Titanium tandem by Waltly

I've already documented my previous tandem projects here before. The primary use of the tandems is for family bike rides with the kids. Two years ago I replaced my old Bike Friday tandem with the Experia tandem and have been happy with the results. Heather has still been using the modified Raleigh I acquired several years ago, but it's very heavy and never has been a very good fit for her. Now that the kids are both tall enough to ride a full sized tandem, it is time to consider replacing the Raleigh. The primary challenge is getting a good fit for a tandem pilot who rides a 50 cm road bike, and with the potential to fit a stoker who is taller (our 13 year old is already taller than her mom). The M/S sized tandem by Cannondale comes close, but is still a little big. So, getting a good fit would probably require a custom frame. In order to keep costs down (the goal was to build the complete tandem for a price close a stock Cannondale tandem), I went with a titanium frame made by Waltly in Xiamen, China.

I've been following Waltly for a few years as I've considered our options when upgrading tandems, along with Titanproduct and XACD. As I understand it, all three of them build OEM frames for various bike companies, and well as offering custom frames direct to consumer. All of them can be found on Alibaba or Aliexpress, along with a few others that I'm less familiar with. Just during the last few months, Waltly has re-done their web site to be by far the most professional looking I've seen, including a nice form to fill out for requesting a quote.

I initially contacted Waltly through a link on their web page and got a response the same day from Amy. Her English is pretty good, and she generally responded to my mails quickly given the 13 hour time difference. I sent her a picture of a frame with similar geometry and specified all of the key dimensions. Waltly's process is to quote a price, and then to ask for 50% of the cost to be paid up front before their engineers start making detailed drawings.

I made two key choices that dictated a number of the other details. One was the the Boost through axle standard. This means 148x12 rear and 110x15 front axles. This is an MTB standard that is relatively new, but I think makes a lot of sense for tandems, especially the wider front wheel (rear hubs wider than 148 have been used on tandems before). I did this because I want durable wheels and because I hope the standard becomes sufficiently common (for MTBs if not for tandems) that there will be many stock wheel options available in the future. The second choice I made was to try as much as possible to replicate the geometry of Heather's road bike on the front end of the tandem, but simultaneously eliminate the toe overlap that her road bike suffers from, because I think toe overlap is much more important to avoid on a tandem. Both of these choices led to the decision to have Waltly make a custom fork to go with the frame because no stock carbon tandem forks currently offer the wider spacing, and because I needed a higher than usual fork offset. My original proposal was parallel 73 degree seat and head tubes, but this was putting the front wheel far too close to the front bottom bracket. Eventually I settled on a 71 degree head tube. While this may make the handling a little more sluggish, it is frequently done on smaller frames, including Cannondale's smallest road tandem. With the slacker head tube it is possible to extend the fork offset to 55 mm while still having a reasonable amount of trail. I asked Waltly to allow for 700C tires between 32 mm and 40 mm width, with the idea that I would have the option of 32mm road tires or 40mm gravel tires. The distance between front and rear bottom brackets was determined by two considerations. First, I want the option of a Gates belt drive in the future, and second I want the spacing as far apart as possible to accommodate taller stokers, so I chose the largest spacing that will support a Gates drive.

After making my initial specifications and paying the deposit, we went through several iterations of drawings before I decided they were ready. Much of this had to do with trying to increase the distance between front bottom bracket and front axle because of the toe overlap problem. Now that I've done this I realize I could probably have used something like Bike CAD to figure that out beforehand and get through the process much faster, but Amy was patient and responsive with my continual tweaks. The final drawings looked like this:

In addition to the frame and fork, I asked for an adjustable stoker stem. About 6 weeks after I approved the drawings, Amy sent me an email with a set of detailed photos of the finished product.

When I gave my approval based on the photos, the frame, fork and stem were shipped by DHL, and arrived in the US just 3 days later. The build quality of the frame looked great. I'm not an expert on titanium welding, but the welds on the finished frame all look very neat. As I got started on the build I discovered that Waltly had made a mistake on the stoker stem, building it for a 28.6 mm diameter seatpost rather than the 31.6 mm diameter I had specified. I sent Amy a photo, she consulted with the engineers and builders, and they agreed that they had made a mistake. They created a new stem as I had specified and sent it to me at no charge. I commend Waltly for their responsiveness in fixing their error.

Before completing the build, I added some yellow and green paint using stencils. I love the look of titanium, but wanted to add a little more color to go with the yellow and green trim I was adding to the bike. I think this is a great solution for customizing a titanium frame that's relatively easy to do and still allows the titanium color to show through. The saddles don't match the rest of the scheme as well because they happened to be preferred saddles from previous bikes.

I built the bike up using a SRAM Rival drivetrain with mechanical disc brakes so that I could add bar-top auxiliary brake levers.

