Since building this SRAM kitted Iron Horse MkIII
back in March, I’ve logged well over 600 miles, so I think it’s fair to call this a long term review.
First let’s get into the frame details a bit. The Iron Horse MkIII has nice simple lines, which tends to jive with my taste in bikes. By “simple lines” I mean the bike uses a traditional front & rear triangles, which are made of nice custom butted AL 6061 tubes. The bike’s main feature is the dw*link
suspension system which give you a plush ride with a minimum amount of pedal feeback.
2006 Iron Horse MkIII
On the front you will find a headtube designed for the use of an internal headset (e.g. utilizes upper and lower internal cups). At first I was a bit skeptical about using internal headsets, but I haven’t had any issues thus far. The only problem was trying to find a way to add stack height to the bottom of my headtube – something I will get into later in the review. From what I know, the advantage of using internal or integrated headset is that it makes it easier to weld a large diameter down tube onto the larger headtube without having to resort to ovalizing. Especially for aluminum frames that use super large diameter tubing.
dw*link - a work of art
Each pivot uses sealed Max Enduro Bearings and each pivot bolt features dust free caps to prevent grit from getting into the bearings. This makes for a smooth and maintenance free linkage system. For 2006, the lower swingarm bearings have a custom extended inner race – so there is no need for spacers like on 2005 frames. The upper links are made of 7075 T6 which are super strong and stiff. The bike uses a standard 7.5" x 2" length shock with 30x8mm mounting hardware.
Lower bearings with custom extended inner race
The Iron Horse MkIII was designed with an elevated drive side chainstay, which in my opinion 1) helps protect the stay from banging on rocks 2) prevents chain suck and 3) a bit less chain slap. The MkIII has a replaceable derailleur hanger which is pretty much the norm nowadays!
The frame with shock was approx 7.3lbs.
For this project, the frame was adorned with some of the most lusted components in the business - fully kitted with SRAM
parts. Except for the wheels, saddle, tires, tubes, seatpost collar and grips this bike has completely been outfitted with SRAM bits.
I’ve been using SRAM drivetrains for a few years now and I still stand behind my words when I say it’s currently the best drivetrain money can buy. The SRAM X.0 line is aesthetically pleasing, reliable, light, adjustable, smooth, precise and low maintenance. Even after months of riding my drivetrain still shifts like butter – every single shift is still precise and effortless. The only issue I encountered was with the new PC-991 chain. After only a few rides I’ve had a link seize up – causing ghost shifting. This was my first time experiencing this with SRAM chains. I had an older PC-99 lying around in the garage and threw that on and it’s been smooth ever since.
This was my first time using and installing Truvativ’s Giga X Pipe Interface. Installation was simple and I haven’t had to adjust a thing since the initial build. I did double check the crankarm bolt and chainring bolt torque after the first few rides to make sure everything was still nice and tight, but that’s about it. The system has been noise free (e.g. no creaking) and is quite stiffer than my previous ISIS setup, which is what you would expect from an external bearing BB system. The 7075 alloy chain rings are strong and offer perfect shifting every time.
The Dual Air Pike 454 fork and Pearl 3.3 rear damper handled bump absorption duties. The Pearl 3.3 shock features RockShox Motion Control damping. With the Motion Control you can go from a rock hard lock-out to Floodgate (platform) mode to full open just by flipping the blue lever. You also have the option of adjusting the floodgate while in platform mode to basically dial in how much you want the rear suspension to move. That feature alone is head and shoulders above other dampers I’ve used in the past.
The Floodgate on my Pearl has 22 clicks of adjustment and the rebound has like 55+ clicks and that’s not a typo. For my buck fiddy I had to use super lower pressure – about 30lbs to be exact. I was surprised that I had to run such low pressure in order to get proper sag and full travel. That’s a lot less than the manual suggested, but it’s nothing to worry about since the Pearl was designed around a low pressure system. Low pressure has the advantage of less friction, and is typically less prone to leaking. The other cool thing about the Pearl is that RockShox makes 3 different negative springs to help accommodate various rider preferences, bike designs and rider weights. I had to replace the stock one with the soft version.
I like to run my shock (and fork) fairly soft and rarely use the full lock-out mode. I only use the Floodgate mode when doing long sustained climbs to resist bobbing, but still have the suspension move on those bigger bumps and rocks, which help maintain traction. When in the fully locked out setting you tend to loose traction over things like water bars and/or square edged rocks, but by using the middle Floodgate setting, you get the best of both worlds. Once you reach the top of your climb you can simply open it up for the fun flowy descent coming up!
I run quite a few clicks of rebound and I can feel it catch – but using the softer negative spring I can feel and hear a distinct knock when the suspension tops out. But it doesn’t affect the performance of the shock in any way.
