[Closed] Have we done this yet? - latest Chris Porter Geometry article

Low BB - pedal strikes and OTB pain
Slack - Fall off the back climbing up hill
Long Wheelbase - great at speed shit in the tight stuff

It's all a compromise really

I once put my 2003 Spesh SX into 'low and slack' mode, which combined with it's shorter air shock meant 62.5 HA and a very low bottom bracket ... yeah it was great hammering down a hill, but like hell could you pedal it in even the slightest rut and it felt like a floppy whale at slow speed.

I do agree clutch mechs are bad as a lot of frames have silly suspension designs in relation to chain growth. My DH frame is lovely, 2.5" of chainstay growth but almost zero chain stretch makes it a beauty over fast bumpy stuff like roots and rocks (Canfield Jedi).

he is correct about compromises and big wheels
The problem is he wants to ride downhill pretty fast and most of us want to do everything adequately without death

I've been following this, Chris Porter has always been quite opinionated and I don't agree on everything he says, but some of it rings true.

Seat angle (steep is actually good!)

Agreed - a steeper seat angle noticeably improves a bike's climbing ability by keeping the rider weight centered. There's no place for a slack seat angle on anything other than a DH bike in my humble experience.

I also agree that a longer reach is a good thing, so long as it's combined with a steep seat angle. I'm willing to sacrifice some low speed agility for stability at faster speeds.

However, it all begins to fall apart for me when he introduces the vague moto-x analogies.

But this:

A bigger wheel rolls over bumps better than a smaller wheel… zzzzzzzzzzz. Sorry, sent myself to sleep there with those fairy tales.

I was very skeptical too, until I tried a 29er out. Now I'm converted, but I also understand that there are other factors at play here other than just the wheel size - geometry is paramount here but you can't ignore the fact that a decent 29er rolls pretty darned well.

And this went a little too far for me:

A bad designer and a lazy bike tester will take these negatives and say it won’t climb. As they ride the slack(ish) bike with no thought to locking their core muscles and taking control of the bike, the bars flop from side to side and the bike gets the blame for the rider’s failings.

I feel that his argument falls apart here. Not every rider will have the same technique, indeed they need to be user-friendly enough to avoid intimidating relatively new and inexperienced riders. We keep being told that we want ever slacker, ever racier bikes on which we must go faster and in doing so improve our technique. That's all well and good if you're riding bone-dry trails in Utah or wherever but such a bike will be unusable on the typical soggy, slippery UK trails that the majority of us have to endure for six months of the year when our average speed falls dramatically and we're having to negotiate greasy Southern-British chalky hillclimbs.

A bad designer and a lazy bike tester will take these negatives and say it won’t climb.

Interesting read, he really doesn't like 29ers though! I disagree with the heavier/wider tye comment. I thought wider rims allowed lighter tyres for the equivalent volume.

At this point I would also challenge anyone making claims like this to get off their arse (or back onto it) and design a bike, get a prototype made up and prove em wrong, you'd be sorted if you were right....

http://www.bikeradar.com/mtb/gear/article/chris-porters-custom-nicolai-ion-16-super-bike-41048/

good on him, has anyone else ridden it?
That was May wonder when it will hit the shops?

Long Wheelbase - great at speed shit in the tight stuff

It's all a compromise really

I think CP's argument is that you build the bike to be fast/safe on the most difficult bits of a trail where you actulay make up time. The feel of the bike is secondary to how fast it is for him as a racer/team manager. On a flatter, tight bit of trail there probably minimal time to be made up compared to being able to hit 40mph rather than 20mph on a rough open bit of track.

The bars don't 'flop' you just fail to hold them straight, thats a defficiency in the rider not the bike, and I can see his point.

He's been on the same oppinion for years though, he used to ride a 223 with Fox 40's for XC/trail/enduro as he felt it had the best geometry for it, but could just about pedal as well (and it was down to the low 30's lb weight).

There's always a comprimise, but why comprimise away from "this makes it faster, but..........".

I jumped back into sailing this year and there's similar differences between boats (but there is a handycaping system to try and give a fair race rather than allow it to become a pure arms race).

