trying to get my head around tight switchbacks,on bigger wheel bikes is it only the longer wheelbase making it harder to turn, or a combination of all of the above?
for example
i have a L mega 26inch with wheel base of 1188 and chain stays of 440, i also have a L mega tr 650B with wheel base of 1160 and chain stays of 430, i am sure that the 650B turns tighter.
is there more to it than just wheelbase, will somebody cleverer than me explain it better please.
( getting ready for trip to the alps)
cheers Lester

there’s much more to it than wheelbase.

The chainstays on my Horsethief are roughly 7 yards long*, this (among other things) means i don’t have to fight to keep the front wheel down, this means it’s easier to climb, even/especially twisty stuff.

different bikes are different, that’s about it. It’s almost impossible to predict what a bike will feel like just by looking at numbers.

(*ok, about 460mm)

tyre choice, tyre pressure, bar width, bar height, stem length, saddle height, in-line/offset post, etc. There’s a load of stuff that affects handling before you even consider the frame.

that has not helped me 🙂

i didnt think it was as simple as “bigger wheels do switchbacks as well as smaller wheels”

Interesting question, can’t say I know the exact answer as there are so many variables on each switchback.
I would think front centre distance may have more of a bearing on how switchbacks feel.

i was thinking it was a combination of wheelbase and chainstays and short reach, but i need help getting my head around it

TBH the bike you feel most comfortable on is probably the best at most switchbacks, I run out of skill and nerve before the bike really gets the chance to cause trouble.

I second the run out of skill way before the bike does!

i agree to the bike i feel best on, which is the 650b but im sure some of the stuff i will do in the alps will more than challenge me and i expect a fail, i dont want to let my mates down by taking the wrong bike, but i expect a lot of “you should have brought the 26er” whereas i dont think thats why i will fail

Good idea to base what bike to take based on one type of event which will most probably make up 5% of the riding?

Alps is faster, more tiring, id be more worried about stability and energy preservation on the way down, longer travel and bigger wheelbase is the one id be going for.

im doing 3 countries tour, 4 or 5 hours climbing, including switchbacks.
less than an hour down inc switchbacks.
The 5 % will be on the most crucial, tight switchbacks with consequences, ive been told by the others who have done it before, we will all hit the wall on the way up , and we will probably all not come back unscathed from the pointy down bits, and they are all much better riders than me!!
its scary and exciting, cant wait

From how you describe the riding the numbers will make sod all difference. Which bike you find easiest to climb on will. It will be the soggy human bit that will be the weak link.

HTH 😉

Take the one you feel most confident about. I’m better (less bad) at riding switchbacks on my 27.5 full-sus in its lowest/longest/slackest setting and worst on my much shorter 26 hardtail, simply because there’s far more bike in front of me and I can throw it into the turn without worrying about departing through the front door.

the easiest bike to climb on just means they will be waiting for me slightly further up the hill, whereas if i dont manage the stiff cliff side switchbacks, i might be unexpectantly be waiting for them at the bottom sooner than they thought.
i am going to try both bikes back to back this afternoon and report back.

You won’t be pedalling up any switchbacks tight enough to be worthy of the name.

Going down, 650b vs 26″ makes no difference. The TR has a marginally steeper head-angle than the AM, which will make it turn a little tighter.

For the TMB, I’d take the TR.

I did the TMB last October and I don’t remember any particularly switch-backy riding – or any high-consequence riding at all. Descending the Grand Col Ferret into Italy had some tight ones, but most of the challenge was in water-bars they’d put all over the place!

Doing it the other way round, Col de Balme down to Le Tour (via les Posettes) does have some pretty tough switchbacks.

I find looking where you want to end up the best bit of advice for tight switchbacks up or down (and any corner really). Don’t notice a huge amount of difference between my 29er HT or my 26er 160mm FS really.

thanks guys, im feeling a little easier,

@stevomcd, why the tr? the wheel size seems to make the gear ratio harder than the am, and i hope you are right 🙂

Jesus. OP you are over thinking it….. and trying to come up with an excuse for lack of skill

Don’t know about the science witchcraft but do know my 29″ 5 is as good on switchbacks as my 26″ version was with the benefit of running smoother in low speed situations.

@ funkydunc
no im not overthinking it, the original question arose as i was thinking about which bike to take, the topic interested me and i thought id ask.

am i excited about going, yes, am i scared, yes, am i using as an excuse for lack of skills,maybe i,ll let you know. 🙂

Lester – the gear ratio is the last thing I would be thinking about! And the difference in ratio between a 26″ wheel and a 650b wheel is minute anyway.

