Low vs. High Trail Bikes? What is Bicycle Trail? 

Love the video, Russ! That trail chart is also up on our Cyclopedia if anyone wants to get a closer look. We agree that Trail is one of the most important specs for determining a bike's handling, so we calculate it on Bike Insights for every bike we can. We even calculate the trail number for different wheel/tire configurations. Look for the "Configure" button (wrench icon) on our site to play around with this. A cool new trend we're seeing take off this year is configurable-offset forks (especially for gravel, all-road, and off-road touring bikes that can accommodate both 650b and 700c wheels). This means you can adjust the amount of fork offset to maintain the same trail figure when running two different wheelsets. I'm optimistic that this technology can eventually be used to correct for the issue you point out where smaller bikes are being forced into higher trail numbers by way of head tube angle manipulation.

Absolutely love the fact that you're delving in to the mysterious world of Trail. Every article or blog always talks about the standard formulas for calculating or measuring trail, with little more than "Slow" or "Quick" to describe how it affects handling. I didn't really start to "get it" until I started building bikes. Then, when you start to actually see and feel what wheel-flop is, or steering with your body vs your hands....makes a huge difference. Most folks don't have the luxury of building bikes, or testing as many different rides as you do. Keep up the good work, man. At this rate, you may end up enticing the bike manufacturing community into adopting some form of your "color wheel" descriptor.

That's some great info again and stuff that I never really thought much about actually. Would like to see the bicycle flavour wheel as a fridge magnet or something similar.

Thanks for this Russ! This was the content I needed.

another great video and really solid insight. I've been a bike trail (steering) junkie for a long time and your video makes one think about what they actually need and want. Very high trail (80-90mm) with a mid length stem (90ish mm) and drop bars may not be ideal for steep and slow grinding climbs which I seem to ride on a pretty regular basis and was what I was looking at... So much info! thanks again

Thanks, Russ! This is a really helpful consideration for my next ride!

Good discussion. I had a low-trail fork made for a bike that was around 65 mm trail. The new fork was about 30 mm trail. The high trail fork was unstable at low speeds as you say. It was also very exciting in a gusty cross-wind. Wide tires and front mounted weight both reduce the twitchiness. My low trail MAP never goes anywhere without at least a heavy lock in the front rando bag.

Excellent and helpful, thanks Russ.

Best video on the topic!

This was fantastic, thank you.

Thanks for that explanation. Yet it really took me some time to not confuse trail and steering tube angle anymore.

I was just looking this up. Bike trail is hard to google 😂

This is a thing that has to be consumed slowly, especially for me not hearing my motherlanguage. Very informative and the comparison of different framesizes is such an interesting thing, and it is one thing that the most people never think about and so far out of the awareness if people make decisions. Here in Germany, Canyon builds (some models) the same bike with different wheel-sizes depending on the framesize to prevent different angles to change from size to size and not to change the whole geometrie to prevent toe-overlap for example.

Great description! Now i understand why i prefer my fatbike to have higher trail. Makes going over poor surfaces more relaxing rather than the worry of losing the front end on an ice windrow.

If you want a more intuitive look at trail and head angle just pick up a caster (from a broken office chair or something) and push it along a table at different angles. The castor swivels to put the wheel behind the pivot when the pivot is vertical. This is analogous to a 90 degree head angle where the bike would be very unstable with negative trail. Eventually with the pivot at enough of an angle the wheel will stay in front. The threshold where the wheel stops wanting to around is a trail of 0.

great video, very useful info! I just checked the geometry chart of many expensive models (10k+) and it seems than many of them have just one fork for all sizes, which means that they have huge differences in trail measurements (for example pinarello f12 has 81mm for the the smallest size and 54mm the largest size). Though I've never seen a brand produce more than 2 forks for a model, so there can be a range of 11-12mm to about 20mm in trail. Smaller sized bicycles "suffer" from high trail numbers and contrariwise larger sizes have smaller trail measurments.

THANK YOU ! VERY INTERESTING OUTLOOK & HELPFUL ! BE SAFE ! HAVE FUN ! GOD BLESS YOU ALWAYS ! ENJOYED !

Great insight! One thing I would love to know is how to calculate trail on a specific bike. Most of my bikes are parts bikes and frequently don't even have the same wheel size front to rear. I tend to just shift parts around until I find something I like. I have a few that I really enjoy, including one that I refer to as my "tomacahawk" (long live john tomac!) that started as a flat-bar 700c hybrid and now has fat tires and drop bars (perfect for the new gravel pump track in town). Perhaps one of your upcoming bike whisperer episodes can be on bike-geometry metrology? Many manufacturers don't provide complete geometry info plus, as you mentioned, modifications can change geometry. Cheers!!

