WTF Are Offset And Trail On An MTB And Why Should I Care? |

[@muzzarobbo]

offset is measure relative to the steerer tube and not the fork lowers, its common for the fork crown to provide some of the offset

[@j.albertogratacos2076]

This is true, I changed the offset on my forks by changing the crown/stanction section. This pushes the full forks outwards or inwards, the relationship of the tube to the axle remains constant.

[@nwimpney]

Yep, it’s probably more often mostly offset at the crown. A lot of those other straight non-suspension forks also have an offset created by angling the legs forward slightly, and obviously on older road bikes, it’s also done by curving the leg. The important thing is just how far the axle is ahead of the steering axis.

[@ThunderStruckMTB]

I live in the SoCal high desert (always dust, never mud) and I use compressed air to blow off the dust then a damp Costco microfiber to finish it off..... bearings last forever, no water near your fork seals and overall just way better than washing. In places with actual rain, you have no choice but to wash.

[@TheDustyShredder]

YESSS, I built my own wheels and I have never had to worry about them. They are amazing, and you can build some really good wheels for under $300 for the set. For handlebar width, shoulder width also factors in. A bar that's too wide for your shoulders will give you less leverage than a more narrow bar that fits your shoulders. Indeed, the topic of air vs coil compatibility of the frame is a fairly complex one, but the simple matter of it is this: a progressive frame will work with air and coil, but with air will feel bottomless. A linear frame is only compatible with air and can damage a coil shock or itself. How can you tell? If it's equipped with a coil shock at the shop or in the box, you can likely use either. If it's equipped with air, use extreme caution when installing a coil.

[@mattkavanaugh5623]

Thank you Anna for the great explanation of fork offset and trail. I think I get it now! :)

[@netposerx]

GMBN can take a simple concept and ramble on forever about it to the point it gets more confusing then when you started. Should have shown the lines are the start and left them up there.

[@Mavrik-60]

Some of these settings if changed can damage your frame. I saw a Ti frame come into the shop with a broken frame. Snapped in two places at the end on the chain stay. Because he went from eighty mill fork to one twenty mill fork. Put to much strain on the frame. Ok good stuff as usual do keepemcoming wont you?

[@mattiniemela]

I am pretty sure shorter offset is often for 29"/slack head angles and longer offset is for 27,5"/steep angles. I think you mentioned this the other way around.

[@longdang2681]

Offset is there to enable you to attach the front wheel in front of the fork instead of at the fork(tube). This increases your wheel base and for the same bike it would increase the room you have before toe overlap would occur with the front wheel. Steeper head tube angles and larger wheels brings the front wheel closer to your toes to increase the risk of toe overlap. This would be fixed by increasing your fork offset. Therefore it's bigger wheels and steeper head tube angles need bigger fork offsets to prevent toe overlap with the front wheel.

[@galenkehler]

Lol nope, they got it right. And yes you need smaller offsets with smaller wheels, all else being equal

[@ROSE-by5su]

For a quick math I compared 2 offset with different angles and this is a 29er DH Bike, Offset:57 63 HA 114trail 62 HA 118 Offset:47 63 HA 123trail 62 HA 128trail

[@tomvonderharr865]

Only mentioning Shimano for the bleed bite point question? Would've thought you should at least add SRAM to that, where the reach is supposed to be from 75-80mm center of grips to tip of the lever, and contact adjust fully out opposite the arrow.

[@skymaracle]

Axis of steering is the steerer tube I believe, and not the fork legs.

[@stujm8376]

I’ve just gone from 680 to 760 on my hardtail, on my full sus it came with 780. I’m thinking of cutting them down to 760, it just seems to be the perfect size for me. I’ll have to spend a bit more time on the 760s to make a decision.

[@floydblandston108]

Re: bar width; when I was starting out, I asked an experienced rider why bars used to be narrower. He told me it was because of the distance between the trees they rode in!😂🤣

[@jonathanlindup3269]

I always wondered what fork offset was, does it have the same affect when the fork crown differs like when the stachions are set back closer to the steerer tube?

[@galenkehler]

Maybe. Fork offset is simply the perpendicular distance between the steering axis and the wheel axle, so it doesn't matter how you get that, by a fork crown or dropout. And so long as the motion of the suspension is parallel to the steering axis then the offset won't change. Some forks, like many linkage forks and the intend forks, have suspension that changes the offset through the fork travel, and this may or may not be a thing you want.

