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I just bought a new MTB and am planning to change my previous MTB into a Road Bike.

How do I do it? What kind of parts do I need to change or add or remove?

I am not looking to for a full conversion into specialised road bike. But like the answers are suggesting, I am looking for a bridge between commuter or road bike. My majors concerns to be met are:

  • Should be fast enough to compete with road racers over short distance
  • Should be light as a road
  • Should be as close as possible in as cheap as possible.
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  • 6
    Your mountain bike can be converted into a good commuter road machine, but it can't be converted to keep up with a road racing machine, because the differences are too extreme. Does your bike have disc brakes? Are you willing to spend a bit of money to do it, or do you want to do the bare minimum? Can you post pics of the bike you want to convert?\
    – zenbike
    Mar 17, 2012 at 14:38
  • @zenbike, No my bike does not disk brake? And I am willing spend a bit but not much.
    – Starx
    Mar 17, 2012 at 15:45
  • 8
    You might want to explain what you want to achieve with it in more detail. Are you going for speed or for practicality? When I set up an MTB for road use I primarily just change the tires and ensure it has good mud guards for practicality. Mar 17, 2012 at 18:53
  • 2
    If you want to compete with road racers you need a road bike. Maybe not a fancy-dancy carbon frame one (a few extra ergs of your energy will make up for that), but one with good road geometry, 700C wheels, and race gearing. (And drop bars, of course.) Mar 18, 2012 at 1:38
  • 2
    Starx -- I'm reminded of a saying in the computer engineering trade: "Fast, cheap, reliable -- you can have any two." Your requirements above are unattainable. Aug 28, 2012 at 1:12

16 Answers 16

33

A mountain bike will never really be a road bike. The geometry and construction of the frame is different. Mountain bike frames are designed for a different posture and are often designed for a suspension fork, as well as generally being beefier.

You can set up a mountain bike with slick tires and drop bars if you want. I've tried this before and the ride quality is a bit off compared to a road bike.

If you want to take it all the way, you'll need to swap out the following:

  • you may need a rigid fork
  • you'd need to make sure that your frame and fork can accomodate 700c wheels and is drilled for caliper brakes. Many mountain bike frames will fail on at least one of these counts.
  • You'd also need to replace your crankset. Mountain bikes generally are geared much lower than road bikes.
  • your brake levers would need to be swapped to short-pull models meant to be mounted on a drop bar.
  • you'll need different shift levers probably.

All in all it's probably going to be a lot cheaper to get a used road bike and refurbish it than to convert an entire mountain bike.

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  • 2
    Yeah... this sounds like a lot of work.
    – Starx
    Mar 17, 2012 at 15:49
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    I agree with the suggestions, and add two more options: 1) use mountainbike stem, flat bar and reguar mtb brakes and shifters, but caliper brakes, 700mm wheels with skinny tires, and road shifters and geartrains; 2) In case you can't put 700mm wheels, use the skinnest smooth-high-pressure tire you can get for 26in wheel. In the end, I think the most important and distinctive part of a road bike is the skinny, smooth, hi-pressure tire. It makes your bike fly! Mar 19, 2012 at 0:12
  • 1
    You could also use cantilever brakes instead of calipers. It's a lot easier than drilling for caliper brakes. And it may be impossible to put a road crankset on your mountain bike. The chainstays are probably too wide.
    – jimchristie
    Oct 19, 2012 at 13:07
  • 3
    @user973810 why does a road bike need rim brakes?
    – Mark W
    Feb 1, 2013 at 16:36
  • 5
    @user973810 note the key word "rim". Of course brakes are needed.
    – Mark W
    Mar 5, 2013 at 12:38
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The first thing to consider is tires. You'll want to mount the smoothest skinniest tires at the highest pressure that your wheels will accommodate. The knobbies add a lot of rolling resistance.

You'll know after the first ride if you need to make changes to the gearing. The most effective change would be to swap the the big chainring. The 42-tooth is pretty much standard for mountain bikes, somewhere near 50 for a roadbike.

This can get pretty involved. You have to research the maximum tooth capacity of you derailleur, if your crank bolt pattern will match the ring gear and if your front derailleur will work with a larger gear. Not as effective but easier and cheaper is to swap the cassette. Common MTB sizes are 14-28 to 14-34. If yours is in this range you can swap to 11-26. You won't see the big improvements of a ring gear change but it will be much cheaper.

If you'll be riding on smooth roads and you can, lock out the front fork.

