Bullhorn and Dropbar Options

[ratz]

Funny you should ask

Eric that's a good question. I have done 4 test rides between snow storms. I specifically tried that hand position because I like that as a down hill relax position. As speed, when the hands are in the drop bend; it's is more sensitive to hand input but not bad. In that position I can steer just by twitching my hip weight; which I like, it was would be a fine position for big arching turns. The street at the bottom of our hill has manhole covers ever 50ft and the are very recessed in the pavement. I ran over 6 of those in a row at 19 mph with the hands in that tight positions; I had no control problems and held my line pretty good. The suspension probably has a lot to do with that.

 

[John Tolhurst]

rats, 
Did you just say your

rats,
Did you just say your trainer is measuring 20% more power off the silvio than you can achieve off the trike?

 

[ratz]

Bridging

Hi Ak,

Yeah I was testing the "pull" positions. I know a lot of people like to sit up for stability at slow speeds; or for climbing a surprise hill. So I wanted to see which positions on the bar gave a firm enough grip to quickly get into a situp positions. For pure power I do bridge. I'm good at gett my weight off my seat without actually lifting physically off the seat; and you right you can generate a lot of power. On the trainer I can sustain about 480 watts for 60-90 seconds in a bridge position. That's about 95 more watts than can push on my trike. So I'm excited to get this rig on the road for real.

 

[ratz]

Power

John,

Yes, it's about 95 more watts that I can comfortably push for a burst sprint. I only did this in passing I will repeat it this summer more formally. But that's mighty encouraging no?

Here are the details for this completely unscientific comparison; and my plans in this area for the summer.

First, I do not have a direct power meter on the trike nor can I configure it for one as currently built. So I use a cycleops powercal heart rate based power meter to compare the trike to other bikes. I have historical data with the powercal that lead me to trust it's average readings for efforts over 15-30 secs. By direct comparison I found it to be within 2% of a crank based meter and others have achieved similar results so I trust the readings for gross comparisons of vehicles. The powercal is very useful for things like that because it's portable. If you use it with the same rider on the same day; I feel you can safely compare the results. I don't know that I would use it to calculate CdA and Crr because I do not trust the instantaneous data yet. The readings are best considered"crank" readings. If there was a massive power loss between the pedals and the wheel; the powercal isn't going to show that without a speed reading to plot it next to.

With the trike mounted on this trainer right now I can push 385 and hold that steady for a 45-60 second sprint then it starts to fluctuate; winter has trashed my cardio or I would do a 5 minute stress test. I put the Silvo on the same trainer and was messing around and decided I was warmed up enough to do a sprint to see how well I had the handle bars dial in, I was actually testing for tendon pain from the brake cable. When I held 480 that caught me off guard; so I redid the test about 10 minutes later and yep 480 (rounding down to nearest 5). That shows me one solid fact; the Silvio's triangle works to give me a rigid pedaling platform in a way the trike boom never can.

For background, the trike is pretty dialed in but it has some unique characteristics so drawing a conclusion against trikes in general might not be appropriate. It's a Catrike 700, 16in model with custom 20in wheel mounted that alter the geometry and raise the bottom bracket 1 full inch. It has a Mountain drive on the front, a custom triple idler and an N360 continuous variable hub on the back a 58T ring pusing a 20T sprocket. At 48lbs, I've had it up to 60mph down hill at 110rpm and I can hold 20 - 25mph in a flat ground 2 minute sprint; cruising speed is 17-18 mph. All and all it's pretty efficient for what it is. Average rides in this area are 2500-3000 ft of climbing average gradient are 4-14%. So lots of up and down. A the typical 50 mile ride will net an average trip speed of 15.5mph. Climbing speed is the Achilles of this trike. Took two years to dial that all in. Time for a new project... hello Silvio

So back to the comparison. On the trainer I guess/attribute the power loss on the trike to the flex in the seat and flex in the boom, both of those inhibit my ability to maintain a powerful mashing stroke on the pedals. I can spin a nice high power rating but a sprint for me is still about mashing down on the pedal as hard as I can for as long as I can. At those high mashing level; the front boom pogo and seat bounce eventually interferes with the pedal stroke and form.

For the Silvio it should be said that the trainer is giving me near perfect posture; no power lost to balance, and a solid arm bracing. The only loss I can feel on the trainer came from the bouncing of the rear suspension as that's set pretty loose right now. Body bounce felt to be about 1/3 to 1/2 of what I get from the trike seat. Not sure how that could be measure other than subjectively.

