Plan 2020 - CycleOps 300 Pro

One of the most critical things in the 500m time trial is the start. Actually, it's the most critical thing, and it makes sense. The goal with the 500m time trial is to cover the distance as fast as possible. You can do one of two things to do that. You can go faster or you can get to speed quicker.

The problem with going faster is that you're working against aerodynamic drag, which increases exponentially. It will take an incredible amount of power to increase speed meaningfully, and at what I presume is the goal speed, about 40 mph, you're covering about 60 feet per second. There isn't a lot of time to go faster.

With limitations to top speed, it makes sense that the rider should accelerate to top speed as fast as possible.

And that's what all the big racers have been doing for the last 20 years. The top speeds are about the same so they work to get up to speed faster. That means every iota of power has to go into the pedals, not into moving the bike around. So no real rocking of the bike

I first saw the unusual starting technique with Chris Hoy in 2002. I wondered about his technique since there was no rocking of the bike initially. It was more like he was on a spin bike and pushing down. Ends up that is exactly it - you basically lock your leg, push down as hard as you can (which means pulling up on the bars), and you end up putting down massive power and saving your quads for later. Here he is in 2002 (and incidentally he does the 500m in 31 seconds, which would win Nationals for me by a wide margin). And here is a crazy fast sea level kilo in 2019 (go to 21:00). That guy does a 30 second 500m. It seems to me that a 34 second 500m will put me in the ball park for Nationals.

Everyone has acknowledged that starts are critical. Therefore riders practice starts all the time, going to the track if possible. There's a unique resistance with standing starts that simply not cannot be replicated on a trainer - it's high resistance at the start due to the rider/bike inertia, but then it turns into a speed thing, turning the pedals fast with high power. You can't replicate that with the light flywheels on trainers, the 6 lbs or even 12 lbs ones. There are whole training days for starts, using different gears, doing start efforts (50-100m), etc.

For me getting to a track is not possible so I needed to find an alternative. Based on some intranet help from fellow trackies, the low buck way to replicate starts is to get a high inertia wheel. There's a bazillion dollar machine out there but a cheap and usable alternative is the CycleOps 300 Pro. New they were about $1500-2500. I saw them at Interbike in 2009, but I remember thinking, "why would I want one?". I liked the 400 for its ability to adjust power (so you could record a ride and then "replay" it at home, or set power test steps, etc).

Picture from the post linked above.

The 400 (above) is a smart trainer, i.e. it can adjust resistance.

The 300 is not a smart trainer but uses the same frame and wheel.

The 300 was initially sold as a fixed gear bike but later it went freewheel, I think for mass market appeal. When I contacted Saris (the manufacturer) about conversion kits to fixed gear I was told that the 45 lbs wheel still has the fixed gear threads, they just put a one speed freewheel on. I'd just need to remove the freewheel and install a fixed cog and a lockring.

With that settled I decided to look for a 300. They're available locally for about $500, I saw them for less outside the area.

The biggest problem was fit - I vaguely recalled being unimpressed with the bar drop when I sat on one in Vegas. When I looked at the local one I measured what the drop would be from saddle to bars. On my bike it's 14.5 cm. On a 300? About zero. When I measured where the "top tube" intersected the "head tube" it was about where I'd want the stem. With a huge amount of vertical adjustment, I figured that if I modified the frame so that the top of the head tube was as low as possible then I'd be good.

I bought the 300.

And got to work.

First off, the thing is really heavy. Shipping weight is 140 lbs, actual weight about 135 lbs. I struggled to get it out of the Suburban, and it noticeably weighed down the rear of the vehicle. In the process of moving it around I managed to break the plastic mount for the computer. On the good side I figured the weight would help anchor the bike, and the flywheel would really make a difference in replicating high inertia standing starts.

Stock head tube. Very tall.

Black insert in tube.

The black insert is a slippery plastic, sort of like cable housing liner. It's tough, resistant to rubbing forces, and flexible. It makes it possible to have a less than perfect head tube and still clamp the tube tightly. On a regular frame the seat post and stem have to be perfect to within 0.1 mm. With the sleeve, not so much - the tube is probably misshapen by a solid 2-3 mm from top to bottom, with significant distortion around the welds.

