Let's offroad / mountain bike / mtb / ride dirt

That makes sense, so maybe the spikes of power would be higher but the average might end up the same or less for a similar effort level?

Estimated power is 100% fictional. Ignore.

Years ago I used an HR strap that estimated power from heart rate, once I moved onto proper power meters I found that it seemed to have been guessing pretty accurately.

For MTB, where a lot of your power spent during the ride isn’t turning the pedals it might be a better guide than pedal torque.

power is 100% pointless unless you are Elite. Ignore.

Thanks for the advice people gave in this thread.

In the end I went for a Chameleon - as it was in stock, I could port everything over from my old bike and it was yellow. First ride last night after finishing putting it together and it’s awesome.

Will need some winter tyres and some mtb ability at some point soon.

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i love those

It's a very good looking bike

Will need some winter tyres soon

Not too soon, I hope

Very pretty!

Oh my... that really is a lovely bike!

I am a subscriber to the Lee Likes Bikes /Ride Logic school of thought re mtb fit.

Am more and more coming to the conclusion that my Bird Aether is too long and low. LLB has the notion of RAD rider area distance (from bb to the centre line between grips) SHO steerer hand offset (how far off the steerer tube axis the centre line between grips is) and the RAAD rider area angle in degrees - the angle from bb to centre line between grips. I have got the RAD perfect and the SHO to 1.2 (his view is anything within +/-10mm is great but it means the RAAD is 55degrees. His view is xc bike should be 56degrees, trail bike 58 and downhill 60. So effectively the BIrd is set up as a super fast xc bike! But it should really have a higher front end.

I think I am going to try and find a second hand bird frame one size smaller and swap parts over. Currently If I try to raise the bars the RAD becomes too long and the only way to mitigate this would be to find bars with a huge sweep back but then the bars will be behind the steering axle with a negative value SHO

So it appears I need to swap out to a smaller frame at which point I can achieve near perfect RAAD SHO and RAD.

So if I can find someone selling a secondhand frame how much should it be. Brand new the aether 9c is £1740 what kind of ballpark should I look to pay for a second hand one (and then this will also give me an idea for the resale value of my own frame)

How does it feel to ride?

I recently reduced the RAD number got rid of spacers under the stem and SHO (rotated bars back a bit) and the bike is much more manoeuvrable but the front end is low so still makes it difficult to lift the front. I think the length gives a feeling of comfort but also leaves me feeling like a bit of a passenger.

New forks for hardtail build arrived yesterday

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LLB has the notion of RAD rider area distance (from bb to the centre line between grips) SHO steerer hand offset (how far off the steerer tube axis the centre line between grips is) and the RAAD rider area angle in degrees - the angle from bb to centre line between grips. I have got the RAD perfect and the SHO to 1.2

I feel like I just walked into a room of accountants talking about spreadsheets

Yeah it's not that deep. You sound like you're prepping a launch sequence to visit the international space station.
Just get higher rise bars and ride your bike.

You should definitely go into your LBS and explain your predicament.

noted on your RAD becoming too long, have you considered cycle training?

Could you test ride a smaller one, back to back with your current one, before making a financial commitment to change?

I accept that e.g. Jack Moir, Bernard Kerr etc are on smaller bikes than is now conventional for racing - but they choose them because they're less stable, IIRC Moir rides a bigger frame when he's not racing.

I'm put in mind (hear me out on this, I admit it's a stretch) of modern jet design being to deliberately make something that is dynamically unstable which is then made flyable via the electronics, the results of this combination being very high manoeuvering potential when compared to an inherently stable design.

Not sure an LBS can help with the question which was “ if I can find someone selling a secondhand frame how much should it be. Brand new the aether 9c is £1740 what kind of ballpark should I look to pay for a second hand one?

It’s definitely not very rad.

I have gone down a rabbit hole on this. Lee Mcormack is one of the few people to have considered dynamic bike fit. Most people say “just follow the manufacturers size charts” despite huge changes in stack and reach over the last few years.

Under the ridelogic fit system the most important dimension is the rider area distance then the angle (for type of riding) and then the steerer offset for ease of turning.

About 5 mins into this video they discuss rider area distance, get it right and pumping etc will become easier.effectively locked out straight arms and legs will bring the bars up to your hips giving maximum power to that lift of the front end.

https://youtu.be/HyppZOpHocM

After that comes the angle from bb to bars - lower angle (56 degrees) better for climbing and sprinting (eg xc), higher angle (60 degrees) for descending (downhill). So general trail riding is somewhere in the middle.

Steerer offset if reduced to a low number makes turning the bars easier as you are not having to reach so far forward (if it’s out front like an old style xc bike)

So it’s not that I want a super short bike but I am on the cusp of sizes between birds medium/large and large sizes. If I raise the bars on my large it will compromise the most important measurement on the bike so that does not work.

https://youtu.be/rHagRovHSYs

https://youtu.be/5pn6Mnl4AAw

I mean, that's just bro talk for stack and reach.

Kind of but more importantly it’s the hypotenuse that is the most important for basic fit. Then stack and reach need to be adjusted for the type of riding. Also the basic stack and reach of a frame don’t take into account the huge variations available due to stem lengths (32 -110mm),bar rise (o-40mm) and bar backsweep (often ranging from 10-60mm) and spacer stack

So with my current bike I can get the hypotenuse but the front end is about 4cm lower than I need it to be. Raise it up with spacers or bars and then the hypotenuse becomes too long because the reach is too long.

Stem and bars can only do so much to accommodate but I need inverse shim stem as the frame is just too long.

Wow