So my HD feels nervous on the steep stuff...
...I am currently waiting on my back ordered KS seat post dropper to help with this. But I am wondering if upping the travel on the front fork from 160mm fox air to a 180mm fox spring would fix the issue?
It should help the issue by slacking the head angle, and lengthening the wheelbase, but it also raises the bottom bracket.
If your fork steerer will permit, try using an angleset which will slacken head angle, lengthen wheelbase and lower the bottom bracket. This could be the better option of you don't need the longer travel in the fork.
You could also look at your cockpit setup. Sometimes running a shorter stem and wider bar can help on the steeps as well. If you are running a 90mm or 100 stem and narrow bar, it can make handling skittish compared to more "modern" all mountain setups.
I've slacked out my bike significantly, and I really like it thus far. Totally different bike though - a GT Sensor 29er. I removed a spacer in the fork to go from 120 to 140, which slackened the HA by about.8 degrees (measured on my digital level). This also raised the BB about .5 inches. I then installed Burgtech offset shock bushings which dropped the BB by .25 and slacked the bike another .5.
I lowered the bars and adjusted the seat so that my position on the bike is about the same. Contrary to what I expected, it seems to handle fine on the tight stuff. It feels a little better going fast, and it's definitely more secure on steep bumpy downs. Overall, I really like the way the bike handles now. I picked up a little flop in the steering, but I can live with that.
You might want to try a test run with the rear shock sagged more than normal, and the front sagged less than normal, just to see if you can live with the change. Try some switchbacks and steep climbs, as that is where the higher front-end may put you at a disadvantage.
You can also run the change through this geo calculator: geometryCalc
Wow, you learn something new every day.
Thanks for enlighting me to this new invention, the angleset.
It seems to be a great solution , judging by the google results of previous posts ( mtbr) on the subject.
My LbS says it should go on my bike without a hitch and I am upgrade to the stock headset it came with. Win win!
66 degrees seems to be a good angle for the HD and it won't raise the BB. Height like a taller fork would.
The other thing to consider is sag and low speed compression. Too much sag and / or not enough LSC will make the fork feel like it's diving. Check your sag and get that right first, 20-30% depending on riding style. After that, try adding a click or 2 of LSC.
What do you mean by nervous? does it feel twitchy? at speed? too responsive? I think in order to give you suggestions we need to know what equipment you have, stem length, handlebar width, wheels, tires, etc. Your riding background, preferences, how steep is steep for you, etc.
Don't make the mistake of going slack for the sake of it, 67 deg is more than enough for the HD's intended purpose if you attain the skills needed. Hell the faster the bike goes the better she feels.
The world needs a huge socio-economic change...be it. We all need to ride more....
Well, I can't really add low speed compression. My fork is a FIT( float 34,160). I do run it in the middle soft setting ,if that makes any sense.
As for the sag, that is set up right-ish( close 30%).
I think the biggest issue , for me, is that the Ibis is a little steeper in head angle and shorter in wheel base than my trusty old Ventana.
This angle adjust head set sounds like a great t
Thanks, I think I have the question answered but here goes.
Handle bar is all mountian size ( haven carbon? )
Wheels: the ones that came with the bike .
Tires are 2.35, big knobs.
The nervousness only happens on the steep sections.
Feels like my weight is too far forward. To remedy this I need to lean way back off the rear of the bike . My old bike never had this twitchyness to it.
By installing the angle set, I can lengthen and slacken the head tube to match the comfortable feeling that my old bike had . I think one degree and and a half inch to an inch in wheelbase willmatch my old bike.
Your old bike may have put your bars a little taller, the integrated HS lowers things a reasonable amount.
I runn a touch more sage so the bike sits in its travel a bit more. I run a Roco TST air
You may want to consider a shorter stem. 80mm seems a bit longer for a bike that will have a 66 degree HA once the angelset is installed.
There seem to be some great suggestions in here, and your headed in the right direction with the angleset.
