K9 Angled Reducer Cup Kits

Jul 29, 2009 at 7:58
by Simon Paton  
K9 Industries are a new company to the mountain bike world and already have tongues wagging thanks to their seriously in-depth R&D and the frames they have produced that James McKnight is currently running.

Louis from K9 asked me to test these bad boys out, unfortunately I don't own an Iron horse or an Intense. Therefore I needed to ask someone with an engineering background and who can ride a bike. Please enter John Young, Masters winner of the SDA Rd1 at Pitfichie and Rd 2 at Fort William. Credible? You bet!

This is what he had to say:
Their first product to hit the market is the much-anticipated K9 Angled Reducer Cup kit (ARC). This is a pair of headset reducers designed to fit into specific 1.5” head tubes for use with standard 1 1/8” fork steerer. The cups change the head angle of the bike by either +2 or –2 degrees. The ARC will fit bikes with the following head tube lengths; 4.625”, 5.000”, 5.250”.

As well as the ARC cups, you also get a rather nice Cane Creek IS3 integrated headset included in the box. I won’t go into the material it is made out of etc. this is all available on the K9 web site.

The whole kit comes nicely packaged and with good instructions. It is advised that you read the instructions and understand them fully before installing the ARC, if you don’t then there is a good chance that you will just end up doing extra work and having to read them any way.

The first thing that you notice when you take the cups out is that they are clearly a quality bit of kit, the machining and finish is absolutely first class. The whole kit including the headset comes in at under 170g.

I followed the instructions to the letter, even though the ARC is not the easiest item to install on your bike. The reason is that when installed the 2 cups will sit with the correct alignment with each other, but when you start to install the cups you have a 20mm flange at either end to accommodate, which makes everything look a little squint during the initial installation.

The alignment of the 2 cups was not a problem, the instructions provided are good and when followed allow for good alignment of the cups. There is a notch on the top of the cups that allows you to line the cups up with the tape that you put on the frame. It would be nice to see a small hole 3mm or so up from the base of the cups to further aid in alignment. I simply added a pencil line to the cups to help the initial alignment.

I found that after installation I had to add a couple of thin spacers (3 are provided) between the top race and the top of the headset to accommodate for the change in head angle of the top of the headset.

The bike:
I was installing the cups onto my medium Iron Horse Sunday. Measurements from between the wheel axles and to the mid point of the top crown gave an initial head angle of 63.5 degrees. Fitting the cups changed this to 61.9 degrees, not quite 2 degrees but not far off. This could have been because my alignment was around 0.5mm out from perfect. The K9 made the axle to axle length of the Sunday change from 114cm to 116cm. The actual length change was 23mm. This change effects the front of the bike only from the lower crown of the headset to the fork axle. Due to the change in head angle the front of the bike also sits slightly lower with the ARC fitted, around 8mm lower.

The ride:
Most people know how the Sunday rides, how it corners and how difficult it is to pedal. Adding the ARC to the Sunday makes for a bike that handles differently than the stock frame as you would expect and with that comes some time getting used to the changes in the bike. I rode the ARC on the bike for over a month on many different types of terrain, gradients and weather. The ARC makes the Sunday feel more stable in a straight line, when things get fast the change in the head angel made the bike feel like it is on rails, for big open fast corners this was a good thing and the added confidence this gives is apparent very quickly. When things get real steep the change in the head angle made the handling of the bike on the front end feel really nice also. As with all changes to the bike it is never all rosy when things get tight and the corners sharpen up the ARC makes the bike handling a little sluggish compared to standard as you would expect from something the slackens the head angle. I only tried the ARC in the –2 degrees position as this is where most people would be using it. I would normally do a comparison on several tracks using my timing system but did not have this opportunity as the watch has decided that it no longer wants to play.

-If you are riding somewhere with lots of fast tracks and find that when things get fast that you feel a little un-balanced on the bike then the K9 could be a good investment.
-If you have a bike where the head angle is steep and want to slacken it off then this is exactly what you need.
-Although I tested the ARC on a DH bike, there could also be good uses for the headset on some of 6” travel bikes where the head angle may be a little on the slack side for woodland riding where people are looking for a burly single track bike.
-Intense are also renowned for having a steep head angle on their 6” bikes, the ARC could be a nice addition to these bikes to slacken the head angle.

