carleton

I need help with a project.

About me:

I'm a masters track sprinter. I sometimes compete in elite events also. I am using the trainer to train for sprint events like this:



The Equipment:

I own an older Cycleops PT300 like this one:


It uses V Brakes combined with cloth brake pads to provide friction resistance to the large flywheel:



The current setup uses the "aero bars" above with TWO braking mechanisms. The first is an old school non-shifting brake lever on the left (pull to apply manual friction) and a dial knob on the right (dial to apply constant friction) that both apply fiction on V brakes in rear. They are two brake lines that meet at a 2-1 coupler (not sure of the proper name) and pull a single line that goes to the V Brake.






The Problem:

The current "aero bars" simply suck for practicing standing starts (as illustrated in the video above).

I have figured out a way to attach a standard stem and handlebar setup. I intend to use basic Nitto B123 bars (this was a project in itself).

Imagine this:

with these bars:


I want to go with a single braking system. Maybe a Friction Brake Lever of some sort where I can set the resistance, then grip the bars and do my efforts.

Here's where I need help

I would like a sort of friction brake lever to mount to either the new handlebars or to the frame of the trainer itself. What might my options be?

Why am I doing this?

I can mod the thing that I have or I can shell out $2,500 for this:


https://predatorcycling.com/product/ergobike/

Which still doesnt do what I need it to do

Thanks!

fietsbob

No clue offered as how Your stem and those bars will integrate from the Web Pictures
of a different machine..

Check with one of the machine shop owning Frame Builders in PDX..

I've got an Old pair of Steel Cinelli Track bars from the 60s [C&V] to sell .

bigfred 

A couple things come to my mind:

1. A simply old friction style thumb shifter drilled to accept the larger diameter brake cable and barrel end. Super easy and cheap. Might need to increase the friction in order to reliably hold brake tension.

2. A old front Sram grip shift that had umpteen zillion detents for triple fronts and every imaginable rub free cross chaining combo. They are firm as heck. Not sure how they would do at holding brake cable tension instead of the fairly light loads of a derailleur. But, the detents might make repeatability of tension easier.

3. Oversized barrel adjuster of some form. The threads would prevent it ever loosening off. I'm thinking of the cable adjuster off an mtb or motorcycle lever, or similiar to so many of the stationary bikes which use knobs to adjust braking friction on a front mounted flywheel.

Looigi

If it were me, I consider two approaches. Fabricate a block out of aluminum that will clamp to the horizontal portion of the existing stem with a cross hole in it that would clamp the track bars either passing above or below the existing stem as needed for the desired height. This would most likely be accomplished with a milling machine and appropriate tooling.

Or. Cut off the top of the existing stem and tig weld and adapter to it take a standard stem.

In either case, test by applying a lot of force, much more than you would in use, in such a way that you won't get hurt if it fails.

bigfred 

What do the tandem crowd use for their drag brakes?

Looigi

One more approach. If the existing bars are steel, cut off the ends, fabricate drops of the desired shape from steel tubing, and weld them on.

carleton

I've already got that part figured out. Now I just have to get a good friction brake system going.

bigfred 

Loogi,

I think it sounds like Carleton has figured out "how to mount the bars" and that he's onto "how to control the drag".

bigfred 

Another thought:

Mount a Barcon on the the end of the returns. Quick, easy, readily availabe, should be able to hold sufficient tension, used by some tandem teams for adjustment of drum braking.

carleton

To clarify:

Envision this:

- Disconnect the stock cables and slide the stock aerobars off of the horizontal rail. PUT IN TRASH.
- I'm using the big aluminum collar to attach new stem/bar combo. Slide that on to the horizontal rail.


I will have to find somewhere to mount the friction lever on the new handlebars or the frame itself independent of the bars. This is actually how the current generation of the trainers are setup.

They disconnected the bars from the friction system so that users can swap between aero and drop bars quickly without having to deal with cables.

See that yellow knob on the top tube? That is the friction adjuster.


They sell optional bars:



My setup is older and does not have that knob on the top tube.

Bonus points for a solution that mounts to the frame. That way I can use any bars by just swapping bars/stems like on a normal bike.

My proposed system would be better because I can use any bars I want. Even new buyers of the CycleOps spin bikes can only use CycleOps bars.

carleton

This sounds like a great option!

Anyone got a source for these?

fietsbob

More to the point WTF does Portland Not have an INDOOR velodrome like, say, Manchester or Ghent?


winter is Now, the racing season.