My boat (well not mine, but the same class), a Blaze huge sail, huge racks for leverage against it, probably what CP would sail as it's fastest when things get really hairy, an bit less than nimble on a tight course in light winds.
[img] [/img]

A boat I sailed last weekend, a D-zero, 25% sail area, 33% less beam, not as fast, posibly actualy harder work though (different muscles). It'll be more popular for one reason or another than mine, mostly a mix of marketing and it looking less threatening, but it isn't faster.
[img] [/img]

 

mikewsmith - Member
Low BB - pedal strikes and OTB pain
Slack - Fall off the back climbing up hill
Long Wheelbase - great at speed shit in the tight stuff

Those are generalisations though - my current bike is longer, slacker (65°) and lower than the bike it replaced, and still climbs better, is more agile and I never notice pedal strikes.

Good design trumps bad design, basically. Most of his principles are sound - if biased towards his own riding styles and preferences.

but you can't ignore the fact that a decent 29er rolls pretty darned well.

[img] [/img]

To slack and you'll bend stantions 😉

[img] [/img]

Whenever I read something that he has written I end up thinking that he is a knob. I'm sure that everything that he writes is 100% accurate for his riding, but guess what, not everyone rides the same way or on the same terrain! each to there own and debate is good, but he always comes across as opinionated and up his own arse.

It is interesting but too often, he contradicts himself- he was banging on about the overwhelming and unmistakable superiority of 26 inch wheels right up til the second he decided 650b is better (but obviously 29ers still suck). And he never has a middle of the road opinion, it's always thing A is amazing and thing B sucks.

The thing about clutch mechs just strikes me as utter pish tbh- the difference in forces between a standard mech and a clutch mech is pretty trivial, and in any case works in parallel with the shock which is dealing with much greater forces- I'll happily bet one scottish pound that he can't actually tell the difference.

I'd still love a go on that Nicolai though

I'm intrigued by his ideas, but having met the guy at the TP this year, he can come across a bit off - misreading your map, then in retaliation trying to tear the timing monkey a new arsehole just made him look rather stupid. (he did say sorry a day or so later)

While I suspect his geo ideas would be great on fast, long, steep, loose descents, they didn't seem to work very well on the super tech trails around Sospel as the bike (a one-off Canyon at the time) was just too damn big to go round the corners. Horses for courses, and that Nicolai is a very specific horse for a very specific course.

<<edit>> One could argue that my Rocket is a less extreme example of the Nicolai - pretty slack, pretty long, pretty low, fairly steep SA, but not extremely so in any department, and that does work as advertised. The "steel is real" side is irrelevant, it's the geo that makes it special.

but he always comes across as opinionated

Well it is journalism. You can't take opinions away from them - they'll have nothing left!

He's mostly bang on.

thisisnotaspoon - I think CP's argument is that you build the bike to be fast/safe on the most difficult bits of a trail where you actuality make up time.

This

Northwind - I'd still love a go on that Nicolai though

+1.

There is a definite trend in the market to longer / lower / slacker, something I am all for, however, he needs to cover that all with 'I lives in south wales, and rides technical trails all the time' comment. He doesn't plug round fields in Hertfordshire 95% of the year where a sharp handling 9'er would be way more fun.

JCL, I agree.

Head angles could go slacker and seat tubes steeper to make the downhill sections of rides much easier while retaining climbing ability.... Don't know why it hasn't happened yet TBH...prob just the industry wanting to move in baby steps (and wanting us to replace our 'redundant' bikes each year in the meantime), after all why move straight to 63 degree head angles when you can make the consumer buy one at 64.5 degrees first...then another at 64 degrees the year after etc etc...

He's great.

I haven't seen him mess about with fork rake/offset though. Which strikes me as odd.

Marketing genius, build a bike so horrific that it gets you loads of press coverage.

I've never put much truck in what he says and after his treatment when I rang Mojo once, I certainly won't be spending any money with him.

