I always get a little confused around how certain things relate to and effect the next thing.

My bike has flip flop steering at lower speeds but point it downhill & let it go & its absolutely rock solid & stable. This aspect I love but the floppy steering I don’t. I also find it slightly short with its 35mm stem & was considering putting a slightly longer stem on it.

Does anyone know what I should expect? I know the longer stem will make for slightly slower steering but will it also effect the flippy floppy feel?

Also, I’ve plenty of spacers to play with – would lowering or raising the stem height have any effect on the steering?

vague in = even vaguer out

but I’m sure chiefgrooveguru will be along later to help solve your quandry

Aah geex,you’re so cool

Also, I’ve plenty of spacers to play with – would lowering or raising the stem height have any effect on the steering?

Yes. And it’s free. Go play!

“but I’m sure chiefgrooveguru will be along later to help solve your quandry”

Hello!

“vague in = even vaguer out”

Indeed. Does not compute. More data required.

I’ve never got on with stems shorter than 50 mm, but that’s probably just a matter of being used to old school XC bikes. If you feel your stem is too short, probably trying a 50 mm or 60 mm stem would make sense. Just buy a cheap Brand X one or something like that until you figure out what you like. Playing with spacers costs nothing, so obvious place to start.

Just curious op, is it a 29er?

My Jeffsy 29er can be a bit how you describe. I’ve only done a limited amount of messing around as I don’t really mind it too much having got used to it. My first 29er you see.

That said,I went from a 60mm stem to a 35mmm initially and it felt very direct but a bit too twitchy for my limited abilities on the downs.

Went to a 50mmm and its a nice compromise. Got higher rise bars to try soon but that’s as much about having gad neurosurgery in my neck as much as anything. I like a sit up and beg riding position.

This is only one variable you ask about though. Forks are 46mm offset incidentally but I’d be a liar if I said I really understood the effects of offset. Particularly when tied into all the other variables.

I suppose the best (limited) advice I can give is swap out one item at a time and ride it a fair bit then make a second change etc if you need/want to. Starting with cheap/free stuff first of course. Spacers then stem blah,blah.

Edit: A lot of what hols said basically.

Have you seen/used this?
http://yojimg.net/bike/web_tools/stem.php

Orange Alpine 160 2016 MY so 650b wheelsize.

Head angle – 65 degrees
Fork – Bos Deville 160mm travel with 555mm axle to crown and 41mm offset.

I’d try a 50mm stem – I feel the longer stem calms the steering, so any uphill/slow flip-flop is lessened somewhat.

I do think shorter offset is a good thing but I’m not buying a new set of forks to try that! My 29” and 27.5” bikes have very similar steering geometry bar the wheel diameter (head angle, stem and bars are all near identical) and the 29” wheel which is on a short offset fork is less flip-floppy at low speed. Not quite sure why the industry made offsets longer on forks as the wheels got bigger…

Swapped to a 50mm stem & took out a 10mm spacer. The bar height feels no different and it does feel less floppy.

It’s a nice compromise but any longer would have me feeling like too much reach. I’m 5’11” with a short body & long legs.

Longer stem probably means the saddle needs shifting forward.

“It’s a nice compromise but any longer would have me feeling like too much reach. I’m 5’11” with a short body & long legs.”

I’m the same and have found that having my bars higher than I thought ‘normal’ stops the reach feeling too long and better suits how high my hips are due to my long legs. So try swapping the spacer back underneath. And slide the saddle forwards if you can.

AFAIK, some DH WC mechanics insist to match fork offset and and set length. Greg Minnaar’s comes to mind.

My former long travel 29er had a 51mm OS fork and 35mm stem. Steering wasn’t aweful, but sometimes a little quirky.
My current one has a 45mm stem and a 44mm OS fork. Steering feels much more composed, predictable and natural. You feel it specially at those tricky steep tight corners where you steer with your shoulders instead of leaning the bike.

This is highly anecdotal and we’re talking about two different bikes, but considering what I feel and the input from pro mechanics I find it plausible to have a positive influence

Variable angle headstock for bikes

“AFAIK, some DH WC mechanics insist to match fork offset and and set length. Greg Minnaar’s comes to mind.”

I think it’s just coincidence though I remember the article where they claimed there was some kind of magic link between the two.

From a steering geometry standpoint, the fork offset actually is what it claims to be, a forwards offset to the steering axis measured perpendicular to that axis. But for the handlebars the equivalent offset is not the stem length but the perpendicular distance from the steering axis to the line between the centre of each grip.

Handlebars have backsweep, so the actual effective stem length geometrically is much less than the length of the stem fitted to the bike.

Also, quite a few pro DHers are now fitting short offset fork crowns to their bikes and I doubt that’s happening in conjunction with fitting shorter stems.