PDX,100, so a Bike shop on every block and you cannot find any?

bigfred 

Any of your LBSs with a QBP account. Or, off the top of my head, Velo Orange, Rivendell, Peter White or any of the normal Retro-Grouch avenues:-)

bigfred 

Hell, stop by a bike co-op. Chances are pretty good you'll have your choice of bar-end shifters and cheap old friction thumb shifters for the cost of a decent bottle of beer.

fietsbob

No shortage of Microbreweries there Either ..

carleton

Los Angeles, the rain-free city in which people can race on the velodrome year round has the indoor velodrome.

Portland, the rainiest and most bike friendly city has the outdoor velodrome

Does not compute.

brawlo

Having used a Star Trac V-bike in the past when I got back into cycling for standing starts, I think this might be a good option. The star trac had a different resistance style to the cycleops, so it may be a different feel. You could really screw the resistance on for the initial inertial part of the standing start, but once you broke that inertia and got the wheel spinning, the resistance became too easy. Still hard, but not standing start hard. All that would be needed would be a little supplementary brake that you could dial on as you got going. I would do the friction style thumb shifter brake and sit it near where your thumb would sit on the standing starts. Not too attention grabbing so that you lose focus on the start.

As for the bars, I just dropped them down to where my sprint bars would be for standing start stuff, and for anything else, I would just bump them back up again. I had to actually get the seat tube extended on my bike, so dropping the bars down was an option, however if you can't get away with this, then the drops may be what you need.

bigfred 

Hmmm, two stage resistance:

Use a braking sized inline adjuster in addition to the barcon or thumb shifter. The inline adjusters just like the those used for shift cables but sized up for brake housing, cables and loads, that are being used to take up the slack by folks running mechanical discs. Use the inline adjuster to set the base resistance and the barcon or thumbie for standing start resistance which can then be decreased as the effort continues and inertia is developed.

What do you think Carleton? Could that work for you?

bigfred 

Is that thing actually considered a viable or preferred option at this time? I've seen garage projects that looked more professional and better sorted.

Given the lack of prodution of the old cateye and minoura mag/fluid units and the lengths some of you guys are going to get what you need:

Is there a market niche for a training tool that doesn't currently exist?

A high initial resistance, standing start, sprint trainer?

What qualities would be most imortant in such an item?

carleton

That might work. But, how is that different than if I turn the bar-end shifter to, let's say, 80% then adjust it as the effort continues.



There is a niche market for it. Actually the Wattbike is making headway into the field. The British National Team uses it and one of our own Olympic Sprinters used it as he trained in the Fire House (he was a full-time fire fighter as he trained for London).



Sarah Hammer (USA's Cycling Super Woman) has used it:



As well as Dutch sprinter Teun Mulder



https://wattbike.com/uk/blog/post/the_summer_of_wattbike

But notice how they have to use the stock bars? These elite athletes of different sizes are tuned into the bars of their choice for their event. Having a 31.8 clamp *should* be an option, but sadly it is not.

Also, the wattbike is $3,500.

I don't think the predator bike is a good option either. I don't' think it has instant torque as a friction or mag trainer would.
Here is how one guy did it with his standard spin bike. His system is obviously too flexible.


Don't laugh. The dude is very fast.

The Cateye CS-1000 is awesome. I've clocked over 2,000W on one of those But, they are discontinued and hard to find used. A BF member who is on the British Cycling team commented that they bought all they could off of Ebay at one time a few years back

carleton

Jimmy Watkins is this guy:



https://www.pezcyclingnews.com/page/l...news/?id=85880

fietsbob

get a committee together for a Portland Based Olympics, bid, Win,
and they will Build one, thats how the LA one happened .

WheelsNT

Tandems usually use a barcon or a MTB thumbshifter mounted on the bar tops to control a drag brake.

bigfred 

My thought was that you could use the inline adjuster to set a base line resistance comparable to laps 2-4 of the kilo. Then use the barcon or thumbie to simulate starting resistance. This would provide you with the ability to lessen resistance with minimal thought and no chance of over adjusting while going flat out. Just a way of providing greater consistancy with regard to where you end up late as you complete the accelleration phase.

If you're using it like the video below, there wouldn't be an advantage. But, that doesn't look productive to me. Or, at the very least, far, far from ideal.

I'm also wondering if a multispeed tt/barend/aero shifter would have sufficient resistance in it's detents to hold braking pressures. Having 10 consistent set points in addition to the inline adjuster might be advantageous with regard to repeatability.

Let us know how your experiment works out.

WheelsNT

Folks have also used indexed barcons to control tandem drag brakes for exactly that reason, seems to work well. I have also read of one tandem setup that used the shift portion of the left brifter to control the drag brake, moving the front shifting to a downtube lever.