Jipe

Even if some people use it offroad, the Birdy is a road bike and its suspensions are short travel road bike suspensions, not comparable to a mountain bike suspension.

Both Riese & Müller and Pacific Cycles warn that the Birdy isn't made for offroad use.

glye

Of course. I don't use it offroad. I'm talking about road riding. If it was all a smooth race track it would be fine, but roads have cracks, holes, curbs, grates, pebbles, occasional gravel etc etc. The Birdy has too short travel for comfortable road riding for me, though with 44 mm wide tyres it's acceptable. Suspension needs are highly subjective, it depends on the rider, the road, the luggage, etc.

Jipe

Compared to other folders, Dahon, Brompton... the Birdy is in another category of bikes.

I used my Birdy with Kojak at their maximum pressure on ugly cobbles and I could ride as fast as I wanted while this is impossible with my Brompton with which I am forced to slow down.

gleearch

Ran across this today:
https://www.facebook.com/watch/?v=1975412095836936

Birdy R Plus with 406 wheels. Obviously only available in Asia and in limited edition. Pacific cycles finally cotton on that people do want a Birdy with 20" wheels.
Additional searches turns up Yahoo Hong Kong listings for HKD 33,000.
https://translate.google.com/transla...26sort%3D-curp

That's roughly USD $2,400 and change.

YouTube CF:

Jipe

The Birdy R+ on the website of Jesler Bike : **********?? jesler bicycles

The price is 125000NTD

Any Birdy can be equipped with 20" wheels with up to 28mm wide tires. The R+ is equipped with 28x406 Schwalbe Durano tires that do not exist anymore, replaced by the new 28x406 Schwalbe One.

secret_squirrel

28mm is fine and is still a good average size for most road bikes. The current fashion for adventure bikes is driving that wider but the vast majority of road bikes are still in the 25-28mm range. Personally 28mm + an inch or so of suspension is fine for me on some pretty lousy British roads, I find both gearing - even at 58x9 - and aero are bigger blockers. Would love to see an official Birdy with drops or bull bars where the fold isn't compromised.

Minor grumble - I note Pacific Cycles birdies invariably are sold without mudguards - which would be unworkable for me in Rainy Britain - what do you do in Monsoon season - for those of you who get Monsoons or a local equivalent.

Jipe

I have a Birdy with ETRTO 349 wheels and 40mm wide tires (Greenspeed Scorcher, 43mm in practice at 7bar). These tires are very fast and nevertheless, my current transmission = 52-16 front and 9-32 rear provides long enough developments (something around 9.3m).

58-9 seems to me not necessary with my tires that have an overall diameter of 435mm and surely not with ETRTO 406 wheel and 28x406 tires (overall diameter of 462mm.

Note that I tried to put ETRTO 406 wheels with Schwalbe Pro-one 28-406 tires that are in practice about 32mm wide on my Birdy and that this wasn't possible with the mudguards (the mudguards self are OK but the fastening of the mudguards hit the tire. It could be possible to make it fit with some modification of the mudguards fastening).

Pacific Cycles indeed sells Bidy without mudguards but also sells mudguards.

It seems to me normal to sell a sport oriented Birdy without mudguards same as for all sport road bikes.

A picture of the folded Birdy R+ with dropbar, seems OK ?

grayrest

That's roughly the equivalent of a compact double. If you're racing I could see it as an issue but otherwise what are you doing over 55kph and not willing to coast?

For the normal 52x11 setup, I agree on both counts. My Birdy is in pieces right now getting the wheels rebuilt to move to a 9-32 cassette and 406 rims. I use a loop bar (Origin8 Strongbow, matches the flat bar sweep) and that gives me a reasonably aero position but I'm relatively tall at 190cm so a bit short on reach even with the sport stem. It doesn't impact the fold but the loop sticks out 1-2 cm past the pedals when folded. Not an issue for my local public transportation but could be fixed by something like the Tern rotating handlebar clamp thing.

Do we have the gear ratios on the R+? Chain ring looks like a 52 and the derailleur is SRAM so a 52x10 would be the top end?

Jipe

I have only found that its a SRAM Rival.

