The stirrings of radical geometry…

2manyoranges

Old School Grand Master
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I‘ve just been meandering through the things which various inebriated people put on eBay last night but came across this rather nice photo of a Fisher which displays really well the way in which Gary Fisher was playing with geometry…the stirrings of the geometry which has had such an impact in the last decade. It’s always been a surprise to me that geometry changes so slowly. In this photo you can so easily see the way in which the top top has been stretched out, the head angle slackened a little, and the stem shortened. It was seen as ‘radical’ and yet ‘long low and slack’ took the ideas way further … even it took SO long to creep through into the mainstream. Before GF was stretching the front out, Marin already had taken what Joe Murray had started, and stretched their Team models‘ toptubes - the ti and nickel ones - without any comment or fanfare. But I noticed it when I built up a nickel steel Team in ‘96 - looked at the frame, scratched my head and got the tape measure out - and finding a tt two cms longer than the other Marin models was able to push the saddle forward to get the steeper seat tube which bikes of the time desperately needed for better climbing, and shorten the stem for better downhill performance. We still had steep head angles, though, and very short head tubes giving very low stack height. Yikes. Fast on the flat, superb up hill and although more stable on fast smooth downhills, very scary on drop offs.

Very few test mules were made at the time - testing different angles - which always surprised me. The geometry seemed to freeze in the 90’s. May be it was the lack of cnc and cad and sheer effort and cost of ’playing’, combined with the inherent conservatism of the MTB market. I think Keith B would have done more if he had been lonely and thoughtful in his garage rather than grappling with a Trek sell-out, and Chas Roberts and co might have done more if they had not been working flat out to meet demand. Even when in the early 2000s Mondraker pushed the envelope so successfully with their ‘Forward Geometry’ the industry laughed publicly but seemed to sneak back to their next years’ models and secretly tweak the angles a little - not a lot but a little - towards the stretched things I ride today. But this photo really nicely shows the influence of GF on emerging geometry. Many scoffed. A few didn‘t…and they were right….

1667727490813.jpeg
 
Nice find … yes, that’s the kind of stuff…indeed less twitchy…good to trace the threads….
Pace had all that nice milling machinery….
 
So……nice photo…bit like a RA of today….(see below)….what‘s interesting is the stretching, but the head angle remains steep…no one thought the ‘steering flop’ of slacker head angles was a good thing or could be mitigated (eg by changed fork offset), nor was there much 1990s commitment to steeper seat angles, despite the steepness of the seat tubes on the hill climbing frames of the 1950s.

https://static.wixstatic.com/media/...7a4_76411a0708a44a38b63c15514f85be15~mv2.webp
 
Not-at-all-coincidentally, talking of Pace, wasn’t Doug Bradbury doing a similar thing?
Yep….although you were only just out of the car park before the frames cracked…..

I think Litespeed were ‘thinking‘ about it, but didn’t actually do much about it. Gary H was messing about a little bit.

https://mmbhof.org/gary-helfrich/
But it was all so tentative and only ‘out there’ ideas became industry talking points with these kinds of collaborations:

https://www.bikeradar.com/features/mojo-nicolais-geometron-plots-a-future-for-mountain-bike-design/
 
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well...

<clicks knuckles>

*the following is a coffee fueled brisk rounding up of reading RB material from the last 15 years or so - it is not meant to be word for word accurate! Please feel free to correct any erroneous material!

Back in the dim and distant, the earliest generation of commercial mtbs came from the cyclocross/ roadie mind of Tom Ritchey. The Breezer bikes being designed solely for the wanging down Marin County, the Ritchey frames took the MTB along a bit so it could go up as well as down

Thus the mid 80's MTB/ATB took shape and hung around into the 90's by quite some way

But, there was a small event in the UK where many influential US/ UK riders/ builders/ designers were splattering themselves with mud and snot. This included Andy Powell, his Pioneer model had debuted in early 1986 and exhibited a radical change over the Stumpjumper shape of the day. This and Jacquie Phelan with her Cunningham went on to influence the likes of Kona and Rocky Mountain - just look at how different they were and still are to the bikes of the time

So, the 1990's - suspension

I doubt anything else had any more influence than Fishers' RS1 being ridden up the steps, it certainly blew my mind anyway, enough to blow £250 on a set of MAG20 in 1992 after seeing the RS1 doing its stuff

Riders wanted more, the DH scene was cool and bikes like the Mountain Cycles San Andreas would go on to influence just about everything as soon as it appeared, the single pivot Marins took the crown for accessible full suspension from Proflex so by the late 1990's and into the 2000's things settled. 4 bar linkage was everywhere, hydroformed aluminum gave us the futuristic swoopy shapes that had always been promised by science fiction

But it got dull.

by the 2010's bikes were a bit samey with few standout models to get excited about and the Roadie was back with a vengeance, MTB sales were a bit sluggish... A whole slew of Specialized designs were popping their suspension pivots like it was going out of fashion (it was) and Youtube made the once radical seem like a ride to the shops

Another 'but'!

Somewhere back in the dim and distant, the 26'' wheel was considered a bit small and 700c had been used in many 'hybrid' designs. A few designers ran with this idea and in the 2000's the 29er popped up here and there.

Materials and manufacturing had come on and carbon fibre was taking over allowing designers free reign over suspension placement and wheel size

That pesky front mech!

Rumour/ internet/ urban myth states that SRAM didnt want to pay anyone for front mech patents so did away with that pesky lump of shiftin' iron thus releasing the burden placed on designers and pretty much blew the cobwebs out giving us what we see today

The future! (...ure ...ure ...ure)

After the suspension travel arms race, the bike park bike histeria, the e-bike has taken over and theres no getting away from it. Travel has got shorter but the geometry has settled around big wheels, a central motor and the battery. The tweaks and nibbles of tube lengths is now kind of irrelevant as the current bikes are kinda just sit on and ride it, bitch! Where it goes from here is anyones guess as there are approximately 3.5 billion more people since the late 1970's, the internet and its social media

Personally? I'm stuck in the Tom Ritchey era, arse up, head down roadie style of MTB along with the more sedate cross country style of the horizontal top tube wide bar bike of the UK's mid 80's bike - but I do like a good full susser. I find the modern bike just to much at odds with how my body has shaped with age, I dont like sitting 'in' the bike.

Anyway, enough, I need breakfast
 
I understand steep seat angles on a long travel 'winch and plummet' bike, when you're seated, climbing something steep and all your weight is through the rear end, the rear suspension's sagged, the forks extended, putting the 77º angle back to the 73-74º wanted for efficient pedalling. Seems daft on a hardtail or even a short travel FS aimed at all day riding. If it was better for all day pedalling surely it would be a thing on road bikes too.
 
Can you give some examples of radial and modern geometry?
But stick everything to a 26" wheel example and convert it to a rigid frame (as suspension and length and wheel sizes buggers up comparisons).
You cannot compare a 29er 140mm hardtail to a 26" rigid/40mm front sus bike.

Take a standard RM 20" frame from 1992
Race frame 40mm travel - front sus
HA :71.5
SA :73*
TT (eff):23.5
CS :16.7
BB :11.75 (depending on tyres ;-))


Enduro frame rigid- front sus
HA :70.5
SA :73*
TT (eff):23.2
CS :16.7
BB :11.5

*(changes up/down sizes)

Entry Enduro
HA :70.5
SA :72.5
TT (eff):23.0
CS :16.9
BB :11.5


What would you expect to see them as now?
 

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