15 Jun 2006

     Most of the little cosmetic stuff was completed.  I also figured that seeing as how I had to take the SRAM 7 shifters apart to install the new full-length cables, I would paint the silver grip shifter parts flat black, and grease and re-grease absolutely everything inside the twist shifters.  I must say, I like the simple push-pull SRAM shifter mech better than the wrap-around Shimano type.  At any rate, the trike shifts beautifully and smoothly, every time.  Not that it wouldn't have before, but now I know that I have lots of lube in it, so it gives me some peace of mind.  I hate derailleurs that are sluggish.

     A couple Catrikes I have seen, had the chain tube running over the crossmember instead of under it like on mine, and I liked the straighter route for the return side of the chain, so I moved mine over top of the crossmember too and it really took the big loop out of the return side.  I made a small AL bracket to zip tie the chain tube in it's new position, and took the opportunity to paint the pulley assembly flat black too.  Also in the picture are some small AL and plastic water bottle mounts that are designed for attaching water bottles to handle bars.  They mounted perfectly to the seat frame and they keep two bottles close at hand and out of the way.  You can see the chain running over the crossmember now, and instead of letting the power side of the chain rattle off the powder coat every once in a while, I zip-tied a larger diameter piece of water tube to the side of the other tube to stop the power side from hitting the frame.  Two small pieces of rubber inner-tube are sticky enough with the zip tie on them to prevent the tubes from sliding in relation to each other.  There is no extra noise from this arrangement, or if there is, I'm used to it and don't hear it after less than 40km of riding :)

     The biggest thing I needed to do of a non-cosmetic nature was to shorten the cranks.  The Ultegras came as 165's but they felt extremely long and uncomfortable after using cut-down 130mm cranks for almost 1,000km on my high racer.  To say I was a little nervous about chopping up a pair of $350 cranks is a huge understatement.  The last thing I wanted was to have mis-aligned cranks from my home made jig and little drill press.  I had to make a new adapter for the ISIS cranks and a different jig, but I was as careful as I possibly could be, and after installing them on my new boom and taking a 15km shake-down ride, either they are perfect, or more likely, the hole mis-alignment is so small that I can't even feel it.  A couple other people test rode it as well, and they had nothing to say about either the shortness of the cranks or any "weird feel" to the pedal alignment themselves.  I'm very pleased with how they feel and primarily about the fact that I didn't screw them up :)

     One thing I do need to change pronto, is the top gear.  On even a slight downhill, I spin out in no time in the top gear of 94.5 gear inches, and that is even with me being able to spin up to close to 150rpm with the short cranks.  I will look into a 55, 58 or 60 tooth chain ring and may have to make a 110BCD to 130BCD adapter plate depending on what kind of chainrings I can get.  One other thing I need to do is to clean up the pedal steer associated with my legs being so far forward on a long boom and the short wheelbase of the trike.

     While I was muting things out, I also painted the headrest, rear derailleur hanger, the disc brake rotors and the tie rod.  There's just something I like about black - not sure why.  Not sure what I want to do with all the flashy bits on the end of the boom yet, but I'll definitely hit the new chain ring with paint before installing it.  Below, the trike is pictured so far with it's new boom and painted bits.  I asked for a different colour on purpose, and in hind sight, I should have gone for black instead of the silver-grey because I thought the silver-grey was darker.  I also like the silver stickers on the green instead of the red ones but these are minor issues.  Next thngs to deal with are first a mirror and speedo, then the front fenders, then the tailbox/storage/fender, and lastly the wheel discs.  So far, I'm very happy with it.

23 June 2006

     The trike is running fine but I have a slow leak out of the left front wheel's removable core Presta valve.  I tightened it up, but it's still leaking a little by the feel of it. I'll see about a new core possibly on the weekend.

     In the mean time, I fabricated a small AL "L" bracket and used it to mount the speedo's pick-up on the right front wheel.  I removed the rear disc brake mount bolt, took off the spacers, and put the tab on in place of the spacers because the mounting bolts are pretty short.   I filed the mounting hole a little elongated in the little L-bracket so I could fine tune the spacing between the magnet and the reed switch.  I had time to kill so I carefully wrapped the speedo pick-up cable around the brake cable housing until I got up to the handle bars and zip-tied the computer to the bar.  It's working fine, seems fairly resistant to vibration and it's a suitably clean mount.  As a side note, Catrike now sells a small arm for mounting the computer sensor on.

