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-   -   V-Rex Speed Question (http://www.bikeforums.net/recumbent/935782-v-rex-speed-question.html)

AerobaticDreams 02-26-14 06:52 AM

V-Rex Speed Question
 
My V-Rex rebuild on a trashed bike is getting close to being finished. Frame comes back from powder coating this week, and it shouldn't take much to assemble after that. I have a question about riding:

On my road bike I keep an average speed of about 14 mph when riding the bike path in my area. That's not killing myself the whole time, but trying to keep at least something of a decent pace. Will I be able to keep this same pace with about the same effort with the V-Rex? When I first got it and tried to ride it, it felt like it took a lot more effort to ride than my road bike. It was set up really weirdly with a bunch of non-stock parts, and I wasn't as fit then either.....so I don't know what I can expect.

Is the transition to a 'bent hard? I am supposed to ride a Tour de Cure 50 mile event in just a few more weeks, and wonder if I could transition to the V-Rex by then....

JanMM 02-26-14 12:47 PM

You will have a period of adjustment.
Hard to say how long. will probably take a while to get the thing adjusted just right for you.
And, of course, even though you'll be using the same legs you've always used for cycling, it'll take a while for those legs to get used to the somewhat different pedaling mechanics of bent-riding.
I seem to remember a few weeks of seemingly weak legs and having some transient soreness - mostly upper legs - that was about 8 years ago for me.
But, no arm, wrist, hand discomfort, etc.
Starts from a standstill can be a challenge at first, especially if uphill. You'll work it out soon enough.
The Rex is a very user-friendly bike. No reason to think that you won't be able to ride it at 14 mph.

Come back and share your progress and ask questions.

BlazingPedals 02-26-14 01:22 PM

Are you rebuilding it back toward stock? Mine seems to be good for up to about 17 mph; but then I rarely ride it and am definitely not acclimated to the position anymore. Doing 14 should be well within the realm of the possible. But, like Jan says, expect some work getting your 'bent legs.'

punkncat 02-26-14 07:34 PM

It is a rather funny thing you will find about 'bent' legs....they work well for the DF, but it doesn't work the other way around.
I could well be wrong, but a good part of the average speed will have to do with wheel diameter (among other things), so if they are similar I don't see where you couldn't achieve those results. The difference in speed between my trike with 20" and road bike with 700's is significant, but there is much more at play than just wheel diameter there.

cplager 02-26-14 08:37 PM

Quote:

Originally Posted by punkncat;16530682.
I could well be wrong, but a good part of the average speed will have to do with wheel diameter

Yup. You're wrong. :D

Wheel diameter doesn't have anything to do with it. Not having the gearing, tire choices, aerodynamics, being able to produce power in new position has much more to do with how speed on new bike.

downtube42 02-26-14 08:43 PM

I would not expect you to match yor DF speed right away. I think it was a full season of riding before I was completely up to speed.

AerobaticDreams 02-26-14 09:15 PM

Thanks for all the input. I had posted a thread about a year ago when I stumbled onto the bike and got a lot of great advice on rebuilding it. I was full speed ahead until the chance of a lifetime dropped into my lap....and I joined an Unlimited Class Air Racing Team and worked on the aircraft build (Precious Metal/ Race 38) for the Reno Air Races last September. I had less than zero time to even get out and ride, much less work on a project for myself. When we got back from the Races, I had to dig out all the parts I had removed, and find the ones I had already ordered. I think I have 99% of what I need to complete it. It will be basically stock for now. It had a number of junkyard components on it, which are now more current and higher grade (Brakes, headset, etc).It had a bizarre steering set-up on it when I found it.

Hope to have it all together in a couple more weeks. I think I'll be switching off between my road bike, walking and the recumbent to get my fitness level up. I don't think my wife wants to slow down on our rides. so I will stick with the roadie on them for a while. I'll post up information once its together and I start riding it.

BlazingPedals 02-27-14 06:46 AM

Cool! Don't forget pics of the new setup. We like pics here. :)

Aushiker 02-27-14 09:25 PM

Quote:

Originally Posted by JanMM (Post 16529460)
You will have a period of adjustment.

I agree. Personally moving from a diamond frame as my daily ride to a Bacchetta Giro ATT 20 and now a LoGo P-38 I estimate I rode around 1,500 to 2,000 km before I started feeling I was seeing some evidence of my recumbent legs developing. Still some way to go before I get back to a reasonable level of performance but.

Andrew

downtube42 02-27-14 09:33 PM

At 14 you're not seeing much aerodynamic advantage, yet you're using different muscles. If you add any hills, the (likely) heavier V-Rex will slow you down. The faster you get, the more advantage you're going to see in the V-Rex over your road bike. On a long downhill you'll clearly see the V-Rex coast past everything except a tandem or another bent.

jyl 03-03-14 12:48 AM

I don't think a V-Rex is particularly aero. The seat back is quite upright.

downtube42 03-03-14 11:37 AM

Quote:

Originally Posted by jyl (Post 16543068)
I don't think a V-Rex is particularly aero. The seat back is quite upright.

When I first got my V-Rex I was curious and looked online for anything about it's drag. I found somebody had wind tunnel tests that showed it comparable to a DF TT bike/rider, but not as good as other bents. But the OP was asking about coming from a DF. Again, at 14 mph I don't think there's going to be a ton of difference.

BlazingPedals 03-03-14 03:15 PM

A VRex is pretty upright compared to a racing bent; but it's still better than a standard upright being ridden on the hoods and very similar, but not quite as good, as riding a standard road bike on the drops. Even when they're stretched out over the stem, upright riders tend to forget about their legs hanging down perpendicular to the airflow. The pecking order for frontal area goes something like this (in rough terms)

Upright - on tops - 5.2 ft^2
V-Rex (SWB) - 3.8 ft^2
Upright - on drops - 3.6 ft^2
TT bike - aerobars - 3.0 ft^2
Lowracer (stock) - 1.8 ft^2

AerobaticDreams 03-09-14 07:26 PM

Nothing important to add..but...I took the frame to the powder coaters a couple of weeks ago. They had an equipment failure and it screwed up everything for them. Everything in their shop is now over a week behind schedule. Seems they got my fork finished for my project and the machine died...!

On the positive side, my wife and I ride together, and have added walking to our fitness program on days when its hard to get a ride in. She has finally become interested in at least checking out recumbent trikes and we plan to go rent a couple for a trail ride for her upcoming birthday! (There is a trail and place about 40 or 50 miles away). She also seems to think I should get a 'bent trike since seeing some fun videos on-line. Wow...didn't see that one coming...guess I need to find a job to be able to pay for all this now.

Just venting because its making me crazy to not have this ready to ride yet....!


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