BCATC

I just picked up a '93 Stumpjumper for the purposes of creating a sort of do-it-all commuter for mixed terrain and to preserve my road bike. What sort of tires are most of you running? I'm checking out Tioga City Slickers currently. What came on the bike were knobby 1.95 tires but I would assume that a 1.95 is a little unnecessary and slow for my purposes?

mjtull

What comes first, the bike or the surface we ride on? The point is we all tend to ride where we want or need with the bike(s) we have and adapt and compromise to suit. If you get to the point that you just can't decide on that perfect new bike, there's a good possibility you already have it.

Teamprovicycle

Thw term moutain bike is thrown around too much . a mtb is a bike made to go up and down an off road trail . most of these so called mtbs would not make it one day . they call most of these mtb road bikes hybrids gravel grinders and cx . so really what is a mtb if its on road with road tires is ir not a road bike , or a bike on road ????

Kapusta

You make a valid point on the sematics, but I am not sure it serves the purpose of this thread, which (as I understand it) is discussing the use of bikes built on mtb frames on the road. Some have then set up for trail riding as well, others not.

There are usually real differences in the frame geometry of mountain bikes and bikes built with drop bars for road, CX, and many of the bikes grouped into the loose term “gravel”. And these differences have become more pronounced over the past 20 years.

fireaza

Every cycling enthusiast I've ever talked to seems to think it's madness to use a bike with suspension (i.e MTB) on a road. But then I wonder, cars have suspension (even ones that wouldn't handle driving off paved roads very well) so is it really that crazy for a road bike to have suspension too?

General Geoff

No, but from the perspective of an enthusiast or racer, suspension adds weight and complexity, and reduces pedaling efficiency. These drawbacks are magnified in hilly terrain.

If you don't mind going a bit slower and/or putting out more effort, then no, suspension is not a crazy thing to have on a road bike.

People have been using spring-suspended saddles on road bikes for a hundred years.

Kapusta

I am thinking maybe that is why so few people find the need for suspension on the frame.

As I get older and my back gets more precious, I am seriously considering one of the newest generation suspension seat posts geared towards road/gravel bikes (because a spring saddle would be too straightforward and sensible) Otherwise, the full bike suspension I get from set of 38mm Compass tires at 38f/48r psi is all the suspension I really need or want on the road.

I love lots of suspenson on my MTBs though.

rachel120

How does suspension make traveling on roads worse? I mean, what are the actual mechanics? How much does a suspension system actually weigh? Why is it that losing or gaining 5 pounds from your hips doesn't make a difference but the weight of the suspension fork does? Why does the bit of bobbing up and down matter so much, but the bike rocking a bit back and forth with every pedal stroke isn't even worthy of mention when it comes to a loss of energy? It seems people really rag on them, but don't compare them to other variables that don't rate a mention when loss of energy is discussed.

cyccommute 

It's not necessarily the weight that is the problem with using suspension while road riding but the movement of the suspension that is most of the problem. The longer the travel, the more the suspension robs momentum. My mountain bikes have lockable suspension and/or suspension only on the fork. Locking out the suspension goes a long way towards making it more efficient when riding on the road. My dual suspension bike even does it automatically on the rear. Unless it hits a bump big enough to open the valve, the rear end is rigid and puts power to the pedals instead of absorbing it in the suspension.

Bikes shouldn't rock back and forth when pedaling. Any movement outside of a straight line is energy lost. I see lots of people with poor technique that are weaving when they pedal but that's not optimal. If you want to get the maximum (or even good) efficiency out of your bike, you should teach yourself not to weave as you pedal.

Same goes for the "bobbers"...i.e. people who bob their bodies up and down as they pedal. That just wastes energy. They are more like what people experience with an active, poorly controlled suspension system.

On out of the saddle efforts, rocking the bike from side-to-side is natural and allows you to put more power to the ground but the line of travel should be straight. It's also not terribly energy efficient but it's kind of like stomping on the gas on your car. It makes you go faster but it takes a lot more energy to do it.

rachel120

How don't you though? You put your left foot down to the bottom of the pedal's rotation, you're leaning a bit to the left because the foot going all the way down shifts your center of gravity. You put your right foot down, you lean a little to the right, again center of gravity going sideways.

So yeah, why are forks nagged on so much, when so many other things changes your center of gravity to the point your body weight goes along for the ride, no pun intended.

cyccommute 

You are thinking about how you pedal wrong. You don't "lean to the right (or left)" as you pedal. You are actually countersteering the bike towards the opposite side to regain balance. As you push down on the right pedal, for example, you start to fall to the right and to regain balance, the bike steers left. A new rider will wobble down the road from left to right trying to correct the movement, sometimes to the point of losing the balance entirely.

