Where is the Head Angle Sweetspot for Enduro/Trail?

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2/13/2019 8:20 AM
Edited Date/Time: 2/13/2019 8:31 AM



With the mountain bike industry fully in the grips of the "lower longer slacker" fever, it's easy to lose perspective and get carried away by the hype sometimes. For example, when we recently posted an article about Canyon's new Strive, we were somewhat taken aback by the number of comments on social media calling the bike out for being "not slack enough". At 66 degrees, this 29er was even labeled "unridable" by some particularly vehement keyboard warriors. This stood in stark contrast to our experience with the bike on the trail, which should come as no surprise to experienced riders who know that the whole of the bike is always different to the sum of the parts no matter how good you think you are at reading geo charts. Also, in some of our recent testing we found a few bikes with just slightly steeper head angle to be a bit easier to ride and a whole lot of fun on a great variety of trails. Maybe that 64-degree head angle looks good online, but do you actually have the trails and/or the skills for it? Not that many years ago, proper enduro bikes had a 67-degree head angle and once you went under 66, it was DH bike territory. We're not so crusty as to want us to go back in time (we love our dropper posts too much!) but there does come a point where a lot of people are probably best served by a little less extreme angles. With all that said, what are your thoughts and experiences? Have you gone super slack only to then backtrack? Have you embraced the stretch geo and the super slack head angle? Vote and discuss!

(Yes, we do realize that this question is a bit strange in isolation, given the large number of other variables in frame design and intended use and all that, but we still think there is merit to discussing it in its own right.)

Where is the Head Angle Sweetspot for Enduro/Trail?

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2/13/2019 9:30 AM

Oh I like this poll, here it goes:

Currently on the new GT Sensor (130x130)* as my trail bike.

Granted the bike is a custom build, one of the first things I wanted to do was bump the fork up to 140mm. This effectively changed the HTA from 65.5°(130mm Fork Travel) to 65°(140mm Fork travel). (low positioned flip chip). See some notes I just wanted to put that disclaimer first and foremost.

*Geo Context (Based with 140mm fork):
140mm Front Travel, 130mm rear
65° HTA, 75.5° eSTA
470 Reach, 435 chainstay length
35mm spacers under stem(including bearing cap), 40mm stem length, 780 x 25mm rise bars.

So far I really enjoy this bike in its current setup. The fork change slackened my eSTA a touch but it doesn't really affect my opinion of ride quality. (It's a rocket ship when pointed down hills. I'm not the fastest nor fittest guy going uphills so optimal pedal efficiency doesn't weigh too much in my book).

Here in the New England (US) its quite rocky/rooty and this time of year the frozen dirt mixed with some wet leaves is generally the norm. That being said with the 140mm fork I openly welcome the added BB clearance while simply pushing the seat forward alleviating at least some of the slacker pedaling position (76° to 75.5° eSTA with the larger fork (Again, bike lives in low flip chip setting).

I'm sure that a steeper HTA and eSTA may make a more efficient handler on paper but having a pedal-able bike on the slacker side that is still perfectly at home pushing the limits on descents really plants me firmly on the slacker side of this debate. If you made it this far, I applaud you.

TL;DR - I'm very much enjoying a slacker trail bike. Descents are always more fun than climbs. Even on a 140x130 29er.

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2/13/2019 6:14 PM

ctbiker888 wrote:

Oh I like this poll, here it goes:

Currently on the new GT Sensor (130x130)* as my trail bike.

Granted the bike is a custom build, one of the first things I wanted to do was bump the fork up to 140mm. This effectively changed the HTA from 65.5°(130mm Fork Travel) to 65°(140mm Fork travel). (low positioned flip chip). See some notes I just wanted to put that disclaimer first and foremost.

*Geo Context (Based with 140mm fork):
140mm Front Travel, 130mm rear
65° HTA, 75.5° eSTA
470 Reach, 435 chainstay length
35mm spacers under stem(including bearing cap), 40mm stem length, 780 x 25mm rise bars.

So far I really enjoy this bike in its current setup. The fork change slackened my eSTA a touch but it doesn't really affect my opinion of ride quality. (It's a rocket ship when pointed down hills. I'm not the fastest nor fittest guy going uphills so optimal pedal efficiency doesn't weigh too much in my book).

