secret_squirrel

timo888 

May I ask, what are a couple of decent ISO bottom brackets measuring 68mm x 127mm (for my older Birdy BD-1)?

I would like to move the chain out a bit since it's rubbing the left leg of the V-strut on the pivot arm when the chain is on the largest rear cog. The width of the BB on the bike now is 116mm. I'd rather not spend a lot of money, just looking for something sturdy and well made that will last. No need to shave grams.

glye

Not what you're asking, but I think it's easier, and cheaper, to use chainring spacers instead. Lighter too. These can be had in various thicknesses from 1 mm and up. If you need as much as 3 mm, you may also need longer chainring bolts. Another advantage is you get to keep your current Q-factor, which is good unless you prefer more widely spaced pedals.

https://duckduckgo.com/?q=chainring+...ages&ia=images

timo888 

Thanks for the suggestion and link.

50PlusCycling

I use a Shimano Dura Ace 7800 crankset with the hollowtech bottom bracket, it weighs about half what the original parts do, and is easy to install. 105 or Ultegra work just as well, and are still quite light. I have no issues with rubbing using an 11 speed rear sprocket.

glye

Curious... do you use a roadbike cassette? They are not spaced as far inwards as 11-12 speed MTB cassettes are, so would be less likely to rub.

50PlusCycling

I run an XTR mountain bike cassette.

timo888 

I am pretty new to the world of bottom brackets and chain lines, and will have to read up about the hollowtech approach, where there's no spindle in the BB, rather it is part of the crank. With the hollowtech approach, what corresponds to a square taper BB's spindle width? How do you set the distance between the cranks? Are the crank shafts available in different widths?

50PlusCycling

Yes, the hollow tech bottom brackets come in different widths, and use the same measurement system as square taper.

al101

al101

timo888 

I bought a Tange Seiki 68x127 BB for my BD-1, and installed the chain-ring on the outside of the spider, and now there's a good 6mm clearance, and even when the chain is on the largest cog there's no rub. The chain feels and acts perfectly fine, better than it had been with the 68x116 BB.

glye

My rear hub failed The freehub mechanism on the Sunrace hub (Capreo-style for 9t cassettes) suddenly isn't freewheeling anymore, but is so draggy that the derailer arm bends, and the chain goes slack and derails. And this is after only 300 km. Looks like a warranty matter. I really hope the replacement is longer lasting. If not I'll be switching either to an SRAM style hub for their 10-42t cassettes, or to an Alfine 11 (not cheap).

Winfried

Hello,

I have the opportunity of buying a second-hand Birdy City with an Alfine 8 gear hub and hydraulic disk brakes from 2011.

The owner says the front brake works fine, while the rear brake needs a bleeding (or possibly, just a burping; They're Shimano BR-M575).

What should I check during the test ride?

Thank you.

glye

The brake is cheap to replace if bleeding doesn't help, no worry there. The expensive bits are the frame, fork and gear hub. R&M specifies that certain bits should be replaced every 3 years or 10000 km or so (front and rear fork, handlepost and bars, see earlier posts in this thread). Ask if this has been done, if they say yes, ask for receipts. If they say no, you'll have to consider the cost of replacing those parts, vs. the risk of keeping them (you probably don't know how the bike has been ridden). Check the frame and forks carefully for cracks.

Try all 8 gears, listen for nasty noises, shifting trouble, or an uneven feel when pedaling. Lift the bike and spin the wheels, look for wobbling in the rims (wobbling in the tyres don't matter as much).

Personally, I think the Alfine 8 has too little gearing range for hilly terrain. In fairly flat areas it's good.

Winfried

Thanks for the tips.

As for the gearing range: I've read some people use a double chainring with a Nexus/Alfine hub without issues. I might do this :-)

grayrest

3T makes a pair of 11 speed 9-32 road cassettes (Bailout, Overdrive) for SRAM XD driver hubs. I think the gear range is ideal on the Birdy and should be easier to fit than long cages with dinner plates but they're relatively expensive.

I bought a bailout but got tripped up on swapping from the shimano freehub body to the SRAM one since there were multiple options that looked like they might work and I didn't want to deal with guessing and returning. Then the weather got nice and I decided to put it off until I swap my chain.

glye

Interesting option, thanks. I switched from 10-speed 9-32 to 11-speed 9-36 to get that extra range, so the 3T isn't very appealing to me, but it surely will be to some. I'll wait and see if my replacement hub innards will hold up better (covered by warranty). If they don't, I'll have to conclude that the Sunrace hub is too weak. The SRAM XD hubs are built for MTB and ought to be strong enough. Though getting the 10-42 cassette to work with the 52t chainwheel without having the chain sawing the rear fork off will be a challenge.

