Road bike vs. recumbent comparison

[Osiris]

I can vouch for that. This front flat on ice feeling can be experienced in all its glory on other bents. I hit a nasty little but deep pothole lurking in the shadows. Immediate front flat. In fact the impact was so great, my rear wheel left the ground. Having grown up riding my bikes on frozen ponds in the North, I could keep it upright but zero steering. The road was sharply off camber and angled to the left, where I wound up in a 2-3 foot deep ditch next to a colonial era graveyard. The poor souls were covering their ears by the time I was done. So, I can confirm a rear drive, reclined bent is a handful with a front tire blowout.

Just out of curiosity, what kind of bent were you riding when you had that blowout? Was it an M5 CHR by any chance?

 

[ed72]

Just out of curiosity, what kind of bent were you riding when you had that blowout? Was it an M5 CHR by any chance?

yes

 

[Osiris]

yes

I knew it. The M5 is hard to keep upright even when you don't have a flat front tire.

 

[Balor]

I can vouch for that. This front flat on ice feeling can be experienced in all its glory on other bents. I hit a nasty little but deep pothole lurking in the shadows. Immediate front flat. In fact the impact was so great, my rear wheel left the ground. Having grown up riding my bikes on frozen ponds in the North, I could keep it upright but zero steering. The road was sharply off camber and angled to the left, where I wound up in a 2-3 foot deep ditch next to a colonial era graveyard. The poor souls were covering their ears by the time I was done. So, I can confirm a rear drive, reclined bent is a handful with a front tire blowout. Certainly running tubulars would minimize this effect but I was thinking it could also be (perhaps?) mitigated with a different rim width/depth. Some of the new rims are so wide that there is no sidewall or more importantly tread to "cover" the rim bead edge. In effect, the width of the entire casing is taken up by the rim well. Well? Is this plausible?

Plausible - maybe. But it would require a VERY wide rim, much wider than tire itself (like a niner enduro rim with, 25mm+ (likely 30) or so INNER width for a 23mm rated tire), or you will in fact be pinch flatting sidewalls which is actually worse. You'll have something akin to 'low profile' rubber and may be actually scraping your rims when leaning into a corner... which may itself lead to a fall.

Certainly worth experimeting, but I in fact installed 23mm rated tire on a 23mm inner width rim and got a nice aero shape, but when you squish the tire flat, it still gets pinched between the floop and rim, a small section of a sidewall.
It may be different (and actually worse) when hitting a real pothole. Plus, you'll likely destroy your rim if hit was hard enough without tire rubber damping the blow.

What is needed is 'Huck norris' for road tires. I guess you can buy one and cut it in half? When applied to a tubeless tire, it should negligibly affect rolling resistance but, if tests are of any indication, considerably lessen impact of pinch flats.

 

[ed72]

I knew it. The M5 is hard to keep upright even when you don't have a flat front tire.

The 2-3 foot deep ditch wasn't the problem?

I knew it. The M5 is hard to keep upright even when you don't have a flat front tire.

I kept it upright. Right into the ditch. Up and over. Upright and upside down in the pricker bush.

 

[Balor]

Heh, I've just tested my hypothesis about running on an empty tire... punctured a tire on a railroad crossing (90 kg normal load is a bit too much for a 23mm tire pumped for 100 psi I presume), sealant only slowed air escaping down a bit... well, I've come to a pretty graceful stop.
Too bad I cannot fit a tire larger than 23mm 700c upfront. Ok, 25mm 27.5 tire time!

 

[ed72]

Heh, I've just tested my hypothesis about running on an empty tire... punctured a tire on a railroad crossing (90 kg normal load is a bit too much for a 23mm tire pumped for 100 psi I presume), sealant only slowed air escaping down a bit... well, I've come to a pretty graceful stop.
Too bad I cannot fit a tire larger than 23mm 700c upfront. Ok, 25mm 27.5 tire time!

The sealant made a hissy mess? Maybe those couple extra seconds are enough to prevent a fall? This is my working theory. I was getting a flat every week once my 25 mm GP4ksii without sealant but they also had over 4,000+ miles on them. Since I swapped them with new ones, not a single flat but also latex and sealant. I suppose I will get three flats today. LOL> Starting to get nervous now that the "new" ones are getting worn down. Maybe change out after doing a 600K in a few weeks. Probably time to reflesh the sealant......

 

[RojoRacing]

Take a look here for my latest tubeless review after getting a front puncture tonight. https://cruzbike.com/forum/threads/crash-due-to-flat-tire.12426/page-2

 

[RojoRacing]

Ok here are few screen captures of my strava data for a 6 mile 8% climb in the middle on a 200 mile ride. Both were at similar efforts with very similar times but on two very different machines. The V20 was faster by 1:11 over 52 minutes with only 5 watts high average power. I don't think wind is much of a factor on this climb or at least I don't recall there being much if any.