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    Tyres are the biggest change for the smallest amount of money.
    – Phelan
    Mar 19, 2012 at 13:15
  • 1
    Smooth tires first (friction and noise), then improve the engine (you :-). IMO, weight is too costly to address, gearing not necessary to address. Apr 2, 2012 at 19:20
  • I don't believe I have seen 14t small cogs, most often it's like 12. Still, from 12 to 11 may be a bigger change than one might realize.
    – Vorac
    Nov 21, 2014 at 17:25
11

On my Hard Rock Pro I've changed tyres to Marathon Plus, upgraded crankset to a lighter one with bigger outer ring, better chain and faster/lighter rear cassette, wider contoured grips, squeezed a full rear mudguard around my disc brake and fitted a front mudguard...I'm now told that I shouldn't be running 60-70psi because stock MTB wheels can't take it, so unless I pay out for better wheels I'll have to be slower by limiting myself to 50psi.

If I didn't need a strong bike for my 800 metre potholed driveway I would definitely have sold it out for the best used road bike I could get and started my upgrading from there.

I can hit over 36mph downhill on the road but even now, the speed at which road bike riders pass me is just embarrassing.

Even if I changed over to Tourney bigger crankset gearing and front mech to accomodate it, I think there's nothing I could do to make this bike as light and fast as a decent road bike - starting with a road bike will be much easier and cheaper for you.

5
  • Thank you for sharing your experience, I am starting to see the bigger picture now. BTW, Welcome to the site, and your first vote up from me (+1) :)
    – Starx
    May 6, 2012 at 1:18
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    Many mountain bike tires are rated at 60PSI. I would double check that information.
    – mattnz
    Sep 6, 2012 at 3:00
  • The force on the wheel is volume and psi. Double the psi at 1/2 the volume is the same force on the rim.
    – paparazzo
    Nov 21, 2014 at 17:37
  • no, force is area x pressure. The rim surface has a fixed area, I think it's only the outside part of the tyres that will vary in size.
    – bdsl
    Mar 9, 2015 at 23:17
  • Though Marathon Plus is not a fast tire according to the specifications given by the manufacturer. Its speed is 3 out of 6 for some variants whereas other models like Marathon Supreme or Marathon Almotion have 5/6 and 6/6, respectively. Apr 2, 2015 at 3:46
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Yeah, so long as you're more looking at simple recreation/commuting and not expecting to set any speed/distanced records, you can do a fair job of conversion.

First get smoother, higher pressure tires, ideally a bit narrower than your current ones. You do not have to switch to 700C rims, though your choices with 26" rims will be somewhat limited.

Next, try to increase your top end gear inches. A larger front sprocket and/or smaller rear cluster. You will almost certainly need to change your chain length for this, and might run into a tooth capacity problem with your rear derailer, depending on how you do it.

Lock out or stiffen up your suspension. If there is no lock-out on the bike you can use pieces of plastic drain pipe, cut open on one side, strapped to the cylinders. (Someone may make a commercial product to do this.)

The main thing you'll be missing after all this is the geometry of a road bike. For shorter rides this is not so much an issue, but for, eg, touring you'd appreciate the longer wheelbase, more appropriate posture, and more stable steering of a true road bike.

Added: One might consider replacing the flat MTB bar with drop bars, but that's complicated (new bar, stem, shifters, brake levers, etc), expensive, and unnecessary for simple recreational/commuting purposes. Many tourists use flat bars, preferring the more upright posture, and you can always add aero extensions if you feel you need them (mostly for the more varied hand positions).

1
  • I have used my MTB, for all purposes, commuting, cross country, and a lot of ways, it was not built to. So, since I have another MTB, I just want to bring my prev bike as close as possible to a road bike in as cheap as possible. I would prefer buying a road bike, rather than getting huge changes.
    – Starx
    Mar 18, 2012 at 1:57
8

I performed such experiment sometime. This is what i did:

  • Changed my wheelset for one made of light narrow rims and the smallest 26" tires I could get at the moment. Those where 1.9 or something similar and they where almost "slicks". The tires were inflated to their maximum labeled presure, 65 psi.

  • I kept the brake system, it was v-brake. Just adjusted the brake pads, shifting the spacers to the inner part of the bolt, making the pads protrude more into the rim, in order to keep the brake arms roughly paralel when applying the brakes.

  • I used a shortened handlebar and instaled a long stem angled down. Also I moved the saddle a bit towards the front.

At this point the bike had a very weird feeling. I think I was a little bit faster, but it felt awkward and dorky so I never really enjoyed the ride.