[@phil_dubss8335]

Very helpful as always guys

[@gmbntech]

Thanks! We're glad you liked it 🙂

[@ElDiablo223]

Thank you, great info. Cheers 🍻

[@PVVI2015]

Very interesting as always😊

[@DirtRoadie]

Fun fact: Stanchions can be offset a bit too.

[@KP-ol3tc]

Would running a 46mm fork on a hardtail with a 47mm headtube angle risk cracking the frame? Would an angled headset help reduce the added stress?

[@SubversionGarage]

The range of available offsets among forks is not enough (alone) to cause any damage. You would have to dramatically increase the trail to have any concerns

[@KP-ol3tc]

@@SubversionGarage Thank you kindly, that's super helpful to know

[@tomhopkins3431]

#AskGMBNTech I have a new bike with a 100mm rockshox recon gold fork, my weight is 100kg and I have had to add 140psi to get the correct sag with compression fully open. This is way higher than I have set on longer travel forks and they don't feel as plush. Should I reduce the pressure but add in some clicks of compression? What is the difference between more psi and fully open compression vs lower psi and compression added on? Thanks.

[@The_One-Eyed_Undertaker]

#AskGMBNTech I understand the importance of a correct saddle width according to your sit bones to achieve adequate support. But what's the difference between a MTB saddle and one intended for road cycling? Even within MTB saddles there are different models intended for XC, trail, Enduro or DH. Is there any valid point to these subtle design differences or they are just trying to sell us N+1?

[@komoonkh]

Road vs mtb is different because of the position of the rider. But I have seen people use the same saddle for mtb, gravel and road or whatever and be happy. So I guess it is a matter of you a**😂

[@Bugle25]

#Askgmbntech Hey Doddie and Anna great to have the gang together again, I have installed Magura MT5 brakes, they work great,but the front brake rotor has an annoying ring when I rolling at speed and rattles when you tap on the rotor, everything is torqued to spec and it’s driving me mad…what’s the cure?

[@DennisKhaye]

#askgmbntech Is the trail measurement shorter when you switch to mullet? Lower back hub would decrease the trail measurement, wouldn't it?

[@PBeBeR974]

exactement les points intéressant 🤘🏾

[@45graham45]

So is "trail" the same thing as caster angle that is a term widely used in the automotive industry? If so, why not just call it caster angle?

[@miyui9269]

one should never really worried about trail, just make your body stronger and by then you can ride better than almost everyone who can afford dentist's bikes.

[@mikehiggins461]

Anna could you explain the offset thing again?? Long story for a short story

[@TypicalGuy84]

#AskGMBNTech Why do the officals blow a whistle after each downhill racer goes by? Its not the fans. Its during practice i noticed

[@TheDustyShredder]

It's to let the next guy know you're comin down so if you wreck between em and can't move/call out, they can find you faster and potentially save your life.

[@John3-16Clothing]

#AskGMBNTech could you make a vid on why my brake lever is slow to go back to neutral and why my brakes feel spongy without being on hydraulic brakes.

[@allyw7405]

I prefer round grips so I have one less angle to be concern with.. oh brother..

[@thebeaglebeat3615]

Love the WTF lol, & nice long hair today, well done, thank you for explaning the trail.

[@tomquimby8669]

good show

[@richardgarza7083]

Please note that everything she said was around the larger wheel now used. AKA....alllll gravity bikes, allll downhill bikes, nothing you can ride...like a ...bike.

[@Ghostina1]

x eye party! love it

[@jonathanzappala]

Mtb journalists and KZbinrs are to blame for going on about head angle, when trail is what actually matters. Offsets didn’t come about, they have always been there. This is century old bicycle geometry design stuff.

[@user-fy6rr6sz2n]

Can we get long, long looks at the bikes and parts?........... we know what you look like, and its good. I want to see the bikes and just simply listen to you.

[@SamIam69]

What does offset do? A longer offset increases the wheelbase, enhancing stability, especially at high speeds-ideal for downhill riding. On the other hand, a shorter offset is better for cross-country (XC) biking, offering greater maneuverability and responsiveness.

[@James-e4d6h]

I’ve come away from this both confused from Anna’s explanations and bored

[@DiamondbackAxis]

is it really necessary for you to use "WTF" as a part of the title? don't you have young viewers or kids? What's ironic is you have guidelines yet you yourselves need to be guided .

[@joshuaanothereraseddad]

No need for the WTF. Like why even add that? Seriously, it is irrefutably unnecessary...

[@DopeSmoker]

😮you don't have to swear in the video title GMBN Tech! how uncouth of you! not very posh and rather rude! un-subbed! 😯

[@BruceLeeX3]

If you're replacing headsets that's not from washing too much, it's from washing incorrectly