     As for the matter of running out of gears, I got a hold of a 40T and 60T AL chainring and made a 110BCD to 130BCD adapter so they would fit the Ultegra spider.  Why not buy a 110BCD spider instead of making the adpater?  Well, I enjoy the challenge and a little fabrication time, to me, is infinitely less expensive than shelling out about $100 for a new spider when I have a perfrectly good, practically new set of Ultegra cranks.  Anyway, I used a piece of .080" 7075, picked up the two sets of bolt circles, trimmed the excess material, and tried it out.  My holes had drifted off a little, but filing a couple of the holes a little produced a more than workable prototype adapter to test the new rings.  I decided to go with a double chainring instead of a triple because using as simple an adapter as possible would mean that the two big rings would have good spacing for the chain, but the small chainring would either be too far or too close.  Not only that, but I spend 95% of the time on the big ring anyway, and only drop to the smaller rings on hills.  I did the math with a 40/60 set of rings, and that gives me a 25 to 109 gear inch range.  More than adequate low gear for me and a suitably high enough top gear to satisfy my need for speed.  So, with that decision done, I loosened off the front derailleur cable, and slid the front derailleur up a little.  I removed the right crank arm (gotta love self-extracting crank bolts :)) mounted the adapter to the spider, then mounted the two chainrings and tightened the bolts.  I sized up the state of the chain and found I only needed to add about 3" or 4" of chain.  With the 60T chainring's circumference about 4" bigger than the 52T original, the rear derailleur appears to be maxxed out when I drop down to the 40T ring and the chain is too slack to use the 40T ring and the two smallest rear cogs.  I anticipted some chain management issues and as I only really want the 40T ring - 32T cog combination for hills, the loss of 9th gear with the 40T ring is not an issue as I would be on the 60T ring at that speed anyway.  After getting the chain lengthened, it shifted from the 40 to the 60 tooth ring remarkably easy, and smoothly back down.  Without the ramps and shaped teeth of the original chainrings, I expected some problems, but there aren't any.  I adjusted the high/low stops for the front derailleur, and took it for a test ride.  No problems shifting or with gear selection options.  I have a feeling that even though the 7075 adapter plate is pretty tough, it might be a little on the thin side, so I'll maybe make a .090 or .100 plate to replace it and give myself a little peace of mind.  I'll be doing the work commute on it tomorrow so I'll see how it behaves at that time.  After I get the new plate made, I'll paint it and permanently mount the plate and rings.  One more project down :)

     I bought some 6mm fasteners and lengthened the threaded portion on them to be able to use them to replace all 4 handle bar bolts.  The extra long bolts will be used to secure the fender struts by spinning a SS Nyloc nut and washer onto the protruding bolt shanks.  Pictures will make it clearer and hopefully this weekend I'll be able to start fleshing out the fender mounts.

13 July 2006

     A picture of the speed with the new 60/40 double chainring on it.  Details of the 130mm BCD to 110mm BCD adapter are here.  After a few hundred km, no flex, no twist and no shifting problems.  I just need to test out the new top speed on it.

14 July 2006

     I made a coroplast tailbox for the Speed so I would be able to use it to commute.  I could have put a rack and saddle bags on it, but I wanted something a little more aero than that.  :)  The tailbox still needs a small section on the front and the lid, but it is usable as it stands right now.

     The rear shot shows the storage slots, one on either side of the rear wheel that stretches in and under the seat.  The storage space is actually quite big, but it is long and narrow.  I just need to plan things a little better when I pack them and so far, I have still had lots of space left over for all the things I take to work each day.  Coroplast is cheap and easy to work with once you figure out what it does and does not like to do.  After I get the top and front section made, I'll likely spray paint it flat black.

