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Is anyone riding the R20 Birdy?

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Is anyone riding the R20 Birdy?

Old 03-17-20, 09:48 PM
  #1  
keyven
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Is anyone riding the R20 Birdy?

Just wondering if anyone is riding the R20 Birdy with 20" wheels? What do they think of it, and how much difference does it feel compared to the earlier models?
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Old 03-18-20, 04:55 AM
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Before deciding about the wheel size of my new wheels, I tried it temporarily with ETRTO 406 wheels from another bike (but without front brake as the Birdy disc needs a special hub with the disc on the right side at a different position than the standard left side disc).

The real difference doesn't come from the wheel size but from the tires type+width.

Since you can only put narrow up to 28mm tires on the ETRTO 406 wheels and that all 28x406 tires are high pressure road tires, it rides more or less the same than similar tires on the ETRTO 355 wheel but is different from what you normally experience with the Birdy because all usual Birdy tires are much wider with lower pressure.

Te results is a faster bike, more reactive. For me the comfort is still OK due to the full suspension but others may consider it not comfortable enough.

FYI, after this test, considering that there are too few tires types possible with the ETRTO 406 wheels, I decided to mount... ETRTO 349 wheels for which there are now more tires types than in ETRTO 355 (and especially more high performances road tires).
My Birdy is equipped with Greenspeed Scorcher 120 tires inflated at 7bar which are very fast tires, as fast as the best 28x406 tires (the Schwalbe Pro-one).
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Old 03-18-20, 07:10 AM
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Thanks for the informative reply. I'm still holding hope that I can install a less racing-oriented tyre and one that's more off-road. Do you know what's the widest tyres (or model) that can be used? It seems here the R20 comes with Panaracer Minits pre-installed (20 x 1.25).
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Old 03-18-20, 06:34 PM
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I do not have an R20 but I do have a set of 406 rims on my Birdy using 28-406 Conti Contact Speeds. Since it's hard to find actual information on the mod, here are some pictures showing the front clearance (the rear has quite a bit more space) and how the fold is affected.






Last edited by grayrest; 03-18-20 at 06:41 PM.
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Old 03-19-20, 03:33 AM
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The first limitation is the front mudguard especially the two bolts.

With my wheels equipped with Schwalbe Pro-one 28-406 (old model, not the 2020 ADDIX model) that are in fact 32mm wide, I had to remove the front mudguard.

If you do not want a front mudguard or if you modify the mounting of the front mudguard with flatter head bolts, it will be possible to mount wider tires but I do not know how wide. I doubt that you could mount MTB ETRTO 406 tires that are much wider than 28mm.

For the Conti above, I guess they are really 28mm wide (I have Conti Grand Prix 28x406 on another bike and they are really 28mm wide).

I also have Panaracer Minits Lite PT and on my wheels these are only 30mm wide while they are announced as 32x406 tires.

BTW, my Birdy is a Titanium gen3 Birdy, I do not know if the tire clearance is the same as on the aluminum Birdy. The only thing I can say is that the mudguards are the standard mudguards used for the aluminum Birdy.
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Old 04-24-20, 05:34 PM
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Lowhenry
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I don’t know whether I should get Birdy GT or R20
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Old 04-24-20, 11:39 PM
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Originally Posted by Lowhenry View Post
I donít know whether I should get Birdy GT or R20
That very much depends what you intend to do with the bike but I have no interest in the GT. I think 355 wheels work well for packed dirt or crushed limestone but are too small to handle most gravel. The suspension helps but it's sized for stuff like cobblestones or cracks in the road and not for chunky gravel rocks. I didn't put in a lot of miles on anything rougher than crushed limestone while using the wheels and Marathon Racers my bike came with but I didn't feel the bike handled particularly well and I wasn't in mud or loose dirt/sand don't think knobby tires would improve the experience. I'm not a regular gravel rider in general so maybe someone with more experience would find it better.

