Dammit’s adventures in mountain biking

Reverse mullet

It's called LoPro darling

I fully intend to go fully coil on my short travel Marino build next year and I was torn between going 26 with a Rockshox Lyrik Coil U-Turn or 27.5 with a Cane Creek Helm Coil...

Coil is the only way though.

26/27.5 mullet?!

Marzocchi z1 coil is a reasonably priced option too. But it would maybe disappoint anyone who’s owned an original Marzocchi as it’s Marzocchi in name only. Just a rebadged Fox fork.

Excuse my ignorance but what is the benefit of a coil spring?

I see my self making a rash decision with the credit card for an Ohlins coil fork next year.
But you should definitely go first.

It can be swapped back and forth from coil to air too.

It can be swapped back and forth from coil to air too

That's certainly more appealing for those wanting to try it out

I wonder why the RXF38 isn't available as a coil fork

I’m not sure but it maybe shares some aspects with the 38mm dh fork which is air only. Maybe in the future?

The Ohlins rfx36 coil is completely home serviceable too which is a appealing.

On another note, I’m at Legoland right now and just spotted a member of staff wearing Neils new POC troosers… defo waterproof

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Lego approved!

I can see nothing made from Lego in that photo

Refund please

I know, right?! A massive disappointment if I’m honest.

Jokes… maybe the best day of my life so far.

Excuse my ignorance but what is the benefit of a coil spring?

Coil springs (unless you buy a progressive one, more on that to come) have a linear spring rate.

So, for the 500 pound spring that I have it will take 500lbs of force to compress the spring 1", 1000lbs for 2" and so on.

With an air spring you have a non-linear spring rate through the travel, initially it's very stiff, then it softens, then as the air is compressed it stiffens again - and this last part is progressive, so it takes more and more force to compress the spring a constant distance as the air chamber gets smaller (and therefore the air pressure gets higher).

I don't think you can now purchase an air-sprung shock or fork that doesn't have a negative air spring that counteracts the positive (main) air spring for the initial part of it's travel these days, and that's because the negative air springs job (in terms of spring rate) is to reduce the spring rate at the very beginning of the stroke (off the top) so that the suspension starts moving far, far more easily than it would without the negative air spring.

The negative air spring loses pressure quite fast, which means that it stops counter-acting the positive spring as the shock gets into the mid-stroke, and from there on it's just the main air spring doing the work.

What is considered desirable about an air spring?

1. It's light - air being rather less dense than spring steel
   
2. And you can change the spring rate (pressure) with a shock pump, rather than buying and fitting a new coil spring
   
3. The progression at the end of the stroke is useful as it stops the shock bottoming out harshly
   
   

What's less desirable?

1. The initial stiffness can be countered by a well-sized negative air spring, but (so far, even with developments like the Rockshox Meg-Neg air can which features an enlarged negative air spring) it's not as supple as a coil. Air spring itself to one side, you have to overcome a lot of seal stiction, which is surprisingly high.
   
2. And you then need to balance that initial spring rate with the mid-stroke, as a characteristic of all air-springs is that their spring rate is regressive - they get softer.
   
   

It's due to 2 that I swapped to a coil on my 295, because to get the springy, poppy mid-range that I liked I had to run a pressure that made the first part of the stroke quite harsh.

Also, the Rockshox MegNeg air-can has a larger diameter than a coil, so I can't fit one.

That leaves me with the issue of bottoming out, which I guess I'll have to see about. TF Tuned insist that with the correct spring weight/spring rate that won't be an issue as I won't be blowing through the mid-range as I am with an air-shock, and that greater support will mean that I use the end stroke a lot less.

An issue for me may be that the kinematics of the frame are perfectly linear - other bike designers engineer in a leverage ratio that can for example counter the characteristics of an air spring - so a high leverage ratio initially followed by a lower one in order to overcome the initial stiffness, but then not blow through the mid-range.

Airsprings are also more expensive to produce as they require more moving parts and higher tolerances. You can also fuck them completely by getting dirt in to the air spring chambers.

You can also fuck them completely by getting dirt in to the air spring chambers

Are you still throwing away your shock pumps after every use ;-)

To add: on my 295 I fitted a Fox DHX with an Ohlins coil to the rear, and anticipate that I may need to fiddle with the spring (500lbs currently installed).

For the fork I fitted a Vorsprung Secus, which effectively gives the Lyrik a much larger negative airspring to overcome the initial spring rate and stiction of the Lyrik air-spring. It's also meant to enhance mid-range support.

I went this route rather than coil for the fork as it's adjustable with a shock pump (just not Howards shock pump) and I had the room to fit it - the Secus is a can that attaches to the base of the left hand fork leg.

Nah I just never, ever attach one to my forks.

I put a Luftkappe in my MY17 Yari to increase the negative spring. It's a simpler fork but I could notice the difference

https://www.instagram.com/p/CU6pYNyszT9/?utm_medium=copy_link

If you fancy hot rodding those brakes?

It's worth noting that most coil shocks with a piggy back will come with a hydraulic bottom out, which is actually a very small high pressure air spring, either bladder or IFP by design.

There's another company doing a variation on this called Everflow

Thanks for the info! Interesting stuff

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But more excitingly

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These look nice!
is the small one for bar or saddle?

These are for the hardtail?