[Closed] Bird Gravel Bike - Unofficial

That is very cool! Looks fantastic & OEM.
Would love to have something like that.
Look forward to hearing how you get on. I always try to work out how different something like this would be to the standard setup with some XC tyres and light sus forks with lock-out.

thanks!

From initial rides the Venture max bars are good width on the drops but feels a little narrow on the hoods. I got their 440mm width, perhaps the largest 460mm would have been better

Hmm. Interested to see these, but pics don't work for me ... 😔

That doesn't look all that bad, it look a heck of a lot better than some current off the shelf gravel bikes.

Bike design is all about compromises

It's really nothing like the cannondale topstone, your overlay shows that they are way off.

The bird zero is an aggressive MTB. The geo places the front wheel as far forward as possible for descending when the rider is not seated. The seat tube is steep so the bars are a comfortable distance from the saddle when pedalling back up. There is a compromise here, fun on the downs is valued more than undulating seated pedalling position as the most efficient seated position has a slacker seat tube.

The cannondale is primarily designed for seated pedalling, less so than a road bike but more than the bird. It's also longer than a road bike for more fun on the downs, but not as long as the bird and not so long as to require a steep seat tube. And as it is designed for drop bars, it's shorter overall than the bird.

The drop bars you've added put the bar reach way further out, and sliding the seat forward will further compromise the seated pedalling efficiency. On the downs you will be leaning much further forward than with flat bars, this puts your weight over the front compromising the bikes fun on the downs.

So you have compromised both seated pedalling and downhill stability by adding those bars. Worst of both worlds?

Usually when fitting drop bars to an mtb you would downsize the frame and use the shortest stem you can find.

Whether the result is an engaging ride is for you to decide, but it looks cool all the same.

actually the centre of saddle to bars dimension for the Zero build and the Topstone is within 9mm of each other that is not a big difference really and with a flatter stem on the topstone comes down further.

just purely looking at ETT+ stem(ignore other geo issues) the zero is 680ETT+35mm Stem (715mm total), the Topstone is 596ETT+110stem (706mm total)

also think in terms of weight distribution i think on the downs a higher percentage of my weight would be on the Top stones front wheel (i have had a number of drop bar bikes for road and offroad and always found them not to be that stable on the downs).

Anyway am going to do some longer rides to see, if it does not work out, will try the swept bars and if that does not work, easy enough to convert back to a proper hardtail.

saw it as an exaggerated version of this:
https://www.ridefustle.com/products/causeway-grx600

Shame I can't see the photos... sounds awesome. Very much tempted to try something similar with my SolarisMax.

@theOO and @hardtailonly -

this work - one of the pics as an example? google share
https://photos.app.goo.gl/oFMmSaBCmHW2NMg16

and embedded

@theOO and @hardtailonly –

this work?
https://photos.app.goo.gl/oFMmSaBCmHW2NMg16

Yep. Well, it links to just one photo. Would love to see some more!

You tease! I see one photo

I can see them all, report it as shonkey to stw mods

@theOO

No idea why some can see and other not?

put some pics in an album here:

https://photos.app.goo.gl/ytGgngwNByTSahSU9

as a note on the geo comparison, the saddle position is std on both the std bird outlines - not slide forward, the green one if further forward due to the shorter fork but is the same as a sagged 130 fork. cannondale seat position accounts for the 20mm setback on the std seatpost

You are forgetting a bike works as a system.

You can't just match one dimension and expect it to ride the same. It has an impact on everything else.

Might ride brill for you and that's fine.

I'd have just bought a topstone if that's what you wanted.

I don't care how it rides (I hope it rides brilliantly). It's bloody gorgeous!

That looks ace. I would! Reckon that could hammer down some chundery gravel!

I think that’s brilliant! Just saw your geometry comparison on Facebook and it makes total sense to me. The slightly more forwards position should weight the front wheel that’s so much further away than on the Cannondale, and if you find it too racey you can just raise the bars a bit.

I’m still convinced that most road-ish bikes have compromised geometry for solo riding due to the influence of aero in a pro peloton.

