Road bike vs. recumbent comparison

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Gary123

Zen MBB Master
Must be me. Crashes on an upright over 40 years were extraordinarily rare compared to a bent. There must be some physics involved. And a front flat never once took me down on upright but not so on a bent. First front tire flat on the bent....down. As I said, must be me. Over and out.
It's not just you. There are numerous posts here concerning front flat wipeouts. Most people are shocked but the sudden loss of control as I was. Second flat I managed to stay up although I was only going about 15 mph uphill. On the other hand some people say how easy mbb is to self correct after a slide and when a flat occurs they just slow to a stop. Personally I don't see it. Just wondering if anyone has had bad experience flatting in rear wheel drive such as bacchetta front or rear.
 

Leif

Active Member
I recently had a front flat near-disaster. Wasn't going very fast, made a slight steering adjustment and almost went down. Very surprised at how quickly the loss of control happened. Was also surprised that the tire still had enough air to keep most of its form, just kinda squishy. Must have been a slow leak.
Anyway, I've been checking both tires more regularly especially before heading down hill.
 

ed72

Zen MBB Master
I think there is something in all this talk about blood and feet being elevated. My power on a 'bent is limited by breathlessness. Actually I hardly ever sprint, because it always nearly kills me. There is a long hill near me, and I can only just reach the top, and my lungs are working to the max. I never go at maximum effort, because I know that if I do I will have to stop. The only way to get up that bastard is to go slowly on purpose. I never thought about this when I rode a DF. Maybe I need to wear some kind of vest that squeezes my body so the blood is pushed into my legs.

Here is another bit of anecdotal evidence for you: I am a mid-footer, and I turn my ankles and scrape, because it seems to give me a tiny bit more power for the same effort. I need every bit I can get.

I have had some improvements in breathing and power and therefore, max heart rates. I think it might be three factors. I have been using a so-called PowerLung breathing device to exercise the breathing muscles and I also position my neck and scapula to maximize airflow to the lungs. One year ago, I could barely hit 125 BPM and my FTP was under 150 watts. I was slow. I can now do a 10 mile time trial at 150-152 beats and 240 watts (nothing special in an absolute sense but the improvement is large). It is delivery of oxygen to the legs. I am breathing deep as expected. There is clearly an adaptation that I have undergone. N = 1 for sure. I would love to regain my upright power. Maybe next year.
 

ed72

Zen MBB Master
It's not just you. There are numerous posts here concerning front flat wipeouts. Most people are shocked but the sudden loss of control as I was. Second flat I managed to stay up although I was only going about 15 mph uphill. On the other hand some people say how easy mbb is to self correct after a slide and when a flat occurs they just slow to a stop. Personally I don't see it. Just wondering if anyone has had bad experience flatting in rear wheel drive such as bacchetta front or rear.
What is the natural response to a front flat on a DF? I don't know about anyone else, but I polish the roids. Little weight on the front tire. Use rear brake gingerly. The truly cool raise their left hand.
 

jond

Zen MBB Master
Must be me. Crashes on an upright over 40 years were extraordinarily rare compared to a bent. There must be some physics involved. And a front flat never once took me down on upright but not so on a bent. First front tire flat on the bent....down. As I said, must be me. Over and out.

Probably just unlucky. Remind me not to buy your m5 lol.

Any tyre flat that presents only one edge of the rim is going to result in a slide and an off most likely. Pray for flat straight roads.

The vendetta seems to get more front flats and wears front tyre out first. But the advantage of the evenly weighted wheels means no front wheel wash outs.

It’s better for me to flat on any bike the rear. That’s because it tracks straight and follows the steered inputs of the front. Right before I either stop or crash lol.

It’s a lottery. Go get tannus tyres .

Coming off df at a head height of 2 m is highly dangerous give me low feet first heads up safety.

I crash no more or less on the vendetta compared to the df. The mtb is sold. Lol.

The fat bike crashes itself usually in soft sand. Ahhhhh. But still hurts.
 

Balor

Zen MBB Master
It's not just you. There are numerous posts here concerning front flat wipeouts. Most people are shocked but the sudden loss of control as I was. Second flat I managed to stay up although I was only going about 15 mph uphill. On the other hand some people say how easy mbb is to self correct after a slide and when a flat occurs they just slow to a stop. Personally I don't see it. Just wondering if anyone has had bad experience flatting in rear wheel drive such as bacchetta front or rear.

It is absolutely an issue with any bent, FWD or RWD, provided you are reclined enough to severely hamper your ability to make quick body balance corrections.

Theoretically, FWD bent are a bit more affected, because usually they 'use up' both steering and driving traction on their front wheel, and as I understand the 'traction pool' is shared if drifting cars are of any indication. Whether our relatively puny (compared to hundreds of HPs) power outputs are enough to contribute to front wheel drift I'm not sure at all, though. Effect is likely minor unless you are driving uphill and in that case high speeds are attainable only by Jason and he's too good to crash :).

MBBs are even more affected, though. Somebody mentioned jackknifing, as much as I recall? Well, it happened to me too on my 65 deg MBB a couple of times when tried to hit dirt roads wit slick tires. If trail force that stabilize steering at speed is to suddenly disappear and balance is perturbed, front triangle is free to flop under it's own weight in direction of the lean, and due to no front tire grip you will not actually STEER into the lean hence no 'lean-correcting' force would be generated, and unless you 'muscle' the front triangle back and lean the body to correct for balance - down you go.

