berninicaco3

I'm just getting into biking, I want to commute to my job 5mi away --and in the fall, to school-- instead of burning gas in my 15mpg station wagon!
I'll be getting a "comfort" bike, but was weighing the consideration of a proper road bike. A difference between the two seems to be shocks on the former, and never on the latter, and I'm curious why that is.



I know cars and am an ase master tech... for cars.
You'd never consider a car without a suspension. Stiffer suspensions help handling, that's all-- and you can't just make it infinitely stiff for the best high-speed handling. No suspension at all, just a rigid frame, and you'd lose contact with the road on 2 tires around tight turns. You want every tire in continuous contact with the road, mostly a level vehicle with equal amounts of weight on each wheel, and ideally, for every bump, the tire rides up and then back down: in one half of a cycle exactly (obviously, picking a set of shocks will always be a compromise). Bumpy roads require a softer suspension to perform, one example where a stiff racing suspension for the refined and paved asphalt track would be worse on a rally track..
Other considerations is that, say, for a drag race in a rear wheel drive car, a soft rear suspension lets all the weight transfer to the back for traction.

Details aside, why would one prefer NO suspension on a road bike? What's the advantage of no springs, no shocks, at all? Plausibly a good bump will cause your front wheel to bounce entirely off contact with the pavement (and then you can't steer for that moment), where a suspension could have kept it on the ground.

Coworker tried to tell me it's because shocks absorb your effort in pedaling and saps energy/endurance. maybe... is that the real reason...? Cause once the suspension compresses, it'll stay compressed, I don't see how the forward momentum of the rear drive wheel is lost into the front suspension all that much. If this IS true for bikes... then likewise, do stiffly sprung cars ALSO get better fuel economy? ;-) (tell your doubting wife that you put coilovers on the car to save gas money, hah). But seriously, suspension is up and down, keeping the wheels planted on the ground for performance, absorbing hits for comfort-- shouldn't affect lateral velocity/inertia?

Burton

The simple answer is that at the speed road bikes travel, weight is more of a concern than suspension, and although you're correct in your description of an excellent suspension system - that's NOT what you'll find on a comfort bike. A decent front fork costs more than most comfort hybrids.

Yeah - when you start exceeding 50kmh during decents on less than perfect roads - it becomes pretty clear why there are larger tires and suspension systems on motorcycles, and a good mtb is the ticket there. But personally I find that at most speeds in the city a 2" slick and rigid front end gives all the suspension I need.

no1mad 

Commuters (for the most part) don't like suspension forks primarily because they add weight and are one more moving part that needs to be maintained.

MichaelW

The small-wheeled Moulton bikes use suspension in the way you suggest, to maintain road contact and they are considered high-performance machines. Most bike use large wheels to overcome road roughness and it works well.
The quality of suspension found on midrange "hybrid" style bike is of such low quality that it is just extra weight. The high-end suspenion on competition MTBs is tuned for another purpose.
Note that road-race bikes are not practical everyday commuter rides. They have tyre clearance too tight for fenders or medium tyres, they often lack threaded eyelets for luggage rack and fenders and the gearing is too high for many riders/routes.
You can get less racy road bikes with these useful features, you can also get cyclo-cross, touring and flat-var roadbikes that are usually quite practical.

To compare a bicycle to a car:
Cars weight 10x the load carried; to ensure a suspended mass, cars need suspension. The total fuel efficiency (energy in the fuel, used to propel vehicle) is maybe 20%.
Bikes weight 1/10 the load; on a non suspension bike, 90% of the load is (the rider) is suspended (using arms and legs).
Bikes are , in energy terms, 95% efficient, sometimes higher.

-=(8)=-

Since you are a mechanic, think of driving a car that is missing its front struts/shocks and only has 3lbs of air in its right from tire

Your co-worker is correct.

That said, Id love to have a full-downhiil bike for a 2nd commuter, but I ride very slow and dont care about making time.
If you think like that, and want a mountain bike, live the technicalities of them--thats what is going to make you want to ride--get one!
Dont worry what other people think, just you!

Don in Austin

If you cut through unpaved alleyways, jump curbs, or the streets are full of potholes suspension will help. I disagree with those who say a cheap suspension is worthless. Any suspension is better than none if the surface under your wheels calls for it. Yes, it adds weight and absorbs some of your pedaling input. A good suspension has a valve that locks out most of its travel.

If you are exclusively on smooth pavement the slight flex in your frame, fork and tires is adequate. Tires are part of a vehicle or bike's suspension.

