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A Surly Maverick
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2,698 Posts
Discussion Starter #1
Greetings Fat friends, before we start, a word of caution......

This thread will be long, retro and antrospective, geeky, obsessive and a bit weird.

If this is an issue for you , do not go down this Rabbit hole.:nono:

If it isn't, jump on in !:D
 

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A Surly Maverick
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2,698 Posts
Discussion Starter #2 (Edited)
it all began (for me ) on the 29er forum on MTBR in 2007.

Mikesee among others had some rather interesting looking bikes.

They were fat and could go anywhere.......

https://forums.mtbr.com/29er-bikes/...-about-those-big-beautiful-steeds-362489.html

I live on a Peninsula and there is a lot of beach here.

I had been riding on the beach since I was about 9 yrs old

On this ....

Raleigh Grifter , 3 speed Sturmey Archer hub and fat tyres.

The need for a Fatbike was growing and so I imported a Pugsley from the USA.

I had never ridden anything like it !

Crazy Endomorph tyres with self steer made beach riding sooo much better :cool:
 

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A Surly Maverick
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2,698 Posts
Discussion Starter #3 (Edited)
It was a fun and crazy time :)

There were not many fat bikes or components available at the time, so a lot of fettling and bodging went on ( translation :- making stuff that wasn't meant to, work with Fat).

I ran Maverick SC32s and than DUC 32s using 47mm wide 26" trials rims with Endos.

Pug got a re-spray and went all dark on me.

Larry also arrived on the scene, before he got big and fat.

https://forums.mtbr.com/fat-bikes/journey-darker-side-pugsley-you-have-been-warned-634292.html

The other thing that happened was IGH.

The beach is not kind to drivetrains.

The grinding noises can be , 'distracting'.

The Alfine 8 worked quite well .

https://forums.mtbr.com/fat-bikes/`s-all-fine-my-pug-549168.html

The only downside was low range was not quit low enough....
 

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A Surly Maverick
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2,698 Posts
Discussion Starter #5
They were all great fun but still the drivetrain issues bugged me.

Then Rohloff did this !

https://www.rohloff.de/en/company/news/news/170mm-speedhub-for-fatbikes-update

Oh WOW !!!

But .... big buckaroos and even bigger if you wanted 12mm TA compatibility.....

Then then was the issue of wheels.

You would have to have a Rohloff hub for each wheelset so big Buckaroos X 2 !

I thought about it a lot....

I even sold bike stuff with the full intention of getting one....

But rear wheel spacing was changing from 170/177 to 190/197, more problems.....
 

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A Surly Maverick
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2,698 Posts
Discussion Starter #6 (Edited)
So long story short, I never bought one.

I continued to beach ride and gradually made my way to a Lynskey Fatskey XL frame.

This bike felt good :)

It fit me well and rode well.

I ran it with Laufs, but settled on Mastodons as I am 240lbs and they felt better.

So this bike was FaTi, but no Pi yet....
 

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A Surly Maverick
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2,698 Posts
Discussion Starter #7
And still the drivetrain issue.

Then this appeared.

https://pinion.eu/en/p-line/p1-18-gearbox/

GAME CHANGER !

18 speed internal gearbox with a massive range......

Not without it's issues though.

1) big buckaroos again.

2) initially , not Fatbike compatible due to low Q factor cranks.

3) will not work with a normal frame.

Then Pinion produced a fatbike specific set of Cranks .....

https://pinion.eu/en/pinion-fatbike-accessories/

And some Niche manufacturers got fat.

https://en.nicolai-bicycles.com/frames/argon-fat-pinion/
 

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A Surly Maverick
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2,698 Posts
Discussion Starter #10
Now I was brought up as a Mech Eng many years ago, and I like to think about stuff.... well , Ok , maybe obsess a little too :)

I was browsing a well known selling site and there was a P1.18 for sale.......

I think you can guess what happened :)

Now I have a (good) problem, I do not have a frame I can fit this to.

All of the offerings available are great but they are not quite what I wish for and are very expensive.
 

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A Surly Maverick
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2,698 Posts
Discussion Starter #11
Soooooo..... what to do.

I'm 53, and I've been lucky enough to ride a lot of different frame over the years.

I know what i like and I know what I would like to build.

Time for my big fat custom frame journey !

But where to start ????

Well , how about with the Fatskey for basic geo, but with some 'tweakage'.

Frame material, Ti for corrosion resistance and ride ( notice I did not mention weight, that's deliberate).

Splittable driveside chainstay for belt compatibility is wanted.

Internal dropper routing , why not ?

NO bottle cage mounts ( personal pref as I always use a frame bag)

197mm x 12mm TA.

Downtube clearence for a Mastodon fork 100mm EXT (A2C 531).

150mm 44mm dia headtube. I prefer a more upright posture and am fairly tall .

68 degree headangle too.

But how to get it made ?
 

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A Surly Maverick
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2,698 Posts
Discussion Starter #13
Ti frame Manufacturers do not exactly grow on trees, especially for custom build that do not require major organ donation to be achieved !

I got in touch with a Chinese company via Alibaba and asked if they could help.

I also wished for sliding dropout and the ability to run 26 x 4.8, 27.5 x 4.5 and 29 x 3.0 wheel combinations too.

I was able to directly measure the Pinion with cranks attached giving a 188 mm clearence between them.

I ensured that there was no risk of crank/ frame contact under ( my considerable ) load, by giving a good clearence margin.

we ran through a few drawing iterations and settled on this .
 

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some might say mini
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10 Posts
Such a beautiful bike. I see lots of smiles down the beach in your future
 

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Rippin da fAt
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8,437 Posts
Way to go, Doc! Lotsa imagination has gone into fat over the years.
 

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A Surly Maverick
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2,698 Posts
Discussion Starter #18
Thanks CK, wow , nearly 9 yrs ago. I'm older, but no wiser :D

Superfat Pug is looking good too :)
 

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A Surly Maverick
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2,698 Posts
Discussion Starter #19
Ok people , strap in , more nerd-age to come !

Lets talk about gearing :D

I had been running a 28 (oval ) x wide range 11-42 cassette , and it was ok most of the time.

It did lack a bit at both ends of the range.

Especially in soft sand into a headwind ......

I used Sheldon Brown's gear calc to help.

https://www.sheldonbrown.com/gear-calc.html

i struggle a bit with gearing , and found it easiest to visualise in 'Meters development'.

Simply put , this tells you how many meters the wheel will travel with a single rotation of the cranks.

ie:- in the '11' cog , the wheel will travel 6.1 meters, and in the '42' cog the wheel will travel 1.6 meters.

This makes sense when you are pedalling, as if you are in the biggest cog (42) you are spinning those cranks, but the bike is moving really slowly.

Pinion also have a calc on their site too at the bottom of this page.

https://pinion.eu/en/p-line/

With 18 gears to play with , my aim was to add roughly 3 easier gears and 3 harder gears to the range of the 11-42 SLX.

Sheldons calc allows you to do this too :)

You will note that have set wheel diameter at 29 x 3.0 which is roughly equivalent the the tyre size I'm running.







.
 

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