickr

...but also the "shoulder" of the shimano chain tensioner hitting the front hub/spokes:

https://live.staticflickr.com/65535/...e88213ec_c.jpg
IMG_20200619_112725124 by gunnsteinlye, on Flickr

If the tensioner "shoulder" was less beefy it could fold closer. The Rohloff tensioner seems narrower, but also has less chain uptake, so might give a slack chain when folding.

Assuming no tensioner, the next limiting factors are the fork hitting the rear mudguard stay, and the front pannier distance bar hitting the rear wheel spokes. Perhaps also the QR nut hitting the cassette, if you have one. With no mudguard and no front carrier, the fork would hit the upper part of the rear dropout, unless stopped by the tyre/frame touch point.

https://live.staticflickr.com/65535/...c7b6f4da_c.jpg
IMG_20200619_112915235 by gunnsteinlye, on Flickr

https://live.staticflickr.com/65535/...a25f9f73_c.jpg
IMG_20200619_113049811 by gunnsteinlye, on Flickr

Top view of the fold:

https://live.staticflickr.com/65535/...f98c3333_c.jpg
IMG_20200619_113237200 by gunnsteinlye, on Flickr

I ordered a pair of Salt(wethepeople) “tracers” tyres in 18”x2.20” (apparently are only 2.11” wide)

to replace my 2” big apples, as I saw there was easily 8mm clearance on each side of the 2” big apple tyres so should be doable.

i got them in Teal colour, as it’s summer after all, I didn’t have the guts to go for the neon red ones. Ha.

am hoping I can run these tyres faster than the big apples, but with similar air suspension properties :)

I’ll post some pics when I get them installed later this week.

and if they run well, l’ll May venture into more bmx tyres ha.

now if only some genius can figure out how to install 20” skyway tuff wheel 2s...
with panaracers of corse :)

Does anyone know if a 30mm crank fits the Birdy?

I know the following:
BSA threaded (so in theory we can fit in BSA24 Bottom bracket)
24mm cranks work with BSA24 BB.

Im thinking of getting a BSA30 BB, which will allow me to fit a 30mm crank.
While the Bearings of the BSA30 BB will fit the crank, I'm not sure if the CENTER of the BB (inside the frame) will allow a 30mm crank through.

Thanks!

New Birdy!
 

Just ordered a Birdy City from Mighty Velo here in Singapore, spent 3 days reading through all 53 pages of this thread. What I only say is "wow" at the passion for this bike! Can't wait to get mine!

What a nice way of saying that we fight too much :D
Congrats with the bike, wish you tailwind and great rides!

Congratulations. Don't forget to post pics and let us know how the buying experience was. Did they carry the new Birdy R20 11spd?

I know there are Birdy cycling groups in Singapore. Enjoy your bike.

Thanks.. shipping is scheduled for next Monday, apparently they have a huge backlog of orders not just for Singapore but throughout the region. Bromptons are all out of stock in LBS and secondary market is going crazy, with used bikes going for more than MSRP for new bikes. Some are just snapping up whatever new ones left to sell for a profit.

Yes Mighty Velo carries R20 as well and locally they are advertising 17 colors to choose from. Not sure if they really carry that much stock but guess Taiwan is not too badly affected by COVID19 so the supply chain has not been disrupted. Guess we are lucky in Singapore!

Too bad I can't sell my used folders there. Makes no sense that people would pay over MSRP for a used bike.

Changing from 7speed to 8/9speed
 

Hi, I have the old Mk1 birdy with 3speed hub with 7speed/cassette gears on the back wheel.

is it easy to just change the “cassette” 7speed gears with a 8speed or 9speed cassette?

and then prob would have to change the grip shift gear selector on my handle bar also to a 8-9speed setting one.

as I’m after a couple more slower/lower gears to save my knees from surgery in the future ;)

any help would be appreciated :)

The simplest and cheapest way of getting lower gears is to get a smaller front chainring. But that also gives you a lower top gear. It requires no other changes except maybe shortening the chain.

