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I have a Specialized Camber Comp 29er full suspension MTB. I want to use this bike for the DK200 (a one day 200 mile / 320 kilometre gravel race through the Flint Hills of Kansas, USA) and would like to be reasonably competitive. I know, this guy is nuts.

That being said, I'm planning on gravel tires, bar end grips, possibly aero bars, bike sizing, and 'locking the suspensions'. I understand I will be sacrificing weight and efficiency/torque with the longer chain stay and suspension flex, along with gears that aren't quite tall enough on the downhills and long straights. However, I just do not like the feel of the gravel bikes. They're too stiff and bone jarring, and just don't like the general feel when I'm on them. I'm thinking over the long haul on my full suspension bike, that my suspension soaks up a lot of the potholes, ruts and rough roads will pay off in the long run.

What else would you recommend that I do to my bike to properly prepare it? Any specific brand add-on pieces you'd recommend?

I am in good shape and currently outrun others on carbon gravel bikes on 45 mile / 72 kilometre rides on my stock MTB. I will be in excellent physical condition in 5 months when it comes race time. I do have some issues with my lower back and shoulders/neck area currently at a little over 45 miles / 72 kilometres, so needing to get more comfortable and in better shape.

I know this was lengthy, but much appreciate some expert advice! Ride on!

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    Could you please edit that to break up the wall of text and make your actual question obvious. Right now I get the impression it's "Im goin ter due this eny advice"? – Móż Feb 1 '16 at 21:33
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    320 kilometres is a very long ride - you're looking at 10-14 hours in the saddle. Have you done at least 75% of that time in one sitting before ? – Criggie Feb 1 '16 at 23:56
  • Bill - come the race can you please remember to add an answer with your findings, and how it all worked for you? – Criggie Feb 2 '16 at 23:59
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Between mass and aerodynamics you would be expending a ton more energy on the MTB if the roads are in decent shape. Rather than roadify the MTB you might consider MTBifying a road bike. Tires are the key, really large, supple ones to soak up the bumps, at an appropriate pressure. Perhaps aiming for tubular cx tires that you can run really low pressures on.

  • Really should be a comment - Its not answering the question asked. – mattnz Feb 1 '16 at 20:26
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    One of the questions asked was "am I completely delusional". My intent was to answer that question, as well as the question following it about how to prep the bike. – jackmott Feb 1 '16 at 20:28
  • Depends on the size of the gravel. If it’s fine gravel even 28mm wide road bike tires at relatively high pressure would be fine. – Michael Feb 14 at 18:37
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You should prepare really well for flats - flint shards can be very sharp and will cut through tires.
As for using a full suspension bike, to each their own. But you will carry up to 10 extra pounds of weight for a dubious advantage, and will suffer on any faster segment.
If your outlook on the issue is "I want to ride the DK200 on a full suspension bike (or fail)", good luck! But training rides of 75 km do not prepare you for a 320km race, and a full suspension bike will make you lose hours over what's possible with a more usual bike. Also, it's more likely that you'll get dropped, and that might hurt deep inside your soul (and make you more likely to abandon)

P.S. I took a rigid fat bike to a race where everybody else used hardtails, so I'm not totally sane myself :) (fortunately it was a short race, under two hours)

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So you "just don't like the general feel". Over the long haul soaking up a lot of the potholes, ruts and rough roads will not pay off. That comfort is sucking up power and adds weight to the bicycle. Have fun and you may flat out overpower some riders but it is not going to be a competitive bike.

Gravel racers and bike manufactures have come to what is considered an optimal design and they all seem to be in pretty close agreement.

It is near the end of CX season - you can often find some great deals on used CX.

The line between CX and gravel is pretty narrow. Since CX is a 1 hour race they tend to be stiffer. But I own a very comfortable TI CX.

Running larger tires at a lower pressure will absorb a bit (but maybe not optimal performance). Not all CX / Gravel take up to 40MM (and some take even larger).

DK200 recommends 40mm+ tires. Even on your mtn bike you should not ride narrow tires.

It is not the ruts and pots holes that wear you out but gravel size vibration. A good carbon fiber fork with a large soft tire deals with gravel sized anomalies in an optimal way.

As for shoulders/neck discomfort drop bars have multiple positions to spread the fatigue. I just don't see how aero bars on a mtn bike are the way to go.

At 200 miles you are into offroad endurance racing. Look into off-road endurance bikes like a CutThroat.

That is a pretty brutal race. Over 1/2 the field is going to be out right animals - you would need to be a near world class mtn biker to be competitive on a full suspension bike.

OP comments on new bike selection. We don't really do recommendations here but I suggest you break it down by what you want and translate that to specs.
Need/want:

  • Gravel type race efficiency / speed

  • Comfort hands, back

  • Endurance (10+ hours)

  • 40mm+ tires based on race course

If you are serious and have some coin then you will need mud and hard pack set ups. Buy an extra set of wheels and experiment with some tires. If you have a support team then you dould even change out at the check points.

Spec:
What dominates the needs is the 40+mm tires. It addresses both race course and comfort. Not all gravel bikes are going to take bigger ties. That is why you need to look into endurance off road. I would run tubeless and run them at the mid to low end of the pressure. In that size it will actually be mtn bike tires. If 40+mm really limits your options then look at at smaller. The down side to off road adventure is that in a shorter normal gravel it will be a little slower than a pure gravel bike. But you have a bike you could off road backpack. Of even put touring tires on it and use it as a touring or commuter. It is kind of hard to $2K - $3K for just one race - are the other things that could help justify the expense. Look used - there was used Fargo in my town for just $1200 recently.

When I compare your modified bike to what I would consider an optimal setup it is not close. Not even sure you could add lockout to those shocks. If it takes replacing the shocks then very costly. Add up what it would cost to optimize your bike compared to a new optimal bike. From there make a decision. I can tell you drop bars may seem clumsy at first off road but after you get used to them you will get it.

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    Really should be a comment - Its not answering the question asked. – mattnz Feb 1 '16 at 20:26
  • @mattnz Its a pretty waffly question in the first place - both of these answers have addressed some parts of the initial question(s) – Criggie Feb 1 '16 at 23:54
  • Thanks for the advice fellas. Yes, I'm very aware of the length and grueling nature of the DK200; That's why I took on the challenge. What model of the Salsa Cutthroat would you recommend? Also, are there any good Specialized brand models you'd recommend (that's what our local shop sells)? Thanks again – Bill Feb 2 '16 at 18:18
  • I like Specialized but the problem there is tire size. I think their Adventure is called Diverge. I am not sure it will take wide (40+mm) tires. Cutthroat is just an example as I know it will take larger tires. I am reluctant to revise my question as it is getting down voted but I will. – paparazzo Feb 2 '16 at 18:47
  • On the cutthroat the more expensive is a 1x and has nicer component. If $3K does not scare you then also look at like a Niner RLT 9 as I am pretty sure that bike will take bigger tires. – paparazzo Feb 2 '16 at 19:48

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