See where you’re coming from but in my mind compensating for geo using sag is still a bit out. While riding you’ll spend most between sag and say 80% travel which would steepen things more. In reality I’m not convinced until you reach the extremes that a single degree will make much difference anyway. Have ran my 27.5+ hardtail with a 29er front as well. 29er raised the front and slackened the whole bike. The initial change either way was noticeable but within minutes I was used to it.
The stirrings of radical geometry…
- Thread starter 2manyoranges
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See where you’re coming from but in my mind compensating for geo using sag is still a bit out. While riding you’ll spend most between sag and say 80% travel which would steepen things more. In reality I’m not convinced until you reach the extremes that a single degree will make much difference anyway. Have ran my 27.5+ hardtail with a 29er front as well. 29er raised the front and slackened the whole bike. The initial change either way was noticeable but within minutes I was used to it.
2manyoranges
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blimey we could be converging on a radical geometry for rigid 26ers with 26+ tyres ...
Please do, everyone’s tuppence welcome.
No right or wrong here, just different opinions.
No from me you won’t, pretty sure I’m talking an almighty load of pish.
You are forcing my hand here
I've had to have some chocolate energer to hopefully make a reasonable post in a midst of wine. It may be wonky because I haven't properly formulated it really.Let's back track sometime, a lot, and forget about a MTB for while. I know it's hard for some of you. Double diamond frames, two wheels and a rider sat on bike goes back a few years. In the beginning, before lot's of smooth roads, we had very very slack angles, a very short stem, long rake on the forks for suspension / bounce and that was that. Roads got better, gears developed and as a consequence speeds increased and suddenly an odd thing happened ...... bikes with that geometry were uncontrollable at these new speeds. Probably way upto the 60s or 70s a stem longer than say 80mm would have been a very odd thing.
I have distinct memories from a very well known UK frame builder who talked to me about this. "Trying to descend with pissy short stems, there was no way we could keep up with continental riders". He was referring to more-or-less that the Italians mastered road geometry who upped the stem length into triple digits. Suddenly a road bike was not twitchy as fcuk at +70 kph even with steep angles, narrow bars an average rider could yank the bars around coming into an hairpin with crap brakes and provide enough steering leverage to get around corners without that deadly "the bike wants to take a line of it's own" feeling where the rider would literary freeze up and go off the edge off the tarmac. Even today you can see this effect in women's professional road racing.
So ..... this would be in the 80s-ish. I get there were practically two camps on the MTB scene - Cruiser origin and stay there, fun gentle off roading not dissimilar at all to French Randonneur type bikes, or Tom Ritchey make 'em fast. Make 'em fast is borrowed out of Italian road design - no question about it. Fast means aerodynamic come into play, so low, narrow bars etc. Making a bike less twitchy - considering things all equal - was to increase the stem length. And that was done, and that was the way back then to mop up in races. And it worked.
I urge anyone here into normal riding to ride a Parkpre MTB full rigid with 72 degree parallel which is probably the oldest of the old road frame geometry to just see how capable it is off-road and just how good it is at slow speed and fast speed. It's on the nail IMHO.
When Norba geometry came along it all got normalised across industry because it worked well, but suffice to say, at that time that bit of 1" squish up front was most likely never a real geometry consideration. A bit of shortening or raising the head-tube is about it all it merited.
I can't comment when things got to 80mm travel. It get's specialised which is understandable. Perhaps that's were we are today still? Dunno?
I think my point is, nothing is radical. At all. Ever concerning bikes when history as a whole is taken into account. For a bike to be accepted, it's always been about gradual tweaks so it performs in it's intended arena for today.
2manyoranges
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.....just bought that karate monkey that was on eBay this week - med in orange...
and yup to a point Lord Copper - note the seat tube angle, i'd tighten that up quite a bit. but it's a very nice thing.....
Nice, do have a soft spot for a Surly. One of the few companies beating its own drum without worrying about the rest of the industry.
2manyoranges
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Pink Donut ….Oh Yeah……….
(note impossible bike generally - but in the hands of Reme M, six seconds faster on a DH course. Not 6/10ths … six SECONDS)…..
benjabbi
Bontrager Fan
Joe told me in 2018 that 36" wheels were the future and he's not been wrong to date. The fact they cropped up on Doddy's IG and Pilgrim's YT channel recently suggests that it's not as mad-cap as it sounds. On that basis, rip-up the rule book and start again
My fav bit of bonkers design is '99 Stab Dee-Lux. Most modern day enduro bikes have a S-bend downtube, so the logic was there...the short wheel-base wasn't
Credit to @Buzzsaw
My fav bit of bonkers design is '99 Stab Dee-Lux. Most modern day enduro bikes have a S-bend downtube, so the logic was there...the short wheel-base wasn't
Credit to @Buzzsaw