From the picture, it seems not to be the 10-42 cassette and also not the long cage rear derailleur.

To fit the 10-42 cassette (or any cassette with a smallest cog under 11 teeth), the hub should be XD or XDR don't know if the hubsmith wheels can have a XD or XDR hub. On the Birdy R11 that has also hubsmith wheels (but ETRTO 355 instead of ETRTO 406) its a 11-28 cassette.

glye

Or the Sunrace small cassette hub that allows 9t cogs, I hear it's a Capreo clone. It comes standard with the current R&M Birdy 10-speed. But I wouldn't recommend that, as it's too weak: https://www.bikeforums.net/20927760-post1146.html

With the SRAM 10-42 cassette I imagine one would have trouble with chain rub on the large cog. I had trouble already with 9-36 and 52 front, had to space the chainring out to a pretty bad chainline to avoid rub. (One more reason why I went for an Alfine instead.)

Jipe

The R+ has 11 speed. As far as I know, the Sunrace is only 10 speed ?

I mentioned the SRAM XD or XDR because the rest of the transmission is SRAM.

Shimano microspline also allow 10 teeth but its mountain bile only with only huge mountain bike cassettes while XDR is road and SRAM has a 12s 10-33 cassette.

Note that there are cassettes with 9 teeth also for XD and XDR with two 9-32 cassette models from 3T. I have one of these cassettes on my Birdy and it work fine with the factory installed Shimano 105 rear derailleur.

glye

The Sunrace is 10 and 11-speed. My Birdy came stock with the 10-speed 9-32, which I upgraded to 11-speed 9-36 for more range (there is also an 11-speed 9-32 cassette). Just after that investment the cassette freehub body broke, and I found out how weak the construction is. The SRAM XD(R) is stronger, I expect, since it's supposed to handle the higher forces you need for large wheels.

Jipe

There are several manufacturers making XD and XDR hubs.

I guess there are differences between their several implementations.

But the XD is now on the market since several years without problems. XDR is newer but its just an extension of XD.

My XDR hub is from Hope.

secret_squirrel

Tbf to Sunrace a sample size of 1 says nothing about their reliability. Mine has done 2 salty grimy UK winters now at 11 speed without missing a beat. YMMV of course.

glye

That's true, though it's a sample size of 2 really (still tiny) and I have some "inside" knowledge. I have a Sturmey Archer X-RDC (made by Sunrace) on another bike, and it failed in the same way. I took both apart, and found the ratcheting mechanism looked exactly the same, and the failure point was the same. (Only difference was the SA one was made of steel, the other aluminium.) Picture earlier in the thread. They have three pawls, and where the pawls are attached the supporting material is very thin, less than 1 millimeter. Both had cracked at this point. So I have some reason to say the design is too weak.

Other factors matter too of course, like rider weight, strength, riding style, and gearing. My Birdy at the time was geared 45 front, 36 (max) rear. With a larger chainring / smaller cassette the forces will be lower. Good for you that yours still works. I can only recommend to be careful with it.

gleearch

Found some comparison photos of a Birdy with 18" wheels vs 406 wheels on the Birdy Global Community on FB.


Some stats provided by a one of the members as a comparison, using similar set up with 18" wheels and 20" wheels. Interesting that it's only a 3kmh or roughly 1.8mph difference.
Begs the question is if it's worthwhile going through the effort to make the change.

Jipe

The first question to ask is what is the goal of the change ?

If the goal is to have bigger diameter wheels to ride faster at the same pedaling speed, then changing the transmission (for instance a bigger chainring or a cassette with smaller sprocket) will produce the same effect for less money.

If the goal is to ride faster with higher performances tires that aren't available in ETRTO 355, then there is no other solution than changing the wheels.

The picture show the 20" Birdy with Schwalbe Kojak tires that are also available in ETRTO 355, this is not the best option since the Kojak have poor performances. The better option would be to use Schwalbe Pro-one or Schwalbe One.

timo888 

Did you have to adapt the brake mount in any way to use ETRTO 349 on the Birdy? Special low-profile brake shoes?