He talks out his arse in my opinion. The fitting of a bike to someone has never been a one size fits all. I cannot for the life of me get on with Specialized bikes, regardless of wheel size. Many can and do. I happen to prefer a slack as possible head angle but hate long chainstays, maybe a bike feel slow to turn (IMO!). I like 29ers for covering distance but not for technical stuff. Others feel differently. To berate large proportions of the buying public seems pointless and somewhat childish. Build a bike that suits your needs by all means, I'm sure most would if they could. But don't then claim its the future and rubbish everyone else.

Incidently, he harps on about how awesome Mondraker forward geometry is. When Brook Macdonald was on MS_Mondraker he found he really didn't get on with the bike until he changed the stem to something normal. He immediately when measurably faster.

Different strokes for different folks..

http://theteamrobot.blogspot.co.uk/2014/05/zero-zero-length-stems.html

Been playing with the head angle on my Mojo HD, Stock is 67 deg, I now have it at 65 deg. I think I've gone a smidge too far, its great at speed/downhill, but on flat slower (but not slow) corners you really have to have decent technique to stop the front end washing out, its significantly less forgiving of poor body position.

He's probably technically correct with his thinking, but I dont reckon his thinking would suit your average weekend warrior.

The problem he's highlighting is that many bike companies, just look at what they've just launched, tweak a couple of things according to market trends and release it a year later.
His example of taking things way too far and riding it until your used to it, seems like a great way to try and evolve quicker.

-
e.g.
I was really nervous of going from my 680mm bars to 780mm that I test rode on two bikes last week. Previously I've just felt daft on wide bars. But after spending 2 full days on it, going back to my 680s seem very weird too - really eye-openingly weird. Made me think that going to a halfway house of 740mm was pointless.

There are some good points amongst the combative writing - and quite a few typically journalistic bits of hyperbole to get people talking. 😉

Something no-one ever talks about is how handlebar shape and rotation interacts with stem length. What actually matters is the forward offset of the centre of the grips (or possibly the back of the grips depending on which loading matters most?) from the steering axis. The big problem I see with so-called zero stems is they actually result in negative effective stem length with typical handlebar shapes.

That forward offset of grips from steering axis gives you a stabilising tiller effect when you lean on the bars. Make that offset backwards and any imbalance in force between left and right grips and the bars want to flip left or right.

As with all things in engineering the extremes, though exciting sounding, are rarely the best solution. Low, slack and long is good. Lowest, slackest and longest is good too - but in fewer situations. I do think there's an issue with super-short chainstays and very long front-centres. Longer (not necessarily long) chainstays give a much better handling balance at decent speeds but might not seem as appealing when you're messing around at low speed thinking how a bike 'feels'.

julians - Member
Been playing with the head angle on my Mojo HD, Stock is 67 deg, I now have it at 65 deg. I think I've gone a smidge too far

You're riding something of a bodge, though - a bike that wasn't designed to be 65 at the front and may not be suited to that.

Porter does talk a lot of sense when it comes to riding bikes fast over technical terrain.

My sadly departed Blue Pig had a daft slack HA (64deg static I think) and Steep SA and long-ish Chainstays.

It was a f****** hoot on steep or fast downhills.

Flat singletrack you had to muscle it around a bit but you just as CP states have use your core.

Uphills we fine, either sit and spin and I winched myself up some truly daft steep stuff on that bike or stand up which makes the HA irrelevant.

That being said on flatter less technical terrain the bike just felt bored.

I haven't seen him mess about with fork rake/offset though. Which strikes me as odd.

He mentions it in one of the articles, using a modified 26" wheeled Fox 36 on a 650b wheeled bike. He mentions not even Honda knowing all about the effects of offset etc. That is unless I am terribly jet lagged and made all that up!

Chiefgrooveguru, motorcycles have been lengthening the swingarm for ages now, it is accepted that this provides better handling at speed, the swingarm axle on bikes has been moving more towards the middle of the machine year on year.

Not sure bicycles can do this as it would put the chainstay pivot point way in front of the cranks/BB/rider's feet.

I have a bike with an adjustable shock mount and I recently slackened it which was an interesting experiment because it was the same bike, same wheels, shock etc with different angles.

