this sub is absolutely full of that kind of discussion. everyone has a different idea of what constitutes a "gravel bike," so many threads cover different approaches. I can't point to one particular thread, but if you scroll down and scan the titles, the right ones will pop out at you.

 

I did peruse the first couple of pages and really saw very little in the subject headings that suggested "conversion to gravel" although there is one about adding drop bars to a modern MB.

I'm interested in converting cheap old hybrids to gravel

 

I'm interested in converting cheap old hybrids to gravel

The process is mostly the same. It depends on the bike you're starting with. What specific changes do you plan to make? There's not much stopping you from taking most hybrid bikes on multi-surface adventures, except maybe a tire swap for something with more bite on loose conditions. Frame & fork tire clearance is the main limiting factor there.

Note: nothing says a gravel bike needs a drop bar. Stick with the flat bar controls and put an alt-bar or alternative hand spaces on it. Many people have documented converting a mtb to a drop bar—successfully or otherwise—and you would face the same challenges on a hybrid conversion.

 

Over on nsmb.com (different site) there's a whole section of their forum dedicated to this very topic. That could be a place to start, and then bring it back here on mtbr.com.

Check "Forum" at the top of any page to view what's in there.

 

A hybrid conversion sounds great as long as you can get the tire clearance you want. Plus 5mm... 'cause you never know....

Orrrr

Couple of weeks ago I did an event and there was a guy in our group smashing it on a mountain bike from well over 10 years ago. It had disc brakes of course, but it was old enough to have a QR rear hub, the fork was what was normal at the time, 80mm travel 32mm with lockout. He had put a drop bar which allows multiple hand positions and most importantly, a way to get low for going into the wind. He had mounted 29x2" Continental Race Kings, perfection for the stupid rough sections we had to ride though. This was a western states kinda gravel event, so the road surfaces vary widely. The Race Kings were absolutely perfect. Being a Continental they were as fast or faster than most of the "famous gravel tires". It was a great build.

Older XC hardtails are perfect for gravel, their 'outdated' HTA is just about perfect for rough gravel, their 80mm forks superior to these micro 40mm gravel forks on the market today, just make sure the lock out works for road sections. The old school shorter ETT works very well with a drop bar. And you can put any tire you would ever consider riding miles of pavement on all the way up to full knob 2.3+ mountain bike tires for events you know are going to be crazy rough. And they are CHEAP. Oh, just make sure the road brake levers you get are compatible with the POST Mount calipers required by the mountain bike frame/fork.

DT

 

Oh, just make sure the road brake levers you get are compatible with the Flat Mount calipers required by the mountain bike frame/fork.

MTB requires post mount calipers

 

My conversion was to take my hardtail and ride it on gravel.

Also tires and lowering the bars as much as I could, but who is counting, still the same bike.

 

Gotta go to work for a few hours but the major non-negotiable need for me is the drop bars. I want drop bar positioning and drop bar brakes and drop bar aero bars. I want to feel like I feel on a road bike, at least on road. I did want brifters but read that could be problematic with MB front derailleurs so I may settle for bar end shifters which I'd probably put on the aeros. It will almost certainly be a 90s Trek 700 series makeover.

 

Assumption: your '90s Trek 700 is a 3x8 w/a Shimano rear derailleur.

"Most* 8- and 9-speed Shimano mountain bike and road kit is inter-compatible because they both use the same cable-pull ratio. This means you can use an 8- or 9-speed mountain bike derailleur with road shifters, or vice versa"

R8 Drop Bar Shifters 3x8 | Microshift

R-Series drop bar shifters are designed to make life easier. Upshifts and downshifts are handled by separate, discrete levers and the brake lever is completely fixed, meaning accidental shifts are a thing of the past. External shifter cable routing is easy to replace and avoids kinks in the...

www.microshift.com

 

You're not going to like this but electronic shifting solves all your issues

 

I think hardtail with short fork with lockout would be fantastic TBH. Need to calculate geometry tho.
Alloy Grizl on 2.2 tires is pretty fun (but very inefficient)

 

I used Bike Insights and Geometrygeeks websites to overlay the MTB I used as "target" for the build with the geo of my current gravel bike (that I only use on the road). Allowed me to eyeball the stem angle + length for the drop bars.

 

Here’s the second one I built.
1992 DB Override
Surly Kanard 700x41’s
SLX 1x12 36T oval chainring
MT200 brakes 160mm rotors
CF Corner handlebar
Origin8 31.8 1” quill

 

That's pretty! But too nice for me.

 

My current "adventure" rides bike is a 2011 Lynskey Ti hardtail that get runs rigid, squish, geared or SS. Seriously pondering trying some drop bars on it. But would need some 2x11 hydro brifters with mechanical shifting - that would work with the pull ratios on MTB derailleurs.

