Stem or Steerer Flex?

[love2fly]

I have a fairly new MTB with Truvativ alu stem (105mm).

Carbon Trigon straight bar.

Rockshox RL Gold fork.

 

I notice that when I alternate hand pressure in riding position that I get quite a lot of flex, depending on which hand is pushing down.

I can replicate that when standing over bike also by pushing down on one hand and pulling up on the other at the same time.

 

I think it is not likely flex in headset, is it possible that either the steerer or the stem are flexing/twisting.

Pic attached.

 

I'm leaning in direction of getting a better stem - can anyone comment on the one I have?

 

Cheers

 

 

[BaGearA]

Fork lowers or handlebar for sure 

 

How much do you weigh ? 

 

Check if you can bend the handlebar when just standing over the bike , if not then its probably the fork and you might be better off with A fox 34 or Rockshoc yari ( both are expensive upgrades tho )

[Chavo]

Could it perhaps be that the handlebar is cracked behind the mounting plate? Since it's carbon,have you inspected the length of the handlebar for cracks?

[DuncanCT]

Removing some of the spacers under the stem will make it slightly firmer. Also you have a bunch of spacers and the stem is set with a negative rise. Drop some spacers and flip the stem. You'll land up with a similar hand position with fewer spacers.

 

What frame is it? Do you have a strait or tapered fork?

[love2fly]

Could it perhaps be that the handlebar is cracked behind the mounting plate? Since it's carbon,have you inspected the length of the handlebar for cracks?

[love2fly]

Could it perhaps be that the handlebar is cracked behind the mounting plate? Since it's carbon,have you inspected the length of the handlebar for cracks?

Nope bar is fine and strong.

[Vetseun]

Check it out. Bloody dangerous. I saw a stem break in a road race. It was the last thing I saw before me and half the bunch ate tarmac.

Dont take chances, search for the reason.

[ichnusa]

See if its not wheel flex

[arendoog]

Make sure that the stem fits over all of the steerer and not just the top end .Disassemble and remove spacers so that all of the stem has purchase when tightening it .Look for cracks .Flip the stem like DuncanCT says

[love2fly]

Make sure that the stem fits over all of the steerer and not just the top end .Disassemble and remove spacers so that all of the stem has purchase when tightening it .Look for cracks .Flip the stem like DuncanCT says

Good call. Plan to get someone to flex and me to spot and ascertain if stem twisting or steerer

[Ryno.]

I would just sell the bike and get a Cannondale with a lefty , flex issues will be something of the past.

[bikebloke]

carbon handlebars flex(some more than others) thats the nature of carbon  ....why would you assume its the stem(aluminium doesnt flex) or the steerer (shouldnt have movement unless its fitted wrong or your headset is loose etc..)

 

but carbon bars flex ..a lot if you pull and push on them

[love2fly]

Definitely not the bars. My brothers Trek has carbon bars and much less flex than mine. From what Im seeing it looks like the front tyre has a lot of deflecrion. Maxxis Ardent 2.25 @1.1 Bar. And the Bontrager tyrex seem to have stiffer sideaalls....still need another pair of hands...

[bikebloke]

before you buy bits take your bike to a bike mac cause tires shouldnt have anything to do with flexing bars or stems

[love2fly]

Make sure that the stem fits over all of the steerer and not just the top end .Disassemble and remove spacers so that all of the stem has purchase when tightening it .Look for cracks .Flip the stem like DuncanCT says

Yip thanks guys. I flipped the stem and dropped it 2 spacers. Its lowered the COG noticeably but there is still flex of which it seems 80% is in the tyre and some sideways movement in the wheel.

[porqui]

I thought the idea behind carbon bars are that they flex.

 

I'll go with bikebloke.

 

Otherwise just replace the front end of your bike. According to the previous posts there are just too many variables.