Has anyone bought one yet
A few people on the Bird owners FB page have - seen one or two built up on there I think. Only been out about 3-4 weeks though - and frame only I believe due to lack of available components.
Yes!
But only yesterday. And only frame + bits so I’ve a long and tedious task ahead finding and sourcing the remaining parts to build it up.
Really interested to see how they ride and whether is is worth a change ...
Really interested to see how they ride and whether is is worth a change …
What are you riding now?
I hope they have sent one to Steve at Hardtail Party to review.
JoeBristol
Cotic FlareMax
Production Privée Oka
JoeBristol
Cotic FlareMax
Production Privée Oka
Nice bikes!
Had a quick glance at the Oka (not sure what year yours is) and it looks like the forge is longer, slacker HA, steeper ST and has 29er wheels can 650b on the Oka?
Guess they’re both steel - whether the 2 x 853 tubes on the forge make a difference over 4130 I don’t know. Perhaps a fraction lighter and whippier - and the 853 badge is nice 🥰
I guess overall it’s going to be faster, more stable and possibly a bit easier on things like the lower back (that’s why I went from alloy to steel on the hardtail and 2.3 to 2.6” tyres). Might be less playful and nimble on the flip side.
Joebristol
yeah the Oka is 27.5 - and with a decent set of 140 pikes etc. It is probably more a vanity thing - I ride it occasionally but being old, the FS is definitely more likely to be ridden.
I have changed frames a few time over the years
On-One 456 -> Soul -> Bfe -> Solaris Mk1 XL -> Solaris Mk2 L -> Production Privee
And being honest , no hard tail is really that comfortable ! And i loved the $%^ and it was made from drain pipes.
I do prefer 29 wheels - they seem to roll easier. That said on the trails here that I have covered on both, times are vet similar whether FS 29er or HT 27.5.
The obvious choice would be to go a Bfe at some stage - but I not too sure I can handle the 4 million bottle mounts
I think the sta looks too slack on the Forge given the other geometry, the fact it has a curved seat tube will also make it even worse for taller riders
Oh yes. It does look like it needs another 1-2 degrees.
I wonder what the rationale is for that, and also quoting it sagged - it just makes it harder to compare to everything else.
Slightly odd. Especially when you consider that the Aether geo is pretty much perfectly specced and was their last one before the forge.
Scienceofficer
I wonder what the rationale is for that, and also quoting it sagged – it just makes it harder to compare to everything else.
Except Cotic, who also quote sagged geomerty. I guess we know who Bird are gunning for 🙂
I wonder what the rationale is for that
Because it makes it about the same as our FS bikes when climbing, and a little different to cater for the lack of suss when on the flat/descents. HT's steepen when ridden, even uphill, FSs seat angle changes all the time, but are overall slacker uphill/on the flat, so we make our HTs slacker in order to:
- Make them to feel roughly like our FS bikes when climbing
- a little slacker on the flat which makes them feel a little more natural and reduces the weight on the bars when riding on the flat
- A little shorter in the wheelbase when descending/standing which makes them feel a bit more agile.
All of which I think adds up to a more enjoyable HT ride. Not everyone will agree of course but thats why we have choice in the market not uniformity.
On the flat the Forge will have the same true seat angle than the Aether - a hardtail rotates about 2 deg steeper under sag whilst a full-sus rotates up to a degree the other way.
And uphill a full-sus usually slackens out more than a hardtail.
You don’t need crazy steep seat angles on a hardtail, especially if the chainstays aren’t super short, to go uphill. And less steepness pedals better on the flat. I also think I generate more power with the seat angle more reasonable. My Bird has a 74.5 deg seat angle and I slide the saddle back of centre. I can stand to use more quads, sit for more glutes and hamstrings.
“ I wonder what the rationale is for that, and also quoting it sagged – it just makes it harder to compare to everything else.”
The geometry chart I’ve seen quotes both static and sagged and for three different fork lengths.
I was just going to say, sagged and unsagged geo on the Bird website, under frame data..
Surely a hardtail needs to take account of seated and standing sag, seated will be how the bike will climb and standing will be how it will descend. Seated will put less weight on the front of the bike so might only change the head angle by 1 degree as opposed to 2 when standing. This means a slack seat tube angle won't correct itself under sag as much as a slack head angle.
"Surely a hardtail needs to take account of seated and standing sag, seated will be how the bike will climb and standing will be how it will descend. Seated will put less weight on the front of the bike so might only change the head angle by 1 degree as opposed to 2 when standing. This means a slack seat tube angle won’t correct itself under sag as much as a slack head angle."
It's the same but worse with a full-sus - with the sag that most people run (more on the back than the front) and the fact that rear travel is pretty much vertical whilst fork travel is at ~65 deg, a full-sus gets slacker when you stand on it descending and even slacker when you sit on it, and even slacker still when you stay sitting and ride it up a steep climb.
Because they all do it much they same, we ignore the fact that the static geometry chart doesn't match the actual riding geometry. But if we're going to ride hardtails in a similar way then we have to think about it if we want great handling and well-fitting bikes.
Surely a hardtail needs to take account of seated and standing sag,
Can we have sag quoted when you are:
- over the bars doing the 'it is funky, look like a monkey' thing?
- the Cathro attack position
- heels down, weight back for braking
- the arse over the back that is steep
All the above also need two figures, one with enduro bum bag and one with all day in the hills rucksack.
For the avoidance of doubt 😉
Lol @ Matt
I think it’s a balance as always with bikes. Steep SAs are mainly to combat sag on fs bikes but they do have a place on some hardtails.