Last year the Pike made my “top ten products of 2005” list, and will most likely make it to my 2006 list. I did however have some problems with my MC damper – after a few weeks of riding it started leaking at the Floodgate knob. At first I thought I had too much oil, but it appears I had a defective MC damper since RockShox replaced it and the new one has been problem free.
On the Pike, Floodgate adjustments (e.g. rotation of the gold ‘gate’ knob) are only noticed when in the “Lock” setting. Just like the Pearl rear shock, you can fine tune where you want the “Lock” blow-off threshold to be. Run a little Floodgate means it will only take small forces to make the fork active - Run a lot of Floodgate and greater forces will be required. That simple!
Using independently adjustable positive (top) and negative (bottom) air chambers you can really dial-in the Dual Air Pike to your riding preference. I generally like to run the same amount of air in both the positive and negative chambers – that gives me a real plush and active ride. Running less Negative air pressure will give you a firmer ride and will loose some small bump sensitivity. Also remember to always start off by setting the Positive air chamber first, then the Negative.
I’ve been running Dual Air Pikes for the past two years now and it’s been a solid, problem free and low maintenance fork. It’s adjustable and the damping is really constant. At times you almost feel like you have more than 140mm of travel. With the help of the 20mm Maxle, the Pike is a stiff fork which offers precise steering. It’s not stiff to the point that it deflects off obstacles, but just has enough give to give you predictable steering feedback.
Last but not least – when you have a bike that goes lightning fast, you need some good reliable brakes to slow you down! No better stoppers than Juicy Seven Carbon’s and as an extra bonus they go hand in hand with the new SRAM Carbon X.0 Triggers and rear derailleur. But looks isn’t the only thing going for these brakes! Their performance is on par with the Juicy 7’s but with the addition of Ti hardware, nice aluminum pad contact adjuster knobs and carbon lever blades.
Installation was a piece of cake –bolt on, align the calipers, adjust the reach of the levers and off you go! Didn’t even need to bleed them - they worked great right out of the box and have been stopping me on a dime since. The Carbon lever has this distinct feel to them, and they get right along with my index fingers. At fist I was worried about damaging the carbon in the event of a crash – but after a few good diggers they still look like new!
The only thing I would like to see SRAM improve upon is their front derailleur. I would love to see them come out with an X.0 front derailleur which would complete the X.0 grouppo.
Oh and another thing I forgot to mention about the X.0 triggers - they are sharp little buggers (e.g. edges)!! If you’re the type rider who rides aggressively and like to attack corners and obstacles – watch those knees. A few times I’ve came into corners with a tad too much momentum and ended up banging my knees on the shifters
! No big deal - they say scars give you character ;o)
|Make||Iron Horse Bikes|
|Year/Model||2006 MkIII Team|
|Frame size||Large 19” (also available 15", 17" and 21")|
|Rear Shock||RockShox Pearl 3.3|
|Fork||RockShox Dual-Air Pike 454|
|Headset||FSA orbit ZS Carbon Zero Stack, BETD cups, Chris King Headset |
|Crankset||175 Truvativ Stylo Carbon Team|
|Bottom Bracket||Truvativ GXP|
|Cassette||11-32 SRAM PG-990|
|Rear Derailleur||SRAM X.0|
|Front Derailleur||SRAM X.9|
|Shifter Cable/Housing||Avid Flack Jacket/Straight Jacket|
|Shifter triggers||SRAM X.0|
|Handlebar||25mm Truvativ Holzfeller risers|
|Stem||75mm x 5º Truvativ Team 3D|
|Grips||ODI Lock On|
|Brakes||Avid Carbon Juicy with 160mm rotors|
|Front hub||DT Swiss 340 TA|
|Rear hub||DT Swiss 340 QR|
|Front Rim||DT Swiss XM4.1d|
|Rear Rim||DT Swiss XM4.1d|
|Tires||at the moment - Hutchinson Barracuda|
|Saddle||Selle Italia Flite|
|Extra||Hope seatpost clamp|
When I first got the Iron Horse MkIII, I did a few comparison tests with another 5” trail bike I owned and had been riding for the past year. Since I loved my current trail bike to death, I though it would be a good test to compare it to the Mk. I did many back to back rides on the same tail, alternating between bikes. I also want to point out that I don’t ride clipped in and use flats for all types of riding – so for me it’s operative that the bike has an efficient suspension design. I’m also the seated type of climber – e.g. I prefer climbing while seated than out of the saddle.
On the first weekend, I did this longish 3+ hour ride Saturday morning. I then did the SAME ride on Sunday using my other trail bike. Then another short ride Monday morning on the MkIII, then the same short ride on Tuesday on using my other trail bike – lather, rinse, repeat… you get the general idea.