I used Sugino XD cranks front and rear. We wanted a low gearing range, and don't particularly need high end gears because we don't go that fast, so I used what's currently being referred to as "subcompact" gearing: 46/30 chainrings with 11-32 cassette. This is of course not something SRAM designed their 2x11 road groups for, and I found I had some difficulty getting the front derailleur to avoid overshifting and dropping the chain to the outside. The Sugino cranks are designed as a triple, so I installed a chain guard in the position of the outer chainring, and it seems to have solved the problem for now.

The one mistake I made in my design was forgetting to specify a front derailleur mount, which was my original intention. There are many clamp-on front derailleurs available, so it wasn't a big deal, except for the fact that the location of the water bottle mounts on the rear seat tube have limited the range of movement available to me for vertical placement of the front derailleur. So far I have been able to get things working. If I were to do it again, I would want either a derailleur mount with a wide vertical range, or put the bottle cage mount in a different location.

For the captain's pedals, I happened to already have a pair of old Shimano M324 pedals. To go with the yellow color theme, I took them apart and painted the main body with the same yellow paint I used elsewhere, and did the same on the platform pedals I currently have installed on the rear. I also found some gold anodized chainrings for the timing chain. They were originally intended for BMX bikes, so they required a 1/8" timing chain.

The wheels were custom built by ProWheelbuilder.com, using Hope Pro 4 hubs and Velocity Chukker rims. When we discovered that they offered colored spokes, we couldn't resist paying a little extra to get yellow spokes, which turned out to match the existing yellow trim very well. Currently the wheels have Kenda Happy Medium 40mm tires installed.

I included mounts for rear racks in the design. I built the bike with 203mm discs front and rear for maximum braking power. Waltly only had post mounts available for 160 mm rear rotors, so I used a 160-203 mm adapter on the rear brakes. The fork had IS mounts.

Even with the 700x40C tires, there is plenty of clearance. I tried inserting a MTB wheel in the frame with 27.5x2.1 tires and they appear to fit, so that will be an option we consider in the future for riding gravel roads.

Overall I had a great experience working with Waltly and would definitely do it again.

Short Cranks for Kids on Tandems

In my first post about my Bike Friday tandem from last year, I showed a picture of the Ride2 crank shorteners I first used for making the rear crankarms a more suitable length for riding with small kids on the back. Crank shorteners get the job done, but they are a bit expensive ($110 on Amazon right now), and they have the effect of spacing the pedals out further away from the bottom bracket (the so-called Q factor). I would assume this is more noticeable to riders with short legs, so I think it's a less than ideal solution. Since the Bike Friday was already set up with single side drive due to the DualDrive shifting, the rear cranks can be replaced with any standard crankset.

When we acquired another tandem last year, I put the crank shorteners on that bike and tried using a short crank on this one. The cranks pictured here are made by Sinz, who make parts for high-end BMX bikes. These cranks are available for both square taper and ISIS bottom brackets, in lengths from about 130 mm to 180 mm in 5 mm increments. They can be found online for about $60, and occasionally less. The ones in the picture are 145 mm ISIS cranks. (Note that the bike comes with square taper bottom brackets, but I found an unusually good price on an ISIS crank and happened to have an extra ISIS bottom bracket.) The cranks have a 110 mm bolt circle diameter, which matched the old cranks, so I just moved the original chainrings over to the new cranks.

I think this is a superior solution for tandem riding with kids. It's not adjustable in length like the crank shortener, which has three different lengths. However, it is possible to buy two Sinz cranksets in different lengths for not too much more than the cost of one pair of crank shorteners. If I did it again, I would do that, getting them in lengths of 145 and 155. Using this approach requires single side drive, but in this era of compact road cranksets and 11-speed gearing, one could theoretically convert even a standard double side drive tandem to use cranks like this without losing much in terms of gearing range.

Raleigh Tandem With Customizations

I wrote a couple of months ago about acquiring a second tandem. As I noted then, the Raleigh tandems look like a great option for riding with children because they are reasonably priced and can accommodate relatively short riders with just a few modifications.

Fit Customizations

The most important modifications are to get it to fit its riders. The goal was to be able to comfortably fit an 8-year-old on the back and a 5'4" rider on the front. It should be possible based on my measurements of the frame, but the suspension seatpost that came installed in the rear made it impossible to get the seat down as low as I needed. Furthermore, the oversized seat that came on the bike added some extra height of its own.

In the front, the seat went low enough, but the reach to the handlebars was a bit far for a shorter rider, so I wanted to reduce that by moving the front seat as far forward as possible and installing a shorter reach stem. The set back of the stock seatpost on the front limited how far forward the seat could move, so I moved that seatpost to the rear and installed a smaller saddle I happened to already have. The challenge, then, was to find a seatpost for the front with the right diameter and no set back that didn't cost a lot. The diameter turned out to be 29.2 mm, which appears to be common on tandems, but in general is a somewhat non-standard size.