 

To be clear, I don't plan to have disc brakes, suspension, or use an expensive recent bike. I might try disc brakes at some later date. But It will be a 30 year old frame and wheels I pick up for free to 50 bucks somewhere, or possibly, the one older Trek 950 frame I alread have that I paid $14 for. But I also won't be doing any serious mountain biking, just dirt roads and maybe an easy trail if I happen across one. But it will mostly be road rides, with modest dirt capabilty, so I think a hybrid with 700's will be a better start than the 950. It may be fun to do both for comparison too, since I never ride the 950.

Assumption: your '90s Trek 700 is a 3x8 w/a Shimano rear derailleur.

"Most* 8- and 9-speed Shimano mountain bike and road kit is inter-compatible because they both use the same cable-pull ratio. This means you can use an 8- or 9-speed mountain bike derailleur with road shifters, or vice versa"

R8 Drop Bar Shifters 3x8 | Microshift

R-Series drop bar shifters are designed to make life easier. Upshifts and downshifts are handled by separate, discrete levers and the brake lever is completely fixed, meaning accidental shifts are a thing of the past. External shifter cable routing is easy to replace and avoids kinks in the...

www.microshift.com

Interesting. Thanks!

You're not going to like this but electronic shifting solves all your issues

Well maybe... Nah You're right, I don't.

 

I built it for my son so I wanted it to be nice. I only have about $800 in it all up.
The early Trek Multitrack 700-790 hybrid would be a good way to start.
Steel frame, 700c wheels. I don’t know how wide a tire would fit. I paid a whopping 180 with shipping for the DB because they can take a 45 or bigger.

 

Like has been said it depends on your idea of a gravel bike. To me converting a mountain bike to a gravel bike is basically making it more efficient for road/endurance type riding while still maintaining some off road ability. In my opinion that involves a more aerodynamic handlebar position with multiple hand positions with a rigid fork for maximum efficiency. Ive been toying with the idea of a corner bar on my ECR or instigator which both have rigid forks but big tires making trails or gravel fine but sluggish on road. Jones loop bars also make a good "gravel" bar letting you get a bit more aero

 

Like has been said it depends on your idea of a gravel bike. To me converting a mountain bike to a gravel bike is basically making it more efficient for road/endurance type riding while still maintaining some off road ability. In my opinion that involves a more aerodynamic handlebar position with multiple hand positions with a rigid fork for maximum efficiency.

Zactly. Jones's wont work for me so drops it is.

 

I must be getting old and grumpy. Decades ago you had to do crazy stuff to get practical bikes. You had get road shifters to work with mountain bike rear derailleurs, and get road front derailleurs to work with MTB cranksets with their larger chainlines. There were hacks like clamping your front derailleur cable differently to alter the cable pull. Travel Agents solved the problem but were costly and seemed like cheating, so you avoided them. You would hang on to your old 9 speed road brifters because they worked with your MTB rear derailleur. You had to somehow get low gears onto a road bike, go to tandem-specific catalogs to find wide drop bars, or find frames originally built for 27" wheels and then mount 700c wheels so you could get more tire clearance. But now, you don't need to do these kinds of things. The bike you want has already been built. Get an actual gravel bike. Or get a circa-2008 rigid 29er if you want a more heavy duty flat bar gravel bike. If that sounds too conventional, get a monstercross bike. Or just get a current hybrid bike with a 1x drivetrain and disc brakes. Let Shimano and SRAM do the jerry rigging for you. There are budget options like Poseidon.

 

That was a beautiful rant but it sounds like this thread isn't for you.

 

I really don't understand why you would convert an old MTB without any suspension to a gravel bike. The entire idea of converting a MTB is to have suspension. Otherwise just use a normal drop bar frame? Pretty sure the only advantage of a rigid fork is the much lower weight. A decent suspension fork with a lockout if you need to sprint out of the saddle will work fine.

 

Most of the drop-bar vintage mtb I've seen converted were specifically chosen for the aesthetics and simplicity of a rigid mtb. Using an old frame means you enjoy the nostalgia, a (usually) well-made frameset, and it's often cheap. A rigid fork means you don't have to mess around with clapped-out old suspension, either.

People near me give away or trash older bikes all the time, the the price is usually great. Very few people who has ridden a modern mountain bike probably would want to use those old bikes for mountain bike trails these days, so repurposing them as a unique, thrifty (until you start spending on purple ano brake levers, Rene Hearse tires, and Japanese handlebars imported by niche retailers), and waste-reducing fun bike is a trend of which I approve.

 

I have an older Niner EMD that I haven't touched since I got my Roscoe 9. Thinking of making that into a gravel conversion.

 

@OldBlue950 , look up Drop Bars & Knobbies. Their Instagram page is FULL of old hybrids and atbs conversions. Hybrids often lack tire clearance to be worthwhile if you want something bigger than 38mm, which is why 26" bikes are more popular.