Here in the New England (US) its quite rocky/rooty and this time of year the frozen dirt mixed with some wet leaves is generally the norm. That being said with the 140mm fork I openly welcome the added BB clearance while simply pushing the seat forward alleviating at least some of the slacker pedaling position (76° to 75.5° eSTA with the larger fork (Again, bike lives in low flip chip setting).

I'm sure that a steeper HTA and eSTA may make a more efficient handler on paper but having a pedal-able bike on the slacker side that is still perfectly at home pushing the limits on descents really plants me firmly on the slacker side of this debate. If you made it this far, I applaud you.

TL;DR - I'm very much enjoying a slacker trail bike. Descents are always more fun than climbs. Even on a 140x130 29er.

Pike 29" 130mm axle-to-crown: 531
Pike 29" 140mm axle-to-crown: 541




Moving to a 150mm fork might be worth a look as well.

Pike 29" 130mm axle-to-crown: 531
Pike 29" 150mm axle-to-crown: 551


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2/14/2019 3:51 AM

The same head angle for trail and enduro?????

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2/14/2019 4:07 AM

63 degree 170/180 travel and downhill bikes too anything slacker is too slack in my experience
64 degree 160/150 travel
65 150/140 travel

But its all dependant on the reach number being spot on too, ive found as I have gone towards longer bikes (im 6ft 3) that the reach (515mm on the trail bike 510 on the DH bike) has given me more ability to really weight the bike correctly, or better anyway. Longer chainstays would be a bonus.

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2/14/2019 4:07 AM

I have to admit to be part of the hypocrisy:

I rolled my eyes at canyon's 66 headangle on a 2019 enduro race bike, especially considering the shapeshifter.

But... The slackest enduro bike I have owned is my commencal meta with 66, my previous 2 bikes were 67, always with a 40mm stem.

Hoping to get down to 65 for the next one: don't think you will gain much descending ability going lower, but climbing and slow speed should start to suffer beyond that.

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2/14/2019 4:53 AM
Edited Date/Time: 2/14/2019 4:54 AM

Love you Vital but this is kind of a funny question. There are other variables that play into the equation. EG, STA and rear center plays into this too.

That said, I'd like to suggest mountain bikes will eventually figure out what moto figured out 30 years ago. 63-64 is good for just about everything.

Get offset right, get the rest of the bike's geo right and I could see a time where XC bikes have very similar geo to enduro bikes.

"But it'll wander while climbing" - no, not really, you just need to get used to how a slacker bike handles going uphill

"But the front tire will come up while climbing" - not with appropriately sized chainstays

"But it'll only be good in the steep stuff" - Not once you learn to weight the bike properly.

Anecdotal Proof: The best handling bike I rode in 2018 was the Stumpjumper Evo. I smoked more uphill KOMs on that bike than any other bike I've owned in the last 3-4 years. Raced XC and did well. Was faster on any kind of single track on this bike. The bike had other shortcomings (stay tuned for the full review) but yeah, my YZ250 handles well in the woods, and so does a mountain bike with the same headtube angle...


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2/14/2019 5:45 AM

jeff.brines wrote:

Love you Vital but this is kind of a funny question. There are other variables that play into the equation. EG, STA and rear center plays into this too.

That said, I'd like to suggest mountain bikes will eventually figure out what moto figured out 30 years ago. 63-64 is good for just about everything.

Get offset right, get the rest of the bike's geo right and I could see a time where XC bikes have very similar geo to enduro bikes.

"But it'll wander while climbing" - no, not really, you just need to get used to how a slacker bike handles going uphill

"But the front tire will come up while climbing" - not with appropriately sized chainstays

"But it'll only be good in the steep stuff" - Not once you learn to weight the bike properly.

Anecdotal Proof: The best handling bike I rode in 2018 was the Stumpjumper Evo. I smoked more uphill KOMs on that bike than any other bike I've owned in the last 3-4 years. Raced XC and did well. Was faster on any kind of single track on this bike. The bike had other shortcomings (stay tuned for the full review) but yeah, my YZ250 handles well in the woods, and so does a mountain bike with the same headtube angle...


Well that is why we stated clearly that "yes, we do realize that this question is a bit strange in isolation, given the large number of other variables in frame design and intended use and all that, but we still think there is merit to discussing it in its own right," so no bonus points to you Captain Obvious for pointing that one out.

On the more serious note, a little more food for thought here: suspension forks (at least the current ones) tend to work better when they get to absorb impact forces along the direction of the stanchions. Hits that deliver force at an angle can lead to bushing bind issues.



