Birdy thread
#676
Could it just be that the hanger needs to be tweaked? We've had some issues with EdgeRunner cargo bikes that come with 20" rear wheels and long cage derailleurs. Takes a bit of work,but in the end we get them working properly.
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C'dale BBU('05 and '09)/Super Six/Hooligan8and 3,Kona Dew Deluxe,Novara Buzz/Safari,Surly Big Dummy,Marin Pt Reyes,Giant Defy 1,Schwinn DBX SuperSport,Brompton S6L/S2E-X/M6L-X/S12 T Line


C'dale BBU('05 and '09)/Super Six/Hooligan8and 3,Kona Dew Deluxe,Novara Buzz/Safari,Surly Big Dummy,Marin Pt Reyes,Giant Defy 1,Schwinn DBX SuperSport,Brompton S6L/S2E-X/M6L-X/S12 T Line

#679
Junior Member
Joined: Oct 2015
Posts: 5
Likes: 0
birdie is a tad flawed in design.
solutions i know of are fit narrow tyres, change to ihg .
else change to a short cage rear mech which also improves ground clearence. then the cage doesnt reach down to the tyre. if you do this you may want to fit a chain tensior,else chain falls off in folding, 70 pounds please. but then you can get rid of the chain catcher that gets stuck inthe rear cogs and breaks transmission parts as it locks up. it worth shelling out on the new chain tensior in the long run.
solutions i know of are fit narrow tyres, change to ihg .
else change to a short cage rear mech which also improves ground clearence. then the cage doesnt reach down to the tyre. if you do this you may want to fit a chain tensior,else chain falls off in folding, 70 pounds please. but then you can get rid of the chain catcher that gets stuck inthe rear cogs and breaks transmission parts as it locks up. it worth shelling out on the new chain tensior in the long run.
#680
Junior Member
Joined: Oct 2015
Posts: 5
Likes: 0
[QUOTE=Winfried;18305271]This one from Pacific Cycles:

QUOTE]
Hi Winfried Thanks! Do you know if this still works if I change to a smalle chainring?
QUOTE]
Hi Winfried Thanks! Do you know if this still works if I change to a smalle chainring?
#681
#682
Senior Member
Joined: Sep 2008
Posts: 3,027
Likes: 3
From: York UK
Bikes: 2X dualdrive Mezzo folder,plus others
I don't know if medium cages exist. I use the short type with larger cogs.
I don't see why a smaller chain ring would make any difference to the functioning of the chain tensioner.
The long cage on a birdie is to keep the chain tension in folding to stop it coming off when folding. I changed to a short cage to get more ground clearance. This reduces the amount of sticks caught in the toggle gogs, I bought the large cogged rear mech so the chain turn was wider to reduce jamming. Seems to have worked well. Shimano Alturus mech.
I don't see why a smaller chain ring would make any difference to the functioning of the chain tensioner.
The long cage on a birdie is to keep the chain tension in folding to stop it coming off when folding. I changed to a short cage to get more ground clearance. This reduces the amount of sticks caught in the toggle gogs, I bought the large cogged rear mech so the chain turn was wider to reduce jamming. Seems to have worked well. Shimano Alturus mech.
#684
Senior Member
Joined: Sep 2008
Posts: 3,027
Likes: 3
From: York UK
Bikes: 2X dualdrive Mezzo folder,plus others
Yes short cage minimises debris stuck in rear transmission. Reduced to same level of problem as my mountain bike. Solves cleareence issue with 2 inch wide big apple tyres catching rear mech.
Yes chain tensioner keeps chain on when folding 99% of the time.
I realise not all disraillered# birdies may have issues with rear mechs catching wide tyres.
# keeping up snafus tradition of mispelling this word.
Yes chain tensioner keeps chain on when folding 99% of the time.
I realise not all disraillered# birdies may have issues with rear mechs catching wide tyres.
# keeping up snafus tradition of mispelling this word.
Last edited by bhkyte; 11-11-15 at 03:59 PM.
#686
I have tried short, medium, and long cage derailleurs on Birdy bikes. The medium cage derailleur doesn't have any issues if your chain is the right length, and you are running taller tires. When I ran the long cage derailleur the cage reached to the brake surface of the rim, and could catch things on the ground if I wasn't careful. I like to run a mountain bike rear cog on my Birdy as it makes climbing the steepest hills quite easy, and pulling a trailer with my daughter in it. I am running and XTR cog with a 34 tooth ring.
I now run a medium cage XTR derailleur with a set of 20" wheels, and have no worries, there is plenty of ground clearance. I run Panasonic slicks, which are quite narrow, but with 20" wheels the cage isn't going to come close to the tires anyway.
For a tensioner, I found a spring-loaded parallelogram type which bolts around the bottom bracket, with a jockey pulley just below and behind the chain wheel, it works perfectly. I couldn't easily fit the original tensioner to the new XTR derailleur, so I needed another option.
I now run a medium cage XTR derailleur with a set of 20" wheels, and have no worries, there is plenty of ground clearance. I run Panasonic slicks, which are quite narrow, but with 20" wheels the cage isn't going to come close to the tires anyway.
For a tensioner, I found a spring-loaded parallelogram type which bolts around the bottom bracket, with a jockey pulley just below and behind the chain wheel, it works perfectly. I couldn't easily fit the original tensioner to the new XTR derailleur, so I needed another option.
#688
No, it was not difficult. There is no real "conversion" necessary, the wheels bolt on and fit with no clearance issues. The only modification necessary is to the brakes, the bosses are are not in the right spot. There are two options for the brakes, the simplest one is to use brakes with pad adjustment slots long enough for the pads to center over the rim, or to use offset adapters.
The bike is noticeably faster with 20" wheels, and the ride is more stable, but the bike does not fold as compactly, though it setill easily fits into a Birdy bike bag.
The bike is noticeably faster with 20" wheels, and the ride is more stable, but the bike does not fold as compactly, though it setill easily fits into a Birdy bike bag.
#689
Senior Member
Joined: Jun 2008
Posts: 90
Likes: 0
From: Sarasota, FL
Bikes: Brompton - Surly Cross Check - Birdy Red
No, it was not difficult. There is no real "conversion" necessary, the wheels bolt on and fit with no clearance issues. The only modification necessary is to the brakes, the bosses are are not in the right spot. There are two options for the brakes, the simplest one is to use brakes with pad adjustment slots long enough for the pads to center over the rim, or to use offset adapters.
The bike is noticeably faster with 20" wheels, and the ride is more stable, but the bike does not fold as compactly, though it setill easily fits into a Birdy bike bag.
The bike is noticeably faster with 20" wheels, and the ride is more stable, but the bike does not fold as compactly, though it setill easily fits into a Birdy bike bag.
Any specific things I would need to know before purchasing 20" wheels? Also any chance you could post a picture of the bike with the 20" inch wheels.
Jim
#690
Junior Member
Joined: Oct 2015
Posts: 5
Likes: 0
No, it was not difficult. There is no real "conversion" necessary, the wheels bolt on and fit with no clearance issues. The only modification necessary is to the brakes, the bosses are are not in the right spot. There are two options for the brakes, the simplest one is to use brakes with pad adjustment slots long enough for the pads to center over the rim, or to use offset adapters.
The bike is noticeably faster with 20" wheels, and the ride is more stable, but the bike does not fold as compactly, though it setill easily fits into a Birdy bike bag.
The bike is noticeably faster with 20" wheels, and the ride is more stable, but the bike does not fold as compactly, though it setill easily fits into a Birdy bike bag.
#692
The Metropolis, UK
Joined: Aug 2007
Posts: 2,353
Likes: 2
Anyone who wants to talk and share about Birdy Bikes can also join us on our new FB group as well:
https://www.facebook.com/groups/1649726268626764/
https://www.facebook.com/groups/1649726268626764/
#693
Senior Member
Joined: Jul 2014
Posts: 288
Likes: 17
From: Newcastle upon Tyne, England
Bikes: Brompton H3L, RAF, M3L, Dahon, Giant NRS, GT
#694
Senior Member
Joined: Jan 2016
Posts: 2,244
Likes: 19
From: Bali
Bikes: In service - FSIR Spin 3.0, Bannard Sunny minivelo, Dahon Dash Altena folder. Several others in construction or temporarily decommissioned.
Any issues swapping out the stock wheels for 20" (406) on the disc brake Birdys?
#695
Senior Member
Joined: Jul 2014
Posts: 288
Likes: 17
From: Newcastle upon Tyne, England
Bikes: Brompton H3L, RAF, M3L, Dahon, Giant NRS, GT
#698
Senior Member
Joined: Oct 2014
Posts: 88
Likes: 0
From: Australia
I've just bought a Birdy Blue with the SRAM dual drive. I think this is last of the old frame in pale blue. My question is, is there a trick in folding this bike? At the moment when the front wheel swings around, it hits the clickbox and because it doesn't fold in tight enough the handlebar does not have enough room to drop down past the main frame.
So at the moment, it is folding into a big mess of parts!
Thanks :-)
So at the moment, it is folding into a big mess of parts!
Thanks :-)
#699
Senior Member

Joined: Aug 2005
Posts: 564
Likes: 1
From: San Francisco, California
Bikes: Brompton H6, Schwinn Mirada, Cruzbike Sofrider. Used to own: ICE B1, 2 F-frame Moultons, Koga Myata Elevation 5000 mtb, Challenge Hurricane, Riese & Mueller Birdy Silver, Actionbent Tidalwave 3
Can you attach a picture of the bike, folded as far as your can get it? It will be easier to help if we can see what's going on!