The clamp (with the big lever) looked to me like it can be removed. This was my big gamble. I figured they would make the frame modular, with a one piece cast piece for the clamp. No reason to do fancy brazing and lug work on this thing, so all the raised bits would probably be molded into the cast piece.

My request for help on Facebook.

The clamp assembly is circled in red.

The yellow vertical line is my lowering goal.

Note the spot weld bits on the clamp assemble. There are two on each side. When I removed the sleeve there were no weld marks at the top, only a lip to keep the clamp from sliding down too much. I gambled that the clamp assembly was slipped over the cap, a couple welding tacks put in place to hold it, and done. If they used more to hold it I'd be in trouble.

Starting cutting at work.

I didn't have a cutting wheel so I brought the 300 to work and borrowed one. When I started cutting I was afraid of ruining my $500 investment. Plus I'd never cut so much metal at once. I was timid, unsure, and eventually stopped.

Did the cut at home.

I started cutting the welds holding on the clamp assembly.

At home I was a bit less timid. I didn't have to clean up before close, I could work at my own pace (no work interruptions), etc. I generally work well like this although sometimes I end up veering down the wrong path. It's how I did the suspension and quarter panels of the Civic, built the inside of the trailer, fixed the Sentra, got the now-red frame repainted, and it would be how I approached modding the 300.

Cut head tube in front, the remaining frame in the rear.

I needed to cut out the rectangle for the stem clamp.

I tried to mirror the rectangle opening for the clamp wedge. I also notched the tube for the alignment bumps in the clamp assembly.

Notching the frame for the alignment notches.

One thing that I didn't anticipate was just how low I cut the head tube. I knew I cut it lower than the clamp height, and I planned on cutting down the clamp, but it was close. I underestimated how much the clamp overlapped the head tube - it went much further down than I thought it would.

Trial fitting the clamp assembly while holding the cut bit of the head tube.

Red thing is a flashlight to look inside the tubes.

At this point the clamp was about 5-8mm too tall - the lip that was supposed to sit on the top of the head tube (visible on the left side of the clamp) was 5-8mm away.

The pieces in my hand.

You can see how tall the clamp assembly is at the back, opposite the yellow lever. It's over 10mm tall, and I needed it much shorter.

The clamp assembly cut down.

I did smooth it out after.

I cut the back of the clamp assembly almost to the top - I'm just short of the cosmetic trim lip of the assembly.

You can also see the lip around the edge of the clamp assembly. There are notches cut out for the plastic sleeve. The springs spread the wedges in the clamp bit - there's another wedge that is not in the picture, and that one is the one that presses against the tube.

Close up of the finished product.

Note how low the head tube is now - the "stem" protrudes below the frame now.

I had to remove a stop that kept the "stem" from protruding down below.

I can't weld so I planned on using a metal epoxy to resecure the clamp assembly to the head tube. However, I actually did not do the last step in the process. I'll do it later but the metal epoxy I have was dried (I used it on the Honda quarter panels about 10 years ago!) and the clamp is holding fine right now without any adhesive.

The finished frame bit. 

The wheel still needs to be converted to a fixed gear.

The major mod is done now. I still have to remove the BMX freewheel off the wheel and install a fixed cog and lockring. I want to put different pedals on it also - the Keo Max pedals are too easy to slip out of, which is why I don't have them on my road bikes (I've unclipped multiple times during sprints). I may use my old SPD-Rs (the kind that don't unclip easily), or I'll use the one Look pedal that doesn't release accidentally, the original Look Keo Carbons that I still have in my pedals bin.

I gave it a test launch last night. I was in my PJs, no socks, and went to do some lifting before bed. I slipped on my shoes barefoot, adjusted the saddle, and did a Chris Hoy imitation. Junior has watched a bunch of starts with me and even he knows the drill.

Beep at 30 seconds.

Do what you need. Look around. Look down. Wiggle your hands on the bars. Think of the upcoming effort.

Beep at 10 seconds.

Focus. Hands still now. Prepare to send it.

Beep every second from 5 seconds.

At 2 seconds you lean a bit forward.

At 1 second you throw your butt way back, and start launching forward so that...