I swapped over to 406 rims a day or so before I posted the pictures above. Now that I have a couple hundred miles on the new wheels, I have opinions. The handling on the larger wheels is noticeably more stable. I'm not really comfortable riding no handed with the larger wheels but I couldn't really take my hands off the bars with the 355s. I'm not sure if it's the higher trail or higher center of gravity but the bike also feels less nimble; I'm riding in NYC and there are a couple 180 degree turns when going over bridges and whatnot that I take wider than I used to. I have a section of cobblestones in a park nearby and don't notice much of a difference in terms of harshness between the two wheel sets so I presume the lower angle of attack on the larger wheel more or less offsets the loss in tire volume. I'm faster on the new wheels than the old ones for Central Park loops but I swapped wheel size, tires, and drivetrain so I don't think there's a lot of insight to be gained there.

My bike is fairly close to the R20. I use a Dura Ace bar end shifter on a Paul's Thumbies for shifting instead of the trigger shifter (fits better on the handlebars) and a 3T Bailout 9-32 cassette. I have an aftermarket suspension with a Multi-S G5 front shock, which I recommended if they still make it, and a coil+elastomer in the back since I'm 200lb/90kg and wanted a stiffer rear than the green elastomer. I have a set of Velocity A23 rims on a Hope rear hub instead of the Hubsmith wheels. Everything else lines up. If you're interested in the R20 for the wider tire selection at 406 and nice 105 shifting, you're in good shape. If you're expecting it to be road bike fast, I think you'll find it to be under-geared. The cheap way to fix that would be to go to a 54 or 56 tooth chainring and the expensive way would be to use the 3T cassette. I found I also need the loop bars (mine are Origin 8 strongbow) to comfortably get low enough to go fast. The front loop works kind of like aero bars with my forearms resting on the back and riding in that position is more aero but I also get better glute recruitment so I produce more power.

I'm happy with my bike and I don't think there's a quick folding bike that performs better. I did a century on it last year, partially to say that I had and partially because I think the other participant's pitying reactions are great. I have a lot more 50-70 mile rides mostly because I prefer riding recumbent if I'm going to be pedaling for more than 4 hours. The fold isn't that compact and the front of the loop sticks out a bit more but I don't think fold size makes a big difference on NYC transit. I'm content taking it on a full but not packed subway, I stand over it at the end of the car and don't feel I take up an excessive amount of space.
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Old 04-25-20, 03:13 AM
  #8  
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A first comment: the overall wheel size with ETRTO 406 rims and 28mm tires like the Continental is not much bigger than with ETRTO 355 and 40mm Marathon Racer: 462mm vs. 435mm.

ETRTO 355 with 50mm wide Big Apple is even closer: 455mm vs. 462mm.

This is the reason why it is possible to mount ETRTO 406 wheels with up to 28/30mm tires on he Birdy that was designed to accept 50mm wide tires with its original ETRTO 355 wheels.

About the modification and the choice of transmission, I did the same choice for my custom wheels for my Birdy, i.e. a Hope XDR compatible rear hub and a 3T 9-32 cassette. I kept the Shimano SL-RS700 trigger shifters but moved to a Ultegra rear derailleur (the Dura Ace doesn't accept s 32t cog).
Note that there is a XDR conversion for the Hubsmith Mantis rear hub but the R20 isn't equipped with it from factory. The 11-28 original cassette gives too short development with the original chainring.

I also tried the Multi-S G5 suspension and for me they aren't good.

The Multi-S rear suspension is much too hard with a very limited travel: it is so hard that I could hardly make it move by hand even by putting all my weight on it (I weight a little less than 80kg). I put it in a vice and measured about 3.5mm travel at maximum (for comparison, the U-design rear suspension of Pacific Cycles has 12mm travel).

The front is not as bad but the spring is shorter than the original one giving less progressiveness in damping and the hook of the frame doesn't fit well to the top of the shock absorber because its shape is designed to hook a spring = a round object. When riding on cobbles, the front suspension makes a lot of noise because of the bad hooking of the hook on the front shock absorber.