It DID make climbing harder because my weight was now further back and the front wheel wandered. Then I shortened the stem because it felt wrong with the forks fully extended.. then I had to slam the stem and now it's amazing - still worse on climbs than it used to be, but I'm prepared to accept it.

Compromise, as has been said.

Not sure bicycles can do this as it would put the chainstay pivot point way in front of the cranks/BB/rider's feet.

Having worked & argued 😉 with Chris he's certainly passionate about his projects.
worked on some interesting designs when I was there.

Re. geometry etc John Robinson's motorcycle chassis tuning books are quite interesting, especially the zero rake & reverse offset equipped bike, which is a great illestration of how there are quite a few ways of getting something to work.
As said above everything is a comprimise with plus & minus points for each individual rider.

I've met Chris a few times and also ridden on some of the trails where he does testing - he really does know his stuff when it comes to suspension and geometry for big bike riding. Maybe for XC riding round fields/bridleways, his methodologies don't make the same difference, or perhaps are counterproductive - I don't know, I don't do that kind of riding.

What I do know is that having slackened my bike out to 65 degree HA and dropping the BB a bit (offset bushings) have definitely improved it's handling at speed. You have to adapt your technique in low speed twisty stuff and not be afraid to load the front wheel, and move lots on the bike to achieve this. Once you get used to being dynamic on the bike and "working" it, the negatives become much smaller.

What about clutch mechs adding an element of compression damping when chain growth occurs?

Covered in the article, suspension works better without a chain/other outside influence, will be a pain for climbing though 😉

Funnily enough I went for a ride with Geoff Apps today (to the uninformed he's an early UK mtb pioneer).
Anyway, his current bike contradicts everything in this article - it's short, tall, has a steep head angle, and runs 2.5" 29er tyres at a very low psi on narrow rims.
Do you know what? I was amazed by how it rode. It is designed for UK conditions (wet, muddy bridleways, slow grindy uphills, and slop, lots of slop) I guess Geoff would call it a bike for 'hacking'. I could clear stuff I would have no chance of on my full-sus, and it actually handles pretty well downhill, once you get used to the handling.
Obviously, all this proves nothing, and this bike would probably do nothing for the average trail-centre warrior. But, CP is talking about bikes with a pretty narrow window of usage. There are other valid ideas out there.

Brilliant read. May not agree with or relate to all of it but strong opinions like that result in out-there bikes. I like them, even if they aren't your cuppa they're worth a try, or make us think.

People adapt to, and get used to using, what they are used to using.

Or in the opinion of Mike Burrows:
“I think part of the problem is that the cycle industry doesn’t always attract the highest achievers"
http://www.cyclingweekly.co.uk/news/latest-news/mike-burrows-cycling-innovator-27010

For an idea of how much the wheelbase can change due to long travel forks on a full suspension bike:

Or an idea of what happens to head angles as forks compress
http://www.btr-fabrications.com/category/geometry-design/

I'm probably being thick, but I don't understand the "29ers/bike with BB drop front braking doesn't work" thing. How's that exactly?

a good read, it's good to hear different opinions. It seems that (as far as I know) his is a relatively independent (from any manufacturer) opinion so it is welcome. Certainly better to read that article than the latest spiel from any bike company you care to name. Not sure he is right but it gets you thinking a bit.

So - after all his whining at TP about the trails being the wrong type (he couldn't get round the corners), will he give it a miss next year, or show up with shorter chainstays?

His hatred of big wheels is getting a bit tired now - especially as he's adopted bigger wheels than the ones he used to say were perfect.

He's also always used irrelevant motorcycle comparisons...

Lastly - does he ride everywhere no handed? Arms are pretty useful things for weighting a front wheel.

Hicksy, They're not as pitch sensitive and the force vector is closer to horizontal. Also the reason why a 29"'or large BB drop bike uses it's suspension more efficiently/climbs better.

Hicksy - Member

I'm probably being thick, but I don't understand the "29ers/bike with BB drop front braking doesn't work" thing. How's that exactly?

He seems to be arguing that if the COG is high, that's weight that wants to roll over the top of the front, which pushes the front wheel down. If the COG is low, that's weight which is behind the wheel, and wants to push it forwards.