I’d go TR because it’s a bit lighter and more pedalable without being too much of a compromise on the downs.

I rode it last year on my Mega AM and, coming straight off a full season of guiding on the big bike, it seemed like the right bike at the time, but having loved a Spring of riding my hard-tail, I reckon if I was setting off again tomorrow, I’d take the hardtail.

Trip report:

http://singletrackworld.com/forum/topic/late-season-tour-de-mont-blanc-trip-report-lots-of-photos

or with photos here:

Throughout the summer, we'd been talking about doing an end of season trip, a chance to ride some new trails with…

Posted by White Room Mountain Biking on Sunday, October 5, 2014

I’m with FunkyDunc on this one. The article at the end of the most recent issue (#98) seems applicable here: we’re naw that good that things like bike geometry make any significant difference.

Stevie, great read and write up, and hopefully i will have lots of great pics, the other guys who have been before teamed up part way with Phil Hennem, who is i think doing a day or two with us.
The questions have arisen because we all talk about the trip and your mind wanders everywhere and discuss los of different points and aspects.
i have more spares in mega am 26 inch flavour, shock, wheels tyres etc.
there are 8 of us and we have a back up van, but its an all or nothing trip, if you drop out thats it you cant come back in 2 days later. i just want to get it right so i dont let anyone down.
The post started out of the wheelsize debate and grew into why i was discussing it which wasnt my intention.i had already read your write up, its a great read, at 62 im a bit old for a hard tail though 🙂

It’s definitely do-able on a Mega AM – that’s what I used after all.

I’ve got to admit, spares/reliability is not really something that crosses my mind. We thrash our bikes all summer long, so we know they’re solid. You’re very unlikely to have any hassles on a Mega AM. Just spec suitable tyres.

Surely if you have a back-up van, you can drop out for a day if necessary and ride in the van to catch up?

we can drop out but we have all agreed that if you drop out you cant come back in,
knowing that there is a back up van its a bit easy to give up and not keep going, its not so much of an achievement, we ride together a lot and we want to start and finish together. i gave up on Snowdon 2 yeras ago and really wished i hadnt, im not doing that again

we can drop out but we have all agreed that if you drop out you cant come back in,

Sounds like a barrel of laughs 🙂

A slightly different perspective – regardless of the bike you pick there are likely to be some sections you don’t want to ride, and that may be due to fatigue, skill, seeing someone else hit the deck, weather, whatever. I would just make sure you are confident in deciding when to man up and when to walk, I think the bike will only be a small factor in that decision.

is there more to it than just wheelbase, will somebody cleverer than me explain it better please.

It’s simple, skill. Doesn’t make much difference what bike you ride if you don’t have the technique down.

I am no great switch back rider by any means, but I do understand a bit about what it takes to ride them. Putting it into practice is a different matter though 😆

When riding switchbacks, typically you will be going slower than for other corners. Often this results in the bike being steered and standing up as the rider has not leant the bike over enough and ends up skidding the back wheel round (guilty m’lord)

What is needed is a set up turn where you make a turn in the opposite direction to the switchback (essentially an exaggerated counter steer at slow speed) and then let the bike fold over toward the turn, keeping weight over the front and trying to not use the back brake too much.

This allows you to get enough of a lean angle to make the switchback at a lower speed.

It takes a bit of commitment when getting the bike to lean into the turn after the counter steer, but it makes a big difference.

What is needed is a set up turn where you make a turn in the opposite direction to the switchback (essentially an exaggerated counter steer at slow speed) and then let the bike fold over toward the turn, keeping weight over the front and trying to not use the back brake too much.

This allows you to get enough of a lean angle to make the switchback at a lower speed.

It takes a bit of commitment when getting the bike to lean into the turn after the counter steer, but it makes a big difference.

I’ll try this later this afternoon on our new stupidly tightly switchbacked trail, thanks! (On my last/first attempt there was a lot of getting off and clambering down them…)

It’s to do with where your centre of mass is relative to the wheelbase.

When you steer your bike it goes round the corner of course – so the mass is undergoing acceleration towards the centre of the radius of the bend. However the bike is also pivoting around an axis through the rear hub. If you get your centre of mass closer to the rear hub it’ll spin around ie change direction much more quickly.

On fast bends it’s good to keep your weight forward to weight the front wheel, but on really sharp hairpins or really windy slalom trails like at Swinley you need your weight back over the rear wheel.