If you would like to sacrifice a little speed for comfort due to riding on poor surfaces wanting to hop curbs, go for suspension and don't worry about what anyone else says.

Fat tires vs. skinny tires are a similar trade-off.

Don in Austin

steve0257

The problem with bike suspensions on lower cost bike is that usually can not be tuned to the rider's weight. Unlike a car, on a bike most of the weight comes from the rider. If the suspension is to stiff you may as well not have it. If it is to soft, which it will usually be for heavier riders, the front of the bike will dive when decelerating. I used to have a bike with a front suspension and I couldn't stand the way the front dove whenever I stopped or too a hard corner.

cyccommute 

What you are missing is that you aren't riding a bike without suspension. A car has a huge sprung weight...the chassis, engine, load, etc...to unsprung weight...the wheels, tires and some other bits. The wheels, tires and other bits weigh a few hundred pounds while the other stuff weighs a thousand pounds or more. A bicycle with rider isn't unlike that ratio. The bike...frame, wheels and other bits...is unsprung but the load...you...is sprung. The 'springs' are your arms and legs. And those springs are controlled by the most sophisticated control system that the planet has ever devised...your brain.

The reason that we call a bicycle saddle a 'saddle' and not a seat is because it isn't like the seat in your car. You don't really 'sit' on it. You float over the saddle on your arms and legs and you can make micro adjustments to how and where and when you apply the 'spring' in your legs and arms instantaneously. It's just like the suspension system in any vehicle except far more adaptive.

If you are on a smooth surface, a suspension system like those that you find on a comfort bike is just going to sap your energy by sucking up the pedal energy. The suspension on a comfort bike is very rudimentary. It's probably a coil spring without any kind of damping or control. It's a pogo stick. A suspension system on a mountain bike...a high end one...has damping to resist the downward push of the rider's pedaling and less linear response to impacts. The damping and control is needed when you are experiencing impacts constantly like you would off-road to keep the impacts from throwing you off your line. Your legs and arms are still your main line of suspension even then.

For road riding where the surface is smooth, all but 0.0001% of the situations you'll encounter on a bicycle can be handled by an unsuspended frame and learning how to ride light in the saddle. Get a rigid for on-road riding.

fietsbob

Legs and Elbows are your suspension, Really .. get out of the saddle,
before you hit the bump you can't go around.

Birdy and Moulton use suspension on small wheels.. Boulder Bikes used to offer a rear suspension Road bike

the damping went in the top tube, back end..

the Forks with suspension: slim to none.. over the years.. Rock Shox made one, someone won Paris-Roubaix using one..
but that was a Long time ago..

Fwiw there is a company in California, Pan Tour, that makes hubs, that use an internal Elastomer .
to suspend the hub shell from the Axle, between the bearings, and the axle itself
(I suppose) offering an inch of travel ..

even a disc brake version, a 4 bolt mount,so uses Rohloff type discs, for the bigger hole
in the center..

that would be the lightest and simplest way to soften road buzz, though an inch of travel
wont absorb the big potholed patches, but the cold-patch lump over them.

DVC45

I prefer no suspension, but there are better suspension forks out there that can be locked up.
If your path is really bad, then suspension is warranted.

BassNotBass

I've never experienced anything like that yet I prefer bikes without suspension. For riding on pothole riddled roads, cobblestones, alleys and gravel pathways the wide moderately low psi tires I use on my rigid frames offer a great ride which is quick, predictable and stable yet adds enough suspension to prevent from rattling fillings loose.

What it boils down to is chose what works for you. Test ride a bunch of bikes and buy the one you like best.

Dave Mayer

I commute every day, and have been doing so for 10+ years. If your commute involves bouncing over head-sized rocks at 20mph down 20 percent grade slopes, then you'll need suspension. Otherwise, suspension will introduce energy-sapping suspension bob, and a whole bunch of surplus weight. And more expense, something more to break, and a front fork that will fill up with water if you ride it in the rain, afterwards it will convert itself into a rusted seized mess.

On the road, properly inflated tires, your saddle, and your legs will provide more than enough suspension. Obviously, you won't be slamming into curbs on your bike, just out of common sense.

The absolute worst bike for commuting is a cheap Wally-world full-suspension MTB with big knobby tires. This bike will slow you down at least 5mph over any cheap road bike for the same energy input. Plus the knobby tires will provide LESS traction over pavement than slicks and will constantly howl away and drive you insane.