The Sunrace 9t cassettes are kind off expensive. The 3T 9t cassettes are nearly 3 times that. They're approaching the cost of the whole Alfine 11 hub. And the Alfine will presumably last longer than many cassettes. It's not for road racers, but might be good for my touring and commuting use. Anyway, crossing my fingers for the new Sunrace hub innards.

grayrest

I'd considered a hub but I've had mixed experiences with a non-Rohloff hub and Rohloff hubs are most definitely not in my budget. I'm not thrilled with the price of the cassette but it's the exact gear range I'm looking for and I'm hoping some less botique manufacturer is in the market by the time I wear it out.

secret_squirrel

Mine has just made it through a British winter with 500km of rain and salt, that actually seized one of my brake calipers so fingers crossed for you, Hopefully you just got a bad one.

glye

I hope so! I got the new freehub body, it works fine so far. I had a closer look at the old one. It turns out the inner part if it has cracked, see the lower part of the photo. It cracked along the "hinge" of one of the pawls, where the material is less than 1 mm thick, according to my calipers. That looks like a weakness indeed. Granted, the hub is intended for small wheel bikes with large chainrings, meaning low torque. Still... while it may be good for a 50 kg Taiwanese, it seems a heavyweight such as myself has reason to worry, and to avoid standing and pedaling as much as possible. Not at all sure it's safe to go on a bike tour with this thing.



https://imgur.com/eNhS7rW

So... I can make an SRAM Xd wheel with a 10-42 cassette, though the 52-42 1st gear will make the chain rub trouble even worse. Or I can cash out for an Alfine 11. I hear some people have cranked the life out of those too, but that's mostly MTB riders with small chainweels. On the Birdy it should have good conditions for a long life. (The Rohloff seems overkill, both in range and in cost.) Choices, choices...

cogarch

I have a pre-disk Rohloff Birdy that is getting on a bit but still rides well. Recently however I have noticed that when I pick it up the rear swing-arm hinges downwards rather like a Brompton - in other words the plastic catch holding the rear frame in place is no longer working. Nothing seems out of place, and the catch does not seem particularly worn. I notice that the screw that it clips over is done-headed and I cannot be sure that the previous owner did not replace the original screw for some reason.

Has anyone else had this problem? It’s not clear how you would fit a new catch to the swing arm.

glye

That screw on my new Birdy is dome-headed too, FWIW. The plastic catch is attached using two bolts on the inside of the stay.

gleearch

I just spent two weeks reading after work this entire 46 pages of Birdy information. You are a dedicated lot of Birdy owners.
That said, I'm thinking of getting one, but a new one is too expensive for me and there's no LBS that carries all the models. Scouring through Craiglist and Ebay nets zero. My preference si for the monocoque design and not the classic.

So since we may go on vacation to Tokyo later this year, I was wondering if anyone who lives in Japan or who is familiar with the bike in Asia could provide some information.
I have been researching the BD-1 and the Bianchi Fretta as options. They seem more reasonably priced and there looks to be more available used models too. So I was hoping to try to snag one while I was there and disassembling it and packing it in my suitcase. Or shipping. Still researching and haven't made that decision yet.

That said, I can't tell if a BD_1 or Bianchi is a Mark 1, 2 or 3. If they don't list the year of manufacture in the ads, it's hard to correlate. Plus I noticed that in some of the latest postings, they are selling Birdys in Japan, so not sure if BD-1s are no longer being sold.

How do I tell if a BD-1 or Bianchi is a particular make? Is it when the handle bar stem and seat post are black? I'm looking at the monocoques. Is there a way to visually tell the difference. Since I'm new to Birdy's, when I look at the frames, I can't see much difference other than colors of the seat post and stems. Well the look of the stems seems different from the Mark 1 and newer models. Are there other things I can look for?

Thanks

gleearch

Another question. I know some of you have replaced the 18" wheels with 20" wheels. I'm assuming from the previous posts, that this is somewhat doable on the Mark 2s and Mark 3s and not so much the Mark 1. Was there a significant difference in performance to justify changing out the wheel size? Did it cause issues with the fold and or with anything else like the derailleurs, parts rubbing against each other, etc?