  • Later I sourced a pair of mtb handlebar extensions from another bike, so I mounted them at a drop angle, rather than pointing up. These extensions had a curved end, pointing inside and a little backward so I swapped sides when installing them pointing down.

  • Then I took it further and mounted the levers (both, shifting and braking) into those levers.

Granted I had the wierdest bike in the neighborhood. How was it to ride on it?

For a start, riding it was like opening a safe: you had to know the combination. No one of my friends knew what to do with the handlebars. I could ride fine enough to keep it going for a while, but no one of my friends has any interest in keeping my pace. I remember that sometimes we performed some kind of short time trial competition, in wich I used to win, but, taking it realistic, I was the only one who took cycling "seriously" at that time (I used to spend all my evenings ridig while all the others used to play soccer)

After a while I realized I was already more efficient on a regular mtb (partly because of my hilly city), and I got bored of this weird "Frankenstein" bike, so I reverted all the changes except the angled down stem.

Conclusion: when I decided my experiment had gone far enough I had observed that:

  • The frame whas too heavy, so it almost negated any benefit of the changes made (This could be just my case, it whas a steel frame).
  • The flat bars keept a too short riding position, real drop handlebars also allow your hands to sit further from the steering axis, stabilizing it. My short setup whas jerky and keept me from focusing properly on riding.
  • Compared my riding times on this bike versus my times in a regular MTB, and the difference was negligible in most cases.
  • Riding posture was unsafe, prone to slipping out of the handlebars.
  • The only change that felt really positive, was the narrow - slick wheelset.

I never managed to get my hands on a bigger crankset, but I rarely ran out of gears in the high end anyway. Over the time I got an old but real road bike and finally learned that the posture and pedaling technique are simply way too different. The experiment was fun, and I had a lot of riding experiences but the lasting one was about the angled down stem, which I still use in my mountain bikes because it gives me a more agresive position and is useful when riding uphill.

If you decide to go for it, I recommend performing one change at a time, and fiddling enough with each one to get acustomed to it before going further. This is because when you ride in a position you are nor used to, you may get weird sensation, get aching from several points and other stuff that will negate any benefit of the change for a while, however once you get the hang of it, and adjust your body and the fit of other parts of your bike you'll start to enjoy the fruit of your work. This strategy also allows you to look for cheap ways to source the parts you need by talking to friends and acquaintances (some of them may simply give you parts the don't use anymore as a gift or just because they need the space for something else) and waiting for bargains and inventory cleanups you get good parts at a fraction of their retail price.

5

Can you turn you MTB into a good, road worthy machine? Short answer: Sure, why not?

If you intend to do any road racing,forget about it, HOWEVER, if having a quick and sturdy bike for commuting, weekend terrorizing, or even the occasional century is what your after, then definitely go for it! I did!

First and foremost, skinny tires are a must. There are lots to choose from, but I'd stick with 1.5 or even skinnier. Slicks are faster, but flat easier. Tires with kevlar belts are nice, but the belts will slow you down a little bit. The Conti Gatorskins get great reviews but are pretty expensive. In any case, a slick or semi-slick will get you scooting along quite nicely. Your choice.

Flat handlebars are nice for a short while, but get old fast. Bar ends are a nice addition and they make a bunch of different types, but I use an old Scott AT2 (I think, maybe an AT4) which is sort of a mountain bike aero kinda thingy. Looks a bit wierd, but works great! Scott doesn't make them anymore, but I see them on Ebay all the time. Any type that will allow you to change hand positions are good.

If you have suspension forks, either dump them or find a way to make them rigid (removing the spring on some forks and putting in a equal length of PVC pipe works). The up and down movement of the forks will rob you of pedal energy. For short hops is doesn't mean much, but on a century at around mile 80, you'll wish you had changed it out. Besides, it's kinda heavy.

If you want, change the freewheel/cassette to road bike gearing. Not very expensive. You won't get the same effect as a road bike, but close enough for not much money.

You can try to lighten the bike up by carbon seat post, stems and even a carbon mountain bike fork, but the costs can start to pile up, and when that happens, the fun starts to lessen. I use my budget MTB/Road UAB (Urban Assault Bike) for just about anything and everything. Finishing a century is an especially rewarding experience....seeing the faces of those on $2,500 road bikes when I ride up....priceless!

4

It can be improved, a pair of club roost cross terra 1.5" tires, and a pair of bar end set inside the grips @ 16" apart, the need to be level to the ground. You want a bunch of your upper body weight toward the front of the bike. The covers the two biggest factors, friction on the ground and body position improving aerodynamics. Think of the bar ends as cheap aero bars. The next step to improve power is to add toe clips to your current pedals or clip less if you're feeling fancy. Proper clothing will also improve performance and decrease effort and don't forget before long ride carb up prior to riding and carbs while you ride. The entire conversion cost you about 80bucks.

