Modifying road bike for safer use on poor roads

Question

I currently own a cheap-ish road bike (2019 Giant Contend SL: welded aluminium frame, wheels with narrow rims, maximum tire size 28mm, fairly few spokes, carbon forks, rim brakes, 2x11 Shimano 105 gears, fairly wide ratio rear cassette)

I've recently moved to a location that has really poor roads - even the major roads have large cracks, bumps, and potholes. Plus on the few stretches of road where the surface is not full of craters, people just feel encouraged to drive like total lunatics, so it's safest to stick to smaller roads or tracks anyway.

Buying a half-way decent hardtail mountain bike or a gravel bike would cost 800-1000 euros, plus choice is very limited here unless I import something, which would add to the cost and hassle.

Hence I'm hoping to use my existing road bike, with modifications if necessary to make it safer/more suitable.

I can obviously put stronger wheels on but there's not a huge amount of clearance to put fatter tires on. Officially the clearance is 28 mm, but perhaps there's room to squeeze slightly larger in? I appreciate fatter tires will improve comfort and grip, but how important are fat tires for protecting the frame and forks from damage due to uneven road surface?

The climate is dry, so I don't need disk brakes or a 1x transmission, do I? My understanding is the main benefit of these is they work better in the wet and mud, so in dry conditions my rim brakes and 2x 11 transmission won't be an issue?

The Contend SL has fairly relaxed geometry, and I wouldn't be hurling it down mountainsides. I think wider handlebars and some adjustment of stem length and saddle position would be fine for comfort and safe handling on rough roads?

Am I kidding myself that this bike could be made suitable for use on rough roads and gravel tracks? Could I risk breaking the frame or the forks? Do gravel bikes in the 800 - 1000 euro price range actually have stronger frames than road bikes of similar price and build quality? Or are they, at this level, just different parts on the same base frames?

Answer 1

28 mm should be OK even for bumpy road. I sometimes take my cheap 25 mm road bike even on stony unpaved trails when avoiding major roads. So far no damage and not even a puncture.

BTW, 2x vs 1x has no relation to dry or wet. It is about the gear ranges you need for steep hills and fast sprints and easy not too steep downhills. With 1x, you may be limited in the hills you are able to climb, because road derailleurs cannot take very large cassettes like MTB ones.

Regarding the rim brakes, they used to be the norm for a very long time. If you know how to use them, you might be slightly limited in the speed you can afford in some downhills, but you should be able to stay perfectly safe.

"Am I kidding myself that this bike could be made suitable for use on rough roads and gravel tracks?" Yes, it can very well be suitable.

"Could I risk breaking the frame or the forks?" Not very likely. If the crap hits the fan, I would be more worried about rims or tyres. Be gentle when hitting sharp edges and maintain sufficient tyre pressure.

"Do gravel bikes in the 800 - 1000 euro price range actually have stronger frames than road bikes of similar price and build quality? Or are they, at this level, just different parts on the same base frames?" They might be somewhat sturdier, but road bikes are capable to take some beating. Like the treacherous pavé of Paris-roubaix.

Answer 2

In addition to what is already posted, a few other things to consider.

• Air Pressure - With rougher roads, running lower air pressure will give some relief from the jarring of rough roads and provide some additional comfort. A tire pressure calculator can be found at the link below. There are other calculators out there as well, but this one will at least give you a good starting point:

Silca Tire Pressure Calculator

• Running Tubeless vs. Using Tubes - It wasn't mentioned in the question, but running tubeless will allow a lower pressure to be run vs. using tubes. Running lower pressures with tubes increases the potential for "snake bite" punctures if the tube is pinched when a pothole is hit. This is not a concern when running tubeless, which allows a lower air pressure (and more comfort) than running with tubes. Your rims may or may not be tubeless compatible, so that needs to be taken into consideration. Also, if one is not familiar with tubeless running, especially on a road bike, there is a learning curve to adapting to the mechanics of mounting and maintaining a tubeless setup.

• Least expensive option to test your environment - Trying some of the options listed in all the answers here will be the least expensive approach to testing your setup in your road environment. If it is still too rough, a gravel bike (or a road bike with more tire clearance) may be worth considering. You will at least have investigated the less expensive potential solutions with your current bike prior to spending more on a new bike.

Answer 3

In my experience, pushing the tyre clearances leads to frame rub as the frame flexes.

The old phrase of "clearance is clearance" is fine when the bike is static in a workstand, but you do need at least 4mm on the sides else you risk chainstay erosion.

Since your bike is rated to 28mm, I'd be leery of pushing to 32mm even if they seem to fit.

