November 1st, 2009
The Story
This whole project started because customers asked if the VF2 was capable of being more
than just an XC bike and if they could improve upon the RP23 that was fitted to the VF2. Awhile
back, Ted Tanouye, head of R&D at CHUMBA, and I were riding the Fullerton Loop in California.
After climbing a steep section of the trail, we stopped, and I asked, “How is that rear shock?” Ted
said “the VF2 with a CCDB could outperform an EVO equipped with an air shock.” For Ted – a
man who developed championship-winning race bikes out of his garage – to make such a claim,
gave cause for serious attention to this rear shock and how it would interact with CHUMBA frames,
specifically, our VF2 linkage system.

So I turned to one of the industry’s most knowledgeable shock gurus – Josh Coaplan,
head of R&D at Cane Creek. Josh helped develop the Double Barrel alongside other engineers at
Ohlin’s Racing, the premier shock manufacturer for off-road equipment, like ATVs, snowmobiles,

I sent Josh a VF2 frame for analysis of axle path and leverage ratio to help us optimize the
complex settings of the CCDB for the VF2. From my conversations with Josh and Malcolm at Cane
Creek – we hoped that this shock properly tuned to the VF2’s linkage would provide the basis in

which to help reduce pedal-induced bob while retaining the superior bump absorption and traction
that the CCDB is famed for. Coupled with the VF2’s linear linkage (more on that later) the CCDB
would offer unrivaled shock tune-ability and performance.

Upon receipt of the frame, Cane Creek proceeded to build their own hardware to make
sure a proper fit of the Double Barrel in the shock mount locations of the VF2.
After Cane Creek received the VF2, they proceeded to equip it with the proper hardware,
and started to do a full analysis of the leverage ratio, axle path, and other relevant data all from
real-world data acquisition.

The data Cane Creek acquired, matched all of the R&D testing that we had confirmed in
our 3-d modeling, as well are our prototypes, and actual production models.

We confirmed that the VF2 had an extremely linear suspension rate, almost like a minidownhill

bike. This means that the force required to compress the shock throughout the travel stays constant – meaning the bike feels consistent, predictable, and smooth throughout the whole

CHUMBA’s frames have the unique advantage of allowing the suspension to behave the
same way at all points of travel, allowing for smooth technical climbing, pedaling through rock
gardens with a fully active suspension, and descending with complete confidence and predictability,
whether riding on the trail, or hitting bigger drops and jumps.

CHUMBA and Cane Creek jointly analyzed shock settings and performance, testing the
CCDB on the VF2 with professional riders, engineers, and test riders both at CHUMBA and Cane
Creek. We then confirmed data between each other and found similar results.

Given the extremely linear nature of the VF2’s leverage ratio curve, the linkage will reflect
a shock’s tuning very closely. This means, if you tune up the low speed compression, you will
immediately feel this throughout the VF2 linkage’s travel without varying leverage rates from the
linkage interfering with what you want the shock to do.

This means if you own a VF2, or are interested in one, you have the advantage to really
custom tailor your Double Barrel to how you want it to perform at low speeds or high speeds, and
the linkage will remain neutral to accept your change, making the combination of the VF2 and the
Double Barrel one of the most customizable rides on the market.

If you are interested in more information on custom tuning with a VF2 or Double Barrel,
you can e-mail [email protected] or call 714-986-9100.
Alan Kang

source: Alan Kany


  • Anonymous says:

    Dont believe the hype! This company does not stand behind thier product. I know a kid who rides for a collegiate team who, after only having his F-5 for 6 months, it broke at the welds. Did they back thier product up….nope! They left him hi and dry with no warranty for the frame. Talk about a quality product with quality service…..NOT!

  • Anonymous says:

    This is not true. We sent out a replacement frame which he currently has right now that is in perfect working condition.