Last point, this Multi-S suspension is about twice as heavy as the original one.
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Old 04-25-20, 09:14 AM
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Originally Posted by Jipe View Post
A first comment: the overall wheel size with ETRTO 406 rims and 28mm tires like the Continental is not much bigger than with ETRTO 355 and 40mm Marathon Racer: 462mm vs. 435mm.
The handling difference isn't huge but I ride the bike often and only notice the difference on specific turns. I still think going to 406 is mostly about tire selection.

I agree the front hook doesn't clip the Multi-S shock particularly well but still holds it somewhat and I don't get extra noise from it on cobbles. I don't have the Multi-S rear. I don't know the actual branding because the shop owner had ordered it for a previous customer who never picked it up and offered it when I was in for a green elastomer. Tried the elastomer, tried this elastomer+coil shock, took the stiffer one.

Nice to know I'm not the only one with the 3T cassette.
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Old 04-25-20, 12:40 PM
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Jipe
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The noise comes when the shock absorber decompresses. You can create it by lifting the front wheel with the handlebar and then putting it again on the ground. It doesn't happen when there is more weight on the front wheel for instance when my front bag is loaded (I added a Brompton front block on my Birdy and use a Brompton S-bag). Your are about 10kg heavier than me, maybe this is the reason you don't experience this problem ?

On my Multi-S front shock absorber I noticed deep scratches at the place where the hook hold the shock absorber and I only used this shock absorber for about 1 month.

The 3T cassette is an excellent solution for small wheel bike. With its 9t smallest cog, it avoid the need of big 60t and above chainrings : 52x9 like I have is equivalent to 63.5x11. The factory 52x11 I had was much too short !
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Old 04-26-20, 08:46 PM
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Originally Posted by keyven View Post
Just wondering if anyone is riding the R20 Birdy with 20" wheels? What do they think of it, and how much difference does it feel compared to the earlier models?
Not a Birdy owner, though for tire size, I did see a speed difference switch from 406 to 451 on the same bike with same setup.
To me it boils down to the bit increase in gear inches, better roll over of slight road imperfections, bit less cumulative frictional losses with less revolutions for the same speed.

Off road wise, wider is usually better and in some cases necessary.
If the gravel is so loose that narrow tires sink in, thats a long walk out of that section of trails.

I have seen a Rhine 20" Birdy clone before (viewed in consideration for purchase).
It looked rather big and wide before and after fold, compared to a stock 18" wheeled Birdy.
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Old 04-27-20, 03:01 AM
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Between ETRTO 406 and ETRTO 451 with the same size of tires (ETRTO 451 tires are usually narrow road tires) the difference is diameter is 45mm, i.e about 10% bigger.

But between ETRTO 355 Birdy and ETRTO 406 Birdy, because most of the ETRTO 355 tires are between 40 and 50mm while for ETRTO 406 rims the limit is about 28mm wide tire, the overall wheel size difference is smaller, i.e. between 33mm and 7mm (435mm to 455mm vs. 462mm).

When moving from ETRTO 355 to ETRTO 406, the behavior of the bike and the feeling of the rider are also changed by the move from wide mid or low pressure tires to narrow high pressure tire.
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Old 02-05-21, 08:15 PM
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Hi Jipe,
Do you have a model number for that 32mm wide 28-406 pro one tire? It would be perfect for the recumbent Iím putting together. I have the pre-Addix Evo micro skin TLE model with OCS compound and unfortunately itís only 26 mm wide on a 24.5 mm (o.d) rim
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Old 02-06-21, 03:54 AM
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Its the very first version of the28x406 Pro-one mounted on Andoza rims that I measured at about 32mm when inflated at 8bar.

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Old 02-06-21, 04:00 AM
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Many thanks for getting back so quickly! Was it already a “tubeless ready” tire? I’m going to try to hunt some down but I don't think it'll be easy (would a photo of the sidewall branding help me do you think?)

Simon
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Old 02-06-21, 04:43 AM
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Jipe
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Yes, it was TL ready and mounted tubeless.

I do not have these tires anymore, one had to be replaced due to a de-lamination between the outer layer and the frame of the tire (there was a kind of blister on the tire) and the second was destroyed by a side wall tear due to a stone.