In practice, does a few mm of BB drop make the slightest difference, considering the COG of the bike is always going to be above the hubs, and the rider makes up 70% or more of the weight of the bike and is almost entirely above the hub, and totally mobile... I think it's probably totally meaningless tbh. Or if it makes a difference, it's one that's tiny compared to the effect of body movement. Just because your weight connects to the bike via the pedals, doesn't mean it acts on the bike as if it's all at the crank axle.

I think if he were to phrase it differently he might say something like "I don't like 29ers so here's a plateful of assorted steaming horseflops to justify that" tbh. Especially since having a low BB on a small-wheel bike is apparently brilliantly, it's only bad on a 29er.

Thanks chaps, that kinda makes sense - can't say I've ever noticed this effect though!

In practice, does a few mm of BB drop make the slightest difference

It did on my Patriot. The reason for moving the shock mount was to lower the CoG. Worked, made the bike much better.

If the bb solely is dropped and all other measurment are kept the same yes to a certain extent.
However in Molgrips case shifting the shuttle will have an affect on headangle, wheel base, bb which as an overall effect it's not just one thing but a number of things giving the result.
2005 my 20" Patriot 66, in slackest positon with 40s was rather good down stuff...

molgrips - Member

It did on my Patriot. The reason for moving the shock mount was to lower the CoG. Worked, made the bike much better.

In the front braking terms Chris was talking in, I meant, not in total. And as Loco says you've changed a whole bunch of stuff, not just BB height

Having spent 3 hours with the man this morning, I'd trust most of what he says regarding suspension & bike set ups for certain types of riding.
I'm hardly the greatest rider in the world, but even for me sitting on his bike that looks so wrong, but feels so right is really bizarre!

I like his bike, or I like the fact that it exists. But there's no way I would want to own it.

The feel of the bike is secondary to how fast it is for him as a racer/team manager.

For racing! This!

but for the rest of us this is not relevant. There's a really interesting course at california polytechnic uni about designing bicycles to optimise handling and one of the things they emphasize is that bikes which handle well all have control spring (handlebar forces at the grip area required to disturb the steering) which fall within a very small range despite their very different geometries - (mechanical) trail, bar widths and stem/tiller - be they road, bmx or mtb.

because how a bike feels DOES matter for being able to control it well at high speed.

He flies in the face of all that

Reading that article made me like bikes a little less...which is a bad thing.....

He seems to be looking for the perfect bike, and of course we all know that the perfect bike is the bike you're riding on RIGHT NOW....

DrP

The feel of the bike is secondary to how fast it is for him as a racer/team manager.

Retrodirect

For racing! This!

One problem though is that 90% of bikes claim to be the best and the fastest, and that seems to be what sells them, irrespective of whether that's what people actually want. Or think they want.

If there was a bit more openeness or clarity, ie a company said "this bike won't win races but it's fun and comfortable" or indeed "this bike will win races but it's a pig otherwise" then there might be a chance for more daring design.

Perhaps it's a symptom of a young sport/industry where we haven't yet got much maturity in terms of branding. Every manufacturer seems to be trying to sell every customer a super car, when perhaps a lot of people need a cruiser.

[i]In practice, does a few mm of BB drop make the slightest difference, considering the COG of the bike is always going to be above the hubs, and the rider makes up 70% or more of the weight of the bike and is almost entirely above the hub, and totally mobile... I think it's probably totally meaningless tbh. Or if it makes a difference, it's one that's tiny compared to the effect of body movement. Just because your weight connects to the bike via the pedals, doesn't mean it acts on the bike as if it's all at the crank axle[/i]

You are wrong, unless your BB is above the hubs.

[i]I feel that his argument falls apart here. Not every rider will have the same technique, indeed they need to be user-friendly enough to avoid intimidating relatively new and inexperienced riders.[/i]

Not all bikes need to be 'user-friendly' for beginners.

You are wrong, unless your BB is above the hubs.

