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Discussion Starter · #1 ·
I am pretty sure I want to buy my first FS mountain bike, not in a hurry but over the next year. Pretty positive I want short travel for my trails in SE Wisconsin. The question to me now is the head angle. How do I know if a Tallboy 4 or Salsa Spearfish is better? For 'moderate' riders not taking huge jumps, is there a downside to these slack angles? Thx. I've been riding a couple of hardtails for a few years.
 

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The two main downsides to a slack headtube are climbing and imprecise steering at low speed. A slack headtube puts the front wheel more forward, which means further away from the weight of the rider (depending on seat tube angle and some other things). That means the front end can be light while climbing.

A slack geometry bike likes to be leaned to be steered. Anytime you actually have to use your handlebars to steer, as in tight and twisties, it's going to be a bit of an adventure that will take some getting used to, assuming you are coming from XC geo. To me, once the bars are turned a bit from straight, they have a bit of a tendency to "flop" to an even greater deviation. Frankly, I still haven't quite gotten used to it.

It's not jumps that slack geometry particularly helps with. It's any time a less slack geometry would put too much weight forward, as in downhill or rough terrain where the front wheel might "stick" in something like a crevice in a rock garden. Also, a slack head tube tends to keep object strikes more "aligned" or parallel with the axis of the fork, rather transverse to it, so it's a bit better oriented to do its job.

Less than 68 degrees gets you toward slack. Getting toward 65 is really slack. There is no right answer. But since you mentioned short travel, I assume that means moderate trails, which might make you a better candidate for the higher-60 degree than the mid-60s frames. Also, until pretty recently, hardtails were rarely or never slack (angles greater than 70), so you are probably used to steep rather than slack.
 

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Discussion Starter · #3 ·
The two main downsides to a slack headtube are climbing and imprecise steering at low speed. A slack headtube puts the front wheel more forward, which means further away from the weight of the rider (depending on seat tube angle and some other things). That means the front end can be light while climbing.

A slack geometry bike likes to be leaned to be steered. Anytime you actually have to use your handlebars to steer, as in tight and twisties, it's going to be a bit of an adventure that will take some getting used to, assuming you are coming from XC geo. To me, once the bars are turned a bit from straight, they have a bit of a tendency to "flop" to an even greater deviation. Frankly, I still haven't quite gotten used to it.

It's not jumps that slack geometry particularly helps with. It's any time a less slack geometry would put too much weight forward, as in downhill or rough terrain where the front wheel might "stick" in something like a crevice in a rock garden. Also, a slack head tube tends to keep object strikes more "aligned" or parallel with the axis of the fork, rather transverse to it, so it's a bit better oriented to do its job.

Less than 68 degrees gets you toward slack. Getting toward 65 is really slack. There is no right answer. But since you mentioned short travel, I assume that means moderate trails, which might make you a better candidate for the higher-60 degree than the mid-60s frames. Also, until pretty recently, hardtails were rarely or never slack (angles greater than 70), so you are probably used to steep rather than slack.
Thanks man. Great post. I have Timberjack at 68.5 now, and an XC carbon hardtail at 69 degrees. I do like to smash into small rock beds. In my head I think 66.5-67.5 would be best for me for a new bike.
 

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Well, you have already tasted slack then. The other thing to prepare yourself for is that they do lower the bottom bracket some, generally. Between that and a compressed suspension, you will experience lots more pedal strikes on an FS bike until you adjust.
 

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I think the handling is getting better and better on the slack bikes. I guess I shouldn't say slack at 67.2 and 67.5 degrees but it is far different than 70/71.

I have an FSR and Chamelon. Two head angles are within 1/4 degree of each other. I believe the fork offset is different (handles differently), or the shorter chameleon stem makes a difference. The chameleon tracks every so slightly straighter than the FSR at slow speed up a hill. I ride a lot of uphills. The compromise for ME to have a steeper head tube angle would make the rest of my riding less fun. So it is definitely a give/take scenario.

Plus you'll get used to it too and it will be 'normal'. If you don't have techy downhills though, the slacker hta isn't too important if you want the climbing ability that much more.

And do your own research on bottom bracket height. Suspension design is going to play a part because my FSR has a 3/4" higher BB height than my Chameleon and I have ocassional strikes with the FSR. Because when I sit on it or when I dip the suspension the pedals are closer to the ground. On the spec sheet, my full suspension has the highest BB of my 3 bikes.
So don't buy a bike just cause BB height doesn't sound high enough.
 

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I am pretty sure I want to buy my first FS mountain bike, not in a hurry but over the next year. Pretty positive I want short travel for my trails in SE Wisconsin. The question to me now is the head angle. How do I know if a Tallboy 4 or Salsa Spearfish is better? For 'moderate' riders not taking huge jumps, is there a downside to these slack angles? Thx. I've been riding a couple of hardtails for a few years.
As described already, bikes with a "slack" head angle are generally better suited for stability at speed. Yes, they handle best when leaned aggressively into corners. Trying to turn the bars too much gets "floppy" up front and a bit tough to handle. Those are the generalities, and yeah, there are oftentimes other factors that go along with the slacker bikes like a longer reach, lower bb, and so on that are hard to tease out the details.