Originally Posted by saidrick
Id also try putting a shim from the fox shim kits in your shock. I'm assuming that you have the fox. If you put the large shim in it should allow you to run a bit more sag (hopefully without bottoming out) which would help significantly.
All of this stuff will help remedy that pushing you forward over the bars feeling in the steeps. In my opinion, the HD will still feel a lot more nervous on steep nasty DH tracks at speed compared to most 6" rigs out there. There is so much anti squat built into the design that you get that weight over the front feeling all the time. The trade off is that the HD pedals better than almost any 6" bike available, and its really, really precise so you can make super quick direction changes to pick your lines. When I made the switch from an SC Nomad that I was on for a few seasons, I sort of had to learn how to ride the HD. That is, the technique I used on the Nomad did not work on the HD for really Chunky, DH tracks. Once you get the feel for the frame and change how you ride a bit you will feel fine. Good Luck!
i changed my nomad 1 to a hd four months ago and i think exatly the same , i needed several days to adapt at the new ride , at the moment i' m very happy whith my purchase but next spring i will get an angleset ,ithink is the way to find a more stable ride. Some friends here in spain go with it and they say that the bike is a lot better.
Originally Posted by elsinore
u're going to slow buddy. let go of the brakes and rip that "steep" section.
Sounds to me like you are running way too much sag in the fork. 30% is a lot especially with the way that Fox forks like to dive. Try upping the pressure in the fork to around 20% sag.
Also remember that the HD was designed around the 36/Lyrik with a 545mm A2C height. If I am not mistaken the 34 is around 535mm which would put your HA at 68 instead of 67.
Wow, thanks for all the advice.
I think that the shim kit for the shock would also be a good idea.
Sales punk, your answer about the fork length would explain a lot of what I am feeling. The angleset seems to address this pretty well.
As for the sag. As a 200lb rider my front fork seems to work really well with 85lb in it.
My rear is a 185lb. The only time my bike dives is off of drops and jumps, which is when it should , right?
As for going too slow. On tight, twisty, rocky single track, I am not sure how you speed up without flying off the trail. Which I done many a time, I call it coming in to a corner too hot.
Again, I can ride the steeps, but I feels like I have exaggerate moving my weight rearward.
I am curious what Hans or Scot think about the angleset?
But thanks again for the helpful tips.
Angleset + 50mm Stem FTW!
Yep Sales punk is correct. The fox 34 fork is shorter (7.5mm-ish) than the 36. The angleset is the cheapest solution to a problem caused largely by Fox.
Can't wait to have my mojo with the correct 67 degree head angle.
Thanks for the help.
Your issues sound more like being a problem with how the bike is setup. Like others have said, an 80mm stem is a bit long with this type of bike. Most are running 50-70mm stems on the HD's. I run a 50mm stem on mine with wide 31" bars. The short fox 34 is not helping you either, since it's effectively making the head angle steeper than it would be with a fox 36 @ 160mm.
A good way to set up the HD is with 30-33% sag in the rear and 20% sag on the fork. Try messing around with settings to get a balanced feel front and rear. Don't worry so much about trying to run a certain psi in the fork - shock and go more by sag. To much sag will cause fork to dive deep into travel on steep sections and if it doesn't have enough sag the fork won't track very well and feel like it's skipping bouncing off rocks instead of absorbing the terrain.
It can take a while to adjust to a new bike, just give it some time and mess with the setup to get it feeling good to you. The hd is a great bike.
The stem shouldn't be the issue. The reasoning behind this is that my old bike never had this issue and it had a 90mm stem. Plus, the new handlebars are wider than the old bars, so that shouldn't be an issue either.
I run the stem that long because I have long arms, so a large Frame size and a medium stem length make for a comfortable up and down bike.
As for the sag. Numbers. I tried various psi combinations on the ride route before deciding on those numbers.
Now, if I get the angle set, seat dropper, installed AND I am still having problems then I will try out a 70mm stem.
I am running a 90 mm stem and have no problems riding the steeps such as Telonics and the like. People are fascinated with short stems, but it is all what you are comfortable on.