     While the fender and storage functions are working great, I'm not sure how well it does with regards to aerodynamics.  I usually commute with a friend who rides a lowracer called a Python, and I usually ride in front.  I commuted a few times on the trike bare (before the tailbox) and he would draft me.  Since installing the tailbox, he's commented that he doesn't get anywhere near as much draft as he used to.  Before I paint the tailbox, I'll try to tape some lengths of yarn to the sides and do a rough tuft test and see what the tailbox is actually doing while I ride.  Even if it isn't that efficient, it is still strong, stiff and inexpensive if I ever decide to remove it.

     In the form of a small rant, I have some observations about the Speed.

     I have in excess of 12,000km on recumbents of a multitude of styles and designs, and I am quite familiar with pedal steer, its causes and its rectification, not to mention having built trikes myself.  On the Speed, the pedal steer is very prominent, is constantly scrubbing off speed, will definitely prematurely wear out the front tires and is very annoying.  I am a spinner and my cadence is usually in the 100 to 120 rpm range and I have never had a problem with eliminating pedal steer, by simply concentrating on smoothly pedalling in circles.  Regardless of how much I concentrate on smooth spinning on the Speed, the ONLY way to minimize it(I can't get completely ride of it) is to grab a higher gear than I should be using and grind.  Grinding is not much of an option for me on a bent because of my bad knees, the fact that I have 130mm cranks and the extra long Catrike boom really bobs and bounces up and down something fierce.  Even on the corners, unless I coast or spin very slowly and lightly, a 90 degree corner ends up looking and feeling like an octagon instead of a smooth arc.  With each pedal stroke, I either get understeer or oversteer and it bleeds off a lot of speed and makes the trike very twitchy, especially on a rough corner.  Additionally, on dry pavement on a flat road, if I have to brake hard with one side or the other, I don't just get brake steer (which I am aware of, used to and can compensate for) but the rear wheel gets unweighted enough that it will actually start sliding sideways . . . on bare, dry asphalt.  Considering that I weigh about 220lbs and I have about 20lbs of gear in my tailbox, to me, that indicates a large weight distribution problem.  If I do the same maneuver on a gravel road or on pavement with a little dirt on it, I can whip the rear end through a 180 degree turn by simply applying one front brake.  ??

     Another problem is a front wheel shimmy.  At any speed, if I let go of both handle bars, smooth or rough road, very soon (within 5 seconds) the wheels start to shimmy and the amplitude and frequency both increase rapidly to the point where they are so violent, the front wheels will end up locking to one side or the other and the trike will violently dart to one side or the other, not to mention the feeling that the trike feels like it is tearing itself apart.  The rims are dead true, the wheel bearings are tight and smooth, the axle skewers are tight, the toe-in is set to 1/16" and both headsets are tight and secure.  I haven't had any accidents, nor run into anything or even hit a big bump hard yet, and with careful inspection, there are no bent or binding parts in the steering linkages or the axle mounting assemblies.  Additionally, if I hit a small bump at anything approaching 20kph or faster, it will also produce the shimmy, especially if I have only one hand on the controls.

     In the variety of trikes I've ridden, I have encountered other homebuilt tadpole trikes that exhibited both the large pedal steer effect and the front wheel shimmy and they did it primarily because too much weight was above and ahead of the front wheels - they were nose heavy.  The weight distribution was biased too much to the front.  I am 6'2", and with the short wheelbase of the Speed and the extra long boom I needed, there is too much weight at the front end.  From commuting, as I continue to lose weight (read "fat" :)) and my leg strength and muscle mass increase, the problems will only get worse as weight will be decreased from the seat area, and weight will be added over and in front of the front wheels.  While these weight changes may not be a lot, it's already bad enough now, and as my physiology changes, regardless of the magnitude, the weight changes are in the wrong direction.  With the added weight over the front wheels, maybe the caster angle isn't large enough either.  I'll take some measurements later and find out exactly what the weight distribution is.

     So, what is the fix?  Well, on the homebuilt trikes, there was a couple things we did.  One thing was to move the seat back as far as possible (depending on the trike design) and as close to the back wheel as possible, and at the same time shorten the boom to bring the pedals back into reach.  If that didn't fix things or the trike design prevented moving the seat, then we cut and spliced a section of frame into the trike to increase its wheelbase.  Adding more caster was also effective especially if the angle was only 10 or 11 degrees to start with.  In each of the 3 trikes that exhibited the handling problems similar to the Speed, the mentioned modifications pretty much eliminated the problems.

