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

Tyre: 29x2.3", diameter about 739mm.
Fork 30mm A-C, 50mm offset
Headangle: 65 degrees, you end up with a crown height of 828.6mm and 117.1mm trail.

Tyre 27.5 (584mm) x 2.6", diameter about 716mm
Using the same headangle, crown height and trail as inputs...
Fork needs to have A-C about 539mm and 45mm offset.

Looking at https://www.cotic.co.uk/product/solarisMAX they say it should take 29x2.5" or 27.5x3.0"...

I think my main issue would be, that i only could fit 2.6 tyres. Could still go bigger in the back, but not sure if that helps with handling..The idea with the pike only came up, as it was cheap.

I'm after some 680-700mm carbon risers. There are numerous cheap Chinese things on Ebay, which I tend to avoid, but are there any less expensive carbon bars that you people out there would recommend?

Decathlon / B'Twin made some I picked up years ago for £30. 720mm wide I think. I've crashed many many times on them and they're still great. Highly recommended if you can find them in a store.

But don't forget 20mm more travel

And it'll look silly. The cheap option is finding a non-boost 29" fork and wheelset second hand.

Cotic's geo chart for 120mm forks says they assume 531mm static length and 25% sag, so I've used 501mm as the A-C in my model.

Using their 120mm large geo, the numbers work out pretty well (unlike OnOne's for example), suggesting their EC44 lower headset adds 10.6mm to the stack. BB height on 749mm tyres (29x25") is 314.5mm, 45.4mm fork offset, 117.07mm trail. (headangle provided is 66)

To get the same BB height on 736.4mm (27.5x3.0") tyres with a 45mm fork offset, the sagged A-C needs to be 520.1mm, the trail becomes 120.7mm, headangle 65.2. Stack increases 609.4 to 616.3mm, reach shortens 486mm to 477.2mm. Assuming the same fork design, that means a 140mm fork at 22% sag.

Isn't maths fun?

Isn't maths tedious and irrelevant in this instance?

No matter what fork you put on to preserve the ride height at the sag point, bottom out will always be lower than the equivalent 29er fork. And nobody in their right mind would do it anyway. So it's academic in the worst possible way.

So i guess this would be a better fit for my cotic:

https://www.chainreactioncycles.com/fox-suspension-34-rhythm-forks-2018/rp-prod183265

They mention 15QRx110 as axle standard.. is this normal boost?

Yeah 15x110 is standard boost. Seems a good deal that if you want a 120mm good allrounder fork.

Or better go with manitou:

https://www.bike-discount.de/de/kaufen/manitou-mattoc-pro-27.5-29-120-tapered-sl-boost-801392

@TvH should I buy this?

I do really rate my Manitous (mattoc is the new name for the Magnum). My lad has some fox 34 rhythms on his mtb and the Manitous do feel a lot nicer in my humble opinion.

No. Judging by the picture and spec it's probably the Comp model, not the Pro as listed. @BareNecessities reckons OEM forks from a Stache

thanks for the advice!

Part of the description is of the Pro version, whereas the pictures look to be of the Comp. Decals are the same as the Trek Stache, and the shorter steerer makes me think OEM

Worth contacting BikeDiscount to clarify, I reckon

Surrey Hills guided ride Sunday 17th of March. All welcome: https://www.lfgss.com/events/4674/ *

*some gnar to be expected.
Also, good times and shredding.

I have 2.6 DHF's in the back of my Ransom, and to be honest if you go any larger it'll start having an adverse effect on handling. The squirm when cornering fast is noticeable even on a 2.6.

Please, please, pleeeeeeeeaaaaaase, vote Baybutt!
https://www.pinkbike.com/contest/bracket/poy2018/

(It's the final, I'll stop spamming now.)

Had voted that picture anyway in the last round without seeing your plea.
Just voted.

Been out for a couple gentle spins on my mtb now. Its pretty sweet but its definitely too big. Reach is good but with the length dropper I've got, its slammed in the frame and fully extended I still feel like I could be about 2cm lower ideally when pedalling so I need a frame that's a couple inches shorter in the seat tube region.
Steel and 2nd hand would be nice.
Genesis Tarn? Latitude? something else?
Frame only, 29er, 31.6 st, 142x12, slack front. What can I get?
Should I just build my own?

Sounds like you have the wrong length dropper?

Shhh. I need a new bike, not a new seatpost

Should I just build my own?

of course

I'm thinking..