[Closed] Should I be concerned about bars swinging around and hitting top tube?

I usually don't worry, but my frames are steel. For carbon I'd worry.

It's presumably only about 5mm of stack height, in terms of bike fit that's princess and the pea territory, the difference between thick and thin grips or 2psi in the tyres (not the effect on grip, the effect on stack).

For piece if mind,  try a couple of layers of helicopter tape on the top tube for protection and levers/shifter set to only 'just' tight enough.

Yes, though with carbon you can at least repair it....

I could change the bar/stem height/angle to prevent it ever happening but that will change my position on the bike

It's only going to happen when your position changes radically any way. Fall off less is a better solution.

Foam grips and a bit of protective wrap around the bit of the top-tube which will take the hit?

Bars are pretty light and rounded, and there's just as much if not more chance of trees/rocks hitting the frame with a lot more pointyness in a crash.

Bars are pretty light and rounded, and there’s just as much if not more chance of trees/rocks hitting the frame with a lot more pointyness in a crash.

I think almost every bike I've had, get's matching top tube dents on each side from the bars.

It's not so much the weight of the bars/front wheel, it's the weight of the bike swinging round into them once the bars have stopped on the ground!

Saw halfway through your bars - then in the event of a crash they will shear off and not damage the frame

I'd go one step futher - Don't crash.

yeah you can generate huge leverage as I found out on holiday while trying to cut off the circulation to my leg.....

Have you tried the slightly raised position on the bike? Could be better

I wonder which material is more resistant to this damage.

With carbon I wouldnt't want to risk it but that probaby isn't rational.

I wonder which material is more resistant to this damage.

The 2 I've seen have both been high speed offs where the front has violently tucked/turned and compounded by rider either landing on or with the bike - took some chunks out of the rider too....so lots of force through a point with no option for deflection/skimming off.

Both repaired fine

With carbon I wouldnt’t want to risk it but that probaby isn’t rational.

Logically carbon composites should

a) dissipate point impacts over a wider area of the tube

b) tolerate a small area of damage better as the loads are taken around it

But I'm kinda used to looking down and seeing a dented steel tube so I can accept that's fine!

I had this issue on my bike due to the brake fluid reservoir sticking out at quite an angle. Used it as rationale to buy some Hopes

I crash quite a bit, wouldn't be happy with a bike where the bars couldn't seeis round.

I'd go with altering your cockpit. You'll forget about it in about 5 minutes.

Presume this is on a mtb?

On a carbon road bike with caliper brakes, if the bars swing round the brake caliper cable adjuster section can hit the frame and damage it

Can cause quite bad damage in a crash

I dented a top tube on my alloy 29er a few years ago when my shifter hit it in a crash. I suspect it might have written off a carbon frame.  I thought my shifters just cleared the top tube, but clearly not.

I now set up my bikes with a good few mm between the lowest part of the bars and the top tube. You won't notice one extra spacer under the stem.

I have seen a broken carbon  top tube from shifter or brake hitting the top tube in a crash when the bars spun round.

I would personally try moving the bars, or if they must stay as they are then put some shelter tape pads on the frame.

Do Canyon race orientated mountain bikes not have something around the head set area to prevent this scenario? Worth a check as It won't interfere with your set up.

My mates 7k focus has a bump stop in the steerer set up, he came off last week and the bars simply rotated past said stop.

He now has a horrible looking gouge on the top tube. I'd fit a 5mm spacer in below, FS bikes move so much that that you won't even notice it.

My trek has a thingy to stop the bars impacting the top tube. You can only turn the bars a certain amount. Plus it has a rubber bumper on the downtube to stop the fork crown from smashing into the downtube.

My gate-like 456SS has this same issue. Not bothered about damage as it's not carbon 😀

Was a pain when i first discovered (can't do x-up, lookbacks/turndowns due to lack of space). Spacers under the stem, higher rise bars and leaving the levers loose so they move easily, sorted it for general riding/crashing though.

Was a pain when i first discovered (can’t do x-up, lookbacks/turndowns due to lack of space).

ahahah another quality reply, an x-up I can believe but when are you ever going to do a proper lookback on a full sized MTB?

Yes.

You should be concerned.

I wouldn't ever buy a frame that this was an issue with as I also like to X-up.
Lookbacks and turndowns are among my favourite looking BMX tricks and I have nothing but the utmost respect and admiration for anyone who can make them look good on an mtb. I have seen it done. (not by me)

ahahah another quality reply, an x-up I can believe but when are you ever going to do a proper lookback on a full sized MTB?

Ive had 3 full-sized hardtail mtbs since 2007 - the 456 is the first i couldn't on. In all likelyhood i'll never do another, as A. They are tricky on a big bike (as you seem to know). B. I only tried them on the MTB to prove a point to myself (it was a badly landed 360 lookback that wrecked my knee and ended my BMX frollicks). and C. I'm almost 50 now and slowly realising i'm too old for that shit 😀

Lookbacks and turndowns are among my favourite looking BMX tricks

Amen to that, Mike Aitken throwing a 360 lookback is all you need to see to understand why.

Ive had 3 full-sized hardtail mtbs since 2007 – the 456 is the first i couldn’t on.

Good lad, respect due then, your never too old!

I have a carbon framed flat bared road bike that I ride to work ( a Giant Fastroad Comax) and last January I had an off where the bars spun round and hit the top tube or at least the shifter did. This resulted in it chipping the paint off but didn’t damage the top tube. It was quite a violent off for the road as I also snapped both the bones in my ankle.

Yes its an issue. Most FS have clearance many HT not if you have a racy position.

I've put a protector on my HT and taped it in position. Going high enough to miss would be almost level with my saddle and no matter how loose controls, a pointy shifter will do some serious damage.