The Pro-one is actually fragile !

To come back on the benefit of ETRTO406 wheels on the Birdy, I have now two almost identical sets of wheels (same hub Hubsmith front, Hope rear, same CX-ray spokes, same Conti Contact Urban tires, only different rims) in ETRTO349 and ETRTO406, both tires mounted on my rims are about 35mm wide (but the ETRTO406 tire is not as high as the ETRTO349 due to wider 25mm inside rim).

I could keep my mudguards (which aren't the Birdy mudguards) by changing the bolts with flat head bold.

No problem at all for the folding, the folding size is slightly higher, but the difference compared to a Birdy with 50x355 tires is really small and not bigger than a Birdy with original mudguards.

Honestly, there is little difference when riding the Birdy.

For me, the only benefit in putting ETRTO406 wheels on a Birdy is the possibility to mount road race tires like the Pro-one that do not exist in ETRTO355.

So, for the four possible sizes of wheels for the Birdy, the pros and cons are:
- original ETRTO355: wide tires >40mm available, balloon and off-road tires available but few types of tires, no real fast tires (Kojak isn't fast, Panaracer almost impossible to find in ETRTO355).
- Brompton ETRTO349: wide choice of tires of many types available, including the ultra fast Greenspeed Scorcher 40x349 but most tires 35mm wide (Brompton standard width), no balloon tire like the Big Apple, no off-road tires.
- ETRTO406: fast race road tires available but max width 32 (or 35mm on wide rims), not that much types of tires usable (due to width limitation of the frame), of course no balloon or off-road tires usable. I do not think that Scorcher 40x406 will fit, even without mudguards.
- ETRTO369: only one tire really available the Kojak, I do not see any benefit to go for this wheel size !
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Old 04-17-21, 06:25 AM
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Originally Posted by Jipe View Post
Yes, it was TL ready and mounted tubeless.

I do not have these tires anymore, one had to be replaced due to a de-lamination between the outer layer and the frame of the tire (there was a kind of blister on the tire) and the second was destroyed by a side wall tear due to a stone.

The Pro-one is actually fragile !

To come back on the benefit of ETRTO406 wheels on the Birdy, I have now two almost identical sets of wheels (same hub Hubsmith front, Hope rear, same CX-ray spokes, same Conti Contact Urban tires, only different rims) in ETRTO349 and ETRTO406, both tires mounted on my rims are about 35mm wide (but the ETRTO406 tire is not as high as the ETRTO349 due to wider 25mm inside rim).

I could keep my mudguards (which aren't the Birdy mudguards) by changing the bolts with flat head bold.

No problem at all for the folding, the folding size is slightly higher, but the difference compared to a Birdy with 50x355 tires is really small and not bigger than a Birdy with original mudguards.

Honestly, there is little difference when riding the Birdy.

For me, the only benefit in putting ETRTO406 wheels on a Birdy is the possibility to mount road race tires like the Pro-one that do not exist in ETRTO355.

So, for the four possible sizes of wheels for the Birdy, the pros and cons are:
- original ETRTO355: wide tires >40mm available, balloon and off-road tires available but few types of tires, no real fast tires (Kojak isn't fast, Panaracer almost impossible to find in ETRTO355).
- Brompton ETRTO349: wide choice of tires of many types available, including the ultra fast Greenspeed Scorcher 40x349 but most tires 35mm wide (Brompton standard width), no balloon tire like the Big Apple, no off-road tires.
- ETRTO406: fast race road tires available but max width 32 (or 35mm on wide rims), not that much types of tires usable (due to width limitation of the frame), of course no balloon or off-road tires usable. I do not think that Scorcher 40x406 will fit, even without mudguards.
- ETRTO369: only one tire really available the Kojak, I do not see any benefit to go for this wheel size !
If I am not wrong the largest tires that a birdy can take is 20 * 1.25 tyres. Any bigger that that it will affect the folding. But if folding is not an issue than any 406 tyres should be fine i guess.
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Old 04-17-21, 10:15 AM
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The 20" ETRTO406 wheel doesn't affect the folding,

The limit comes from the space under the front fork.