Looks ace! If I wanted/had use for a gravel bike, that would appeal to me.

Looks very long, great for getting aero but how does it ride on the hoods, are you in a permanent superman?

You are forgetting a bike works as a system.

You can’t just match one dimension and expect it to ride the same. It has an impact on everything else.

Might ride brill for you and that’s fine.

I’d have just bought a topstone if that’s what you wanted.

Hiya @wzzzz,

Not forgetting at all, had/have a lot of very different bikes (rise pre Covid, could end up riding Brompton, Tandem and then a full sus in the same day) so have a good feel for how designs affect a ride including that this bike was originally a proper HT, 140forks and wide flat (risers) bars, minions etc etc. STD.

yer could of just bought a Topstone. The AL ones are quite cheap, but.. the Topstone is not that removed from my Supersix.. yes more off-road suitable but not very. Tarmac/groomed perfect, but it is limited by tyre width and still in the 'let's make a road bike more off-road capable'. Much like 90s MTBs.. sure that is quite driven by gravel roads in the states etc. Basically 'offroad road riding.

So I never intended to 'make a Topstone' as you say could of just bought one.

I used it for seated dimensions as comparison as a. I had a zero to hand and had ridden and XL Topstone', good off peg option for the tall, and quite similar to my Supersix (and Caad8 for that matter) so would have been an easy option. But the ETT + stem comparison was a sense check, same as riding the HT setup with hands in front of the bars to see. Whilst Bird have a long reach, in the seated position not that dissimilar to lots of other old and new school geo MTBs.

This was just to to see if it might work as an experiment to see and compared to the off the peg gravel options.

Ok being honest, if starting with a blank bit of paper probably would knock 20mm of the ETT and increased the stack by 20mm.

Done a few rides on it now. Steering is light and not floppy, down on the drops is quite an aggressive position. Hoods is good positon, though the Ritchey Ventura Max bars are good width in the drops (good profile for hands), but a fraction narrow on the hoods. A dropper is a good thing for gravel bikes, just adds to the capability.

It is stable / secure downhill, and climbs nicely. Def like fatter tyres.

I think will see gravel design go the way of MTBs, with longer front centres etc not as extreme as this perhaps... See this already with some brands like Fustle Bikes etc already

Anyway going to test the flat bars on it next. And it it all goes wrong only the forks are unique, so can just mount them on the wall and think.. hmnnn oh well!

Also thanks for the all the feedback good and bad. Shame really I am so tall, as be good for other to have a test ride.

Looks great @rootes1 nice job. How are you getting on with the Schwalbe G-One All-round's? Considering a second set of wheels for my hardtail for more road/unpaved lanes/better draining singletrack during winter and looking at tire options, these look good but would appreciate any feedback.

Cheers

Looks great @rootes1 nice job. How are you getting on with the Schwalbe G-One All-round’s? Considering a second set of wheels for my hardtail for more road/unpaved lanes/better draining singletrack during winter and looking at tire options, these look good but would appreciate any feedback.

Not put enough miles in them to see about durability/puncture resistance, but they are surprisingly grippy, and they hold air really well in tubeless setup.

@rstephenson

Bike is now back on proper flat bars (SQLab 3OX 12degs), but done a reasonable number of miles on the G-One's and quite impressed. Hold air well and pretty grippy - obviously rubbish on wet roots and mud, but on other stuff pretty good.

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Looks much nicer with the riser bar than the drops you had in it. Like the fork though - looks ace with the colour match. With the faster tyres you’ve probably got a nice quick rolling all rounder.

obviously rubbish on wet roots and mud, but on other stuff pretty good.

One man's rubbish is another man's near-death sideways hilarity 😁

You could have just bought a topstone but where would the fun have been in that?

I think it looks better with the drop bars. Good work.

Ooey Customs in Camberley painted the forks (inc decals in paint), beautiful finish and spot on colour match - def recommend Stu at Ooey for custom paint work - https://www.ooeycustompaint.com/

With the faster tyres you’ve probably got a nice quick rolling all rounder.

Yer nice to ride and reasonable light, just under 26lbs