I would not discount the short stem thing right away. The reason people are fascinated with short stems is because they work, really well in fact for aggressive descending. There is not a modern DH bike out there with a stem longer than 50mm.
Originally Posted by Salespunk
Sadrick, just because your old bike handled well with a longer stem, does not mean the HD will; especially if you widened the bars a bit. The short stems are a compromise in terms of trading off a bit of climb-ability in the sense that you don't have as much weight way over the front of your bike on steep ups, but its not really that hard to get used to. The payoff in terms of descending, in my opinion is HUGE. If you ride modern trails with Berms, you will notice the difference even more. The bike will be more agile and you can really jam it in and out of turns harder. In short, it is less nervous, which I think is what you are looking for. Id seriously try a 70mm and give it a good 5- 10 rides and some time to change your technique a bit because it will not feel great at first if you try to ride it like your old rig.
Stems these days are not all about sizing, maybe on road bikes but the HD is a 6" travel machine designed to do it all. I'm 5'11" with a wingspan of 6'2" and run a 50mm stem on a large frame. Having said that I used to run a 90mm stem 8 years ago but have gradually shorted my trail bike setup over the years. I really think an angleset and a 90mm stem sound like a bad idea, but again that is just my opinion.
No offense meant Salespunk but a 90mm stem on the HD just makes me nauseous
Thanks Voob. The video featured one of my mountain biking idols: Richard Cunningham.
The FSA seems to be a good option ( pun intended ) but seems to also require a very detail oriented install like the Canecreek.
So I follow Occam's Razor: the simplest solution is usually the most correct one.
With that in mind, it seems that if my bike is Not feeling great on the super steep stuff because of a non- designed steeper head angle. Then it follows that the solution should be to remedy the change in geometry before doing anything else.
This gives me two options:
1. Is to replace the fork with a longer a2c or more travel. This would cost around a grand.
Option 2. Change the head angle with an adjustable head set. This would cost about 200 bucks
As for my old bike: I bought the mojo HD because it seemed very similar but better in every way. So far the mojo is better , except for this little issue that I hope to resolve very soon.
For reference : my old bike was a Ventana El Chamuco.
Thanks again for the insights.
Some headsets have a plus 5-20m stack that goes below the head tube. I ran one on my Foes FXR and many of the top Enduro DH racers run these such as Rene Wildhaber.
Cheap option, and better with the 34 than running an angleset I believe, which may have the effect of lowering the front a touch.
The HD160 has a slacker head angle than the Ventana El Chamuco (67' vs. 68').
Originally Posted by saidrick
HD's longer travel fork's deeper dive than the Ventana when braking hard may be what the difference is you are feeling.
The least cost steep downhill braking improvement would be adding a little more more air in the fork, as was first suggested. And/or lowering the seat before dropping off a steep section to more easily get your weight back and low.
I doesn't sound like your problem is high speed stability where a slacker fork angle helps. For brake dive, a shorter stem is much less expensive and easier to replace than an Angle-set type headset or taller fork. An 80mm stem seems long for the HD unless you are already maxed out in fit on an XL size. Even 10mm shorter makes a big improvement in downhill handling. The OEM Ibis "DH" bars are pretty narrow too. A 725 to 750mm bar with short stem improves stability and control where the HD likes to be ridden.
I'd say get a remote-dropper seat post before spending any more than the cost of a shorter stem and wider bars to improve riding steep drops. A dropper seat post is a huge improvement for trail riding where there is much climbing and drops or rocky and smooth trail mixed often on the same ride.
A slacker Angleset type head set is great for gaining stability at high DH speeds and improve high speed cornering traction on smooth trail loose dirt or slippery sandy dirt, such as is the predominate trail surface in southern California and Arizona and many high mountain trails. And a slacker fork angle does position the same bars and stem further behind the wheel. I'd say do this if your high speed on the HD feels too twitchy, but that wasn't your issue.
Sell the 34 and get a 36, lyric, 55, vengeance (160) fork. You probably won't lose much money if any. I would go to the angleset as a last resort.
