ydono

I haven't ridden a bike in a very long time and decided to get back into it - casual biking on a mountain bike. I suffered a concussion a few years back so want to wear a helmet. I bought a bontrager quantum small helmet. when I have been trying to size it on my head, it seems to fit pretty snug but it rests on top of my eyebrows. does this mean it is too big? also, I read somewhere that it should pull down on my head when I reach halfway when opening my mouth. I have to open my mouth fully for it to pull on my head. Too big? different brand name in helmets as I can't get smaller than a small I don't think.

thanks - yvonne

colnago62

You should go back to where you bought it and seek help.

ydono

I bought it on line so as not to have to go into a store during covid.

DrIsotope

Pretty much every helmet fits different. I've had some sit 3/4" above my eyebrows, while others are right down on my eyebrows. With the helmet buckled and the ratchet dialed in, the helmet should fit snugly but not tight. If you can nod/shake your head back and forth/side-to-side and the helmet moves, it's too big. If the helmet stays put, it's fine. If the helmet still feels like it's just slightly too big, you can try wearing a cycling cap under the helmet to snug it up a little. Helmet fit is a very individual thing, and it's really tough to do online.

IMO, if the dial is all the way in and the helmet moves, it's 100% too big.

Germanrazor

They vary in fit from brand to brand. Usually there is a fit guide to show you how to measure for your fit. Does that mean it always works.....? Nope. But most often it does.

When you say tight and I assume it may have the adjustable dial possibly on its most loose setting, is it tight as in so tight you get a headache​​​​​​?

If so, then you have a wrongly fitted helmet. My experience has been like in my professional wearing some of the most advanced and technical PPE in the world is too tight a fit.....no good. My helmet when I tighten the dial on the back I keep it where it slightly has some very slight rock to it.

Hope this helps.

a1penguin

I have a small head and have a heck of a time finding helmets that actually fit. Don't trust the people who work at the bike shops. One guy tried to sell me a helmet that was obviously too large. I got so irritated I asked him if he would be happy wearing size 14 shoes and just tying them tighter. I turned and walked out the door. No buying online for me; I have to try them on to make sure they aren't too big. I can usually find a helmet in the $100-125 range on sale that fits. My brain is more important than trying to save some $.

The helmet should be a decent fit even without tightening the adjustment on the rear of the helmet. If you shake your head (yes and no directions) it should stay in place on your head and not wobble around. Otherwise it is too large.

canklecat

The Bontrager Quantum appears to be designed for mountain biking. Those often cover lower on the skull to better protect the forehead, temples and occipital region. Usually not a problem on bikes with more upright ride, but could be an issue on a drop bar road bike.

My POC Omne Air Spin covers lower on the skull than my Bell Formula MIPS, so the POC partially blocks the upper part of my peripheral vision when I'm in the drops. Not a problem sitting up or on my hybrids.

There are some road helmets that cover lower on the skull but tapered inward so they might obstruct the forward view a bit less. Check out some of the Abus helmets.

datlas 

It’s probably ok. Tighten the chin strap so when you open your mouth fully you feel the strap is really tight under your chin.

Peruano

You are probably OK if the helmet is comfortable in the end. The drop-your-chin to check for strap tightness is a good test. Too many people wear their straps too loose and the helmet can be peeled off over the back of their head when force is applied by the pavement. Adjusting the junctions of the fore and aft straps close to the bottom of your ear is also useful. The shake-your-head without the strap tightened is also a good test of fit. If your head rattles in the helmet it needs more padding or is too large. You want that lid square on your head, not cocked to the side or riding back on the crown of your head (your forebrain is important too). Have an experienced cyclist assist you in making the adjustments and if that doesn't seem good enough talk to others.

ydono

I did the shaking my head up and down test and it doesn't wobble. I don't feel like the low placement will hurt my vision as I do bike sitting up. thanks for all your helpful advice. I am ready to head out!!

Iride01 

Helmet manufacturers have a sizing guide. All you need to know is the circumference of your head above you eybrows and around the widest part in back.

If you can't try them on, then that is what you should go by. IMO.

If you helmet seems snug now. It might be worse later on a long ride.

topflightpro

Your helmet should come down onto your forehead so that if you go face first, your face is somewhat protected. My glasses and helmet pretty much touch each other - granted, they are large glasses.

As for the opening the mouth, I think that refers to how tight the strap is. I personally don't like my straps that tight.