My older Birdy BD-1 could do with some new wheels but ETRTO 355 is well nigh impossible to find in the US. It seems ETRTO 349 would just barely fit, considering the location of the brake mounts. The brake pads are now midway in the slot and there's just about 6mm of slot available to slide the brake shoe lower down.

Jipe

The titanium Birdy has disc brakes only (no mountings for any type of rim brakes), so changing the wheel size causes no problems for the brakes.

Most people who change their wheels for another size have disc brake Birdy.

Now the position difference of the bake shoes for ETRTO 349 vs. ETRTO 355 is only 3mm down, you should be able to test if you can lower the shoes by 3mm before changing the wheels.

Just for remembrance, Brompton wheels won't fit on the Birdy since the OLD front and rear are different.

secret_squirrel

I ran a 349 rim on the rear of my mk1 Birdy Blue easily when my LBS couldn’t get hold of a replacement 355 one in time. I had Magura hydraulic rim brakes but the adjustment needed to do so was minimal. I see no reason why V’s won’t work.

gleearch

Just ran across this retail store in Singapore that customizes Birdy bikes. They have a R20 (11 speed) Birdy:
https://www.mightyvelo.com/birdy-r20-11sp/
So if you are passing through or live in the region, it's a possible option to consider.

There's a Youtube video included:

They are utilizing 406x32 Panaracers.

Jipe

As can be seen on the picture, there is very little clearance between the front tire and the front arm of the fork. Obviously no space for mudguards with these tires.

glye

I added a mudguard extender, to reduce the dirt spray to the BB area. Here are the before and after shots. In both cases I had ridden on wet, paved roads, no off-road. Granted, the first one shows several rides worth of dirt, but the second one is so spotless that it's pretty clear it works.



Works rather well! This is the SKS Spoiler XXL, 53 mm wide, 150 mm long. The original Birdy mudguard is also from SKS, and the extender fits perfectly. All that was needed was to drill a hole, which was tricker than expected since the mudguard turned out to be metal-reinforced plastic. With that done the mounting was easy, and the bike stays a lot cleaner.

mkatz

Birdy GT advice sought: I had an opportunity to test ride an R&M Birdy a bit over a year ago. I liked the ride but was not then ready to commit. Since then my local dealer appears to have given up on the line; Birdy appeared not to sell well so I appreciate the shop owner's decision. Conveniently, in the last few days, I found that there is a way to buy Birdy models in which I have a greater interest, sourced from Pacific cycles (without unwanted fender and hub generator). Thus, before I order, as I cannot test ride this time, comments sought:

I'm think I should prefer the Birdy GT. I'm "older" with a delicate (post spinal fusion) back and intend to ride street and gravel trails during daylight in good weather. The GT appeals to me (without fenders and hub generator) partly because it is perhaps the lightest model, has a reasonable gear range, and I suspect has the most forgiving ride due to its relatively fat tires. (No curb hopping or jumps for me, but where I live does not have the smoothest of roads.) If I remember correctly, the GT comes with the more upright steering post (preferred as I'm short, with a neck that prefers to be held relatively upright). The weight is very important as lifting something much over 20lbs (and as awkward as a folded bike) into the back of my SUV is, for me, not easy. (I've become such a wimp. ) (Yes, I'd really prefer Rohloff gearing but fear the weight associated with that Birdy model.)

And so, my question: Is my analysis valid? With respect to the GT, am I leaning towards the most appropriate model?


Thanks for indulging me!

Jipe

This model is indeed one of the lightest. If you are short and prefer a more upright position, the 10D comfort stem is the best choice.

But I see two drawback for this model.

First, the transmission with 52t front and a 11-32 cassette for ETRTO 355 wheels is too short.

You would need a much bigger chainwheel something like 60t (which is not possible due to the chain tensionning arm that keeps the chain when the rear arm is folded, the maximum compatible with the chain tensionning arm 55t or maybe 56t) or a cassette with at least a 10t (better 9t) smallest cog what would require another rear hub with XD or XDR body and switch to 11s or find the Sunrace 10-speed, 9-32t hub+cassette that Riese & Müller mount on the Birdy Touring (I never saw this system sold as spare parts anywhere).

Second the black jack tires are low end tires meant for off-road use, if comfort is important for you, you should mount Big Apple road tires.