  • Anonymous says:

    I’m pretty sure JC’s info is INCORRECT, at least from my experience dealing with Alan and the folks at CHUMBA.
    I had one of the original EVO frames and when they came out with the alternative AM geometry they were more than willing to work with me and get me into one of the new AM EVO’s at a fair price. They stand behind their products and take great care of their customers!

    Hey Alan, still loving my EVO and I was wondering if in your opinion going from a DHX 5.0 air -> CCDB on an EVO would have as dramatic results as an RP23 -> CCDB on a VF2.

  • Anonymous says:

    Hey Tom, thanks for the info! Glad to hear your EVO is still going strong. CCBD on an EVO would be an excellent addition – you would feel a dramatic difference, probably just as much as if upgrading on a VF2.

  • Anonymous says:

    So Alan, a used frame is “perfect” for a warranty as long as it works? I work in the small engines industry and see many fouled engies that still run, should I tell people that the engine is still good becuase it runs? Of course not, by no means does it make it suitable for use. Especially if its a quality issue. Tom was your problem a warranty or a personal choice of changing frames…of course they were willing to work with you so they could get more money from you. Thats cool you like your bike and all, but what my friend went threw was unneccesary, costly to his cycling career and to his body. During my friends time laying on his bed from injuries of this incodent, we talked much about his issues with this company and what he was going to do for a bike for the rest of his cycling season. All he wanted was a new frame…not a used scratched and dented frame that went through two previous riders. I grew up with this kid and he is an outstanding and honest person who only wants what is fair.

  • Anonymous says:

    Not true again! That frame did not go through 2 previous riders. It was a frame with very few rides on it that was in perfect mechanical condition and excellent cosmetic condition.

  • Anonymous says:

    he got a used frame as a warrenty replacement? Pardon me if i’m a bit ignorant here and do not in any way shape or form know the entire story, but if a frame has to be replaced under warrenty – meaning the fault alone lies with faulty maufacturing techniques or the manufacturing of that particular frame – why would you not get a brand new frame? If the rider was in fact hospitalized as a result of the frame falling apart while riding i would think this to even more so be the case – especially over yonder where you love to sue each other over nothing.

    I’m currently starting a warrenty case with my own 6 inch frame bought from another brand. All i can say is that if i get a used frame as a replacement – a frame that can easily be identified as being used – then i will not be a happy customer. I would also probably look elsewhere for frames in the future. And yes, i would make it be known as well. I don’t know, after reading this an the somewhat unfortunate rant against DW earlier this year i must say that getting a Chumba seems a less than lightly enterprise in my book.

    happy trails

  • Anonymous says:

    If I were given a used frame under a warranty claim, I would voice my displeasure from the top of someplace very high.

    I surely would expect better treatment than that after shelling out $$$$ for an American made, American supported product.

  • Anonymous says:

    That leverage rate curve is definitely NOT what I would consider “extremely linear”. It is a digressive curve, and is the stiffest at full rebound, gross.

  • Anonymous says:

    It is slightly falling, with a small out of progressiveness at the end for bottom out resistance – what is not to like about that? Still very much linear compared to most leverage curves.

  • Anonymous says:

    Although I don’t believe it’s appropriate to go into full details here, we have one of the lowest warranty incidence rates, and they are usually handled within 24 – 48 hours; and frame replacements are new products unless it is used to get the rider up and going until new parts are available.

  • Anonymous says:

    Been hearing more and more negative stories about Alan and Chumba. I’ll still consider one but it certainly puts bikes like the Mojo, Spot, and Mach 5 higher up.

  • Anonymous says:

    wow, a used frame for warranty replacement, how sad is that. who cares if you have one of the lowest warranty incidence rates in the industry. if you’re sending out used frames for warranty replacement that just sucks. no chumba for me. i’d expect that type of service from ellsworth.

  • Anonymous says:

    so you sent that guy a used frame to get him up and running quickly? must have been the shortest hospital stay ever!!!!!!!!!!!

  • Anonymous says:

    so that guy needed to get up and running super quick in the hospital?

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