This is the 22 lb Trek Domane at 53:14 and 223watts https://www.strava.com/activities/1797657042/analysis/24853/28038



This is the 26-27lb Vendetta at 52:03 and 228 watts https://www.strava.com/activities/576238504/analysis/15402/18525



Here is a comparison of the two runs with the black baseline being the DF and the Purple line as the V20. So on the V20 I pulled ahead 40 secs in the first part but then the DF pulled even in the middle before losing just over a min in the second half. Both attempts where at around the 100 mile mark during double century rides. I cool to see 2 years apart how close my efforts were in wattage up the climb esspecially since last weekends attempt on the DF was a chill ride with a friend and 2 years ago on the V20 it was an race for the Triple Crown series. The temp was slightly higher on the DF ride but I wouldn't say it hindered me at all. It's a shame I forgot my HR strap at home for the DF ride so we can't compare HR up a long climb at similar efforts.
https://www.strava.com/segments/566721/compare/NDUxMTkxMTcwNDIsMTM5ODk3MzQzMjY=



So what does this all mean? Well not a whole lot other then an example of the single test sample over 2 years apart. Take away from it what you will.

 

[Balor]

Rojo, you said that Thor seat made a large difference in your power delivery. Can you specify what 'regions' of the seat do you use to brace against for pedal pushing?
You said you've been an avid MTB singlespeeder. Do you notice that your 'round pedal stroke' singlespeed is very good at instilling helped you particularly well on a bent?

 

[RojoRacing]

I wouldn't say the Thor seat gave me more power, it's more like the stock seat was causing enough discomfort that I was unable to consistently put out all the power I had to give the Thor just doesn't cause me to lose any power to discomfort. There are no certain pressure points when putting out more power, it just fits your whole back so you push on the whole things all the time. Not sure what you're implying with the single speed and round pedal stroke as they are unrelated and dependent on the rider themselves and not what they ride. My experience on the SS I think helps me ride a wider range on cadences comfortably. Where someone like @LarryOz will start freaking out if he drops below 80 I'm comfortable down into the 60's when climbing because on the SS you may have to stay in the 40's for 10 mins at a time. The SS also teaches you to pedal very smoothly at low cadence because when you are below 5orpms you're out of the saddle on something very steep and mostly likely on dirt with little traction so if you're not smooth you'll break traction on the rear just like we do on the front of the MMB. The funny thing is the pedal stroke for smooth climbing on a SS when it gets extra steep is very oval and not round requiring you to rock your whole body between power phases to compensate for the surging power cycle. I will say if you are able to master this type of climbing technique you'll have an ability to control how you want to apply your power on any type of bike or situation better then anyone who lacks the SS experience because the SS example is so specialized and extreme.

 

[Balor]

Well, I *suppose* that you cannot simply get away with 'pedalling squares' (though it is most mechanically efficient) on a single speed. I presume that track racers also might do good on a bent, and not just FWD at that.
What I mean is once used up all the torque your body weight on pedals (given fixed gear ratio) provides, you MUST resort to 'round' (oval, whatever) pedalling including scraping, 'kicking', even pulling up.
I've been a very straightforward masher on my DF and it worked fine for me, especially given that I'm a clyde.
Once I've been on bents for long time, I've gained a MUCH rounder pedal stroke and can do 'track-like' seated sprints by working 'around the clock', hit 50 kmh on MTB recently (though I've overcarbed a bit, admittedly ).
My speeds on DF are quite a bit lower than I've used to have admittedly, but I gained back nearly 20 kg of weight as well and I'm using 2.35 knobbies front / 2.1 heavy touring semi-slick rear (tubeless, though).

Still, my BMI is double of yours hence my woes are likely incomprehensible for you.

 

[ed72]

Impressive Rojo and inspiring for those of us struggling at the bottom of the hill, thank you for taking the time to share your unequivocal data.

 

[bladderhead]

You do not have to be on a SS MTB, a Cruzbike will do just as well. I grind my Silvio up the hill at 4mph and 60rpm, sometimes lower than those numbers. Scraping helps to avoid wheel-spin. Also, it means you are pushing down, which has no effect on steering. So there's less wandering all over the road.

 

[DavidCH]

I've been reading recently about tricks pro riders use. They generally use a size smaller frame than what the weekend warrior rides with a longer stem this allows them to get really tucked down low in an excruciating position for 5 hours riding. It also allows their ride to be lighter ... so much suffering just to save a number of watts.