This seatpost made by Origin8 comes in a huge variety of sizes, including the 29.2 mm that I needed. While it didn't matter in this case, it's also very long at 400 mm, so it would be easy to set up this tandem for a very tall rider using the same seatpost. The relatively relaxed seat tube angle of the frame means that putting the seat all the way forward like this will result in a position that will not feel unusual to a rider accustomed to typical road bikes.

The remaining fit-related customizations included the installation of this short reach stem. It's a Profile Design Boa with a 65mm extension and relatively steep angle (45 degrees if I recall correctly), which brought the handlebars in about 8 cm closer than the original stem did.

I also added Ride2 Crank Shorteners to the rear cranks. The pedals are currently installed in the outermost hole, which results in an equivalent crank length of 145 mm. These shorteners were transferred over from my other tandem.

With these customizations complete, the bike was basically ready to ride, but I wasn't done changing things yet.

Optional Customizations

The other customizations made to this bike were purely based on our preferences. I replaced the 26x1.95" tires with more touring-oriented 26x1.25" tires, which are better suited for the type of riding we do. I replaced the stock pedals in the front with different ones that would take toe clips. Heather and I are both used to road bikes with drop handlebars, so I also replicated that setup on this tandem. The existing drivetrain is a 24-speed Shimano setup, so I got a used pair of Shimano Sora 3x8 speed brake/shift levers, Tektro auxiliary brake levers, and a used road handlebar.

Because road and mountain bikes use different shaped cable ends inside the levers, I had to buy new cables as well. The extra cable lengths required for a tandem required that I do a lot of careful measuring before I bought anything so I could be sure everything was long enough. In the end, I concluded the least expensive option was a complete road cable kit plus an extra cable for the rear derailleur. I bought the Jagwire Racer XL kit, which had brake cables that turned out to be long enough for both front and rear brakes on this frame. The derailleur cables were not long enough, but the rear cable was long enough for the front derailleur on the tandem, and for the rear I bought a Jagwire stainless steel cable in a length of 3100 mm.

The linear-pull cantilever brakes (also known as V-brakes) that came on the bike require a longer cable pull than typical road brakes. In order to match the shorter pull of road brake levers with the longer pull required by the cantilevers, Problem Solvers makes this little pulley called the "Travel Agent". The cable wraps around the smaller disc and then jumps to the bigger disk, effectively doubling the distance traveled by the cable as it comes out. The second hole at the top is so that the effect can be reversed if someone wanted to use mountain-style brake levers with road-style caliper brakes. It works great. The Jagwire cables (except for the extra rear derailleur cable I bought) come with a black PTFE coating that makes them super slippery, and all of the braking and shifting on this bike is really solid.

The choice of red accents actually started with the water bottle cages. I was searching online for some inexpensive bottle cages to go on this bike and found something that came in black, gray, and red. We liked the idea of red and bought those, and subsequently got the cables and handlebar wrap in red. I think it looks great with the otherwise monochromatic black, white, and gray color scheme.

Completed Project

Here's the tandem with all of the customizations complete.

The tandem was bought for $200. The most expensive part of the fit customizations are the crank shorteners, which run around $90. Adding a seatpost, stem, and smaller saddle brought the size customizations to a total of around $150. The other customizations probably added more than $200 more, with the shifters being the most significant cost, even buying them secondhand, but the total cost of this tandem is still well below what I spent on my Bike Friday tandem, so I consider it money well spent.

Part Sources

We don't have many bike shops in Champaign, Illinois, and even a bigger city is unlikely to have a bike shop that stocks a lot of the items I've described here, so I do a lot of shopping online for parts. Given Shimano's constant gear inflation, finding shifters for older drivetrains is something that mostly has to be done on the second hand market, and eBay is an important source for that. For the other items, the one source that seems to consistently have almost everything I'm looking for, no matter how obscure, is Niagara Cycle Works, who I buy from through Amazon marketplace. They don't offer super fast shipping, but everything has always arrived by the date promised, the shipping charges are reasonable, and they usually have the lowest available price of the Amazon marketplace sellers, or are close enough to it not to bother buying from someone else.

A new tandem

As noted in my prior posting about tandem trailers, I've decided they aren't safe and have given up on the one we have. With my children currently at the ages of 8 and 6, we're still a few years away from the age where they can keep up on longer rides, and where I feel comfortable with them riding their own bikes on certain roads (such as the narrow bridges near our neighborhood). As I've already written, I'm a big fan of the Bike Friday tandem, but it's hard to find even a used one for less than $1000 on eBay, so I decided I would spend the winter looking for alternatives that might cost a little less. I've decided I'm less concerned about the portability offered by Bike Friday tandems, so I'm mainly concerned that the rear seat go low enough for a (relatively tall) 8-year-old.