John Young
Cheapest Maxxis Tyres in the World?


  • 4 0
 Hi Guys, I would just like to than you all for your comments, and to let you know that we are currently working of ARC kits for other bikes. If you let us know what bikes would benefit from an ARC kit, please let us and if there is enought demand will put them into production. also, if you email us to enquire about the ARC kits, please let us know for which bike and size the ARC kit will be for. As you know not all bikes have the same head tube length, and the ARC have been specifically designed for each head tube length. Thaks for your time. Sincerely. Luis Arraiz K-9 Industries Ltd www.k9industries.com
  • 3 0
 Yes hard to pedal as the BB is low meaning you have to watch where you put pedal strokes in. Sunday head angle was calculated using the axle to axle, both axle to top centre of headset dimensions. Drawn on ACAD and dimensioned for checking.
  • 6 0
 what will they think of next
  • 7 1
 seems like theres something making bikes better and better everyday ..engineering at its finest
  • 4 0
 i was just wondering the other day when will people bring these head angle degree changing headsets into the cycling world. My dads custom chopper has got them so it is 2 degrees over rake.
  • 3 0
 with 67degress thats exactly what my Glory needs
  • 6 1
 if its the new glory with the 1 1/8 to 1.5 headtube you cant use it
  • 2 0
 i sayd glory, not new glory or glory dh, just glory...look album
  • 3 0
 I really hope they come out with more for different length headtubes as I would LOVE one of these!
  • 1 0
 Retail Price:

£113.40 (including VAT). Please note that we do not charge VAT on items sold outside the EU, but duties and taxes may apply depending on the destination

They will become golden untill they arive to Bulgaria
  • 1 0
 if you want to slacken the head angle on a 1 1/8th head tube look at enduro fork seals headset kit, gave me around a degree on my reign x, 67 to around 66. smooth too.
  • 1 0
 I like it. There are so many bits out there that while they may not be terrible, they won't actually make a difference to you. This is one that will. Simple and effective.
  • 2 0
 Nice write up, seems like a good product. Keep 'em comin!
  • 2 0
 Keep in mind that these will only work with a 1.5 headtube.
  • 1 0
 im guessing u cant have 1 1/8th version coz you need a thinner steerer tube than the head tube - that sucks
  • 1 0
 sucks u have to press the cups out everytime u wana change headtube angles..
  • 2 0
 how else would you do it...and how often would you really change the head angle?
  • 1 0
 im sure u could wana change it for different uses. like i myself ride dh and fr on the same bike. and a steeper head angle may be nicer for one then their other.. as for as being adjustable. have a look at the new orange 224... or a comencal. alan keys hold the adapter.. so it can be loosened then moved around.. mind the grammar.
  • 2 0
 The sunday, hard to pedal? buddy your on crack, My sunday pedals easy as.
  • 2 0
 I think he was being sarcastic (well I hope).
I also think he was sarcastic about the initial 63.5 degree HA because mine sure wasn't that slack until I pressed in some offset cups.
  • 1 0
 Maybe he's referring to how low the b/b is? My sunday with 165mm saints used to dig pedals on roots all the time it was so low. Cornered good though.
  • 1 0
 Yea my pedals do that too, but by making the wheel base longer (even though only by 20mm) makes the bike lower to the ground, not by a lot, but the bike doesn't need to be any lower haha.
  • 1 0
 Great idea but I dont like the price it's perfectly thought but the price is high if you ask me...
  • 1 0
 damn i just bout a new adapter to... if only i had known better Frown
  • 1 0
 may look into this, seems like a good deal they have here
  • 1 0
 Congratulations. Great idea.
  • 1 4
 Nice, but it all seems too much work for not much gain for me. It might knock .5 off your time but is it really worth it?
  • 6 0
 if it changes how your bike rides for the better, then................yes it is.
  • 1 1
 pressing the cups in straight and aligned is key. especially if you don't want your bearings so wear out prematurely. I wouldn't worry about the extra stress on the frame. if a frame is going to fail, it will no matter what the HA is.

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