So what if the real magic pill isn't to make a bike longer AND slacker, but JUST longer? Push the reach out, and then bring the head angle back just a tad? That will keep the wheelbase in check which is probably a good thing for many riders, AND it will allow the fork to work more along its preferred direction of travel. Once the reach has been made long enough, you don't need all that head angle to help keep you centered in the bike, you've already taken care of that issue with the length. Now you can move forward in the bike and put your weight above the front wheel, with the fork at the right angle to deal with the terrain. Like I said, food for thought (which is the point of having this discussion).

And to point out the obvious again...it does of course depend on all those other things. If you care about bar height then you can't have the same head angle for a 150mm fork and a 180mm fork, that kinda goes without saying. But the real underlying question here is whether or not we've reached (or gone beyond) the optimum baseline head angle for enduro and trail bikes already?

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2/14/2019 5:47 AM

Lars TB wrote:

The same head angle for trail and enduro?????

5 questions marks????? you must really be onto something here

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2/14/2019 6:04 AM

Running 64° on 150 29er. 44 offset and it feels fine just more stable, no down sides going slow uphill or anywhere.
Try it.

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2/14/2019 6:18 AM

iceman2058 wrote:

Well that is why we stated clearly that "yes, we do realize that this question is a bit strange in isolation, given the large number of other variables in frame design and intended use and all that, but we still think there is merit to discussing it in its own right," so no bonus points to you Captain Obvious for pointing that one out.

On the more serious note, a little more food for thought here: suspension forks (at least the current ones) tend to work better when they get to absorb impact forces along the direction of the stanchions. Hits that deliver force at an angle can lead to bushing bind issues.



So what if the real magic pill isn't to make a bike longer AND slacker, but JUST longer? Push the reach out, and then bring the head angle back just a tad? That will keep the wheelbase in check which is probably a good thing for many riders, AND it will allow the fork to work more along its preferred direction of travel. Once the reach has been made long enough, you don't need all that head angle to help keep you centered in the bike, you've already taken care of that issue with the length. Now you can move forward in the bike and put your weight above the front wheel, with the fork at the right angle to deal with the terrain. Like I said, food for thought (which is the point of having this discussion).

And to point out the obvious again...it does of course depend on all those other things. If you care about bar height then you can't have the same head angle for a 150mm fork and a 180mm fork, that kinda goes without saying. But the real underlying question here is whether or not we've reached (or gone beyond) the optimum baseline head angle for enduro and trail bikes already?

I more was poking at the fact we've got a chainstays thread, a reach thread and now a head angle thread all being recirculated...and they are all driving at the same thing.... "get a bike to handle well"

There will be a special sauce ratio between reach, rear center, head angle, STA (for climbing) and bb height that'll make for magical handling.

I do think people need to throw out the preconceived notion that "this wheelbase is too long, short, whatever" - again, i go back to moto - I watch dudes do things on far longer motos in tight terrain that the internet would say "that's fake news".

Don't worry about length. Worry about figuring out how to get a bike to handle, then build the rest of the measurements around your body.

My $0.02 - 63.5 deg HTA, 35-40mm offset, 40mm stem (depending on stack/bar height)...Then get your reach and rear center to compliment...which is really the tough part of the equation.

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2/14/2019 6:33 AM

I think it depends on how much travel your bike has. Shorter travel 65º ~130-140mm 64-63º 150-170mm. Given a longer reach head angle does not negatively affect climbing stability i.e. it does not cause front end wandering. Sure a 63º head angle isn't going to make you bike feel "alive" at slow speeds but steep head angles allow your front end to fold when cornering hard. Slacker is better up to a point. From experience anything under 63º requires Champery steepness or it just feels too much.
On another note please stop saying bikes are getting slacker, longer and lower. Most bikes are getting slacker and longer but not lower. We have already figured out what is too low a while back. I don't see any 300mm bb heights on any full suspension bikes do you?

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2/14/2019 6:36 AM

Fred_Pop wrote:

I think it depends on how much travel your bike has. Shorter travel 65º ~130-140mm 64-63º 150-170mm. Given a longer reach head angle does not negatively affect climbing stability i.e. it does not cause front end wandering. Sure a 63º head angle isn't going to make you bike feel "alive" at slow speeds but steep head angles allow your front end to fold when cornering hard. Slacker is better up to a point. From experience anything under 63º requires Champery steepness or it just feels too much.
On another note please stop saying bikes are getting slacker, longer and lower. Most bikes are getting slacker and longer but not lower. We have already figured out what is too low a while back. I don't see any 300mm bb heights on any full suspension bikes do you?