     On the Speed, I can't move the seat because it is integrated into the frame.  I can't splice in a 6" to 8" section of frame for the same reason without adding to the seat frame and totally having to change the seat stay angles.  While I can weld AL, I certainly can't get the frame heat treated after such a mod not to mention the fact that I absolutely don't want to chop up the frame on a $3000+ AL trike.  I can't bring the pedals in because then I'm jammed and it'll kill my knees.  I'll have to measure the caster angle, but there's no real way to increase that unless I swap out the Stelvios for something like Big Apples to raise the front end.  I could also make an adapter plate for the rear wheel drop outs and add a 26" or 700 rear wheel to increase the top end speed, and at the same time I could also drop the rear end an inch or so to increase the caster.  This might not be doable because I would also lose some more of the precious little ground clearance under the pulley.  I could install some kind of steering damper, but why should I have to?  I never ever had to install a steering damper on any trike I ever built, nor on any trike I fixed or modified.  The fix is for the Speed to not have a longer boom, but a longer wheelbase.  While there is no doubt that the Speed is a great trike for shorter riders (than me, that I've seen) but I think it's got too short of a wheelbase to work for someone my height, who rides hard and fast like I do.

     So, with no real fix available, I'll likely not be putting as much seat time in on the Speed as I would like.  I still have more 2 wheelers and trikes to build, and I know that none of the trikes I'll be building will have the same shimmy and pedal steer issues that the Speed has.  I'll probably be going back to my high racer conversion for most of my commuting.  Sort of disappointing actually, to say the least.

17 July 2006

     I did some measuring on the Speed tonight.  The weight bias is 73F/27R.  That's a pretty heavy front bias of weight and partially explains the pedal steer issues.  The boom length, from BB axle to the front of the crossmember is 27½".  I've built other trikes that had biases towards the 70F/30R ratios, but they also had a wheelbase that was about 10" longer, a boom that was about 10" shorter and the longer wheelbase apparently gave them enough yaw stability to allow you to completely eliminate any pedal steer.  With the Speed, it's definitely too heavy on the front, with too long of a boom for the wheelbase it's got.  Even adding 6" to the frame/wheelbase would probably help with stability, reduce pedal steer and maybe even give it a little suspension.

     I re-checked the front end for loose components and toe-in, and everything is nice and tight and the toe-in is only slightly more than 1/16".  I'm not really worried about the toe-in unless it gets nore than 3/16" or so.  I run all my other trikes at 1/8" and there's no problem with handling or tire wear.  I guess I'll keep putting so KM's on it and see what developes.

17 Aug 2006

     With close to 800km on the trike now, I'm slowly becoming accustomed to it.  Front end shimmy and pedal steer are still alive and well.  The biggest thing was finishing the tailbox and putting the lid on it.  The top hinges up from the front so I can access the storage on it.  The whole thing was spray painted flat black with a fluorescent spray paint sprayed on the flat tail section to make it glow from the rear when it's dark(er).  The flag mounts as normal and comes out through a small slit in on the side of the lid.

     The pedal-steer issues are still there, but not as bad due to the effort of trying to smooth out my pedalling, but I can feel that the trike isstill doing the "Salmon thing" at certain times.  One thing that still hasn't changed and that I still don't like, is the amount of understeer it has.  I can't corner anywhere near as fast on the Speed as I can on my trikes and I think this is because the CoG is too far forward.  On my trikes, the tires grip hard during cornering and when you start getting to the edge of control, the inside wheel starts to lift, but you are still getting good steering traction, and by leaning into the turn, you maintain control and speed.  On the Catrike Speed, the trike will not lift a wheel at all, but both wheels start to plow/understeer and leaning in to the corner has very little or no effect at all.  The only option you have to stop from ramming into a curb or ditch is to slow down.  Contrary to what I would have thought, all that weight over the front wheels has not improved the cornering traction at all.  I think later I might switch out to Big Apples pimarily to get a little more ground clearance.  Also, I need to get the fenders on it as the weather starts getting more apt to rain.