But you can train yourself to reduce the wobble. Watch someone who is a "smooth" rider. They are traveling down the road centered over the wheels with minimal side-to-side movement. You may also notice that they are traveling faster than many other people. That's also a key to reducing the need to countersteer. Momentum moves your center of gravity down the road in a much straighter line. The slower you go, the more countersteer you need to move you down the road. It takes a lot of training and bicycle handling awareness to not countersteer excessively.

Some people can move on a bike at very slow speed (or no speed) without letting the bike move from side-to-side. That, again, is all about training yourself to balance the bike.

The problem with suspension (not just forks) is that your center of gravity is moving out of the horizontal plane which isn't "normal". That's what robs you of energy on a smooth surface. Most people learn not to bob up and down as they pedal. That up and down movement robs the ride of energy to the pedals and slows them down or makes them work harder. We usually learn not to do that.

Off-road, it usually doesn't matter too much because the terrain is bobbing up and down. Putting suspension on a bike in that situation helps because it allows the rider to maintain a steadier horizontal center of gravity over bumps. Good riders also use then legs and arms as their main form of suspension and the bike's suspension is just a supplement to that suspension.

Happy Feet

The difference between the use of car suspension and bike suspension is that you are the bikes engine.

As cyclo is saying, with no suspension all your torque (if you pedal correctly) is being put into forward momentum. With suspension some of that torque goes into up and down travel.

I think people weave side to side because they don't shift down enough and can't handle the resistance created, so they bobble the bike to bleed some of it off.

Witterings

I could be WAAAAYYY off the mark here as I'm not a scientist / physicist but I would have thought as you're pedaling you generate a certain amount of energy which needs to be displaced somewhere ... if you have soft forks they'll absorb some of that energy in the down up movement rather than it all maintaining the forward momentum / direction of travel ... as I say I have nothing to back this up with but to me seems reasonably logical.

The only thing I can say from experience is it seems faster pedaling a MTB on road / cycle path with the forks locked out to the extent where we do a mix of gravel track / road I always leave the suspension locked as it feels more sluggish when it's not ... but that's obviously not very scientific either

If I remember I'll ask a rocket scientist in the making tomorrow as he may possibly have some constructive input about the displacement of energy.

fireaza

Ah, that makes sense to me. I was thinking the problem was that when the suspension moves, it takes pressure off the road a bit, while if you have no suspension, the wheels are pushing against the road 100% or something like that. Yeah, it makes sense since pedaling involves a downwards action that some of your force might be used to push the bike's frame down instead of all being directed towards making the wheel spin.

grampa.sb

Some years ago, I did a century on my hardtail MTB. I just put on some slicks, and started riding. It sure wasn't my fastest century, but it was far and away my least painful!

cyclintom

I would suggest a cyclocross bike - the older non-disk versions. They ride so much more easily than a hardtail and you cannot ride a full suspension bike well on a road at all. They really are designed only for going fast downhill.

RunningPirate

Yep..my old commuter was a rigid MTB with Michelin city tires on it. The new adventure bike has a fast knobby (Kendra K-Rad) that gets used for commuting...

RunningPirate

Do you find that you don’t get harassed much with that hatchet showing?

av1

mtb on road? Anytime as long as there are good rims and tires.

North Coast Joe

Now that you mention it, I just thought our local motorists were just maturing and accepting bicycle traffic as the norm lately! Glad you axed

kiramen

Loss of energy?
Only if I try to accelerate really fast, with the GT Lt1.
Otherwise, both of these two GT's are nice to ride on the road. Except that the suspension gives a lot of comforts.
Due to the horrible roads in this city, this year I will be commuting with it.
Well, that's the plan.

ItsMeDave

I road a mountain bike with slicks on the road for years. I always thought that road bike tires and saddles were *too* skinny for me. Then I hopped on a road bike about 10 years ago and, damn, why did I wait so long.

Obeast

I think gravel bike is the future. It can take all sorts of road conditions, on a rigid frame with no suspensions, and those disc brakes can stop in all conditions. If I have money, I think I would definitely buy a gravel bike as an all purpose bike.

Patriot1

Great looking bike! Love the leather panniers...who makes them?

North Coast Joe

Thanks for the compliment! The back bags are Weaver saddle bags, available through most tack and/or harness shops. The fronts are horn bags that were hand made by a small harness shop, though similar models are mass produced like the Weaver bags. Both sets of bags needed modification/shortening of the center leather piece in order to fit on the bike racks, but I'm really happy I went that way. Heavier than panniers, though, but it doesn't affect much.