To keep your current top gear but add lower gears you can switch to 8/9 speeds as you say. Going from 7 to 8/9 speeds you need to replace the cassette, the chain (probably, at least for 9 speed), the derailer, and the gear shifter. You can probably keep the front chainring you have. But there are several important caveats:

You need to know if you have a cassette freehub (good) or a freewheel hub (less good). Your hub is either an SRAM DualDrive or a Sturmey Archer. As far as I know, both are cassette only, but I'm not sure. More info:
https://sheldonbrown.com/free-k7.html

8/9 speed cassettes will normally not fit on 7-speed hubs: https://sheldonbrown.com/k7.html#bodycompat
But you may be able to find an 8/9-speed cassette body that fits your hub, look for it in the 2nd hand market or ebay.

Beware that upgrading from 7 to 8/9 speeds may increase your hub width, which requires spreading the rear dropouts apart, a dangerous operation on a small wheel alu frame. This may be a dealbreaker. Try to measure the hub/dropout width. If it's less than 135 mm, it may not be possible to go beyond 7 speeds safely.
https://sheldonbrown.com/k7.html#up7

If you have the SRAM DualDrive, this has a combination shifter that shifts both the hub and the cassette. You'll need to find an 8/9 speed one, and since they're not made anymore afaik you may have to look for it in the 2nd hand market or ebay. You don't need a special DualDrive derailer, but it must be an SRAM MTB derailer.

If you have a Sturmey Archer hub it's easier, you can choose between SRAM or Shimano style derailer/shifters, just make sure both are of the same type (or if not, verify they are compatible).

If all this turns out to be impossible or too expensive/risky, you may be able to find a 7-speed cassette with more range than the one you have. Count the number of teeth on the smallest and largest cogs, and compare with what's available, e.g. https://www.bike24.com/mtb-cassettes...%5D%5B424%5D=1
NB: If your smallest cog is more than 11 teeth, it may be because your hub doesn't allow that small cogs, in which case you shouldn't buy any cassette with an 11t cog.

Interesting news on the rumour mill. Looks like Campy are poised to announce a 10T or smaller compatible cassette body. Another choice for us small teeth needing Birdy users as an alternative to the SRAM XD/XDR and SunRace hubs.

https://weightweenies.starbike.com/f...p?f=3&t=162492

The original Birdy Blue with Sachs (prior to SRAM buyout, when it went 8sp) had a 7 Speed based dual drive with separate twist shifters both with standard shimano 7 sp pull ratio's. Any old shimano/sram compatible 7 speed Rear Mech and shifter will do the job. I had a pair of standard Sachs Waveys that did the job nicely with an M739 XT rear mech. Still have set in the Shed afaik.

RandomHajile Im surprised the Dual Drive (if thats what it is) isn't low enough for you, with a 52T chain ring I could climb cliffs with it, I must have used that gear <10 times on 5+ years of London commutes. I wonder if the if you have a bigger than standard chain ring?

Right, if OP has this one then they could keep the 3x shifter and replace the 7x one, if they go 8/9x. But the easiest/cheapest way to lower gears is a smaller chainring. And the easiest way to bigger range is a 7x cassette with bigger range, if it exists.

I found a SRAM/Sachs Spectro 3x7 manual at https://sheldonbrown.com/sram/dtm_ghs_my00_e.pdf
According to this, the hub is 135 mm OLD, which means newer 8/9/10 speed versions of dualdrive or Sturmey Archer 3x cassette hubs will fit the frame, in case other solutions don't work.

It also says that a 12-28t cassette is standard (and that others may cause malfunction, but I wouldn't worry much about that on a small wheel bike). And it is indeed a cassette hub, not threaded for freewheels. I've seen that 7-speed 13-34t cassettes exist, this would also give lower gears in a simple way, while sacrificing a top gear.