My current ETRTO406 wheels with 25mm wide rims and Continental Contact Urban 32x406 tires (that are actually 35mm wide on those rims) have a diameter of 478mm in total with tires and just pass with a thin carbon mudguard.

Without mudguard, 3 or 4mm more would be possible, so a total diameter of 484 or 486mm should pass.

For the tire size, it depends of the height of the tire mounted on the rim that depend both of the tire type and rim internal width.
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Old 04-18-21, 08:56 AM
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Originally Posted by Jipe View Post
The 20" ETRTO406 wheel doesn't affect the folding,

The limit comes from the space under the front fork.

My current ETRTO406 wheels with 25mm wide rims and Continental Contact Urban 32x406 tires (that are actually 35mm wide on those rims) have a diameter of 478mm in total with tires and just pass with a thin carbon mudguard.

Without mudguard, 3 or 4mm more would be possible, so a total diameter of 484 or 486mm should pass.

For the tire size, it depends of the height of the tire mounted on the rim that depend both of the tire type and rim internal width.
Your 32x406 tyres according to the website is 20x1.25 so of course there is no issue.
However if you use the 42x406 this will cause an issue with the folding as either the rear tyre when folded will hit the frame or you are unable to fold the front tyres.
Just saying that you should stick to 406 tyres with 1.25 diameter just to be safe.
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Old 04-18-21, 12:26 PM
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Originally Posted by Samidare View Post
Your 32x406 tyres according to the website is 20x1.25 so of course there is no issue.
However if you use the 42x406 this will cause an issue with the folding as either the rear tyre when folded will hit the frame or you are unable to fold the front tyres.
Just saying that you should stick to 406 tyres with 1.25 diameter just to be safe.
As written, even if they are specified to be 32x406, they are 35mm wide.

Below, you can see how much space remains under the fork.

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Old 09-24-21, 08:43 PM
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Hi I have just converted to 406 wheels and using schwalbe one tyres. When i tried to switch it to conti urban (32mm) I realize that I am unable to push the bike anymore when folded as the rear tyre is touching against the frame.

Does anyone have similar experience and if 28mm is the max I can go if still wish to push it around like normal when folded?
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Old 09-25-21, 03:02 AM
  #22  
Jipe
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The picture above of my titanium Birdy show it with Continental Contact Urban 32x406.

But the frame is different and the rims are wider (25mm internal width) .

Where does the tire touch the frame, is it the side of the tire against the main tube ?

I went back to smaller wheels as 20" didn't bring any benefit, only drawbacks: no mudguard clearance, only narrow high pressure tires, no riding improvements, the Birdy with ETRTO406 wheels isn't faster and the fast tires in ETRTO406 (Schwalbe Pro One or One) are fragile.

The faster setup I have for the Birdy is using ETRTO349 wheels (I have now two sets of wheels, one ETRTO355 a second ETRTO349) with Greenspeed Scorcher 120 40x349 tires (for fast tires, there are also Schwalbe One 35x349 and Trublu 40x349).
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Old 06-05-22, 10:29 AM
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Originally Posted by grayrest View Post
That very much depends what you intend to do with the bike but I have no interest in the GT. I think 355 wheels work well for packed dirt or crushed limestone but are too small to handle most gravel. The suspension helps but it's sized for stuff like cobblestones or cracks in the road and not for chunky gravel rocks. I didn't put in a lot of miles on anything rougher than crushed limestone while using the wheels and Marathon Racers my bike came with but I didn't feel the bike handled particularly well and I wasn't in mud or loose dirt/sand don't think knobby tires would improve the experience. I'm not a regular gravel rider in general so maybe someone with more experience would find it better.