I've attempted something similar with an old, steel Scott Laredo and another time with a steel Bianchi Boardwalk. Both times, I could not get a drop bar to work because the bikes would fit me with a flat bar, but a drop bar added waaaaay too much reach, even with a stubby stem.

 

I don't think I need wide tires really, but this is an experiment so I may change my mind. I think I've seen people put 40s on old Trek MultiTracks, but 38 would work too. And I realize I may hate the result no matter what I do lol.

 

Do you have a bicycle co-op nearby? I volunteer with a well-established one and there are enough old bikes in there to build dozens of such bikes. I'd be there all day doing just that, but I need to go to work sometimes.

Experiments are fun. Buying new or nicer used parts is also fun. Just don't go overboard buying stuff that won't transfer to another build if it does not work at first.

 

I plan to keep buying to a minimum. Famous last words.

I've seen where people sink a thousand bucks into one bike. I hope to keep it to one tenth of that, which may not be possible but i can try.

 

When I have to ride a fire or logging road, part of me dies. I can't imagine building a bike for dirt roads.

 

Don't get me wrong, I love singletrack as much as anyone. IMO, Big Bear is lacking in the singletrack department and what we (still, Skyline is going to need some major work) have, a lot of it is of sh!t design. I embrace fireroads, you almost have to up here. Riding on fireroads on my gravel bike reminded me of the early days of mtb'ing when pretty much 75% of what we rode were fireroads.

 

2005 Salsa Ala Carte 26-er frame. Alum corner bar Amazon special. $40 Shimano deore hydro Amazon special—prebled and just-right hose length. Donated 29-er disc wheels from a too-large hybrid with 40mm GR-1 tires. New tape. Otherwise, the rest are reused and spare bin parts. Total conversion cost me about $120.

This one has been on many 50-mi plus gravel rides and even couple of races. Very smooth ride with the right 30 psi, both on and off road.

 

 

That's a prime example for bad design and function. That top tube could be 10 cm lower and out of the way.

The only reason it is where it is, is because Mondraker didn't want to remake the frame for an appropriately long fork.

 

What's being described and being shown are a Hybrid Bike. Plain and simple. There's the infrequent manufacturer model alongside the gravel models - usually w/ an acronym included. It being a model today in 2024 is near to what platform was starting mountain bikes in the 1980's

Gravel Riding™ is about road bikes on dirt. Going back further, further it actually is just a road bike. In the past 5 years during TdF season, it was made mention how over the course of that Tour sectors comprised of Gravel had still outnumbered actually road surface sectors to that day. Unsure what that may be now.

Someone may need to get back in their (Dr.) Ferrari, scope out some (dope) 'Gravel', concoct their own take on these things because they 'know nothing'.

 

Going back to what OP actually wants to ride: he wants a road bike position, to be ridden mostly on the road, with somewhat wider tires so that he can venture onto dirt/gravel roads once in a while. It needs to be cheap. Doesn't need suspension or disc brakes.

The answer: an old cyclocross or touring bike. Nobody wants old CX bikes with canti brakes anymore. Probably $300-500. But you realistically probably couldn't even buy and convert an old hybrid to drop bar use for much less.

 

When I originally started my research it led me to cyclocross bikes too. I don't remember exactly why now, but there were reasons I steered away from them and got led to these conversion thingies. Part of it was the complete lack of any in my local market. That alone would have stopped me but there was more to it than that. Who knows I may end up going that way again later, but today I picked up an old Trek hybrid with 700s for $50 to experiment with. It will not be an expensive experiment, at least to start.

 

I did one with a 91 Schwinn High Plains mtb. I actually really liked riding it but it was ugly as sin. I personally like high bars (even with seat) and most of the 90s mtbs have pretty short headtubes so I ended up with a ridiculously long stem adaptor (this one High Rider Stem Adapter 28.6 to 22.2mm - Soma Fabrications).

I am really tempted to try again but if I do I am going to use an early to mid 80s mtb frame as they tended to have long headtubes some more then others (Raleigh Mountaintour series for example but they have 21.1mm quill stems).

 

I did one with a 91 Schwinn High Plains mtb. I actually really liked riding it but it was ugly as sin. I personally like high bars (even with seat) and most of the 90s mtbs have pretty short headtubes so I ended up with a ridiculously long stem adaptor (this one High Rider Stem Adapter 28.6 to 22.2mm - Soma Fabrications).

I am really tempted to try again but if I do I am going to use an early to mid 80s mtb frame as they tended to have long headtubes.

I was thinking the same thing as I rode my 950 this morning-it would be really hard to get the bars up to where I want them. I don't need them too high but I need them above seat level. But my 700 already has pretty high bars, with a 2-piece bar clamp. I'm not sure why I can't just pull out the flat bar, secure it, and put in a drop bar to test. It would be pretty close to where I want it already. (Although I did realize I actually bought a larger frame than I thought I was buying so it may end up not working for me). But its all for science.