Honestly, the only sure-fire way to decide which bike is better for you on the trails that you ride is to hunt down some demo rides and decide what you like. That way, you can consider them in the "big picture" sense as a complete bike, rather than just numbers on a spec sheet.
 

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For me, the only reason I would buy a bike that wasn't fairly long low and slack is if I was wanting something for hitting dirt jumpers, skate parks and the like. I find the whole cliche that the "modern" geometry is terrible in tight slow tech to be massively overstated.
 

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I find the whole cliche that the "modern" geometry is terrible in tight slow tech to be massively overstated.
In a way, that's very true.

I didn't have a problem adapting my riding technique from old geo to new geo bikes. But I did have to change some things. Some people seem to have real problems with that. They lack the mental flexibility to be adaptable, I guess you could say. There have been some pretty angry posts by some people who absolutely refuse to adjust their riding, too. So it's less the ability to be flexible for some, and more a stubborn refusal to be flexible.
 

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I'm really wondering about the new 65.5 degree Santa Cruz Tallboy. That seems awfully slack for what is marketed as an XCish trail bike, and with the 29" wheels, it would seem the steering would be quite heavy for most riders. The worst part for me about 29ers is the heavy steering, so I wonder who that bike is marketed toward. Stability and wheelbase are good, but I wonder if they've finally gone too far.
 

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Don't look at HTA, or any other single number, in isolation. The current crop of relatively slack (historically) bikes are not going to handle anything like what you would expect of an older bike that magically had a slacker HTA.
 

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They are good for novice riders because having the wheel further forward gives MUCH more confidence when going down something steep. Going over the bars is one of the biggest fears beginners have to get over, a slack bike minimizes that and gets them riding rather than walking.

I think in general they take a little more finesse to handle but the way they give you more confidence and their ability to more comfortably handle aggressive terrain makes up for that. Its a lot easier to adapt to the steering characteristics than it is to throw a 78degree bike down a steep black trail.
 

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Don't look at HTA, or any other single number, in isolation. The current crop of relatively slack (historically) bikes are not going to handle anything like what you would expect of an older bike that magically had a slacker HTA.
100+ mm of trail is 100+ mm of trail. It doesn't matter if it is 20 years ago or now, bikes with a lot of trail have less snappy handling in exchange for greater stability.
 

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I'm really wondering about the new 65.5 degree Santa Cruz Tallboy. That seems awfully slack for what is marketed as an XCish trail bike, and with the 29" wheels, it would seem the steering would be quite heavy for most riders. The worst part for me about 29ers is the heavy steering, so I wonder who that bike is marketed toward. Stability and wheelbase are good, but I wonder if they've finally gone too far.
I saw that and was slightly shocked.
 

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I'm really wondering about the new 65.5 degree Santa Cruz Tallboy. That seems awfully slack for what is marketed as an XCish trail bike, and with the 29" wheels, it would seem the steering would be quite heavy for most riders. The worst part for me about 29ers is the heavy steering, so I wonder who that bike is marketed toward. Stability and wheelbase are good, but I wonder if they've finally gone too far.
I have similar concerns. 65.5 is very slack for trail/XC bike. Now there are ways to mitigate the handling impacts, but that can have impact elsewhere. I really wonder how slack can you go for bikes that mean to be ridden all over?
 

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I have a 65° hardtail. The only time this is an actual issue is in Very tight turns/lines and slow trialsy tech. It helps that the chainstays are only 419mm. Im an aggressive rider, I like leaning the bike hard in turns. Assuming we're not talking about racing XC... I'd say that the question of if the Tallboy is too slack is mostly preference, rider style, what you're used to, etc.
 

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I have similar concerns. 65.5 is very slack for trail/XC bike. Now there are ways to mitigate the handling impacts, but that can have impact elsewhere. I really wonder how slack can you go for bikes that mean to be ridden all over?
That's as slack as my 27.5 Enduro blaster, which for obvious reasons I use to tolerate climbing and enjoy the downhill (and I could make it a bit steeper with an air shaft change). For a 29er, that is excessively slack; many 29er Enduro bikes aren't even that slack. I really wonder where they were going with that. It seems like too much. Even the 5010 at 66.5 is pretty slack for a trail bike, but not intolerable.
 

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I have similar concerns. 65.5 is very slack for trail/XC bike. Now there are ways to mitigate the handling impacts, but that can have impact elsewhere. I really wonder how slack can you go for bikes that mean to be ridden all over?
The way to mitigate that is with more weight on the handlebar. Lol...that's one of the reasons for seat tube angles getting so steep. If you don't keep weight on the bar...it"ll either flop or the bike will end up riding you. The lower the speeds...the worse slack bikes handle.
 

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100+ mm of trail is 100+ mm of trail. It doesn't matter if it is 20 years ago or now, bikes with a lot of trail have less snappy handling in exchange for greater stability.
An old bike with 100mm of trail and a slack STA will handle much differently than a new geometry type of bike with a steep STA with 100mm of trail.

Again, for the OP, don't look at any single geometry number in isolation.

I wouldn't buy the Tallboy without riding it, but I wouldn't avoid demo-ing it just because of the super slack HTA.
 
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