And like many here have suggested don't run so much sag in your fork. This is the first and easiest thing you can do. 20-23% is what you should be looking for.
If you have the CTD Float 34 and run it on the "D" setting your fork is probably diving from no compression and not having a seat dropper all your weight is going forward. Put the fork in the Trail position and learn to shift your hips back and put your chest down, elbows bent. As well make sure the rebound is not too fast in the rear shock, and your front rebound is not too slow. I looked at your user profile and bike setup and you do NOT need a 180 fork or an angleset based off your build and feedback.
I see youre from Petaluma, what trails, are you riding that are steep and throwing you off?
A couple of things:
1. That 34 fork has a shorter a2c than the 36 that the bik was designed around.
Per "Sales Punk" this would equal a steeper head angle. About 7-10mm shorter, which equals a + 1 degree steeper angle.
2. I run my fork in the trail setting with a click of soft added.
3. As for my fork sag. I am only running 10 pounds less than Fox's recommended starting psi.
4. My rear runs no pro pedal, feels too spikey with it on.
5. I have had the best feel with running two clicks from full rebound fast.
6. I adjusted the suspenison settings by riding at Annadel. Climbing Richardson/ canyon and marsh and coming down both burmas(south and north). I have know issues with the bike here.
The issues happen on cobblestone , in Angwin, and even the little rocky section at China Camp(!?).
It seems to be the short,twisty, little steep drops that are hard to carry speed into.
That KS seat post dropper is still back ordered.
Add 2 to 3 more clicks of rebound in the rear, add two more clicks of compression in the fork, and get the seat dropper. You do not need an angleset to ride annadel, when you say steep, north n south burma would never come to my mind. Yeah the fork is a tiny bit shorter, but adding parts, expensive ones that are hard to set up and keep that way, especially, doesnt aound like the answer, you will likely not like the way it climbs when you slack it out.id get a seat dropper over an angleset, and id get one asap. Sounds to ke like ur rear. Shock is a pogo with no rebounc compression and you got the seat shoved up your butt, that would make me nervous too, lol.
Right Burma's are good.
It's cobblestone, rough go and some of the fringe outer areas (ridge?)of Annedel.
That cause the issues.
20mm change in head tube height is about 1' head angle change.
Yodi's tuning suggestions are good for the jumps on Upper and Lower Burma, and Cobblestone. Nothing mentioned is fast or sandy/loose enough for needing a slacker fork angle.
BTW, Is there a rocky section inside China Camp? Sure, the south side of the ridge in the San Rafael City park's Dominican side, there's some rocks.
I ride all those same trails you mentioned on my hd as well as my hardtail with 71 degree head angle. You really wouldnt need a slacker head angle for those trails, plus the angleset is high maintance. I have one on my dh bike. I still feel its your suspension set up. I sell my old bikes and buy new bikes every year so I have had many bikes, including a few ventana bikes. I think the hd could be tricky to setup compared to a lot of other bikes I've owned.
2 clicks from full open rebound in the rear is to fast. You should probably be some where around 5-7 clicks from full closed rebound. To fast rebound will make the bike stink bug on down sections. A few basic tunning tips are,
Run rear at 30-33% (.75inch) sag with around 5-6 clicks from closed rebound and no pro pedal
Run the front 20-25% (1-1/4 to 1-1/2inch) sag with a slightly faster rebound than rear and enough compression to prevent brake dive.
You want the fork to stay high and the rear to settle into travel on downhill sections. Don't pay attention to fox recommended psi, most will tell you that fox setup guides are way off. Set suspension by sag. Try to get front and rear feeling balanced, with the fork being slightly firmer and faster than the rear.
Don't give up on a shorter stem either or maybe even adding a few spacers under your existing stem. Small changes can make big improvements. If your every free to ride weekdays shot me a private message and I could bring a bunch of stems for you to try. I have spares in 50,60 and 70mm.
Good luck, the HD is an awesome bike!
Last edited by fuenstock; 01-02-2013 at 09:53 AM.