More referring to seat tube length and standover height when we say bikes are getting lower.

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2/14/2019 6:36 AM

Fred_Pop wrote:

I think it depends on how much travel your bike has. Shorter travel 65º ~130-140mm 64-63º 150-170mm. Given a longer reach head angle does not negatively affect climbing stability i.e. it does not cause front end wandering. Sure a 63º head angle isn't going to make you bike feel "alive" at slow speeds but steep head angles allow your front end to fold when cornering hard. Slacker is better up to a point. From experience anything under 63º requires Champery steepness or it just feels too much.
On another note please stop saying bikes are getting slacker, longer and lower. Most bikes are getting slacker and longer but not lower. We have already figured out what is too low a while back. I don't see any 300mm bb heights on any full suspension bikes do you?

Curious, do you feel 63-64 is too slack because of what negative handling trait?

I'll agree if you throw a 63ish HTA on a bike that isn't well balanced (too much rear bias) it sucks. But if the stays are the right length for the reach, offset thought about appropriately, I find a slack bike rails corners no matter how flat (or steep) the terrain.

If I was wrong, wouldn't moto bikes have steeper HTAs? They are always going around a flat track...

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2/14/2019 6:41 AM

iceman2058 wrote:

Well that is why we stated clearly that "yes, we do realize that this question is a bit strange in isolation, given the large number of other variables in frame design and intended use and all that, but we still think there is merit to discussing it in its own right," so no bonus points to you Captain Obvious for pointing that one out.

On the more serious note, a little more food for thought here: suspension forks (at least the current ones) tend to work better when they get to absorb impact forces along the direction of the stanchions. Hits that deliver force at an angle can lead to bushing bind issues.



So what if the real magic pill isn't to make a bike longer AND slacker, but JUST longer? Push the reach out, and then bring the head angle back just a tad? That will keep the wheelbase in check which is probably a good thing for many riders, AND it will allow the fork to work more along its preferred direction of travel. Once the reach has been made long enough, you don't need all that head angle to help keep you centered in the bike, you've already taken care of that issue with the length. Now you can move forward in the bike and put your weight above the front wheel, with the fork at the right angle to deal with the terrain. Like I said, food for thought (which is the point of having this discussion).

And to point out the obvious again...it does of course depend on all those other things. If you care about bar height then you can't have the same head angle for a 150mm fork and a 180mm fork, that kinda goes without saying. But the real underlying question here is whether or not we've reached (or gone beyond) the optimum baseline head angle for enduro and trail bikes already?

Mondraker follow that logic by going longer in reach but not super slack like Pole or Nicolai/Geometron. The problem I see is that steep head angles don't corner as well with the front end prone to folding. Under 66º seems fine but above that especially with 150mm forks and you are just asking for trouble. I think XC bikes need to go slacker too.

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2/14/2019 6:42 AM
Edited Date/Time: 2/14/2019 6:43 AM

Fred_Pop wrote:

I think it depends on how much travel your bike has. Shorter travel 65º ~130-140mm 64-63º 150-170mm. Given a longer reach head angle does not negatively affect climbing stability i.e. it does not cause front end wandering. Sure a 63º head angle isn't going to make you bike feel "alive" at slow speeds but steep head angles allow your front end to fold when cornering hard. Slacker is better up to a point. From experience anything under 63º requires Champery steepness or it just feels too much.
On another note please stop saying bikes are getting slacker, longer and lower. Most bikes are getting slacker and longer but not lower. We have already figured out what is too low a while back. I don't see any 300mm bb heights on any full suspension bikes do you?

iceman2058 wrote:

More referring to seat tube length and standover height when we say bikes are getting lower.

Ok that I will agree with that. Long seat tubes are unnecessary especially with 200mm droppers coming out.

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2/14/2019 6:56 AM

Fred_Pop wrote:

I think it depends on how much travel your bike has. Shorter travel 65º ~130-140mm 64-63º 150-170mm. Given a longer reach head angle does not negatively affect climbing stability i.e. it does not cause front end wandering. Sure a 63º head angle isn't going to make you bike feel "alive" at slow speeds but steep head angles allow your front end to fold when cornering hard. Slacker is better up to a point. From experience anything under 63º requires Champery steepness or it just feels too much.
On another note please stop saying bikes are getting slacker, longer and lower. Most bikes are getting slacker and longer but not lower. We have already figured out what is too low a while back. I don't see any 300mm bb heights on any full suspension bikes do you?

jeff.brines wrote:

Curious, do you feel 63-64 is too slack because of what negative handling trait?