At "GO!" your pelvis is thrusting forward so it's over your front hub, your left (track tilts to left so you start with left so you don't take yourself out) leg straightens, and you push down as hard as you can while you pull with your arms as hard as you can. It's like doing a dead lift, max power, hold your breath, just get the bike going.

And I almost flipped over the bars as the rear of the 300 came up off the ground.

Heh.

So I have some more mods to work on, to keep the 300 planted - apparently 135 lbs isn't distributed properly for standing starts.

And then I can work on some full power starts.

Equipment - Modded CycleOps Fluid Trainer, Step 1

Along the theme of "stuff I want to get done this winter" is this idea of modding a CycleOps Fluid Trainer.

One of the biggest shortcomings of a normal trainer is that it doesn't rock side to side. Way back when there was a mild attempt to make such a trainer, manufactured and sold by Technogym. A friend had one and I tried it briefly. To use it you took the front wheel off and clamped the fork into a spring-mounted "fork mount". Two springs, about the size of a coil spring you might find inside an old suspension fork, allowed the "fork mount" tilt from side to side.

I don't remember much of the device except that the springs forced the bike back to vertical with too much power - I felt like I was on a coil spring playground ride rather than on a bike on a pretend road.

Kurt Kinetics has a better design. Theirs rocks from side to side at a natural height, about halfway between the hub and bottom of the tire. Ideally I think a bike would rock around about the bottom bracket - if you watch a rider coming directly at you while rocking the bike you'll see the bottom bracket follows essentially a straight line, the tires carving small arcs under it, the rest of the bike waggling above the bottom bracket.

Having said that I decided that modding my CycleOps to resemble a Kurt would make sense. I'm sure they tried putting the pivot a bit higher and found whatever they found and therefore decided to put the pivot a touch lower.

Having tried one as well as watching numerous other try one, I think they got it right.

In addition the CycleOps and Kurt basically share the same "frame", meaning the trainer frame. There's a connection between the two companies that, although I don't know the details, results in the fact that both companies use what I consider to be the best (aka most rigid) trainer frames around.

A final vote in favor of using the CycleOps frame - I have an extra one. Yes, an extra frame. I had a Fluid trainer and a Power trainer, both by CycleOps. The power trainer, which used a proprietary head unit matched with some electric motor/generator resistance unit, literally started smoking one night, the smell of burning electrical stuff filling the room. CycleOps, to their credit, sent out a Fluid unit as a replacement. Although I asked for just the resistance unit they sent a whole trainer, including the frame. This left me with an extra frame with no resistance unit.

In the meantime I'd switched resistance units to the former-power frame (and for the life of me I don't remember why I thought this was a good thing). This left me with a gray Fluid frame for modding purposes.

A scrap piece of metal gave me the raw materials needed to mod the frame. The thick metal plate would have felt at home as a side skirt on a WW2 tank. It weighed a good 60 or 70 pounds and it was only about 15"x15". Let's put it this way - I had a hard time carrying it on my own.

I recruited the same guy that painted my red frame. He can do some very basic welding and in fact I'd been thinking about having him fix some of the white van's rusty areas. He, in turn, recruited a local metal artisan to cut the metal into smaller pieces with a plasma cutter. That artisan, incidentally, covered his whole house in metal, and who made a local bike sculpture. With the raw plates in hand (the rest of the plate was essentially payment to the artisan) the painter guy could start his work.

First, though, I had to tell him what I wanted from the project. The painter is not a bike guy, and in fact he lights up a cigarette if he doesn't have one already in his mouth. He understands mechanical stuff but really doesn't understand the bike riding part of bike riding.

I tried to get some angles and fit type things in place. I planned on using a 2x6 as a wide base for the trainer, with wooden extensions reaching forward. The regular folding legs won't work because they'd lock the trainer and prevent it from rocking. I know that if I had a 2x4 under the front wheel it's about the right height off the floor, so I figured that if I "fitted" everything with the bike flat on the floor then I could raise/lower it in "2x4" increments.

Thoughts on height, plate angle.

Regular folding legs are the lower tubes, with the black caps on them. They'll go away.