All right, due to many replies about set up and sag. I will measure my sag later on today.
As for the compression in the front , I am very limited by the fork: I have open , closed and half and half( trail). I get to adjust these by one click higher or lower.
So I usually run the trail setting with one click less of compression damping. A magazine said this was a good way to go.
As for the rebound, per Fuenstocks advice, I will try doubling the rebound in the rear and adding a click in the front. So 4 clicks from full fast in the rear and 3 clicks in the front.
I will wait on the angleset, until after the dropper is installed, but I am not giving up on it either. If the bike still feels weird, I think I will give it a try.
Are you on an RP23 rear? 4 clicks from full open is very very fast in my exp.
Originally Posted by saidrick
If you go through the threads you will find many references to 2-3 click out from full slow
On good way of judging rebound is to bounce on the bike and it should rebound and compress back to and not past the sag point, so no bounce
Moto cross guys often setup their bikes from full slow and firm and back it of until it doesn't feel too hard. MTB riders tend to rely on the spring over damping, but in an air fork / shock the spring can vary a lot based on temp, so I personally believe that running more on the damping is better (ie a touch softer with a bit more low speed and rebound)
Often the feeling of the back end bucking around on steeps is down to spring rate or compression rather than just rebound too
Also on many of the pro pedal type shocks, the rebound needle doesn't start to engage the port for the first third or so of its adjustment, so you can actually fool yourself that it is making a diff. On my Kashima RP23 (2012 Mojo) the rebound adjuster did nothing for the first third to half adjustment then became very progressive. This was verified on a Dyno back in the uk.
I would set you sag then make the rebound full slow, then ease back from there. Do it on a few runs on a trail you know well, do the rebound only on the shock only before moving onto the forks
You might want to add some air to the fork as well. You said it's down 5 pounds from your weight on fox's weight chart.
Here is how mine is at.
2012 fox rp-23 with a med shim. one click faster from the middle on your speed rebound.
2013 CTD 160 117lbs or half my body weight. (I'm 220 but I like a touch more air in the fork) Speed in front is faster than my rear, but not a lot, maybe 1/2 way from center to full. maybe a tad less, I would have to look at it more closely. I also keep it in the trail setting. I will move it to climb when I climb, but if I am bombing down a really bumpy or know lots of jumps on a trail, I will switch to "descend". But I don't keep it there long.
The shim really helps the progression of the rp-23. My sag is about 22-25 percent, again a personal preference.
I have an angelset on mine, no problems with it, but I slaked it out .5 of a degree when I took the fork from a 150mm to a 160mm. I wanted the exact set-up I had at 150 and this is what Hans told me to do. I have a dropper post, but ride more BMX style which is more back on the bike so having a dropper post doesn't help me at all. But for most it does. A lot. The advice you have on this page is very good.
I see you're somewhat close, if you have more issues, drop by my house sometime and I will try to get you sorted. Again riding is all a personal preference on how you want your bike to act, you may like it my way, or other set ups, but the cool thing is, you will not have to spend a lot of money fixing the bike to how you want it to react. That's the great thing about the HD it is so customizable.
And the sag results are in: I measured my sag , front and rear. I got some interesting results:
On the rear , at 185 psi I measured 7/8" sag, re-measured it twice to be sure.
Added 5 psi and got 6/8"(3/4") , which would be right around 30%.
On the front things got more interesting. I was sagging at 1". Remeasured twice for accuracy.
I took 5psi out of the fork to get the sag to 1 1/4".
The rebound thing is still a bit of a mystery to me. The new models have between 12 ( shock) and 18 clicks. When I originally set them up, I started in the middle and kept adjusting until the suspension stopped feeling dull and packing down.
To measure front fork sag, you want to kinda crouch over the front a little. Sitting on the seat upright with locked arms, doesn't put much weight on the front. Shoot for %30 sag front and rear. Rebound close to the middle settings. You want the front and rear to both rebound with control, not sticky, not pogo. You want them to be be somewhat similar, so bounce them while on the bike standing out of the saddle neutral body posisiton, and bounce a little and make sure it is fairly the same front to rear.
