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-   -   Are bents stable on bumpy roads? (http://www.bikeforums.net/recumbent/458669-bents-stable-bumpy-roads.html)

CrimsonEclipse 08-26-08 05:33 PM

Are bents stable on bumpy roads?
 
With a 26" upright commuter, a certain series of bumps (think rumble strips with potholes) is more tolerable than my 20" folder, which can get squirley of the same patch.

So, how would a bent take urban bumps.
Does over seat steering -vs- under seat steering change stability?
What about wheel base?

(while I'm asking)
Can a bent handle a dirt or non pavement road with no hills?

Thanks

CE

Floyd 08-26-08 07:32 PM

I will just touch a little on your last question...my findings are that the tire size, just as with DF, help you stay upright on no paved roads...that is bigger tires mean better handleing on the rocks and or whatever.
That is must my own experience...FWIW

gcottay 08-26-08 07:54 PM

Bents, which I ride almost all the time, have ride variations similar to DF's. Design, material, tires and suspension (if any) all make a difference.

The one rough-road drawback of bents as compared with DF's is that it some much more difficult to unweight yourself yourself when you hit a really nasty patch. On a DF you would be off the seat letting your legs absorb some of the shock. On a bent you sit there in your comforble seat and take whatever comes along that you cannot miss.

Many bents and many bent riders can go off road in the dirt. A few exceptional riders would disagree, but I would not want to use a bent as a mountain bike.

Jeff Wills 08-26-08 11:02 PM

Quote:

Originally Posted by CrimsonEclipse (Post 7348690)
With a 26" upright commuter, a certain series of bumps (think rumble strips with potholes) is more tolerable than my 20" folder, which can get squirley of the same patch.

So, how would a bent take urban bumps.
Does over seat steering -vs- under seat steering change stability?
What about wheel base?

(while I'm asking)
Can a bent handle a dirt or non pavement road with no hills?

Thanks

CE

I've had no problems with rougher pavement and decent unpaved roads. A few years back, on Cycle Oregon 14, the route took us down several miles of smooth dirt/gravel road. My wife and I on our Lightnings had no problems, and we went about the same speed as the uprights.

That was the second day of the ride- from Seneca to Crane, Oregon, on September 10th, 2001. The next day we rode to Diamond in the quietest procession I have ever been involved in.

Jeff

LWB_guy 08-26-08 11:03 PM

I found a couple flat sections of road -- one on a bumpy dirt road and one on a paved road -- that I rode over once on my bent. Now I avoid those sections.

Riding down the street of a small town tonight after dusk, I had a frightening experience. I hit a speed bump at around 20 mph, way too fast. The speed bump was unpainted, so I never saw it until I hit it with my front wheel while moving fast.

It would not have been a pleasant experience in a car. It was unpleasant on the bike. I relaxed
my arms and maintained stability and control, and kept going. I am happy my bike is so reliable. I'm also glad I wasn't turning when I hit the speedbump. I ride a long-wheelbase (63.5inches) bike with underseat steering.

My seat height is 23.75 inches above the pavement. That's much lower than on a regular upright bike. The lower your seat is, the harder it is to lean over to one side. However, I find I can easily compensate for this by moving one leg outboard while the other one rests on the pedal.

Yes, my bike can easily handle dirt or gravel roads. It's just the washboard sections caused by heavy trucks driving repeatedly on flat, wet, dirt roads that I want to avoid. The smooth gravel or dirt roads are just as good as asphalt.

One exception: Tonight I was traveling on a two-lane paved road. The shoulder was concrete, sloped pretty well away from the asphalt, like on a freeway. During daylight, I rode over the rumble strips on the concrete with no trouble, just a little friction. After dark, it felt bad when I drove on the sloped concrete shoulder.
I didn't like the feel. It was uncomfortable with traffic passing me. So I moved back to the left of the white lane and felt fine.

Myqul 08-27-08 02:12 AM

Quote:

Originally Posted by gcottay (Post 7349539)

The one rough-road drawback of bents as compared with DF's is that it some much more difficult to unweight yourself yourself when you hit a really nasty patch. On a DF you would be off the seat letting your legs absorb some of the shock. On a bent you sit there in your comforble seat and take whatever comes along that you cannot miss.

I have to disagree with you there. When i come to a "nasty patch" in the road i "sit up" on my HiRacer (so my bum is on the seat but my back isnt resting on the back rest) This has the effect of unweighting the back wheel to absorb the shock

cat0020 08-27-08 09:34 AM

Speed is your friend, your forward moving momentum will increase your stability going over bumps.. to a certain level... until you taco your wheels.

John C. Ratliff 08-27-08 10:26 AM

I have an older Rans Stratus, and have over 9000 miles on it. I have found it to be very stable for minor bumps and pavement interruptions. The Stratus, as as long-wheel base recumbant, has a light front wheel, and so in fine gravel it tends to skid a bit. But in other situations, where you would in an upright be close to off-balancing, it handles very nicely. Because of the low center of gravity, it is more stabe in many of these situations than an upright bike, which has a much higher center of gravity. Being made of steel, and with the long-wheel base feature, the bike also absorbs bumps quite well. I do deload my back by leaning harder against the seat, and lifting my rear off the seat pan, when there is a big bump. My backrest, and upper back then takes the bump and not my lower back and spine.

John

CraigVM62 08-27-08 12:21 PM

Years back I tried several of the Bike-E Recumbents, including their model with rear suspension. It made a night and day difference for me when test riding over some 1" to 2" potholes. I see several other makes and designs out there that utilize some suspension systems. It would be great to hear what owners of those bents have to say regarding this subject.

gcottay 08-27-08 08:20 PM

Quote:

Originally Posted by Myqul (Post 7350979)
I have to disagree with you there. When i come to a "nasty patch" in the road i "sit up" on my HiRacer (so my bum is on the seat but my back isnt resting on the back rest) This has the effect of unweighting the back wheel to absorb the shock

You're right on that. I do the same thing. For me it's sort of an involuntary twitch without even thinking about the purpose. The bad spots do make me wish those nice flexing legs were working as shock absorbers.

JanMM 08-28-08 08:05 AM

"..rumble strips with potholes" sounds like a lot of fun.

crackerdog 08-28-08 09:35 AM

I have a couple of BikeE FX which have shocks in front and back. I found it amazing how much difference it made to have front shocks for handling. Just like in a car, the front shock helps to keep the front wheel in contact with the road. I was riding down a slight hill at maybe 15 mph and decided to try biking in the swale next to the road. I could hardly tell I was off the pavement, it handled so well. Though, I don't care for the BikeE in general, the FX is nice for off road or gravel.

LWB_guy 08-28-08 10:15 AM

My long-wheelbase bent has two separate parts. One part supports my bottom. The other part supports my lower back. Recently, I discovered that by pressing my back against the back support, I can lift my butt off the bottom section. I did that while crossing railroad tracks.

John C. Ratliff 08-29-08 05:44 PM

Quote:

Originally Posted by CrimsonEclipse (Post 7365551)
I appreciate the input.

Um, what does DF mean?
(I'm guessing it means and conventional frame but I can't guess the exact phraseology)

CE

DF = "Diamond Frame" which is a regular bicycle.

John


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