Recommendations:

• Go as light as possible. After riding a 20 pound or less bike, a 30 pound bike is abject misery. Trust me on this.
• City riding, I recommend a flat-bar road bike. For more open road riding, a full road bike.
• You don't need or want any tread on tires. Slicks are the lightest and offer the best traction on pavement. Bike tire manufacterers put grooves on tires to placate naive consumers who think tires need a tread because their car tires do. On pavement they don't - bike tires cannot hydroplane.
• Save some money for a mini pump, tools, spare tube etc. And learn out to use them all before you start commuting.
• Buy a floor pump. Mandatory.

AusTexMurf

Ride on Schwalbe Big Apples, Fat Franks, Delta Cruisers, etc......high volume, reasonably efficient tires that serve to smooth out the bumps in the road...........

Also, switching out the forks on my mountain bike/commuter to Surly Long Haul Trucker forks (greater rake and multiple braze ons) helped smooth out the ride and greatly increased my bike's rackability.

hybridbkrdr

I've riddent banana seat bicycles in the 1970's, a 24 inch BMX, road bikes, mountain bikes, a cruiser... some more expensive, but a lot of cheap department store bicycles.

Anyway, I've gone in every direction for a while trying to determine what I really want. One time I was riding on grass in an area that went down and straight up again. I ended up putting my foot on the ground because I slipped. My crotch area was very close to the top tube. So, I think a compact frame (unlike the tall road bike frames) is ideal to avoid getting knocked down there. As for suspension forks, I got surprises when I least expected them when riding with rigid forks. So, my opinion at this point is to lean towards a compact frame with front suspension forks.

sbslider

I commuted for many years on a mountain bike with a front shock. Getting the shock helped me deal with wrist pain I was having. However, I recently got a cyclocross style bike, which is set up as a road bike with high inflation, narrow tires. No wrist pain, and I am way faster and have way more fun than I did on my mountain bike with a shock.

my experience is the shock is not necessary, or even desirable for just commuting. If you want to do other things with your bike, maybe having the shock will be good. But for just on streets, proper tire pressure, a good compliant frame, and riding smart is all the suspension you need.

a1penguin

Many people opt for bikes that accept wider tires. They absorb some of the bumps from the road. Most road bikes have 23 or 25 mm tires. Hyrbrid bikes have 28, 32 or 35 mm tires. Mountain bikes often have tires that are as wide as 2 inches (that's 50 mm). Wider tires have higher rolling resistance which is why some people don't like them. The downside to skinny tires is that if you do run over some rock, it can cause you a bit of sideways motion unless you go over it square. And with higher pressures that skinny tires take, you often get more flats. The terrain you expect to ride on will help guide the decision of bike purchase.

gpolly1

I switched from a fixed to a suspension front fork. Love the ride and it doesn't add time from my commute. I also switched from 26" to 29" wheels, maybe that's why my time is the same. There were several bumps, holes, and uneven pavement that would make me think my old, fixed fork bike was going to crack (it never did). But, my new bike with suspension rides smooth. Now, I'm looking for bumps, holes, and uneven pavement to hit!

tcs

You might find this study of bicycle suspension and energy loss interesting.

contango 

If you've got four wheels then unless the surface is flat and smooth the chances are you'll have one wheel off the ground at any given time without some form of body flex or suspension (that's why photographers use a tripod rather than a quadrapod). With two wheels it's less of an issue. There's also the relative weight of the two vehicles - in a car you might have an 80kg driver in a 1500kg vehicle whereas on a bike you've got something more like an 80kg rider on a 12kg vehicle.

The front wheel could conceivably rise off the ground in a bike without suspension but it's not something I've ever had a problem with. I suppose if you were to ride at great speed into lumps it could conceivably happen but if I were hitting lumps that hard I'd be more worried about wrecking my wheels than the brief moments where steering was restricted.

Suspension is great on rough surfaces, and if you get a suspension fork with a lockout you can switch between having suspension and not having suspension depending on the terrain. It will add weight although whether that's an issue would depend on why you're riding. There's a gravel path near me that I can comfortably ride at 15-20mph on my hardtail MTB but on the cross bike anything over about 12-13mph feels like I'm shaking my teeth out. That said the cross bike is sufficiently faster on tarmac that I'll either avoid the gravel path, or accept that I have to ride it slower than on the MTB.

For me if I want speed in exchange for rougher surfaces not being so pleasant to ride I'll take the cross bike. If I want more comfort, more "go-anywhere" ability in exchange for outright speed I'll take the MTB.