It's that point about riding uber slack bikes uphill where he loses me:

"Yeah they're a bitch to ride uphill, you have to totally change your technique. People don't want to, so they blame the bike..." Well yeah... Because it's the bike that's a handful to ride! 😕

b r - Member

You are wrong, unless your BB is above the hubs.

In what way? There's about 5 points in there, narrow it down a bit?

In practice, does a few mm of BB drop make the slightest difference, considering the COG of the bike is always going to be above the hubs, and the rider makes up 70% or more of the weight of the bike and is almost entirely above the hub, and totally mobile... I think it's probably totally meaningless tbh. Or if it makes a difference, it's one that's tiny compared to the effect of body movement. Just because your weight connects to the bike via the pedals, doesn't mean it acts on the bike as if it's all at the crank axle.

If wheelbase/rear centre and BB drop are optimised you don't need to move your body around anywhere near as much. Front/rear grip is balanced, you don't need to hang off the back descending or sit on the nose of the saddle climbing.

Porter is correct in that almost all bikes (apart from Mondraker-Zero) are too short in wheelbase. The quest for short rear centres is idiotic. As is running longer than a say 40mm stem. The only thing I would disagree with him is the efficiency of 29". The acceleration/deceleration factor is a barely a consideration compared to the reduced rolling resistance IMO.

agree with a lot of what he says

long reach, teeny stem, wide bars, slack(ish- by porter standards) head angle, long wheelbase, short chainstay bikes are brilliant

getting back on a cramped, steep old skool bike makes you realise how much things have improved, these are golden days my friends 🙂

Like the fashion industry, everyone wants to copy whatever’s popular, and we end up with the bicycle equivalent of X-Factor; just because something’s popular doesn’t mean it’s good. If you followed this train of thought to its logical conclusion you’d end up with every single manufacturer making heavy, rigid bicycles with 4-inch wide tyres. In all seriousness, that would be stupid wouldn’t it?

For racing, a bike should be the fastest it can be, even if that means it's sketchy as hell, cos all that matters is the stopwatch.

For normal riding, ride whatever the hell you enjoy.

It's not rocket surgery.

long reach, teeny stem, wide bars, slack(ish- by porter standards) head angle, long wheelbase, short chainstay bikes are brilliant

He's not advocating "short chainstays". That's the worst idea he bike industry ever had.

Short chainstays are fun, they are moroninc on downhill bikes.

Short chainstays are rubbish for climbing. Draw a diagram and see.

Short chainstays are fun, they are moroninc on downhill bikes.

They make slightly more sense on a DH bike than a trail bike.

Meh, they give more stability in the rough and keep you more centered in the bike.

For climbing short chainstays suck but I quite like my shorter travel bikes to be playful.

I think this article mostly confirms how utterly baffled by geometry I am. I am quite tempted to try a longer bike though as i'm slowly coming to the realisation that my instincts to always buy bikes slightly too small actually doesn't suit my riding style at all 🙁

I definatly agree with the low bb though, though in my head this possibly makes more sense on a hardtail where you are less inclined to pedal through the rough.

What baffles me is knowing that the bike which i probably felt most confident on, especially descending was 100% too small for me (old shape giant reign with 36s on the front in a small), whereas my current bike a fuel ex (virtual 17.5) feels too small and a bit sketchy sometimes. God knows

Meh, they give more stability in the rough and keep you more centered in the bike.

The physics isn't on your side there man.

What baffles me is knowing that the bike which i probably felt most confident on, especially descending was 100% too small for me (old shape giant reign with 36s on the front in a small), whereas my current bike a fuel ex (virtual 17.5) feels too small and a bit sketchy sometimes. God knows

Is the Fuel 26"?

If so, 12mm longer rear centre on the Reign and only 4mm shorter wheelbase, but already half a degree slacker and with a longer A-C 36 it would be at least another degree slacker and 20mm longer front centre.

The Trek probably fits you better in the saddle but the Reign, even though small, was the longer bike and far closer to what Porter is advocating. It's all in the numbers.