23 Sept 2006

      1100km on the trike to date and the pedal steer is slowly coming down some more, but still present.  Shimmy is still crazy as ever.  Everything is working fine with the storage, but next time, I think I'll square off the tailbox a little further back to give it more volume.  I can carry everything I need/want to, but I have to pack it in smaller bits.  Can be a pain at times, but it's liveable.

     Finally got the CF fenders mounted that my friend Larry made for me a year or so ago.  They are for a 20" wheel but I like that they are a little fatter and longer than required because they allow me to easily go to fatter Schwalbe Big Apples when I want to, plus their length keeps the spray down to nearly zero.  I made the fender brackets out of 1" x 1/8" AL straps I bought from the hardware store.  I used extra long 6mm pinch bolts from the steering arms and handle bars to mount the brackets to and so far, the fenders are rigid enough that I can rest my hands on them and use them to steer if I want to :)  I'm still contemplating whether to put small mud flaps on the fenders yet.

     Only thing left to do now is to make the wheel discs.

3 Mar 2007

     I've had the trike on some rollers I made since just before Christmas '06 and put on maybe 2500 km since then.  I did manage to get it out for some rubber tire ice racing in Toronto, ON at the annual courier ice bike races. It performed very well even though it froze in 4th gear and had road slicks for tires :)  We managed a 2nd place.

     On the Catrike forum some of the Speed owners had upgraded their chainrings to a 70T.  While I was on the verge of spinning out with the 60T, I wasn't really in a big rush to switch out the chainrings again for a 70T.  While experimenting with oval rings, I decided to make a 44T 20% oval to go on the cranks with the 70T ring I'd already made.  The 44T oval equates to a 40T in the narrow axis and a 48T in the long axis.  I guess I'll see if I can push that up the local hills or not.  When using the oval, it really accelerates your feet through the "flat" spots.  I might drag the trike outside and try some local hills on the first warm day.

     The nice thing about making your own rings, is that they fit the crank spider and I can dispense with the adapter now.  I also found out that the 70T ring is about the biggest that the Speed will take unless I chop off the little light post on the derailleur tube. As it was, I had to file the attachment band a little on the Ultegra FD so it would better fit around the light post bead.  The 30T jump from the 70 to the 40T part of the small ring is also just about all the Ultegra cage will take.  Up and down shifting is, amazingly, still pretty smooth. At max RPM, I now spin out at somewhere around 110 kph so I am looking forward to winding it out a little.  I only needed to move the boom in a very small amount and it doesn't appear to be anything enough to produce a negative feel for leg length now.

     The bottom picture is the way the trike was set up on rollers so I could ride and exercise over the colder months.

19 Apr 2007

     It would appear that spring has finally arrived, and I commuted for the first time today. The ride was nice, it was great to get some fresh, cool air and some invigorating exercise first thing in the morning.  The trike worked fine, and FD shifting was no problem. The one thing I miss is the gear range I had before.  With the 70T ring, it has fairly pronounced jumps between gears and I find myself wishing for something in the middle of the gears.  What I might do, is put on one of the 60T ovals I made, just to mix things up and see how it feels.  I also have the option of putting the original 52T back on and use it as the middle ring.  I did a little riding with the 44T 20% oval ring and it certainly feels different.  Tomorrow on the commute home, I'm going to try it out on a hill on the commute and see how it feels and how easy I can (or cannot) climb using it.  The 20% ovality might be a little extreme, and if it turns out to be so, I'll simply make a new granny ring, or I will search through my pile of rings and see what is there that is close to a low 40T oval.