I'll agree if you throw a 63ish HTA on a bike that isn't well balanced (too much rear bias) it sucks. But if the stays are the right length for the reach, offset thought about appropriately, I find a slack bike rails corners no matter how flat (or steep) the terrain.

If I was wrong, wouldn't moto bikes have steeper HTAs? They are always going around a flat track...

For short travel I think 63-64º is too slack for the same reason I think sub 63º is too slack for longer travel forks unless you are riding very steep terrain. I used to run a 62º head angle and found that on flat terrain I had to weight the front so much the rear it would slide out too easily when cornering. I also found the fork would bind more rather than absorb the bumps. Motorbikes have more travel and thus with sag their head angles end up steeper.
I do agree with you that mountain bikes are taking a hell of a long time to figure out what motorbikes figured out years ago geometry wise. This is why I laugh when people say Pole and Nicolai/geometron are too extreme. All the big brands are playing catch up and we see that when every year the same model trailbike gets longer and slacker. It makes me question whether or not they even test geometry at all...Pole and Nicolai/Geometron don't keep going longer and slacker because they have pretty much figured geometry out (aside from seat tube angle which they have been making progressively steeper).

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2/14/2019 7:00 AM

Fred_Pop wrote:

For short travel I think 63-64º is too slack for the same reason I think sub 63º is too slack for longer travel forks unless you are riding very steep terrain. I used to run a 62º head angle and found that on flat terrain I had to weight the front so much the rear it would slide out too easily when cornering. I also found the fork would bind more rather than absorb the bumps. Motorbikes have more travel and thus with sag their head angles end up steeper.
I do agree with you that mountain bikes are taking a hell of a long time to figure out what motorbikes figured out years ago geometry wise. This is why I laugh when people say Pole and Nicolai/geometron are too extreme. All the big brands are playing catch up and we see that when every year the same model trailbike gets longer and slacker. It makes me question whether or not they even test geometry at all...Pole and Nicolai/Geometron don't keep going longer and slacker because they have pretty much figured geometry out (aside from seat tube angle which they have been making progressively steeper).

Honestly till I started riding moto a lot I would have agreed with you. "Slack HTAs are only for steep tracks"

I don't think that is the case any longer. The reason we felt that way is the bikes were (and many still are) very rearward bias. Hence going to a slack HTA makes it harder and harder to properly weight the front tire. See also: my silly chainstay thread.

If stays are appropriately sized, reach appriopriate too, you won't have to ride with the bars in your belly to weight the front tire on flat ground.

As far as what you said about a dirt bike, you are actually wrong, they get slacker under sag, not steeper. The front fork (or forks lol) does compress both statically and when the rider sits on it, but the rear end's sag is far greater. I can measure, but I'd wager I'm actually riding at a HTA that is less than 63.5 on trail on my moto.

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2/14/2019 7:11 AM

jeff.brines wrote:

Curious, do you feel 63-64 is too slack because of what negative handling trait?

I'll agree if you throw a 63ish HTA on a bike that isn't well balanced (too much rear bias) it sucks. But if the stays are the right length for the reach, offset thought about appropriately, I find a slack bike rails corners no matter how flat (or steep) the terrain.

If I was wrong, wouldn't moto bikes have steeper HTAs? They are always going around a flat track...

Fred_Pop wrote:

For short travel I think 63-64º is too slack for the same reason I think sub 63º is too slack for longer travel forks unless you are riding very steep terrain. I used to run a 62º head angle and found that on flat terrain I had to weight the front so much the rear it would slide out too easily when cornering. I also found the fork would bind more rather than absorb the bumps. Motorbikes have more travel and thus with sag their head angles end up steeper.
I do agree with you that mountain bikes are taking a hell of a long time to figure out what motorbikes figured out years ago geometry wise. This is why I laugh when people say Pole and Nicolai/geometron are too extreme. All the big brands are playing catch up and we see that when every year the same model trailbike gets longer and slacker. It makes me question whether or not they even test geometry at all...Pole and Nicolai/Geometron don't keep going longer and slacker because they have pretty much figured geometry out (aside from seat tube angle which they have been making progressively steeper).

jeff.brines wrote:

Honestly till I started riding moto a lot I would have agreed with you. "Slack HTAs are only for steep tracks"

I don't think that is the case any longer. The reason we felt that way is the bikes were (and many still are) very rearward bias. Hence going to a slack HTA makes it harder and harder to properly weight the front tire. See also: my silly chainstay thread.