This is why 29ers often have that bent seat tube, to get the rear wheel closer to your body and your centre of mass. Mine has an adjustable rear dropout that lets you move the rear wheel forward or backwards – put it as far forward as it goes and the bike is extremely manoeuvrable,to the point where it’s hard to pedal in a straight line -as your weight shifts as you pedal it steers left and right.

For hairpins, lean back and to one side, and sort of yank the front around. If you are down South practice on Seagull at Swinley 🙂

we’re naw that good that things like bike geometry make any significant difference.

Or… most of us are relatively crap and need all the help we can get?

we’re naw that good that things like bike geometry make any significant difference

It does. Feeling nervous and unstable going down steep stuff? That’s geometry. Can’t keep a line uphill? Geometry. OTB on something not too bad? Geometry again.

Geometry does effect things, but not as much as skill.

Marketeers will be having wet dreams about this thread as it proves their bull is working on customers or you need a bike to do this, a bike to do that etc.

I’m not a great bike rider, but I am a good skier. Apparently you need skis for different scenarios these days. No you don’t. They do have slight advantages/disadvantages dependent on where they are used, but at the end of day they are a plank of wood and plastic and cable of doing much more than the marketeers would like you to think they can do

Marketeers will be having wet dreams about this thread as it proves their bull is working on customers or you need a bike to do this, a bike to do that etc.

Maybe to some, but that’s entirely not what I am talking about. I’ve had the same set of bikes for 8 years now, and I’ve made lots of small tweaks to their geometry and rider setup. That’s the opposite of buying a new bike for this or that.

Geometry makes a difference – and there’s often a tradeoff. If you want a bike for a specific purpose, then you want to pay attention to the geometry and setup. If you don’t give a crap and do the same thing on any bike, then go ahead. If you want to go down steep stuff but your steep angled HT doesn’t inspire confidence, then buying a slack long travel bike will help.

These things are facts, marketing has nothing to do with it.

How hard can it be?

😀

It does. Feeling nervous and unstable going down steep stuff? That’s geometry. SKILL Can’t keep a line uphill? Geometry. SkILL OTB on something not too bad? Geometry again. SKILL

Maybe to some, but that’s entirely not what I am talking about. I’ve had the same set of bikes for 8 years now, and I’ve made lots of small tweaks to their geometry and rider setup. That’s the opposite of buying a new bike for this or that.

Geometry makes a difference – and there’s often a tradeoff. If you want a bike for a specific purpose, then you want to pay attention to the geometry and setup. If you don’t give a crap and do the same thing on any bike, then go ahead. If you want to go down steep stuff but your steep angled HT doesn’t inspire confidence, then buying a slack long travel bike will help.

These things are facts, marketing has nothing to do with it.

Yes geometry makes a difference, but the difference is pretty small compared to skill.

The guy asked about riding switchbacks. This is one skill where it doesn’t matter if you are riding a steep xc bike or a slack enduro bike, if you don’t understand the mechanics of how to ride a switch back, geometry makes bugger all difference.

Yes geometry makes a difference, but the difference is pretty small compared to skill.

It’s not really the same thing. No-one (with a brain) thinks different geometry will make you into a brilliant rider. But given the rider, different geometry will be better or worse for different kinds of riding.

I’m inclined to agree that competence and confidence make the biggest difference. I lack both and really struggle with steep switchbacks especially when peering over a nasty drop. Pick the bike that you feel most confident on.

It’s not really the same thing. No-one (with a brain) thinks different geometry will make you into a brilliant rider. But given the rider, different geometry will be better or worse for different kinds of riding.

You posted a bunch of mtb skills and then equated not being able to do them with geometry. Not being able to hold a line = geometry? Sorry to burst your bubble but that is bollocks.

By all means backtrack if you like 😆

You posted a bunch of mtb skills and then equated not being able to do them with geometry

I jolly well did not.

I said geometry can *help* with certain things. Because it does. I didn’t say you couldn’t do anything. Speaking as someone who’s done Cwmcarn DH on both 7″ travel and XC race bikes.

You trying to tell me there’s no difference between a bike with a 67 degree HA and 71? Or only Pros will notice?

By the time you’ve worried so much about the switchbacks and found the optimal bike for those you’ll find the rest of the ride could have been improved by option b).. or even bike c) that you haven’t even considered yet! Looking for skill compensation in a bike is a never ending quest and there’s always something that *might* make that crucial difference you’ve been looking for… at the end of the day confidence and how comfortable you feel will probably be the main things to get you through.

at the end of the day confidence and how comfortable you feel will probably be the main things to get you through

This is true, and bike setup (rather than geometry) makes most difference here. Because bike designers don’t make bikes that handle badly.