Bird Aeris owners thread

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Posted: Feb 14, 2020 at 3:34 Quote
mrbanks wrote:
Thanks for responses all!

drwavey wrote:
mrbanks wrote:
Has anyone built an AM9 with a 160 or 170 fork? Does it void Bird's warranty?

Yes it does. It's only strength rated to 150mm. Bird have answered this Q lots of times on their Facebook page.

Is it the owners club page you were referring too?

Yes, Bird Cycleworks Owners group on FB.

Posted: Feb 14, 2020 at 5:33 Quote
[Quote="drwavey"][Quote="mrbanks"]Thanks for responses all!

drwavey wrote:


Yes it does. It's only strength rated to 150mm. Bird have answered this Q lots of times on their Facebook page.

The impression I got is that, although it is strong enough to take a 160, It costs bird a lot to do the destructive strength testing and to verify it officially. 160mm is only another 10mm, and presumably you would run slightly more sag anyway. This means that the overall increase in bending moment is very small, especially at full compression, when the force would be greatest. It is probably fine, but the difference in handling is negligible anyway, I would suggest an angled headset instead, or a set of riser bars if its more height you are looking for.

Posted: Feb 14, 2020 at 7:20 Quote
piersgritten wrote:
The impression I got is that, although it is strong enough to take a 160, It costs bird a lot to do the destructive strength testing and to verify it officially. 160mm is only another 10mm, and presumably you would run slightly more sag anyway. This means that the overall increase in bending moment is very small, especially at full compression, when the force would be greatest. It is probably fine, but the difference in handling is negligible anyway, I would suggest an angled headset instead, or a set of riser bars if its more height you are looking for.

I haven't investigated the reasons why Bird won't support it, but the testing issue is likely. It can cost a few thousand to get a frame fully tested - less for a partial test, though still not cheap. Not terribly expensive, but it's also not a terribly important matter.

Interestingly, many failures occur at full extension in a "slap down" (rear wheel first) impact if the fork binds and won't compress initially.

An angled headset can be just as bad. I'm not aware of whether that voids the warranty.

Posted: Feb 14, 2020 at 7:42 Quote
Bird stated that they approve angle sets on the AM9, the restriction is on A2C length.
They also affirmed to have internal validation which surpasses normal protocol, whatever that means.

Posted: Feb 14, 2020 at 7:56 Quote
Arierep wrote:
Bird stated that they approve angle sets on the AM9, the restriction is on A2C length.
They also affirmed to have internal validation which surpasses normal protocol, whatever that means.

Probably means they have an in-house fixture and a steel bar that replicates the ISO (or other) test and it passed. It's an irresponsible company that doesn't have this (though it does occur), so it's not surprising they've bashed a few frames with good results.

Situations like these often represent the difference between what a company knows will work and what they could defend strongly enough to avoid a court case, if it came to that.

Posted: Feb 14, 2020 at 10:02 Quote
My "whatever that means" comment was in the context that I don't know how much above they are testing the validation criteria, so it comes as a vague term

Posted: Feb 14, 2020 at 10:29 Quote
It's impossible to know. Some companies just tell the factory to set up the ISO test fixture at X% over the ISO test load and call it a day. Some build their own in-house test labs and destroy their own bikes and competitors' bikes.

Posted: Feb 14, 2020 at 11:10 Quote
Could also be something to do with frame sizing and rider weight. I guess the safety factor for a size medium with a light rider could be great up to 160/170mm but it will obviously become much more likely to break if you had a 120kg rider on a size xl with a 170 fork. They're just being conservative I think, and I would do the same if I was designing a bike.

Posted: Feb 14, 2020 at 11:53 Quote
It was an xl that they tested and I think failed on a 160 I think it’s orettt rigorous but on the safe side. lots of people on here are pretty open about using 160-170 forks

Posted: Feb 14, 2020 at 12:14 Quote
We don't know the standards to which they test. Maybe they insist on ISO + 50%, while others are satisfied at ISO + 15%. Or maybe it failed ISO without a safety factor. Or maybe some completely different test protocol. We don't know.

Bird's bikes are cheaper than most and lighter than most in the category, including many carbon frames. It would be asking a lot for them to also be stronger than most. Frames don't fail like they used to, so "average" ought to be fine.

Posted: Feb 14, 2020 at 12:27 Quote
R-M-R wrote:
We don't know the standards to which they test. Maybe they insist on ISO + 50%, while others are satisfied at ISO + 15%. Or maybe it failed ISO without a safety factor. Or maybe some completely different test protocol. We don't know.

Bird's bikes are cheaper than most and lighter than most in the category, including many carbon frames. It would be asking a lot for them to also be stronger than most. Frames don't fail like they used to, so "average" ought to be fine.
That is true. Come to think of it, I don't think I have ever seen a picture of a snapped bird frame? Has anyone?

Posted: Feb 14, 2020 at 12:40 Quote
piersgritten wrote:
Come to think of it, I don't think I have ever seen a picture of a snapped bird frame? Has anyone?

A 120 kg friend of mine snapped his main pivot axle in the first few rides. 2017 Aeris 145. At the time, the axles were aluminum. Bird quickly sent steel axles to both of us, which have since become standard. No problems since.

With so few Bird frames out there, it's unlikely to hear of a great number of failures. In some cases, this is why everyone has seen or heard of a broken [popular brand], though there are instances where it's more than just the ubiquity of the product (looking at you, first generation Reverb). It would be more fair to look at failure rate.

It would also be ideal to account for the specific details of a failure or lack of failure. My giant friend tends to break wheels, frames, saddles, and seatposts, so he's a good tester for those. I destroy tire casings and pedal spindles, but rarely anything else. As much as I would like to normalize the failure rate data for hours of ride time, riding style, terrain, rider weight, etc., we can do only so much.

Posted: Feb 14, 2020 at 15:03 Quote
I've cracked my 145 lt large main frame. So far its the only cracked frame I've heard of except gen 1 and 1.5 bird bikes. The weld on the backside of the seattube where it joins the bottombracket/pivot cnc'd part.

That was after 400 km of riding. 200 of which was park or similar dh. 75 kg kitted up and I tend to break stuff Smile I would definitely buy one again.

Posted: Feb 14, 2020 at 16:06 Quote
Did Bird sort it out for you?

Posted: Feb 15, 2020 at 0:53 Quote
R-M-R wrote:
Did Bird sort it out for you?

Yeah, no problems what so ever. Sent a new front triangle after I sent a couple of pictures of the crack to them.


 
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