Stem flipping - and lowering.

paulc33

On my Specialized s works. I run a 100mm 3t stem in -6 degree but with a fairly large amount of spacers under the stem.

This position is comfortable but I find when decending and at speed the bike is a little a twitchy.

Was ordering if I lowered the stem but flipped in round to +6 degree what affect will this have on the reach etc ??

Also how do I work hour how fair to lower it to try and find the same reach?

Would this also help make the bike more stable?

Thanks for help.

simon_masterson

Google a stem angle calculator

paulc33

Yeah I know that's the best way but will doing it help the handling as well or will it handle the same this is really what I'm trying to find out

simon_masterson

Altering the reach will affect the handling of your bike, yes.

mugensi

So your stem is flipped at present in the / position with spacers underneath. Why not flip it to the \ position but leave the spacers and see how you get on? Removing the spacers and flipping the stem downwards would be a pretty large jump in stack height and alter your riding position drastically. I'd do it in small measures and let your body adjust naturally to the reduced height.

keef66

MugenSi wrote:

So your stem is flipped at present in the / position with spacers underneath. Why not flip it to the \ position but leave the spacers and see how you get on? Removing the spacers and flipping the stem downwards would be a pretty large jump in stack height and alter your riding position drastically. I'd do it in small measures and let your body adjust naturally to the reduced height.

I read it the other way round; it's currently pointing downwards but has spacers beneath, so he's considering taking out the spacers and having it pointing upwards to achieve the same bar height / reach. And since the stem will be clamping the steerer lower down close to the headset, hopefully removing a bit of flex from the steering. Sounds a reasonable theory to me

You need to be aware that if you don't cut the steerer down and instead simply reinstall all the spacers above the stem, the stem may be clamping an unsupported section of steerer tube. Depends on the kind of expander bung you have.

On my Scott their bung will only sit flush with the top of the steerer; they insist on no spacers above the stem so it clamps only that part of the steerer supported by the bung.
Yours may have the kind of expander bung you can position further down inside the steerer, sublect to the top cap bolt being long enough. In which case you can experiment with stem flipping / spacer swapping without cutting anything.

paulc33

At the moment the stem is \ with about 30mm stack of spacers under it. I was thinking of flipping stem / and lowering the stack height.

I want to do this to try and achieve more stability in steering.

Or am I better leaving stem \ position and taking 5mm at a time out of stack and getting my body to adjust to the position?

Jut really fed up with having a great bike but finding it twitchy on descents and being dropped my all my ridding buddies and having to put big effort in to catch up haha.

dj58

I'd try moving one spacer at a time to above the stem in the neg. position first to see if that reduces the problem. Could it be something else causing the problem, loose/worn headset, out of true wheel, wheel bearings, or is it a characteristic of the frame geometry, as it always been like that, or is it something that has developed over time?

paulc33

The wheels are brand new and the headset is ceramic and only covered 1500 miles so doubt it's that.
Being an s works I don't think it's characteristic of the frame.

It's worse since I put a shorter stem and raised the bars slightly. As I felt a bit over stretched. So changed from a 110mm stem to 100mm and raised the bars about 5mm higher.

Maybe il try lowering it slightly a bit at a time with the stem in -6 position and see how it feels.
What amount at a time should I take out?

ben@31

http://yojimg.net/bike/web_tools/stem.php

A 110mm stem with an angle of +6 and 30mm spacers has 6mm less reach and is 22mm higher than if it was flipped to angle of -6 .

dj58

paulc33 wrote:

Maybe il try lowering it slightly a bit at a time with the stem in -6 position and see how it feels.
What amount at a time should I take out?

10mm and try, then 5mm, then another 5mm and so on.