If stays are appropriately sized, reach appriopriate too, you won't have to ride with the bars in your belly to weight the front tire on flat ground.

As far as what you said about a dirt bike, you are actually wrong, they get slacker under sag, not steeper. The front fork (or forks lol) does compress both statically and when the rider sits on it, but the rear end's sag is far greater. I can measure, but I'd wager I'm actually riding at a HTA that is less than 63.5 on trail on my moto.

I have read the other thread about chainstays and again agree with you that short chainstays are rubbish. My bike has 460mm chainstays, 520mm reach but I still had to ride way over the front when I had a 62º head angle when riding flat terrain. I remember cornering on a particular trail with lots of quick sharp turns and even though I was running a 2.8 rear tire (I like to test different setups) I just felt the back end sliding around. It looks cool but didn't give much confidence. I suppose I could have run a lower front end to compensate but it would make it harder to lift the front end and it didn't solve the fork binding. The fork I was running was a single crown and I have since switched to a double crown for added stiffness.

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2/14/2019 8:15 AM
Edited Date/Time: 2/14/2019 8:21 AM

As bikes have become more capable (and my skills improve... I hope) I'm finding I need less and less "mechanical" advantages and am preferring a more "spicy" bike to keep the trail alive.

800mm bars have done a great job of stabilizing a front end at speed, while a steeper HTA allows a lot of side to side play on the trail.

But I like to have fun on trails, I don't need to go faster in a straight line and make a trail boring.

Racing is different as it's 100% speed, 100% of the time, which is more plow bike territory.

Maybe mixing Enduro with Trail bike in the original question is too broad.

P

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2/14/2019 9:39 AM

Lars TB wrote:

The same head angle for trail and enduro?????

scarface wrote:

5 questions marks????? you must really be onto something here

Well, these are two very different categories and one of the things that makes them different is the head angle. So the poll stated like this makes no sense.

But you're right, I probably should have used at least 8 question marks to be noticed by Iceman!



On my trail bike I've a 66 degree HA. It works fine on flatter trails, the bike doesn't need to be leaned to get around the corner. But doesn't let me down on extremely steep stuff either. But the 64 degree HA on my enduro bike does give me a lot more confidence on that steep stuff. On flat trails, the enduro bike is a hand full to get around the corner. Both have the same reach.

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2/14/2019 9:40 AM

Mr. P wrote:

As bikes have become more capable (and my skills improve... I hope) I'm finding I need less and less "mechanical" advantages and am preferring a more "spicy" bike to keep the trail alive.

800mm bars have done a great job of stabilizing a front end at speed, while a steeper HTA allows a lot of side to side play on the trail.

But I like to have fun on trails, I don't need to go faster in a straight line and make a trail boring.

Racing is different as it's 100% speed, 100% of the time, which is more plow bike territory.

Maybe mixing Enduro with Trail bike in the original question is too broad.

P

If it works for you great but don't assume long, stable bikes aren't fun! I think it is fun to have a bike that can handle anything in it's path no matter the speed, I think it is fun to drift corners, I think it is fun that my long bike doesn't spin out or have the front wheel lift off the ground when I climb the steepest gradients.I think it is fun to have a bike that doesn't allow you to fly over the handlebars because your wrists aren't right beneath your shoulders on flat terrain...but hey maybe it is just me ;0)

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2/14/2019 10:24 AM

Once you start getting super slack a whole lot of factors become even more important. Even the wrong front tyre can change the riders perception of what works and what doesn't. I've just steepened my Enduro and reduced the sag to try and get front end grip and cornering confidence back. A different tyre has also helped. My HT which steepens from 65 to 66 at least when sagged has far better front end cornering grip on various tyres, even those with unfashionable minimalist tread. My previous 66.5 Enduro seemed to be the best of both worlds...

