Friday, December 19, 2008

Trek Trailer Bike Upgrades

It's pretty hard for me to leave well enough alone when it comes to bicycles. Well... lots of things, I suppose. But bikes in particular.

When it was time for me to try introducing riding to my older daughter Juliana, I bought her a Specialized Hotrock kids' bicycle. It's a little single-speed bike in the BMX vein, except that it's got 16" rims, and is painted purple with puppydogs, rather than chrome with skulls or whatever. But the whole training wheel thing was pretty frustrating. Our driveway looks like something out of Eastern Europe, circa 1983, and Juli kept tipping over and scraping herself up. And a driveway isn't much of a ride anyway, and it's not like I'd let her out on the road on that little thing. It wasn't going to be enough to satisfy my urge to really introduce her to riding.

So I also picked up a 20" Trek Mountain Train trailer bike at the same shop the Hotrock came from (and the Kestrel, for that matter). The Trek started out as a pretty basic bike, but didn't stay that way very long (you may be noticing a theme, here). When it arrived, it had all the stuff a kids' bike normally has: A single-piece (Ashtabula) crank, a gritty rear hub, a bottom-of-the-barrel Shimano rear derailleur, a cheap chain, a low-end Grip Shift 6-speed shifter, a no-name mountain bike rear tire, plastic pedals -- you know the stuff I'm talking about; the stuff of department store bikes. Also, most everything on the bike was made of steel, which is stronger than alumimum, but of course heavier.

For the first season, I pretty much just left the bike as it came. Juli and I started doing some 7-mile rides, and eventually got up to some longer distances around the surrounding towns, using the Paramount to tow her around. She was wiggly, which could be scary at times, but I could feel her working back there. Overall she seemed to enjoy riding and to genuinely appreciate the dedicated time with me out on the bike. So naturally for her second season on the trailer bike, I decided to make a few changes, to further the quality of the experience, and allow us to tackle longer distances more efficiently.

The goals were simple: Make the bike better, make it more like a road bike, and try to make it a little lighter. On each of these fronts there was a lot room for improvement.

The list of targeted upgrades pretty much mirrors the list a few paragraphs back. A lighter crank, decent pedals, a lighter seatpost, a lighter stem, drop handlebars, a brake and brake levers, a better derailleur, a better chain, a new saddle, a repacked hub and a roadworthy tire all made the initial list. And as the project progressed, a few other bits were added.

The seatpost is 25.4mm, and I was able to find an aluminum replacement in short order. At first, I just left the tiny, original plastic-covered seat on the bike, but later I replaced it with a Brooks B-17S womens' saddle. I was worried the Brooks might be too wide for Juli's bum, but in the second season she had started complaining about the original saddle, so I figured it was worth a shot. No complaints since the Brooks went on, so it was apparently a good decision. Note that the original saddle and seatpost are back on the bike now that my younger daughter is using it.

The BMX-style handlebars came off, along with the needlessly complex and heavy multi-adjustable stem that came with the bike. A lighter, simpler adjustable stem went on in its place, along with a set of used ITM drop bars I picked out of a used bars box at Belmont Wheel Works. I also picked up a set of Tektro compact brake levers. These are virtually identical to the Cane Creek units on my wife's Bianchi (compact, contoured, quick release and wide bodies), but the hoods are a little different and they were about a third cheaper.

I tried to keep the original shifter, but discovered there was no good way to mount one to a road bar (I tried several things). So I mounted it to a sawed-off mountain bike bar-end, bolted to the handlebar stem. But it was pretty stiff, so for the next season, I replaced it with a bar-end shifter that I cobbled together from a set of Ultegra bar end shifters and Ultegra down-tube shifters.

The shifter is an experiment that didn't work the way I hoped, but is at least functional. It turns out, though, that Shimano bar end shifter mounts don't work all that well supporting Shimano downtube shifters. At some point I'll pick up a set of better shifters for the Schwinn, move one of the Suntour bar-end shifters from that bike over onto the girls' Trek, put the Ultegra bar-end units back together and unload them on eBay.

There really isn't any place a water bottle cage would fit on this bike's frame, so I put a handlebar mount on, and bolted on an old black cage I had in my parts box. I think it had originally been on the Paramount early on. Plus, every kid needs a bell -- in this case, a purple rotating model bolted to the handlebar stem. The black plug in the left bar end is actually a flashing LED light. They came in pairs, but since the Trek has a bar end shifter, its mate is in the same spot on my wife's Bianchi. The left bar end is the part of the bike closest to the centerline of the road, so both lights are easily seen by drivers approaching from the rear.

One thing I wanted to make sure the girls appreciated about road riding is the need to maintain control over one's speed. For that you need brakes, so I added a brake to the Trek. I had in my parts box a pair of short reach Dia-Compe centerpulls, and wanted to use one of them on this project. Unfortunately, I found that the Trek's frame had a seatstay bridge way too far from the rim to locate a brake properly. So I thought about it and settled on making a bolt-on brake mount. I bought some wide aluminum bar stock at Home Depot, cut a matching pair of trapezoidal shapes, drilled them in two spots, and sandwiched them around the seatstays, bolting them through the brake bridge to hold them in place. Then I bolted the rear brake through the adapter, with a bunch of washers filling the space between the plates to offer some additional support. The brake cable didn't have a frame-mounted stop, so I hung one from the seatpost clamp bolt, and I also added one of the inline cable adjusters I've mentioned before, since there were no provisions for adjustment on this bike, either.