I think CP talks a lot of sense in terms of designing the bike to work for him in the way he wants it to work. Re. the chainstays, I'm a back wheel hopper apparently (I was in 1991....) and just prefer the feel of bikes with tight asses. That doesn't mean that I buy into the myth that short stays = a good climber. I always remember a steep rooty climb circa 1988 that you just had to hit as fast as possible and just keep going. I could do it on my Peugeot Ranger with 18.5" chainstays because the bike would stay planted on the climbs (as long as you didn't stand up). I never did manage it on any of my decent mountain bikes, which always ended up with 5ft long stems to keep the front end down on climbs and royally ****ed up the handling everywhere else.

My current 'XC' hardtail that I designed myself has 650b wheels, a top tube a couple of inches longer than my earlier bikes and a head angle around 6 degrees slacker (65dg. I guess it'd equal around 64dg if the wheels were smaller). I've only been out on it a few times but I've not felt the need for a steeper HA. After ditching the 29er, it's been awesome having a slack front end and longer suspension on steep techy stuff, rather than relying on bigger wheels.
I might play around with chainstay length (set to 16.5" at the mo, but sliding dropouts), but every bike that I've owned with long stays (such as the 29er and Nomad) have ultimately felt boring. That's just me though. I get that longer rear ends tend to be more stable both up and down.

JCL
Yeah its a 2011 Fuel EX so 26" And your right, the Reign definately felt a bit cramped sitting down whilst my Trek feels ok. Is it the front centre that makes the difference then?
Mostly i'm asking because im considering a new hardtail, and probably a stanton slackline or a bfe. I think a medium Bfe would be the right fit but less sure on the slackline. From what your saying the 18" would most likeley work better with a nice short stem.

Cheers

He's describing the type of geometry I dislike. I like modern ish geometry but if its too slack, low and long it feels cumbersome, slow and not as fun to me. Part of the fun comes from feeling a bit on edge and sketchy I think ! This is why I went back to my Trailstar from a BFe - the latter felt good and like it wasn't the bike that was holding me back, it was just plain dull to ride.

Load of old bollocks

short chainstays, short bike = a lot of fun for my type of local tight stuff in the surrey hills.

I have both a mega TR and AM, the AM is a dog around here in the tight stuff due to longer stays and slacker angles
likewise the TR gets out of its depth in the rough rocky steep stuff out in the alps etc.

Cant help but hink there is some connection between mondraker and mojo. Its like a marketing article. Fabien used to visit mojo when he rode for monds.

Yeah I realized he wasnt about the short chainstays, but I love the way a low bb, short cs bike feels in corners, maybe negates the problems with getting a slack, long front centre through the twisty stuff or something, but I find you can (in fact have to) lean into turns and pop out the other side better

[i]or unless your hands are on the bars ? [/i]

Eh?

Think about where your weight is, and it is pushing downwards on the pedals - there is very little on the bars.

And if your BB is below your axles then the weight is 'acting' the opposite to if the BB was above.

Cant help but hink there is some connection between mondraker and mojo

I agree - he completely failed to mention the fact that they fall apart and are designed by children with a pack of crayons without the the use of a ruler.

Who cares about angles when the rear wheel wanders off on its own, the bolts fall out, the rocker link smacks the seat tube on a big drop and the whole thing creaks more than my dads replacement hip.

I actually agree with quite a bit of what he says about geometry, although obviously the bias is more towards DH performance than accommodating the "generalists". I have to say though two key things strike me...

So the development process is more novelty led than performance led. Emperor’s new clothes, anyone?

1- So We're all morons? Meekly buying whatever toss the Bicycle Industry tells us we should... This of course from a fella who imports, flogs and services Fox shox, forks (with there excellent service life) and a [url= http://www.powa-productsstore.com/acatalog/Fox-Fork-Dfender-Mudguards.html ]£50 mud guard![/url]...

2- Why hasn't he put all this breath-taking, deep knowledge and understanding of what's wrong with the modern MTB into producing the greatest ever bicycle known to man? Rather than periodically berating everyone else...

Whenever I read something that he has written I end up thinking that he is a knob.

I don't think He's a Knob, he has ideas, and passion, this is good.
But he is in danger of becoming the UK bike industry's [i]opinionated fella in the corner of the pub[/i], pointing out all the problems with the world and fixing none of them...