When I get on the road the Silvio power output will probably suffer from my lack of skill with MBB at this time, I'm not going to be able to brace nearly as steady and balance etc. I have a Stages crank arm power meter in the plan. I will order that when the tax return arrives. That meter will spend the entire summer on the Silvio and I'll be collecting data on every ride. I suspect at this time that my power output will have a lot to do with my upper body strength and ability to maintain a stable front end to power against. I also suspect that my polished SPIN power output will be unique and separate from my MASH power output; so far those feel like they will be vastly different aggregate muscle groups (which sounds great to me for distributing effort). If the data from a middle age, out of shape rider is interesting to your design efforts I'll make it available. I should be getting a minimum of 2000 miles in this year; hoping to push that up closer to 5000 if the weather is good.

Lastly, because of things like the bullhorns and extension, and figuring out where to hang things like water bottles whether to dish the wheels etc, I've decided to try and "Chung" this thing pretty extensively this summer as time allows. I've identified a circular test loop nearby that is safe to ride at after dark, (I live in the heart of the North America Jet Stream so wind free riding only exists after sundown). The plan is to get a baseline CdA and Crr readings over a couple of weeks at start of the season while I learn to ride. Once those readings stabilize I will know that my riding form is consistent, then I'm going to tweak the bike 1 variable at time until I figure out all the optimal settings for me. I'm curious only to learn which changes make "gross" alterations in the performance. Basically I want to make sure I don't adopt anything flat out dumb with my riding form or bike geometry. For example what exactly will adding a 50mm extension do to the performance, if it makes the bike look cool but messes up, CdA, Crr, and ability to maintain Power input I want to know that. I might choose cool looking or comfort over performance, but I prefer those to be conscious decisions. Given all the info you made available; it shouldn't be too hard as most of the important stuff about riding positions is already documented.

So that's the plan we'll see how reality plays out.

If there is anything specific you'd want tested on the Silvio platform If it's within our abilities and means we'd be happy to put the time in, having goals always leads to more riding so that's a good thing.

 

[Charles.Plager]

And John, it's not a 20%

And John, it's not a 20% improvement in power. It's a 25% improvement in power.

 

[ratz]

Hands not too small

Mrs Ratz has smaller hands than I do and she found all of the grip positions very comfortable.

The brake handle reach was a little long, but these are SRAM shifter so the reach is adjustable. In the end we brought the reach in about 1/3. The next two picture are before we adjust them inward so they look long.

 

[ratz]

The shop is closed....

Ok thanks for humoring that long tangent. Perhaps it will help someone. The basement bike shop is all cleaned up now; and the bikes are ready to transfer to the garage as is the shop; and it will be too cold to work in the garage for at least a month. We'll ride these as they now are for several hundred miles before we revisit them for any enhancement. The only thing left is to find a good mounting bracket for the lights on the front of the bikes. Now if the snow would just finish melting.

 

[3WHELZ]

Trainer

I would recommend reversing your trainer. John has a thread abut having one implode when operating in the reverse direction. Assuming this is only a temporary set up, no harm no foul. I must admit that I went to the extreme of dedicating a wheel and tire (red trainer tire). Changing the front wheel is enough of a challenge and also decided not to wreck the higher end tire on a trainer.

 

[John Tolhurst]

I like it, I do. 
I will be

I like it, I do.

I will be interested to learn how it works in practise, with the finger curl being less on the larger diameter base of the brifter than is the case on a 24mm OD bar.

 

[ratz]

BullBrift part 1

So the last of the parts came on Friday as luck would have it I had time to work on the bike, or perhaps the lack of it is a better assessment..

So Mrs Ratz sat on my bike and decided the she liked the drop bullhorn bars... A LOT. but she has no taste for bar end shifters. So the Brifters on the Bullhorns mini test took on a a full scale project scope. And there

Before getting started on the results.... I did one silly thing that we photographed. IF you have large hands you might want to consider the following upside down installation. It yields almost the same angle and alignment of my setup. We tried to photograph them side by side; and the photo doesn't do the similarity justice, you have to take my word on that. The alignment and clearances are almost the same with the advantage to the brifters. I personally could not ride this orientation because my hands are too small, but I know a number of people whose hands are big enough. What I could grip and test was very comfortable in my hand.

So on to the project (not squeamish cutting into things are you?)