26 Aug 2007

     After about 2900km so far with the double rings, I decided to make a new triple set at 10% ovality using 62/54/38.  The reason is that while the 44T worked fine and I had more power, especially on hills, I wasn't happy with the orientation of the ring to the crank arm, and I think the 20% was too extreme, plus some of the hills I've been on I could use a little lower gearing rather than try to be a tough guy and muscle up the steep hills with too big of a gear.  One thing is for sure though, you can definitely push a bigger gear and/or go up hills easier than with a round ring.  Using the 44T oval was the equivalency of using a 48T round ring when I was going up the usual hills and there is no way I could ever even attempt that with the round 40T ring I had before.  I'm switching down to a smaller tooth count on the big ring too because I really missed the gear selection I had before. I often found myself either grinding too big of a gear or spinning too much in a gear that ws slightly too low. I also didn't have enough opportunity to utilize top gear with the 70T as I felt I would need to in order to make the higher top speed worth it when compared to the loss of gear selection.  When making the new ovals, I wanted the two big rings to be close together for optimal gear selection as that is where I spend 99% of my riding time.  The small ring will only be used to tractor up the steepest of hills and while I lose one or two of the smallest cogs at the back, I'm not worried about it. I also wanted to make the rings adjustable so that I could rotate the rings backward in relation to the cranks to better align the large diameter with the best power spot in the crank rotation. This would also help alleviate some knee pain.

     I stuck them on, un-painted, and went for a little test ride.  The ovals are set right now at about 30º out of phase with the pedals and that combined with the 10º difference between my hip - BB angle and the chain line angle means I'm operating with about a 20º "phase" change in total.  This should be a good place to start and I can rotate the rings forward or back another 10º if I decide to do some more experimenting.  So about the test ride, the rings felt really good, and very smooth. No "pulsing" like with the 20% ring and up and down-shifts were smooth and fast. I need to get some more mileage on them to find out for sure how they feel, and then I'll paint them flat black.

7 Sept 2007

     I've got about 210km on the new rings so far and they seem pretty good.  I used 10% ovals before and with the standard "in-phase" orientation I remember being able to feel the pulsing as the large and small diameters lined up with the dead spots and power strokes.  With the rings rotated back 20º, I can barely feel that at all. I honestly don't know if that's a good thing or a bad thing as far as trying to fine tune the rings is concerned.  I do know that they shift fine nd that there is no problem going up and down through the rings at all, even without the ramps and pins. I'm doing a century ride on Sunday and planning to ride with the fast group (~35kph) so we'll see how that works out.  On a 90km ride on the 27th, I was cruising along in the low 40's with some roadies on some sprint areas and my knees felt fine afterwards so I guess the rings are working at least a little.  I need to get off my currently-lazy butt and commute a few times with the trike so I can get a better feel of how the rings are working on the hills, and then I can compare that to prior effort.

13 Sept 2007

     Coming up on 450km with the new oval rings and I'm not satisfied or happy with the performance of them, and I think it's due to them being rotated back in relation to the pedals.  The 38T/10% granny is definitely harder to do the same hills with than the 44T/20% oval was. I'll have to sit down and do the math to see what the 38T comes out to at max diameter.  Cleverly of course, I only put one set of holes in the granny because I figured it was all I needed, but I should be able to rotate and flip the ring to modify the angle somewhat. If need be, I'll make a new granny ring - no big deal.  While riding with them, I can't feel the familiar pulsing and the pedals definitely aren't being accelerated through the dead spot, at all. While my knees aren't being bothered by them on even a 160km ride, I think that if I can't feel the pulsing (which I could on some 10% rings I made before) then I'm not getting the benefit of the ovals. I definitely know that I am not getting the benefit on hills.  So, first chance I get, I'll be rotating the rings forward one hole which is about 11º.  That should bring me back down to about 10º total of the rings being out of phase and I'll see if I can start feeling that "pulsing" again.  While I'm all for moving the large diameter a little later in my power stroke, I think the detriment of getting the small diameter out of phase with the dead spot is larger than the benefit of moving the large diameter a little later in the power stroke.

12 May 2008

     I have about 150km on the trike so far, and I drilled another set of holes in the chainrings and they are now about 5º retarded relative to the cranks. I can "feel" the ovals again and my cruising speed is up in the low 30's now. The chainrings feel good, speed feels good, and I think all the rest of the ovals I make will have a 10% ovality and a 5º offset.  Next item for the Speed is to make a new, better, larger tailbox, very much similar to the Raptor 74's.