There is no question about it - the Iron Horse MkIII pedaled better than any other FS trail bike I’ve owned! Not only does the MkIII pedal better, but It also absorbs impacts (like on rough descents) like no other. The bike has 5” of rear wheel travel, but it feels bottomless and just like my Iron Horse Sunday – the faster you go, the better the suspension seem to work!
Thanks to the dw*link, when you put the power down, the traction is enhanced because of the anti-squat effect. Anti-squat is one of the biggest advantages of the dw*link suspension system. The dw*link produces opposite forces to counteract bobbing thus increasing traction when you start pushing hard on the pedals. The dw*link also deals well with braking forces – it works really well when applying the stops. The bike remains active and is really predictable under hard braking.
I must say though that it’s vital you have the shock properly dialed, otherwise you will not fully benefit from the dw*link. You don’t need any fancy shock to get the best out of you MkIII. Like the godfather of the dw*link system , Dave Weagle, once said: “There is a sweet spot for every rider. Tuning air pressure on your shock will let you find YOUR sweet spot. The dw*link takes care of acceleration and braking forces, and you tune your shock to take care of the bumps and sag. dw*link doesn't need any extra damping and tune your rebound to suit pressure. dw*link shock setup is about as simple as it gets.”
The low 13.19” BB makes the MkIII super stable – although I almost killed myself during my first ride. Exciting this right hand corner I tired to pedal (where I use to with my other trail bike) and my right pedal hit the tarmac! WOAH!! That scared the hell out of me… but after a few hours in the saddle I quickly adjusted to the low BB. The rear end is pretty damn stiff and really responsive! At times I like to get the rear wheel drifting in corners, which isn’t as fun when you have a flexy rear end, but the MkIII shines in these situations. Same for when you are bombing down through technical rock gardens – you want to be able to steerer the bike where you want to go. In short you want to ride the bike and not have the bike take you for a ride ;o)
Most of my pet peeves about the MkIII, which are very minimal, are based on my riding style and personal preference. What works for me might not necessarily be you’re cup-o-tea!
My first issue with the MkIII was the head angle. At 70 degrees, I’d say the MkIII has a pretty steep head angle for my riding style. Yeah I know, the 2006 Iron Horse MkIII’s are advertised as having 69.5 head angles – but unfortunately the change didn’t make it in.
My previous trail bike had a 69 degree head angle, which I slackened out a bit using a RockShox Pike set at full 140mm of travel. While the MkIII is borderline 69 (more like 69.something) I was definitely able feel the difference and at times the MkIII felt pretty twitchy. The steeper head angle felt pretty good on flat to mid grade trails - especially tight singletrack - but when the trail got steep, rough and fast that’s when I sough for that slacker head angle.
After doing some research I finally found some cups that allowed me to press in a traditional headset
in (when you’re bike uses integrated zero stack headsets).
BETD Cup and CK headset
By using these on the MkIII I was be able to add about 12mm of stack height under the headtube (if you use a Chris King headset) which slackened my head angle a bit. That made a big difference for me!
If you regularly frequent some of the popular MTB forums out there, you might have heard some riders voice their opinion about the 2006 MkIII – well it’s nice to see that the designers & engineers listening to their customers. The 2007 they made some changes to the MkIII which address the top 3 things I’ve heard. The new bikes will have a slacker head angle, will be a tad lighter and have more rear tire clearance! Booyah!
Todd Seplavy is all ears
The new bike will feature a 69.5 degree head angle – this is with a 130mm fork. Therefore by running a longer travel and/or AC fork you will have the option of slackening it even more. At roughly 6.2lbs for a med size frame with shock you’ll be able to build a relatively lightweight trail bike.
I don’t know exactly how much, but there will also more rear tire clearance. On my bike I’ve tried fitting some 2.35 tires and it was a tight fit. In fact it was so tight that at times the tire thread would pick up rocks and file away material off my swingarm – this more noticeable if you use real sticky rubber tires. Riding anything wider than 2.2 tires in muddy conditions wouldn’t be such a good idea in my opinion. Good thing I don’t ride in mud that much. I’ve also settled on a 2.1 rear tire for trail riding.
At the end of the day, especially after a long epic ride, the little peeves I've mentioned above have no bearing on my opinions about the bike. To date, the MkIII is the best trail bike I’ve ever ridden/owned!! My previous trail bike has since found a new home. Having only used dw*link bikes for DH (Sunday) and FR (7Point), the MkIII also satisfied my curiosity about how the dw*link suspension system worked for trail riding – Bravo Iron Horse!
If you’re looking for the ultimate all mountain weapon, I strongly suggest looking into the Iron Horse MkIII. Mated with SRAM’s high end components you get a highly reliable, trustworthy, efficient and low maintenance bike that highly inspires confidence. Independent of your riding skills I have no doubts in my mind this bike would give you the urge to ride more.Eric Schutt
Bikes are cool - get out and ride! Go FLAT out....