That is why Jason can navigate gravel MTB trails on 30mm tires on his DF and emphasize that that is something you can never do on Cruzbike. *shrugs*

Why I sit bolt upright on my 90deg steering MBB, I feel *almost* as safe in moderately loose stuff as on my MTB. No flop, 50mm wide knobby tires, plenty of room to make body correction when you momentarily lose traction.
Almost, but not quite - I'm still much faster on those roads on my unsuspended niner DF. Obviously this is a question of skill, too - I'm a very timid and clumsy rider.
 

Balor

Zen MBB Master
My power on a 'bent is limited by breathlessness.

Here is another bit of anecdotal evidence for you: I am a mid-footer, and I turn my ankles and scrape, because it seems to give me a tiny bit more power for the same effort. I need every bit I can get.

I don't have any solid data, but I suspect that scraping is using other muscles for bracing (same goes for bar-pulling, obviously), hence mechanical efficiency goes out of the window. That's why pros and long-distance cyclist hardly ever use it. I certainly didn't't and was fast enough even on upright DF MTB on brevets...

Track cyclists most certainly do, however, to achieve monstrous watts at very high cadence - but they are not at all concerned about maintaining that effort for long.

Btw, before I learned to scrape and switched to MBB with bars that are easily pulled as means of bracing, I was NOT limited by my lungs - but by *perceived* muscle weakness when I've tried to pedal as on DF.
There is certainly a trade off between losing power outright due to ineffective bracing and lost mechanical efficiency due to requiting more muscles than necessary for more effective bracing.
If you are a cross-country skier, you might take very well to bents - due to having plenty of lung capacity to spare.
 

bladderhead

Zen MBB Master
Scraping seems to be good for me. Maybe because it makes me apply constant force all round the pedal arc.

It might have been me who mentioned jackknifing. I was doing 27mph and both tyres blew up at once and it jackknifed. Everybody is talking about front tyre blowouts, but I had to top that.

Steering restraint would help in this situation.
 

Balor

Zen MBB Master
I was doing 27mph and both tyres blew up at once and it jackknifed.

Ouch. How did you manage THAT, a large pothole?

Steering restraint would help in this situation.

Yea. May not prevent you from going down after all, but would certainly help.

Admittedly, even my MBB will still flop into a lean (as opposed to any conventional MBB that would flop into a TURN as well, and effects are cumulative), but it would be nearly as strong, if still too much for my liking - I can pedal a bit no-handed now, and even coast 'no-legged', but it is too front-heavy and flops too hard and too fast to be truly self-stable... small wonder - it weights about as much as Vendetta (and I'm talking assembled, not just the frame!) There is room to make it at least 1/3 as light rather easily. Self-steering into a lean is actually a good thing for self-stability, but there can be too much of a good thing.

Installing short cranks and bars with shallow drops, so you can have hands comfortably straight AND not have your knees mess with the bars AND being able to sit up without the boom hitting your sternum should be a huge boost to safety on Vendetta - this way you can negotiate tricky ground (like blind turns or stretches of pothole-infested asphalt or dirt/sand) sitting up comfortably.

Non-tilting hamsters bars are much worse, though.
 

Balor

Zen MBB Master
Must be Russian pothole.

Actually, I've personally witnessed how a guy blew both tires on a pothole once (road bike). He didn't crash, btw.
Fortunately, that stretch of road is now repaired, so in theory I can even ride a lowracer there... if I didn't worry about being run over by a truck, that is.
Anything supremely aerodynamic is automatically not very visible... (Low "A" in CdA).
 

bladderhead

Zen MBB Master
After I crashed I looked along the road, but could not see anything that might have caused it. Those Russian holes are very clever. They do not hang around. They are trained by the FSB.
 

bladderhead

Zen MBB Master
I have Tannus on my Grasshopper. The ride feels harsh, and the Grasshopper has springs at both ends. And it has made the bike wobbly. I think that bumps sometimes impart a sideways force on the wheel, causing a steering effect. This force is absorbed by air tyres because they deform. People say tyre deformation is important, and I think Tannus demonstrates this.

I am more scared of sliding on Tannus than on air tyres. They just do not feel safe. I got the Silvio because I wanted a faster bike than the Grasshopper. If I put Tannus on the Silvio I think I would be riding the brakes downhill.
 

Gary123

Zen MBB Master
Thanks. I think I'll look into tubeless. Tannus has some impressive promos but I was looking for some real world experiences.
 

RojoRacing

Donut Powered Wise-guy
Thanks. I think I'll look into tubeless. Tannus has some impressive promos but I was looking for some real world experiences.

Biggest problem with flat tires on a bent is the fact you're not able to glance down and see your tires to see if they are low. On a bent you don't know you're at 40psi until you hit a harsh bump or go into a corner and slide out. With tubeless if the leak is one of those slow silent ones it will surely seal on it's own so no surprise flat tires. If the leak is a fast one you're going to hear it and can take steps to quickly stopping. My only crash on a road bicycle was in a corner due to a front flat tire I didn't hear leaking because I was going to fast to hear, I got big ears that catch lots of wind. This was back in the using tubes days and since then I always gave my bike a bounce to check my tires before starting a descent, this is harder to do on a bent. I still do the same these days but it's less needed now that I have tubeless.
 

Gary123

Zen MBB Master
Yeah I'm not sure I can bounce a vendetta, I usually just hold my breath if I hit a sharp bump or pothole until im sure its ok. Any recommendations on tubeless wheel and tire setups. I'm looking at bontrager, mavic and Shimano ultegra.
 

Balor

Zen MBB Master
The ease of the Mavic UST sure intrigues me. No tire levers or special pump needed.

Not really, depends on tire. Also, good luck finding 'true UST' road tire these days, not to mention they not that stellar CRR - I have one from ye olde days, I know. They are very thick and heavy, basically come with a butyl tube built in.
 
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