 

[Osiris]

After yesterday's result, I'm going to have to revise my previous statement that riding a bent exclusively for the past few years has done nothing to improve my performance on a diamond frame. It certainly looks that way when you compare maximum power numbers. Though I'm stronger than ever on a bent, my max power numbers on the DF have definitely suffered. Back in 2014 it was ~1300 watts. I could routinely hit 1150-1200 watts on that bike when climbing steep hills. My FTP however, was a paltry 210 watts. Of late, my max power on a DF seems to be back up to about 1150 watts. So that's still below 2014 levels, but while on a straight and perfectly flat section of road I looked down and noticed that I was putting out 287 watts, and it didn't feel like I was really pushing hard. I kept going at that level for as long as I could, but at some point I had to slow for a sharp left turn, so that was the end of the run. I felt no lactic acid buildup or shortness of breath, so I'm assuming that I could have gone for much longer at that power output. There's no telling how long, but I distinctly remember that when I was riding a DF exclusively years ago, I struggled just to hold 230 watts for any significant length of time. A 57 watt increase is huge, and since I don't do any other form of training, I can't see what could account for it other than riding the bent. So it seems that while my peak power is still lacking, my "midrange" power has increased significantly.

 

[Balor]

After yesterday's result, I'm going to have to revise my previous statement that riding a bent exclusively for the past few years has done nothing to improve my performance on a diamond frame. It certainly looks that way when you compare maximum power numbers. Though I'm stronger than ever on a bent, my max power numbers on the DF have definitely suffered. Back in 2014 it was ~1300 watts. I could routinely hit 1150-1200 watts on that bike when climbing steep hills. My FTP however, was a paltry 210 watts. Of late, my max power on a DF seems to be back up to about 1150 watts. So that's still below 2014 levels, but while on a straight and perfectly flat section of road I looked down and noticed that I was putting out 287 watts, and it didn't feel like I was really pushing hard. I kept going at that level for as long as I could, but at some point I had to slow for a sharp left turn, so that was the end of the run. I felt no lactic acid buildup or shortness of breath, so I'm assuming that I could have gone for much longer at that power output. There's no telling how long, but I distinctly remember that when I was riding a DF exclusively years ago, I struggled just to hold 230 watts for any significant length of time. A 57 watt increase is huge, and since I don't do any other form of training, I can't see what could account for it other than riding the bent. So it seems that while my peak power is still lacking, my "midrange" power has increased significantly.

That's interesting. I just lack motivation (and butthurt tolerance) to do any long-term DF training, plus I have different length of cranks (150 vs 175) and that is bound to confound things... but it certainly *seems* like my DF power is much less (and speed numbers show it) than it was a few years ago, except, like I said, sprinting power and I am doing it differently now.
How much actual training mileage did it take you to get back your 'DF form'? Do you notice any difference in your pedalling style on DF (like, say, going for a more 'spinner' as opposed to 'masher' style)?

 

[RojoRacing]

Something that gets forgotten is the faster you are as a rider to greater you can take advantage of a bents aero advantage. I know that seems obvious but so my bent riders aren't elite level racers so what may be true for Joe racer may be far less true for casual Bob. I can climb pretty damn fast on my V20 with similar times to my DF bike but if I were to be half as strong and going half as fast up that 6% grade the aero advantage of the bent would drop and the weight advantage of the DF would rise.

 

[Osiris]

How much actual training mileage did it take you to get back your 'DF form'? Do you notice any difference in your pedalling style on DF (like, say, going for a more 'spinner' as opposed to 'masher' style)?

I only ride once or twice on weekends, and I would say that it took about five or six weeks of riding the DF before I regained most of my power. It felt completely unnatural at first, as if my legs were trying to do something they just weren't designed for, but now it feels normal again.

My pedaling style on the DF is totally different. It's much faster for one thing, and I don't use the "scraping" method or pull up on the return stroke. Yesterday I set a personal record on one Strava segment, where I reached a maximum cadence of 167 rpm at 29.3 mph. I've never been able to pedal that fast before. My previous record on the same DF was 142 rpm. That was years ago, before I started riding bents. For some reason I just can't pedal nearly as fast on a bent, which is probably the reason I can't hit the max power numbers that I can on a DF. Kent Polk, who I've ridden with, can pedal up to 180 rpm on his M5 recumbent, which is probably the reason he can hit those incredible speeds in sprints.

 

[Balor]

Given that peak power and FTP are not strictly (and sometimes inversely) related, and if you've trained your FTP much more than your sprint on a bent, it might very well be that you've simply converted most of your type IIb fibers into type IIa over those years - simply because efforts above FTP are so much harder on a bent!
By the way, if you don't 'consciously' scrape and push, it does not mean that you don't at all. You physically cannot hit very high RPMs without seriously round pedal stroke! Wattbike 'figures of eight' of track sprinters show that.

As for cadence difference of DF vs bent, that's totally not uncommon - I've read reports by streamliner pilots at BM that complained about the very same thing. I don't have a cadence meter (I guess I should get one, bit cheaper than power meter ), but it certainly seems same way as well for me.
That's strange indeed because orientation against gravity should not matter much - both of your legs are attached to cranks, so one leg going up and 'counterbalanced' by any other leg going down, but is likely more complex than that...