You'll see that the bike's rear tire is sitting on the floor. I don't have the rest of the bike in the frame, just the rear wheel. I wanted to get an idea of where the trainer would sit, what angle the arms would hit, what sort of angle I needed on my "rocking plates".

Gusset shape, if needed.

I had no idea how strong the welds would be so I figured we'd need a gusset plate. I knew that I had given the painter an extremely heavy piece of steel, significantly thicker than the plates used in the Kurt. Plus if the thing broke I'd just topple over, it's not like I'd be going 60 mph in a tuck.

Probable placement of plate.

After a lot of debate I decided that putting the plate under the U-tube would work best. It gave a lot of surface area to the weld area, it would clear the controls of the resistance unit (the spring loaded lever thing), and it gave me enough height off the ground to give me room for the additional plates necessary to create the non-rocking part of the frame.

The guy welding didn't do the gussets immediately and I told him, after checking things out, that they didn't seem necessary. The welder guy did paint everything so it looks semi-pro. He also shaved the original leg mounts, for the folding legs. Although I wasn't keen on that it does clean things up. It also commits me to trying this out.

Bolting things together, the various plates in the right order.

Wood works really well although it looks pretty ghetto.

I didn't get a 2x6 piece of wood but I had 2x4s left over from my garage organizing binge; I decided to use them instead of going out and buying another piece of wood. This seems to be totally fine, very rigid and secure. I used galvanized carriage bolts, galvanized washers, and stainless steel nuts, all in interest of their anticorrosion properties.

(2x4s are 1-1/2" thick so I bought 3-1/2" carriage bolts to give me 1/2" for threads and washers.)

The carriage bolts come up from underneath - I use a gym mat type thing under the trainer so the rounded head underneath won't hurt anything, and on a rug it won't hurt either. This allows me to periodically check the nuts on top without having to tilt the whole trainer on its side.

Now one error the welder made, not realizing how things were going to work, is that he welded the wide plate to the trainer stand. I meant to have the wide plates sandwiching the narrow plate, so there's more room for the rocking motion. He also assembled them in the wrong order, which to me illustrated that he had not fully realized the idea of the whole thing. This is my bad.

My first trial ride ended unsuccessfully inside of two minutes. I used OEM spec rubber spring tower bushings from the now-gone 1993 Honda Civic. It's a light car, 2000 lbs or so, and the bushings are pretty soft. I bought polyurethane bushings for the car but I actually installed them in the car. I thought I had extra bushings and went looking for them. See, back then I bought the shock install kit as well as a "full suspension" kit, but apparently the full suspension kit didn't include shock bushings.

Note the downward tilt (the rest of the trainer is to the left).

Rubber bushings, not polyurethane.

At any rate the rubber bushings allowed too much tilt to the front. This exacerbated something that already happens to the Rock N Roll. The tilt allows the angle to change between the trainer support arm and the bike, forcing something to flex a bit. It appears the skewer moves within the locking arm but the skewer could easily rotate on the frame. The latter would prematurely wear out the dropouts on the frame, not a good thing.

The solution, at least temporarily, is to insert a nylon washer to act as a (bearing) bushing. A better solution would be to use a thrust bearing, typically used in a clutch assembly to allow the clutch to slide back and forth while allowing the shaft to spin. Thrust bearings allow the shaft to rotate (or something to rotate around the shaft) while supporting mainly a side load. Modding the skewer holder to accept two thrust bearings is a bit much right now but at least I have something to think about.

My plans for step two include a couple different things.

First, I need to get much stiffer bushings, probably polyurethane, hopefully a bit taller. A friend who is revamping his car's suspension my have some used poly bushings for me but if they don't work out then I'll just go and buy some poly bushings. I may get larger ones if I buy them, like bushings that fit between a chassis and body (typically in trucks).

Second, I'd like to tackle that pivoting issue with the skewer and skewer holder. There's a great site McMaster Carr and they sell all sorts of hardware. I've bought things like sway bar clamps, stainless steel license plate screws, and even suspension nuts (metric fine thread), and they have an assortment of thrust bearings. I think just having a thrust bearing between the skewer and the skewer holder will work out fine.

For for now that's where I stand. Everything has worked out well so far except for the too-soft bushings. After I fix that I'll see how the trainer actually works when I do out of saddle efforts.