How much do you weigh and what air pressures are you running front and , also post a picture of the bike so we can see your setup
I will post a pic later today,
I weigh right around 195-200.
The front psi is at 75(sagged 1 1/4")
I also crouched over to do this. Well as much as I could while balancing against my garage door frame. .
The rear is at 190psi( sagged at 3/4").
I think I need to ride the bike again, and maybe run 4 clicks of rebound in the front and 5 clicks of rebound in the rear. To see what the bike is doing.
Also I will try the old rebound test: push the seat down and see if the rear wheel comes off the ground on the rebound.
I would run 25% front end sag 30% rear. Talk to someone like Craig at Avalanche he recommends no more than 25% for trail/am type riding on the front.
Yeah, and %30 really means like %35 once you get on the trail. Personally I usually do front fork air springs by feel, not by sag.
I've installed -1deg angleset together with a 170mm Marz 55 on my HD recently. The bike is more stable and still climbs very well (even with single 32t chainring). It took some time to get used to a new geometry, especially when cornering, but overall it's a step forward. You can find some pictures here Ibis Mojo HD with Cane Creek Angleset | unluckypete.com
I also strongly recommend using short stem (50mm) and a wide bar (at least 750mm). But as guys already said, it's best to get your bike dialed in first, and play with angleset if there is no other way to achieve what you are looking for.
wow, loads of info here, thx to whoever posted the geo calc!
Okay people, thanks for all the help on this. I love my bike, but just need a little help to get it right.
So I sent an email to a industry professional engineer/ former frame designer( Mantis) .
His answer was very interesting. He recommends the shorter stem too.
What was interesting is that he said I should try "offset bushings" for the rear to slacken the head angle without the issues or cost of an angleset.
So I did some research and found a company in England , called Burgtec. They make titanium offset bushings that get pretty good reviews. So the threads here say that I should add a volume reducer with the bushing to help keep it from bottoming out too much
Thoughts, experience with offset bushings?
Btw, 70mm stem is being ordered.
smart move ordering the 70mm stem.
I read you were riding annadel and thinking about an angleset and immediately got confused.
Rough-go and the burmas are perfect for a xc hardtail!
Saidrick, finally you are listening re the stem!
Though for 160mm that is still long but at-least its a start.
Before making any other changes when it still dosent feel quite right DO NOT upgrade to offset or headset angle set until trying a 50mm stem.
2: key reasons, this will not fix what is a bad setup, 70mm is still long with the modern geo of a long travel FS.
3: Your body will be in a slacker position but you will be unbalancing that by being pulled to far forward, offset requires an even more aggressive bike riding style and position/setup.
You are basically trying to ram a square peg in a round hole.
Sort your sag out and your rebound your front is still way to soft spring rate, slow and rear too fast rebound.
Im a ex downhiller I ride mine in 140 mode in no way do I feel the need to run offset anything, basic and correct bike setup will solve all your problems.
I jump the **** out of it and bomb downhills.
Offset bushings and headsets are for advanced riders on steep stuff, I consider myself more a DH Enduro guy now, def not XC and do not feel I need anything other than stock.
I run a 50 mm stem on my bike in 140 mode!
Theyre has been some great info here which I think you are neglecting
Cheers happy trails dude.
Maverick, not sure how I am neglecting the advice:
As a result of this posting, I have researched adjustable headsets, which I didn't even l know existed.
I reset my sag per the forums measurements.
I watched a video that was posted, which said that my stem was not too long.
But I am going to try a smaller one anyways.( btw, the guy in the video is the same guy that recommended the offset bushings)
I learned that my bike is not built the way it was supposed to be.( Fox's fault, IMO)
I slowed down my rebound , per the advice.
As for the 50mm stem. I will see how my back handles the 70mm before I even consider going any shorter.
Thanks again for helping me sort my bike.
Try the 70 before just ditching it. Its not too long. its a personal preference. Ask Hans/ibis about offest bearings.