danbird wrote: ↑Fri May 14, 2021 10:46 am
Hey, Dan here - I design all of our (Bird's) frames.
All our frames have some rising rate designed in to them. Aether 7 runs at around 35% rising rate which is nicely poppy and you'll only bottom out the suspension when pushing pretty hard. It's actually quite difficult to judge the rising rate just by looking at the linkage - moving a pivot point by a few mm in a specific direction can have a dramatic effect on the suspension performance.
If you have any more questions please let me know!
Cheers
Welcome Dan,
As a "nearly" Bird purchaser of a few years ago - but encouraging others to buy them these days, a question for you. (I know you will have been asked this a million times)
I have a Cotic FlareMax - there are various synergies between the brands - and similarities - both being linkage driven single pivots. Buy yours being ally, theirs being steel ( and getting very expensive !)
In terms of the way the rear suspension rides I find my FlareMax very progressive - and find it really difficult to get full travel ever on the rear (but I am not dropping in of house size drop offs).
How does thw Bird rear linkage compare to that of Cotic's in terms of ride?
When will the steel hard tail be available?
South Downs riding mostly BTW ...
Cheers
Hi,
Actually the suspension system is totally different on the Cotic. As you point out the Cotic is a single pivot with a linkage driving the shock (it has a pivot on the seatstays). All our full suspension frames are a 4 bar linkage with a "Horst link" on the chainstay which provides a virtual floating main pivot.
Without properly analysing the suspension on the Cotic I can't comment further, and to be honest even if I did analyse it I wouldn't comment on it on a public forum. What I can say is that the Aether range of bikes offers a nice sweet spot of suspension progression vs travel availability in my view, I wouldn't want to go higher or lower in terms of rising rate or anti-squat on a 130mm travel bike.
Our Forge Cro-Mo frames are about to set sail from the far east so will be landing in about 6 weeks with a good wind. The air ship frames for photos actually arrived yesterday and look stunning. The KVA stainless version is also in production now after a bit of a delay, ETA 4-6 months.
Actually red and pink have historically been male colours, it was the Victorians that created the whole blue for boys rubbish.
"Of all the stories you told me, which ones were true and which ones weren't?"
"My dear Doctor, they're all true."
"Even the lies?"
"Especially the lies."
MingtheMerciless wrote: ↑Fri May 14, 2021 11:57 am
Actually red and pink have historically been male colours, it was the Victorians that created the whole blue for boys rubbish.
You can stop coming here with you metrosexual explanations.
Actually the suspension system is totally different on the Cotic. As you point out the Cotic is a single pivot with a linkage driving the shock (it has a pivot on the seatstays). All our full suspension frames are a 4 bar linkage with a "Horst link" on the chainstay which provides a virtual floating main pivot.
MingtheMerciless wrote: ↑Fri May 14, 2021 11:57 am
Actually red and pink have historically been male colours, it was the Victorians that created the whole blue for boys rubbish.
You can stop coming here with you metrosexual explanations.
BTW, I quite like the pink colour ...
My mate had a sky blue and pink SC Nomad called "Princess". He has a rugby player build and eventually cracked the BB. You can imagine the comments made about the cause of her destruction.......
"Of all the stories you told me, which ones were true and which ones weren't?"
"My dear Doctor, they're all true."
"Even the lies?"
"Especially the lies."
danbird wrote: ↑Fri May 14, 2021 10:46 am
Hey, Dan here - I design all of our (Bird's) frames.
All our frames have some rising rate designed in to them. Aether 7 runs at around 35% rising rate which is nicely poppy and you'll only bottom out the suspension when pushing pretty hard. It's actually quite difficult to judge the rising rate just by looking at the linkage - moving a pivot point by a few mm in a specific direction can have a dramatic effect on the suspension performance.
If you have any more questions please let me know!
Cheers
A couple of questions
Do you think that rising rate is necessary with an air shock, years ago in motocross there was a theory that said with air suspension you got rising rate without a linkage because as the air compressed it became harder.
How do you decide where to put the swing arm pivot?
Both questions are from curiosity, not trying to catch you out or disagree with you.
danbird wrote: ↑Fri May 14, 2021 10:46 am
Hey, Dan here - I design all of our (Bird's) frames.
All our frames have some rising rate designed in to them. Aether 7 runs at around 35% rising rate which is nicely poppy and you'll only bottom out the suspension when pushing pretty hard. It's actually quite difficult to judge the rising rate just by looking at the linkage - moving a pivot point by a few mm in a specific direction can have a dramatic effect on the suspension performance.
If you have any more questions please let me know!
Cheers
A couple of questions
Do you think that rising rate is necessary with an air shock, years ago in motocross there was a theory that said with air suspension you got rising rate without a linkage because as the air compressed it became harder.
How do you decide where to put the swing arm pivot?
Both questions are from curiosity, not trying to catch you out or disagree with you.
Hi,
Yes it absolutely is necessary to have a rising rate without an air shock. Without it the bike feels dead and too "stuck to the ground". The original Aeris frames and the Aeris 145 didn't have much rising rate as I designed them for maximum traction at the sag point. They grip like hell but do not feel as fun or poppy as our newer frames. Swapping the 145mm linkage out for the 160mm LT linkage on the Aeris was a massive improvement as the rising rate jumped up to close to 30% - it was obvious from riding that although the bike had more travel, it was also easier to get airborne and hop over obstacles.
The thing to remember is that while air shocks have progressive spring curves, with negative springs they are not as progressive as you might think, and regardless of the spring progression, the damper does not have any built in progression. Designing rising rate into the linkage means that your damping also increases towards the end of the travel (ignoring other factors inside the shock such as speed of oil flow past the shim stack etc).
Position of the main pivot by the BB is mostly driven by how much anti-squat you want to generate. It's the primary lever for adjusting the total anti-squat. Move the pivot higher up and you generate more AS, move it down and you generate less.
weeksy wrote: ↑Fri May 14, 2021 2:35 pm
Fork air spring kit arrived, so i've dropped the fork at the LBS for a lower service kit and fitting the air spring.
Also picked up 2m of gear outer so i've got nice new stuff on
Well the Bird will be getting fully introduced to the UK weather this week it seems. Still debating whether i head out today or not as i'm waiting on a dropper post shim along with front chainguide. I can live without the chainguide for a local test, but the dropper would be nice in the current conditions. It'll certainly be on the sloppy and slippy side though if i get out.
Mr Moofo wrote: ↑Mon May 17, 2021 1:06 pm
Okay all,
Sweepstake on the Shock?
Who’s in ?
Well, in it's defence it's a 'used' and 'serviced' shock.... but as it's a new frame and i don't expect any of the issues, if this one needs a shock, i'm OK buying a new one in for a penny in for a pound.... or several.
in for a penny in for a pound.... or several.