2

I converted an old Trek Antelope 830 similar to Holly. I added a rear rack, a rack mounted bag that converted to fold down panniers, Specialized 80 psi Nimbus 26X1.5 tires, Planet Bike fenders, and some spd pedals. I commuted to work and back for quite a few years with good results. I did upgrade to a Specialized Roubaix in 2010, and the difference is night and day! If you don't have the money, the mountain bike can be a cheap way to go. You can pick up an old Trek like Holly amd I used for $50 usually.

2

Will the rear dropouts and front fork of your bike frame hold road bike wheels? You can find a 700c wheel to try it out in the front fork. Next place it beside your rear wheel to see if your frame has the clearance to allow the 700c. If the 700c will fit, you're golden! If the 700c size does NOT fit, just buy the same size wheels you have right now in a light weight and skinny (22mm/cc or so) to reduce weight. Buy or swap for tires with a smoothish surface. Then you will have less rolling resistance. Closer to a road bike.

My suggestion is to get to know the different part sizes of road bikes and mtb bikes and what makes them different. Both modern about 20yrs old or less mtb and road bikes have 100mm front spacing. Road frames are typically spaced 130mm at the rear dropouts and support 700c wheels, whereas mtbs are spaced by 135mm and can accept anything from 26" to 700C wheels. Some "hybrids" and most cyclocross bikes accept 700c and most widths of tires usually upto 42c or so, depending again on clearance. You can choose the right axle size hub (WHEELS!) according to your frame and it's front/rear wheel spacing (as mentioned) and clearance (front and rear fork height). I'm doing something similar as you, except I already know the hybrid mtb frame I have accepts 700c, so I'm OK to add 700c wheels. Some marketers decided to call these wheels "29ers" but it's marketing hype. I just bought a new cheap/good 700c alex ace19 rear wheel for 60$ with a 135mm hub. I already have the matching front 700c 100mm hub Ace19 wheel from my summer bike (that's why I chose it). Now I can choose almost any 700c tire I want to go on my new road sized wheels that fit to my mtb frame. Hopefully this all makes sense. lol. I was in your shoes about 3 mths ago before researching and tinkering with bikes. Now I do my own repairs and home build.

2

I converted my Trek 7000 mountain bike into a roadbike.

For the rear brake I used an accessory which my LBS called a horse shoe (horse shoe shaped aluminum which can be bolted into the v-brakes). It was intended to support the frame if you have a v-brakes, but since it has extra holes at the middle, my road brake caliper fitted nicely to accommodate a 700c rim.

I have replaced every component into 105 series. I even replaced the fork with a nice bladed shaped one but I had to alter my headset because the fork is oversized and my frame is standard.

The one thing I have not tired yet which I am a little hesitant to do (because I have this feeling that it wont work) is replace the crank. Although this would ultimately give me the speed I want.

My LBS told me it could be done, I just need to put a spacer so that the chainrings would not touch the frame.

All in all I am happy so far with all the modifications. My bike is now lighter and faster. And since it is a small frame, and I used to drive an MTB, me and my bike are very nimble in crowded spaces. :)

One day I will buy a nice second hand road bike, but for now I am happy with this setup. Besides, my 15 year old Trek 7000 frame has a sentimental value and I can't part ways with it yet. :)

2

I have a 29er Ti hard tail which I equipped with Jones Loop bars and easy-rolling Schwalbe Marathon tires. Very comfortable ride, rolls very well, but of course gearing is very low compared to my road bike.

One thing I noticed was the effect of bar width and hand position on air resistance. By moving my hands into the middle of my flat MTB bars, I could ride 3 kph faster on the flat with the same effort. Try moving your hands in and out on a long flat section and watch your speedo. Big difference! As big as the difference on a road bike between riding on the hoods or riding in the drops.

That's why I opted for the Jones loop bar - it has many comfortable hand positions unlike regular flat MTB bars, and you can even stretch out a bit over your stem to get a lower body position.

I don't notice what anyone else says about wheel base or geometry - my 29er feels stable at any speed, and my body position is quite comfortable. I like the extra give of the shock fork, which has ~ 5 mm of travel even when locked out. Together with the fatter tires, it takes a lot of the jarring punishment out of rough roads.

My next experiment will be with higher gearing. I haven't worked out whether I can switch from the 12-36 rear with 42-32-24 front to something like a 12-30 with 48-36-24 front. If so, it would be pretty good for me.

