Mtn bike to gravel conversion

So I have a mtn bike. And I don’t do any mtn biking as I’m primarily a roadie. The bike is a Kona, aluminum hard tail, w 29in tubeless wheels and converted to 1x10 w nice shimano parts. It has flat pedals and I use it to ride w my son around town, go to Brazilian/Hispanic Bodegas, ride to Boston, etc. It sure is a very good fun bike.
However I feel I could get more use as a gravel bike, and have been flirting w a conversion for a while. I have all parts (sram levers work w shimano gears), but wonder what is the lift here. One aspect is its hydraulic brakes and how to properly convert it w sram 10 speed levers. The bike fits well and I believe I could have a lot more use as a gravel rig. Has anyone done it? What are the aspects to take into consideration?
I already have a super nice modern road bike, so cash outlay should be as close to zero as possible.
Let me know if it’s worth it. Please respond w constructive comments ok? I am not buying a new all road or anything else. Just conversion.
Thanks everyone!
G

Are you trying to convert it to a drop bar to use your SRAM levers? You’ll need new brake calipers and hosing as well as the brakes use different fluid (DOT vs Mineral Oil). And the drop bar will also add quite a bit of reach, so the fit will change.

Surly did recently release their Corner Bar that is designed to help with this conversion, but I believe it’s meant to keep your mountain bike controls and give you a pseudo-drop bar bike.

Alternatively you can just swap to skinnier/faster rolling tires and call it a new-age gravel bike. It would be cheap, keep the fit that already works, and wouldn’t be much different than a Specialized Diverge Evo.

It works with Shimano cassettes, but not Shimano derailleurs. Not certain what you meant by “gears”, so wanted to clarify that.

Hello Gustavo. May be worth some arithmetic because the cost can compound. A good thing is that you won’t want the latest or greatest. Ten speed cassettes and chains widely available, non majors like Sunrace and IRD. So it’s stem and bars, ensuring the right reach. Somafab has some solutions. A brake solution that is not widely considered is Yokozuna cable hydraulics. I have just purchased a pair and there are stacks of lower priced cable levers to connect to. This conversion has a good chance of bringing you happiness. Have fun.

As you might have seen, I have done something similar recently: MTB to Gravel/Commuter - Tech & Product - CT Community (cyclingtips.com)

It worked out very well, but I think I did change quite a bit more than you plan to. Anyways, a couple of things I would consider:

  • the reach, as already mentioned, increases a lot if you go drop bar. Get a much shorter stem and maybe a narrower handlebar
  • Think about the gear ratios. You likely won’t be happy on a gravel with MTB gears (or won’t use half the gears)

You haven’t mentioned which fork you’re on. In case it’s a suspension fork, I would think about replacing it with a stiff one.

I’ve converted a couple of 29" MTBs to drop bar. If done well, they are a ton of fun. For me, the most important part of getting it right was the stem length. Stubby (45mm) worked for me. That said, a flat bar MTB with a rigid fork and some fast rolling XC tires isn’t much different. It’s also way less expensive, and might be a good place to start. That’s what I did, and since I’m an idiot that likes to mess with things, I ended up doing the drop bar conversion. All that does is trade a little bit of off road stability for a small amount of straight line speed (1-2mph at a cruise, it seems, if you care)… and make people think you’re a bit of a moron for doing such a thing to a perfectly good mountain bike.

When it comes to components, 10 speed is A-OK, assuming you can find some nice levers. I have Shimano 685/785 levers and brakes with a 1x11 (40t with an 11-32). Works great around here. I’ve found the limiting factor to be the front chainring size (40t is all that I can cram in there), but that’s really only an issue on a downhill. I’m not strong enough to spin out a 40x11 on flat ground. Ha.

So, to sum up, I’d start with a rigid fork and keep flat bars. See what that does for you. If you feel ike spending a not insubstantial amount of money for a not hugely different gravel experience, then go drop bar. For the fork, I’ve liked my steel Salsa Cromoto Grande. Not too expensive, subtle looks, and available in a few different configurations.

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You got yourself a gorgeous bike there, man. Thanks for your input. I keep getting impulses about making this happen; maybe because I miss riding outside and we’ve been under arctic weather for a long time now (Boston area). That said, yours is one of the most attractive conversions I’ve seen so far. Someone in one of these forums suggested I get the Soma bar, and that seemed like a good idea. Let’s see what surfaces. Thanks again!

I’ve converted several karate monkeys back and forth over the years. A few things.

Agree with the short stem. Mine is around 70mm I think. I also have a short reach bar.
There may be a limit to chainring size as chainstays on mtb are designed for fat tires not large chainrings.
Rigid forks are great but make sure you get one that is suspension corrected as a non-corrected fork will drop the front end too far.
Ritchey also makes some nice bars. Worth a look if you are looking for any flare.
Make sure your tire width is suitable for your rim Internal diameter. I have wide mtb rims on this bike and 42cc tires were too small I now have 50 and they have a better shape. There are charts that tell you what size tires are appropriate for an internal width of rim. Mtb rims tend to be wider.
I have run both road and mtb cassettes on this bike. I live near mountains so the mtb cassette is preferable for our terrain.
Hope some of that helps.

before doing any change you should check a bunch of alternative handlebar setups that allows you to keep regular MTB levers and shifter while offering some more aero positions.

https://www.cyclingabout.com/velo-orange-crazy-bar-review/

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I would suggest you define in more detail to yourself what riding you want to do more, and then conclude what kind of bike is really required for that. Just locking out your fork, and mounting faster rolling tires might already do the trick for you! Maybe you want a bigger chainring to get some extra gearing.

Like others mentioned, next I would focus on a suitable rigid fork and a differently shaped flat bar (with matching stem), before converting to drop bar. Dropbar conversion is a more complicated project due to the ergonomic changes.

FYI: I did convert my rigid MTB to a dropbar bike, with modern 1x gearing. After a year+ riding it, I have decided to keep the gearing but convert it back to a flat bar bike. For the more casual rides and commuting rides I just find it more pleasant to have a flat bar rather than riding the hoods. Luckily this bike has cable actuated brakes, so converting it back isn’t too painful/expensive.