It all worked like a charm, but even with the adapter, the pad reach was a stretch. So this year when I took the long-reach Dia-Compes off the Schwinn, I put one of them onto the trailer bike to give me a bit more leeway for adjusting the pads. You can see all this in the photo below. Important safety note: If this was more than a training/auxiliary brake, there's no way I'd use this configuration!

The drivetrain represented most of the work of the upgrades. The rear derailleur was simple, though. With no front derailleur and only six speeds, a short-cage rear derailleur would be fine, and I had a spare Ultegra derailleur kicking around -- a very nice upgrade indeed! Since the rear dropout didn't have a derailleur hanger on it (the original derailleur had a claw-type hanger), I bought a claw-type adapter and bolted it onto the dropout. The rear wheel is a bolt-on unit, so it holds the derailleur securely with this asymmetrical setup (something I've had trouble with where a quick-release wheel is used).

"But wait!" you say. "There's a front derailleur right there on the seat tube!" Fair enough. But there's only one chainring and the front derailleur isn't connected to a shifter. You see, the chain kept falling off the chainring on early rides, and I had to do something about it. I tried putting on the rock ring you see on the crankset, but that didn't help at all (it does serve to keep socks and pants cleaner, though). So ultimately I just bolted on a front derailleur and it just sits there, keeping the chain where it belongs. It's a Campagnolo unit, bought originally for my Allegro project. But it was pretty cheaply made and I didn't end up using it. I thought about trying a track chainring (which is wider and not designed to shed a chain), but I had the derailleur, and didn't have a track chainring. IMO, it's not really worth putting the derailleur to work by adding another front chainring and a shifter, but that's always a possibility.

The rear wheel was taken off the bike, the freewheel removed and cleaned, and the hub disassembled. There was virtually no grease in the hub, and what was there was mostly dried out and living in the dust caps, not the races. The bearing races were oxidized from the lack of grease, and felt a little rough to the touch, so I used some Simichrome to polish them up a bit. When they were more or less shiny, I repacked the bearings with plenty of Pedro's synthetic grease and some grade 25 balls. The OEM freewheel was a basic Shimano 6-speed unit and honestly it seemed more than adequate for the task. It even has hyperglide-ramped cogs and shifts quite well. The chain is a nice SRAM unit, and the rear tire is a balloon Michelin road tire, installed after I found a Continental recumbent tire didn't fit properly (the rim is probably too wide).

The crank represented the biggest opportunity for weight savings, and took the most investigation. I went over to Landry's Cycling and Fitness in Natick and asked about options for replacing a single-piece crank with something lighter. As it turns out, forged 1-piece cranks are made for strength and abuse, and though there are trick models available, there aren't any one-piece replacements that would be any lighter. But they did point me at an MRP adapter kit that would let me fit a 3-piece crankset to the bike.

I ordered one, and it's a pretty cool idea. These are simple things -- essentially a pair of billet aluminum plates that fit into either side of the Ashtabula shell, and are clamped together with three bolts that hold them in place. Any sort of English-threaded bottom bracket screws right in. I'm using an inexpensive BulletProof 150mm crankset and Shimano cartridge bottom bracket. The adapter seems to be holding up well, and staying tight -- at least under the torque output of a 7 year old.

For pedals, I am currently using a set of MKS Sneaker pedals from Rivendell, though I had been using a set of MKS track pedals. I made the change because the track pedals are single-sided and Ava seemed to struggle with the concept 0f using a single side of the pedal just yet. By the way, if you ever buy MKS pedals, it appears they don't come packed with much in the way of grease. I've found it's worth taking the dust caps off, squirting in a bunch of grease and buttoning them back up before using them.

After a rough start (I literally rode the rig out from under her, and she plopped onto her bum in the driveway) Juli and I got into the habit of taking 21 mile rides on this combination. It'll probably be yet another season before Ava is ready for the same, but my hope is that she'll get into riding as much as Juli has. Ava has been a little less comfortable on the puppydog Hotrock than her sister was at the same age, but seems to revel in fast descents on the trailer bike. It will be interesting to see how her appetite for cycling develops, and how her confidence improves.

As for Juli, she and I spent time rebuilding a 24" Fuji racing bike last summer, and my guess is she'll be big enough for it in the spring. In the mean time, she's joined Ava and me on her 12 speed mountain bike this past year, for 7 and 8 mile rides. And with luck, the Fuji will allow her to join us for much longer rides next summer. That bike will be the subject of a future post -- perhaps my next. By the way, all of these photos were shot this morning in the driveway of my house -- yes, in the middle of a snowstorm. Pretty, if a little gray.

One other outcome of my trailer bike experience is that it's seeded a desire to pick up a tandem at some point. I don't have space for one at my apartment, so it'll probably be some time before a tandem makes sense. In due time.

All for now,


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