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2/14/2019 12:01 PM
Edited Date/Time: 2/14/2019 12:07 PM

I'm 5'6" and just got on a medium Transition Sentinel and starting to set pr's on strava, I was on a 170 F/R medium Capra before, 420mm reach and 65.5 ha on the Capra vs 450mm and 64ha on the sentinel and seattube length 450 capra vs 400 sentinel. They feel almost exactly the same, geo-wise, to me except the 29er carves harder and rolls over shit faster, off camber hi lines are so much more fun now.

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2/14/2019 12:16 PM

I was super happy to see the numbers on that bike. Gave me the sense that it had been designed to work rather than sell purely on the geo being moar slack than everyone else (looking at you every single manufacturer).

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2/14/2019 12:17 PM

I'm not riding at the limits of the bike, not even my own limits most of the time. I prefer a slacker head angle, but not because of its behavior in the steeps; but for the more technical lines (even skinnies!) I have a better feel for the front end when it's farther in front of me. If I'm comfortable with the front I ride better, the rear doesn't matter nearly as much.

My current daily riding bike is 64.5 degrees

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2/14/2019 3:12 PM
Edited Date/Time: 2/14/2019 3:12 PM

This poll is perpetuating the misconception that HTA matters all that much, as you said it’s the sum of all things and the long front center that matter. Major manufactures are gradually moving towards what the others have already figured out (like Pole), that the distance of the front wheel from the BB is what matters most and it’s a combination of fork offset, reach, and HTA that determine this. The gap is closing between the like of Pole and Nicolai and everyone else.

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2/15/2019 11:11 AM

Cyclotoine wrote:

This poll is perpetuating the misconception that HTA matters all that much, as you said it’s the sum of all things and the long front center that matter. Major manufactures are gradually moving towards what the others have already figured out (like Pole), that the distance of the front wheel from the BB is what matters most and it’s a combination of fork offset, reach, and HTA that determine this. The gap is closing between the like of Pole and Nicolai and everyone else.

It is closing which is good news as it will provide us all with more options in the future. I look forward to Trek/Specialize/etc Geometrons in 5 years time!

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2/19/2019 2:18 PM

jeff.brines wrote:

Love you Vital but this is kind of a funny question. There are other variables that play into the equation. EG, STA and rear center plays into this too.

That said, I'd like to suggest mountain bikes will eventually figure out what moto figured out 30 years ago. 63-64 is good for just about everything.

Get offset right, get the rest of the bike's geo right and I could see a time where XC bikes have very similar geo to enduro bikes.

"But it'll wander while climbing" - no, not really, you just need to get used to how a slacker bike handles going uphill

"But the front tire will come up while climbing" - not with appropriately sized chainstays

"But it'll only be good in the steep stuff" - Not once you learn to weight the bike properly.

Anecdotal Proof: The best handling bike I rode in 2018 was the Stumpjumper Evo. I smoked more uphill KOMs on that bike than any other bike I've owned in the last 3-4 years. Raced XC and did well. Was faster on any kind of single track on this bike. The bike had other shortcomings (stay tuned for the full review) but yeah, my YZ250 handles well in the woods, and so does a mountain bike with the same headtube angle...


iceman2058 wrote:

Well that is why we stated clearly that "yes, we do realize that this question is a bit strange in isolation, given the large number of other variables in frame design and intended use and all that, but we still think there is merit to discussing it in its own right," so no bonus points to you Captain Obvious for pointing that one out.

On the more serious note, a little more food for thought here: suspension forks (at least the current ones) tend to work better when they get to absorb impact forces along the direction of the stanchions. Hits that deliver force at an angle can lead to bushing bind issues.



So what if the real magic pill isn't to make a bike longer AND slacker, but JUST longer? Push the reach out, and then bring the head angle back just a tad? That will keep the wheelbase in check which is probably a good thing for many riders, AND it will allow the fork to work more along its preferred direction of travel. Once the reach has been made long enough, you don't need all that head angle to help keep you centered in the bike, you've already taken care of that issue with the length. Now you can move forward in the bike and put your weight above the front wheel, with the fork at the right angle to deal with the terrain. Like I said, food for thought (which is the point of having this discussion).

And to point out the obvious again...it does of course depend on all those other things. If you care about bar height then you can't have the same head angle for a 150mm fork and a 180mm fork, that kinda goes without saying. But the real underlying question here is whether or not we've reached (or gone beyond) the optimum baseline head angle for enduro and trail bikes already?

this seems to be Kona's way of thinking. they are very long in the front center but prefer to stick with 66 HTA's .

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2/19/2019 9:59 PM

same as the preferred underwear of choice for the elderly...






depends

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