I disagree with all the people who say fat tires are slower. Nonsense. They actually have lower rolling resistance and higher wind resistance. If you're a recreational rider, and not a racer, you may even benefit from the lower rolling resistance and never suffer much penalty for wider tires with higher wind resistance because you seldom go fast enough! Grip width and body height make more difference than anything else, although Q-factor is obviously a little worse on the MTB.

And who needs to change brakes? My disk brakes are far superior to anything else I've used. Sure they weigh a little more. So what! My love handles weigh more than the brakes, so it doesn't matter. I'm not riding any tour-de-anything.

2

Keep in mind that, as stated by others, an MTB will never match a road frame. However, should you decide to go on with it, I'm sure it will prove a very nice experience and you will learn a lot more than reading considerations about geometry and bicycle mechanics on a random forum. If you don't want to spend a fortune, look up on that big auction website for second hand components: allow some time (1-2 months) for the occasional bargain to appear and you'll spend (my guess) around 100 quids for what I suggest. I've personally converted a Raleigh Amazon into an hybrid, although I did not go as far as changing the wheel size.

The biggest differences are going to be made by:

  1. Wheels + Tires. It is unlikely an MTB frame will fit 700c wheels. This is because the brakes mounts are positioned in such a way to catch the rim of a 26" wheel. Most likely you would find your brakes at the level of the nipples of a 700c wheel (it would make for really sharp braking though :) ) My suggestion: try to get hold of a pair of road 26 wheels: these were usually used for teenager/women road bikes, and with 26 1/4" tyres make your best bet to approach 700c performances.

  2. Drivetrain. As suggested by others you have to shift to a drive train with higher ratio. You might want an even higher than typically used in your area, as wheel size affects the final ratio between cranks and wheel transmission (26" wheels have a lower ratio than 700c wheels).

  3. Geometry (including drop handlebars). This is entirely up to you. It depends on your MTB geometry. I have seen a few MTB frames (should I say "MTB") with really aggressive geometry to be an MTB.

1

I converted an old hard tail Trek antelope 820 to a commuter recently. Started with slick 2" tires, the found some good 1.5"s made a big difference. I live in Asheville, Nc and its hilly as hell, so nothing made more of a difference than building my endurance! Got lights, mirror, and new big ring because old was cracked. For a commuter, it is great. Only complaint is a bit "heavy" and maybe an inch too big, but it was free. You also need to go in knowing you can't turn a mtb into a road bike. Its like turning a convertible into a suv.

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  • 3
    What exactly do you mean by new big ring?
    – Starx
    Oct 19, 2012 at 4:57
  • 2
    @Starx: I think she means chainring. Oct 19, 2012 at 15:43
1

I have a 29er cube mountain bike and put light weight mavic crossmax wheels with slick continental sports contact tires and changed the forks for rigid carbon forks and it made a massive diference, kept the disc brakes and gears set is shimano XT, I just dont like road bikes and i can ride this bike fast, you should see the look on road bike riders faces when I over take them on a mountain bike, they hate it! Mind you I am a strong rider and would say that 90% of riding fast is down to the riders strenth and not the bike. I did a 120 mile ride last summer and it is so comfortable to ride.

1

I replaced the knobby tires on a MTB with high pressure road tires (Serfas Seca) and they made a huge difference. I looked into replacing other components, but it really wasn't worth it cost wise.

-1

you guys complicate life as usual - if you have a good 26" frame and want to keep it for personal reasons but convert your bike into 28" you just cut off the brake pivots and weld it back 1-2" higher (in case of cr-mo frame any car repair workshop can do that for you for few bugs). Of course prior to that - first check if the wheel will fit - if it does - go ahead. you can do the same with the fork - or just change the fork to 28" Whole operation is easy and each. The bike geometry does not change too much - the bike is a bit higher - and the BB is hihger but these are not noticable differences. I converted my favourite Univega Alpina 5.7 like that - and got a fantastic trekking/cross bike instead of MTB that I was tired of. Plus fun - of making something different and consciousness that nobody has the same bike like you do.

P.S For more complicated alu bikes - you can think of drilling two holes - one in each rear fork tube + threading it - next screw in pivots - adding some glue to make the connection harder. THis is however not recommended for heavy duty bikes. But for city or trekking bikes works fine !!!

1
  • 1
    Welding new brake pivots is non-trivial for a lot of frames and a lot of people (not all frames are steel).
    – Batman
    Mar 24, 2014 at 8:34

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