However remember the front/rear tyre clearances may be different, so its plausible you could have a 32mm on the front and be restricted to a 28mm on the rear.

Answer 4

Road bikes are quite sturdy. I wouldn’t worry about the bike at all unless you are over 80kg or so or riding with luggage.

The main problem is lack of comfort, especially if you have to ride longer distances over particularly nasty surfaces like rough cobblestones. I don’t find controlling on rough surfaces very hard, the biggest danger is if you get caught in a rut or in gutters or in tram rails.

Lower your tyre pressure as far as possible without getting snake bite punctures (pinch flats) and see how it feels. With 28mm you can probably go as low as 4.5bar.

Answer 5

This is an interesting question.

I actually had a Giant Contend in for service recently, so I am familiar with the layout of the bike. Yours has a better groupset but I think the frame and fork will be identical. It's an endurance road bike, with a geometry suitable for riding all day on a variety of roads. It sounds like it should be just the right bike for the job.

First of all, don't worry so much about the tyre size. When gravel bikes had just entered the conciousness of the cycle industry and only a couple of manufacturers were making something specific for the category (eg Cannondale Slate), Trek released marketing images and copy about how the gravel bike category already existed and showed some cyclists riding unpaved roads in the US on Domanes and Emondas with 28mm tyres. I have also ridden rough roads with a standard road bike and it's surprising how capable these things are, especially if you've chosen a tyre with a suitable tread pattern. You will easily be able to move up to a 30mm tyre with no problem, but you should be careful of clearances going over that, depending on the width of your wheel rims.

Jobst Brandt was well known for doing huge off road rides on a normal road bike, and there is a longstanding club in the UK known as the Rough Stuff Fellowship that operate in a similar way. Both these names are worth looking up if you have time.

I would say that your bike has one weak point (the rest of the components will be fine) and that is the wheels. The ones supplied by Giant are a low spoke count and not particularly strong, but upgrading to any standard set of wheels either handbuilt or quality brand-name factory, with a spoke count of 28+, depending on whether you plan to take heavy luggage or not and how rigid/heavy a rim you choose, will give you reliability and robustness for rough surfaces.

Riding on rough surfaces is obviously more fatiguing for the frame materials than riding smooth surfaces. These bikes are overbuilt to comply with modern regulations so it won't be a worry for you unless you keep the bike for many years and have ridden alot in that time. Keeping an eye on it's appearance, I would consider trading in the bike after two or three years of this sort of work so you can benefit from the manufacturer's warranty again on a new bike and remove any possibility of frame fatigue being a problem during your ownership.

Answer 6

Thanks for all the considered answers. It's interesting to get the different perspectives.

I agree that it probably would be safe to carefully ride a road bike on the poorly maintained roads and the farm tracks here, particularly with some adaptions like stronger wheels and lower gearing.

However, in the end I sold the Giant road bike, bought a low-end hardtail mountain bike, and replaced some of the worse parts on it with better quality ones (brakes, rear mech, headset, front forks, tires)

The MTB is not as fast on the flat, but there is no flat here, so that's kind of irrelevant. Plus it's comfortable to ride and it bounces over potholes and ruts.

Answer 7

Unfortunately, this bike is not ideal for use on poor roads, due to the tire clearance catastrophe of which quite many road bikes today suffer.

I have 28mm tires and I know they aren't made for poor roads. They are acceptable on average roads, but for poor roads I'd want 32mm. Ideally I would actually want 35mm, but good low rolling resistance tires are not easily available in 35mm width. So it's probably better to go faster to your destination and suffer the bumps than to slow you down a lot by using inoptimal tires. So, 32mm it is.

Wheels: my solution is wide double wall aluminum rims with double eyelets and 36 spoke holes per rim. For spokes, I use 2.34mm/1.8mm/2.0mm triple butted that are about the strongest standard spokes you can find (thicker spokes wouldn't be better because they are so stiff that the spoke flexibility doesn't offer load-sharing capability as much over a larger number of spokes). Cross 3 always, never radially laced on front, this makes hub flanges capable of withstanding very great spoke tension. Then you tension the spokes to a very high and even tension. That's the key to a high quality wheel: high and even tension (which requires you to use lubricant on nipple-to-rim and nipple-to-spoke interfaces). Stress relieve the spokes during wheelbuilding by strongly squeezing (with gloves) two pairs of spokes and going around the wheel. The best rim I have found that satisfies my criteria is DT Swiss TK 540. They work both for rim and disc brakes.

You really don't want MTB for poor paved roads. MTB is for mud, or a fatbike MTB for very snowy (not plowed or non-perfectly plowed) roads and sand beaches.