I swapped over to 406 rims a day or so before I posted the pictures above. Now that I have a couple hundred miles on the new wheels, I have opinions. The handling on the larger wheels is noticeably more stable. I'm not really comfortable riding no handed with the larger wheels but I couldn't really take my hands off the bars with the 355s. I'm not sure if it's the higher trail or higher center of gravity but the bike also feels less nimble; I'm riding in NYC and there are a couple 180 degree turns when going over bridges and whatnot that I take wider than I used to. I have a section of cobblestones in a park nearby and don't notice much of a difference in terms of harshness between the two wheel sets so I presume the lower angle of attack on the larger wheel more or less offsets the loss in tire volume. I'm faster on the new wheels than the old ones for Central Park loops but I swapped wheel size, tires, and drivetrain so I don't think there's a lot of insight to be gained there.

My bike is fairly close to the R20. I use a Dura Ace bar end shifter on a Paul's Thumbies for shifting instead of the trigger shifter (fits better on the handlebars) and a 3T Bailout 9-32 cassette. I have an aftermarket suspension with a Multi-S G5 front shock, which I recommended if they still make it, and a coil+elastomer in the back since I'm 200lb/90kg and wanted a stiffer rear than the green elastomer. I have a set of Velocity A23 rims on a Hope rear hub instead of the Hubsmith wheels. Everything else lines up. If you're interested in the R20 for the wider tire selection at 406 and nice 105 shifting, you're in good shape. If you're expecting it to be road bike fast, I think you'll find it to be under-geared. The cheap way to fix that would be to go to a 54 or 56 tooth chainring and the expensive way would be to use the 3T cassette. I found I also need the loop bars (mine are Origin 8 strongbow) to comfortably get low enough to go fast. The front loop works kind of like aero bars with my forearms resting on the back and riding in that position is more aero but I also get better glute recruitment so I produce more power.

I'm happy with my bike and I don't think there's a quick folding bike that performs better. I did a century on it last year, partially to say that I had and partially because I think the other participant's pitying reactions are great. I have a lot more 50-70 mile rides mostly because I prefer riding recumbent if I'm going to be pedaling for more than 4 hours. The fold isn't that compact and the front of the loop sticks out a bit more but I don't think fold size makes a big difference on NYC transit. I'm content taking it on a full but not packed subway, I stand over it at the end of the car and don't feel I take up an excessive amount of space.
Iím also thinking of upgrading the wheels on my Birdy to a 406 20-inch wheel set but good ones can be quite costly. Iím still deciding which one to get.
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Old 06-05-22, 03:25 PM
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Jipe
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What is important isn't the rim size but the wheel diameter with the tire on it and the tire width.

With ETRTO406 20" rims, the maximum tire width is about 32mm (I could have 35mm wide tires only because I had very wide, 25mm inside, rims that reduce the tire height and wheel diameter) meaning a diameter of about 470mm.

With ETRTO355 18" rims, its possible to mount 50mm wide tires meaning a diameter of about 455mm which is only about 15mm less than the diameter of the wheels with ETRTO406 rims. But the much wider tires is a big benefit especially on dirt/gravel path.
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Old 06-05-22, 07:12 PM
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Originally Posted by Jipe View Post
What is important isn't the rim size but the wheel diameter with the tire on it and the tire width.

With ETRTO406 20" rims, the maximum tire width is about 32mm (I could have 35mm wide tires only because I had very wide, 25mm inside, rims that reduce the tire height and wheel diameter) meaning a diameter of about 470mm.

With ETRTO355 18" rims, its possible to mount 50mm wide tires meaning a diameter of about 455mm which is only about 15mm less than the diameter of the wheels with ETRTO406 rims. But the much wider tires is a big benefit especially on dirt/gravel path.
Wider tyres have more friction and are more grippy on the road for sure, but on a bicycle, does it also reduce the speed?


Since upgrading to a 406 wheel set on a Birdy actually requires thin tyres, does it mean that the speed gain is more because of the thinner tyres than the larger wheels?

Everyone on the internet told me that the original wheels of the Birdy (Alex DA16 18x1.5) with CST tyres are very bad, but what is a true perceivable gain by upgrading the wheels? Since the whole set easy costs 1/3 of the bike itself, which is not even made of carbon fibre.

Last edited by jackyharuhiko; 06-05-22 at 07:16 PM.
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