So I used a pipe cutter to remove the last bend in the bar at the tip of the horn. Then installed the brifter on the end of the bar. A small plastic insert made from 3/4 inch rubber pipe was inserted in the end to facilitate wrapping the bars.

Cable routing was external and worked just fine. It would also work with internal routing like I did on mine. Just didn't seem necessary to route them internally for this setup.

 

[ratz]

The lady declares it a keeper

So after a lengthy session on the trainer; I was told that this configuration was staying on the bike.

Of course that meant she needed to come back down and model some shots of how the final riding position works out.

I must say I'm jealous of the smooth shifting the configuration gives her. Since I can ride both bikes I'll be checking this out on the road. From a how does it feel stand point; it's about the same as my configuration; just with Brifter shifting which is second nature to me. I like both configurations; will be interesting to see which on I like more.

 

[ratz]

Odds and ends that got left on the cutting room floor.

Couple of odds and ends that never got posted.


Caged animals ready to run. To keep junior cruzbikers off them you some ties have to be creative.

Sometimes we ride blind in areas unfamiliar to us by map. Needed a way to have the giganto phone more accessible in the cockpit. MN is notorious for the unlabeled gravel road. So a premade cut sheet can leave you hanging. A real time map is handy... So add this light weight carbon post. Only weigh 2oz and is $14 from amazon.

Works underneath the boom

And above the boom

Then mount the airbrake known a iphone battery powered case. Man those things are large.

Not something I would ride with daily; but if running a technical and unfamiliar course with lots of turns; the penalty will be worth it to have a real time map course up.

 

[Charles.Plager]

Hi Bob,
If I were you, I'd

Hi Bob,

If I were you, I'd buy a couple of those Cruzbike conversion kits now for the junior Cruzbikers. They'll be ready before you realize it.

Charles

 

[Eric Winn]

As long as you are deploying

As long as you are deploying the airbrake, I'd like to request you include an iPad mini in your Stages PM aero trials...

Let us know the penalty difference between no navi, iPhone navi, and iPad mini navi, or your navi of choice

-Eric

 

[ratz]

Air brakes

Eric,

Would you like the iPad to be on a hydraulic or a pneumatic pivot arm? We could use thumb buttons to control the deployment of the brake with the push of a button. Could be really handy descending on switch backs.

Seriously though I am searching for the smallest case for the iphone I can find; I've resigned myself that the extra battery will be in the trunk. I've ejected my phone from the bike on about 4 occasions so some sort of impact cover is needed, not sure I could run it naked; but most of these are absurdly large / overkill. Lifeproof looks pretty small.

 

[Eric Winn]

Quadlock looks like a good

Quadlock looks like a good candidate for you:

-Eric

 

[ratz]

Quadlock and LifeProof

Yes the Quadlock is on the short list; DC Rainmaker did a nice review on it. The LifeProof one showed up today; it's darn darn impressive. Barely bigger then the stock phone and waterproof to 6 meters. Quite nice piece of engineering. The bike bracket not so much kinda unnecessarily big and bulky, but it give ideas to play with; the case is so good a gehto clamp might be all that is needed. The Quadlock on the other hand looks to be the same size as the wahoo clamp but with a much more sensible case. That might just need to be looked at. Someone on BROL is going to get some nice deals on cases when I dump off the ones that don't work and never got used....

 

[Eric Winn]

Hmmm, I may want to try those

Hmmm, I may want to try those dropped bullhorns to see if they feel any different from mine.

I'm banking a good bit here so it throws the perspective off a little but everything from hands, arms to shoulders is very comfortable and not really quite as high as it looks here. I'd have taken the corners harder, faster, and banked even further but they all had varying amounts of grit so I had to be careful.

Bob, I'd like to see some photos of where your brake cables are routed and your hand position just around the bar without grasping the brake levers.



This photo is a bit closer to the same angle as Bob's photo.



Sans rider in the photo below. I found during Sebring I could ride with hands on the tape area, the area above the brake cable "loop", and inboard close to the center clamp. The inboard position is very sensitive to steering input so not a good place when you are tired and not alert.



-Eric

 

[Eric Winn]

Vendetta bullhorn brake

I have small hands too. Here is a photo of the brake lever reach on my Vendetta:

-Eric

I'll replace this with a better photo later... I normally grasp the lever with all 4 fingers but tricky to photograph oneself. I am grasping both brake levers normally in the 2nd photo in this comment further back in this thread.

 

[ratz]

Interesting...

Those look deceptively further down in the distance shots; makes more sense now.