The low bicycle trail is the one by the river. The high bicycle trail is the one that has the great view of town. 😉

I remember read Jan Heine’s comment section. but I forgot which article... he write to choose very low or very high trail when considering front load carrying because mid trail will be the problem. I choose low trail because my mountain bike is already have very high fork trail. but a bike with very low fork trail comes with very high cost price.

The difference in feel caused by larger frames having lower trail numbers is compounded by the likelihood that riders on larger frames will have wider handlebars.

Hi Russ, i have been researching trail that candle high speed 30 to 40 mph and gusty winds at the same time. I do time trials, and there is a downhill section with gusty cross winds

It seems as if bike stability is also a geometrical calculation of your body weight and positioning at the center fulcrum, maybe including short vs mid or long chainstay based on the bike frame too?!? Nice video piece, its all about understanding the form and function which goes far beyond nerd curiosity, and trail is a major player ~

Great insight as I am in the market right now. Also did I miss the review on the Swift Rove build?

Good overview. I just made a 700C frame with a 46.5cm chainstay for a long wheel base. But it has a 73.5 head angle with a 44mm rake. Also allows for 40mm tires. Decent on gravel, pretty tight cornering.

if you read Jan Heine's BQ articles he makes a convincing point that the tire size and pressure ("pneumatic trail") can often totally counteract the supposed effects of low/high trail in the fork. So a super low trail bike with high pneumatic trail (low pressure wide tires) might handle pretty similarly in some respects to a mid trail bike with high pressure 25s. But throw 25s on the same low trail bike and it will suddenly handle like garbage without the wide tires lending stability to the otherwise "twitchy/nervous" low trail front end.

Also larger frames tend to have shorter trail numbers, just to keep the other dimensions balanced.

Russ, did you buy the Bombora? I see the new setup you got going on there. I want one. Keep up the great work✌😄👍

I'm currently designing a mullet dh bike and the trail has came out at 139, how will that relate to handling in terms of a dh bike?

yeah I'm interested how trail numbers jive with different handle bar set ups. for example you got a 70mm of trail on the same bike lets say and one person sets it up with wider flat bars swept back to the head tube and one person has a 70mm. stem with drops.

Great explanation, cheers. So if I understand correctly, in the diagrams used both by cyclingabout and analog, show a road/racing looking fork, described as high trail and the touring bike looking fork as low trail. This is incorrect, right? It causes some confusion as the diagrams could've been drawn more accurately. Maybe it's just me...

Excellent instructional. Raising one Q that maybe should be addressed in terminology: "What is stable?". In this particular case what is "stable" in Physics conflicts with bicycling terminology. Worse, there are uses of "stable" in cycling that are equivalent to the Physics meaning, ex. longer wheelbase is stable in Physical sense and is used as such term in cycling. Hence confusion. Physically stable cycle is NOT good for lumpy fast MTB downhills... That is why MTBs are typically not long wheelbase. But, they have long trail... I would use term "controllability" for property increasing (to a point!, see later...) as trail increases. Test of the Physical term stability applied to a bike: On a smooth, flat area push a bike (with nobody on it) to be tested with known fixed momentum. How far will it go before falling? Now do the same with same momentum with a different bike (ex. different trail number). How far will it go? Further->more Physically stable. Now to the limits of the benefits from increased trail: Install a bike fork with SMALL trail in the reverse (front to back). You'll get a bike with enormous trail. Try to ride it... Really, try to ride it... ;) Do the stability test as defined above, ... great learning opportunity. Thank for the great content, comment is not about your expertise which is greatly appreciated but about cycling terminology that everyone uses and which maybe needs a tweak or two.

Hammer pants....I think I still have mine. ;)

Have you seen bikedigger.com yet? Its been made by some MTB focused guys, but I would guess you could adapt it and apply your flavor wheel to its rankings system.

Great article. One thing I find it rather strange I got a gravel bike with 700C, 35mm tires, 430mm chainstay, with claimed trail of 71mm on size M and I find it very responsive, hard to not call it twitchy. Any thoughts on that?

Interesting that the high trail numbers on full susp mtb's are from the "Slackness", not the classic curve in your pics. May be a good subject for the future?? I like slack bikes cause i have big feet but it distributes more weight to back wheel... ever do a video on slack head tube fork angles/high trail vs low trail steep heat tube angles

I don't understand the use of the terms twitchy and nervous to describe low trail handling. My experience comes from only one bike, a Kogswell P/R with a 40mm trail fork. For a given steering input it would turn less than a road race type bike. I understand high trail becomes more stable the faster you go, but I felt 40mm trail was more stable, less inclined to turn, with front load or without, than any of the many high trail bikes I've ridden. Perhaps I'm misunderstanding definitions in some way.

Your apartment looks empty of bikes! must be months since it was like that :-)