Historically they’ve been too slack - modelled on road bikes.
Getting further forward does help with climbing - particularly on steep / technical climbs. Longer reach with a slack SA also can give quite a stretched out position which might not be that desirable in a mountain bike for a lot of people.
For me I designed my custom hardtail with a 74 degree seat angle - and I’m happy with that. It does alright on steep climbs (probably not as good as say 76 or 77 could be) - but it’s comfortable for longer xc / trail rides where you’re on the flat a lot. If you go too steep it works well for winch and plummet but less well for long days in the saddle. Just imo.
My full suss is an Aether 7 and with the sag the steeper angle works well.
I built up my Bird Forge last Saturday, took it out for a spin on my local trails on Sunday. I did collect 3 PR's on the downhills I previously set on my MDE Damper full-sus, so that is that.
At first I was concerned about the relatively short rear end compard to my previous bikes but my worries were unjustified. The geometry is spot on. At 5'11 with a rather long inseam I'm riding a ML frame with a 50 mm stem and a 785 mm bar. The frame oozes stability and responsiveness when pointed downhill. No matter how steep/flat or chunky/smooth the trail is. IMO this is also related to the sensible choice of Reynolds 853 tubing for the top- and downtube combined with rather substantial CroMo tubing for the rear end. I did some experiments on hardtail frames with a with a frame builder friend so I have a little so I have developed a bit of a feel for it. The climbing position is very comfortable and effective as well with a 5mm space underneath the stem and am 30 mm rise bar.
All in all, I am thoroughly impressed with the ride.
My build consists of many usual suspects that have been carried over from previous bikes:
DVO Diamond D1 @ 150 mm
Stans Flow MK3 on Syntace MX Hubs
11 spd SLX / XT drivetrain
Formula Cura brakes
Kenda Hellkat / Schwalbe Hans Dampf SG
SDG Tellis dropper 170 mm
Nukeproof Horizon stem, Ritchey WCS trail bar
Specialized Henge Pro saddle
ODI Elite Pro 2.1 grips
Feel free to ask questions. Cheers!
Picked mine up on Friday and squeezed a quick test ride in the following morning.
It’s lovely, it fits me - this low and long trend is brilliant for short-legged riders like me.
Haven’t had a chance to send it down much more than a shortened lap of Mabie’s Red but everything so far feels confidence inspiring and good.
Build spec:
ML Long frame (that blue colour looks ace)
160mm Lyrik
Big ol’ 40mm rise Renthal bars, cut to 780mm (same as my other bikes)
Hope / DT Swiss wheels from Bird
Deore 12 speed everything + XT Shifter
Magic Mary up front / Rock Razor out back - both tubeless
First 29’er in ~ five years and it feels like a lot of bike with those big wheels. First impressions are great, looking forward to a proper test run soon.
I have a 9C and a Forge, fair play to the lads at Bird. They know how to design a bike.
I built one up
160mm lyrik ultimate
Silt wheelset
Conti tyres
Carbon bars 780mm raceface bars
Nukeproof stem. 35mm (length) i think
Carbon cranks raceface cranks for now
Uber bottom bracket
Hope V4’s
Stayed 11sp rather than 12
6’1 and the large is perfect. Front end is high and was worried about doing backflips but for some reason it feels easier and more composed on the hills than the Zero and Am9. Front end stays planted.
Stunning bike to ride. Had their Zero AM. Which was fantastic. Got their Am9 which is a beast but the Forge is something else. Goes uphill like a mountain goat and goes down anything quicker than a tarts drawers so to speak.
Doesnt feel flexy at all but it just soaks up the bumps. And its light for steel. Feels Way lighter than other steel bikes i’ve had or guys in my riding group ride.
Tis the only bike I’ve ever ridden where i think i could finally go to “n” instead of always being n+1. Recon its so good it could be my one and only bike wherever i ride.
And the teal is stunning. More blue but purple flip undertones.
The guys at bird are great to deal with too.
Only problem was getting the spacing sorted on the cranks with chainstay protectors and crankboots. Official spacing had the crank boots catching the chainstay protectors but a little tinkering with spacers and cinch got it sorted. Chainline is not official but close enough and it still shifts clean and crisp so who cares whether its spot on or out by 0.6 microns!
And geometry, boulderdash to it all. Bird know how to build a bike. It rides fantastically well, feels comfortable and is pretty stunning to look at too!
Upcountry, downcountry, left a bit, cross country, enduro….no idea. Who cares. It’s a riot to ride. Anywhere. In the country.
Do i like it, hell yes.
I’m looking at these but the bb is super low. What crank length are you guys running?
170 mm is just fine. On technical climbs you need to look ahead a bit more to get your timing right but then it's so much worth it on the downhills.
Update after 3/4 months ownership of mine.
It's brilliant.
My formerly cherished full-suss Aeris has barely turned a wheel since the Forge arrived - it's the one I grab every single time I head out now.
'Big' / uplift days and any sort of enduro racing might sway me but so far everything I've tried on the Forge it's handled without issue. All the local trails and off-piste stuff (* that we can actually get at after Arwen) - no sweat at all.
For the first time in 5.5 years ownership I'm genuinely considering selling the Aeris (and replacing with an AM9 if or when funds allow) - the Forge is so much nicer to ride. I didn't see that coming at all.
Bird have made a damn, damn good bike with this one. They really have.
It sounds awesome but this thread needs more pictures.