Everyone just smile and nod...

The difficulty I have with articles and views like this is that they seem to focus too much on trying to say that this is 'the' answer rather than 'an' answer. It also is very much focused at the racers, and going measurably faster, which although important to some is not important to everyone.

I tend to agree with CP on most of his points for DH/Enduro and to some degree 'trail' riding (whatever that is to you!), but you need to not lose sight of the fact that people ride bikes in very different ways in very different places. Some people ride exclusively in one discipline, some are more varied, some race, some don't. The bike I ride when racing short-course XC is massively different to the bike I ride when I race Enduro, and same again for 24hr events and when I used to race 4X, but that is how it should be, promoting one particular geometry (long,slack,low) is all well and good but needs to be taken in context of the riding.

I think an uncomfortable truth that many riders wont admit to is that they are at least 50% more Gnar in their head than in real life, there are lot of people riding trails where their bike is massively over-capable, I won't fall on the cliche of calling it overbiked, because you need to ride whatever makes you happy, but if we are advocating the 'by the clock' approach then a lot of people would be quicker on lighter, shorter travel snappier handling bikes, that's not because the long low and slack approach is bad, it's just that your average weekend ride (and rider) in the hills or on a red route doesn't present the kind of terrain and crucially speed, where they come into their own.

If your average ride is hitting the jumps, lift-assisted or general tech-fest buffoonery then it's a different matter, and if I'm off out on a ride or race like that I pick my long low slack bike, if I'm heading into the hills for 40 odd miles of moorland for example, I wouldn't, I have bikes that are better suited to that.

I also think CP has a point about people (personally and commercially) being afraid to change and try new things. I don't think enough people (personally) play around with their bikes, to try new things, sometimes good, sometimes bad, to get a real feel for how things work and experiment.

Commercially it's difficult, the big guys aren't often willing to go out on a limb with something outrageous as they think it'll be a hard sell or they'll make a loss, so it's often left to the little guys to experiment, you have the same problems in racing though, it's unusual to find a top-5/top-10 racer willing to go out on a limb and try something radical for fear of ruining their season, and so it falls to out-of-season testing and incremental changes.

In summary, I agree with a lot of CP's points (if not his style) but I think it's easy to get blinkered by the riding *you* do, and either forget or dismiss others. For certain aspects of MTB I think he is bang on, but MTB is a very wide sport.

He's a contrary bugger eh?

Someone should tell him to sign up to this forum, I feel he'd enjoy himself.

I kind of lost interest in him when he suggested that MTBers throw our lot in with the MX crowd regarding access. Utterly stupid idea.

I've had the misfortune to deal with porter over the phone a few times back in the day when I foolish enough to believe fox was the best suspension out there.

The man is passionate and opinionated to the point where he can't absorb other people's views.

The fact that he clearly lives in his own little mojo world of Dh/enduro racing further denigrates his validity to the ranks of the trail riding commoners.

Like many have said already, it's clear that for his own narrow paradigm of riding, he has lots of ideas that are relevant.

For the rest of us who don't conform to his idea of riding, I think his ideas don't work as well. This is made worse by his inability to write anything coherent (anyone remember his RoW rant)

I'd be very cautious taking anything from those articles too seriously. It's clearly a badly written marketing piece.

my tuppence:

his ideas are not really unique - a lot of people already agree with him. He's just taken it a step further.

it's clear he reeally reeally likes a reeally slack head angle - good for him. But the only way he can get it to work is to balance it with reeally long chainstays.

his bike works because it's balanced (can i join the queue to have a go?)

i suspect he already knows that he could achieve roughly the same thing with a 'normal' slack head angle balanced with merely 'normal' chainstays - resulting in a bike that's much more versatile. but not so radical or provocative, and he wouldn't get so much attention. it would be a bit like a blue-pig, and we already know they're ace (they're not even weird anymore)

summary: mostly i agree with him, and he's taken it even further, probably to prove a point, good for him.

zero reach stems though? - a sure sign he's gone too far.