A few weeks ago, I found a local Craigslist seller selling this Raleigh tandem for $200:

Amusingly, the seller listed the bike as a Schwinn, complete with a similar picture to this with the Raleigh logo plainly visible. Based on some internet research, I was able to determine that this model is from 2002, and is called the "SC Tandem". The frame is a blend of chromoly and high-tensile steel. It appears from Raleigh's web site that they have sold a similar tandem for the last 10 years or so, with varying model names, but more or less the same frame geometry. For a while there was an aluminum frame version that retailed for around $900, but the steel frame version has usually sold for about $650. The official specifications for the frame size are 19.5 and 16.5 inches. Based on my seat height measurements of the other tandem, I concluded that 16.5 inches might be low enough for my needs, so I took a risk and bought the bike.

This closeup of the rear triangle shows the somewhat odd design choice of what amounts to two sets of seat stays. The rear brake is mounted on the lower ones, making the top one more or less unnecessary (though it does have mounts for a luggage rack). The quick release seatpost collar is removable, so in theory it would be possible to cut off 1-2 cm of the top of the rear seat tube to get the seat lower, but it appears that will not be necessary for my 8 year old. If I were trying to get this tandem to fit a smaller child, it seems feasible to simply cut off the upper seat stays and more of the seat tube. This being a steel frame, some paint or rust protection for the affected areas would be necessary, but the result would be a frame with a geometry not much unlike some of the other common tandem frame designs out there.

There are a number of things I plan to modify on this bike. In particular, the rear seat has a suspension seat post, which does not appear to be functional, and will not allow me to get the seat all the way down to the frame where I need it. So, I will be replacing that and making other changes to bring the front seat and handlebars closer together to accommodate a 5'4" rider. I'll write more when I get that far.

Also, at some point I'll consult the owner's manual to learn why night riding is dangerous.

Bike Friday Family Tandem

After buying a tandem trailer, we used that in conjunction with the child trailer for one summer, with each parent pulling one of the trailers. At the time our children were 5 and 2. As our son turned 3, he started to be jealous watching his sister pedal, so we occasionally let them switch places. He couldn't really turn the pedals on the trailer bike all the way around, but he seemed to enjoy it anyway. However, it became clear that soon enough neither of our kids would fit in the trailer very well and that we needed a long term solution. We could have probably got another tandem trailer eventually, but at some point I started doing research on tandems. Sheldon Brown wrote a great article about tandems and kids. There were two primary features I was looking for in a tandem:

• The rear seat had to go low enough for a 5 year old.
• It had to be easily transportable.

In retrospect, the transportable aspect has been less of an issue than I expected because most of the family bike rides we do are from home anyway. My research has turned up a number of very interesting options:

• Bike Friday. A maker of folding and travel bikes that has several tandem models.
• Brown Cycles. I particularly like the "child in front" bikes they make, a feature I'm sure my kids would want if they knew it existed.
• Co-Motion's PeriScope line. In particular, the PeriScope Trident Convertible is something I wish I had sometimes, but it's a serious investment. 
• Circe Helios. It looks like a great bike, but they are in the UK, so getting one in the US would probably require expensive shipping.
• Build your own. If I had the welding equipment and expertise, I would totally build one of these.

Of all these options, Bike Friday's tandems end up being one of the least expensive, starting at $1500. That's still a lot, so I started looking at used ones. Having watched several Bike Friday tandems auctioned on eBay, I have concluded that any opportunity to buy one of these for under $1000 is a good deal. I ended up paying somewhere between $1200 and $1300 for a bike that originally retailed for around $1800, but shipping costs brought it close to $1500.

This is what the bike looked like I first got it in 2010. The long stem on the rear handlebar was originally on the front, but I needed it in the back to get the handlebars closer to the rear seat. The rear seat is in its lowest possible position in this picture, which is low enough to fit an average 4-year-old, with one exception: the crank length. This bike has standard 170 mm cranks, while the typical lengths on children's bikes are 135 mm for 16 inch bikes and 145 mm for 20 inch bikes. We tried one short ride and it became clear that the adult length cranks were not going to work. There are two solutions out there. One is the "KidBack", which is essentially an additional bottom bracket and cranks that attach on the seat tube. It's designed more for full size tandems, though so the second (and less expensive but still pricey at $90) option was what I did: the Ride2 crank shortener. This device attaches to the crankarms through the pedal threads, and provides 4 alternate mounting locations. From my fairly inexact measurements, they subtract 25, 35, 45, and 55 mm of crank length, giving lengths from 115 to 145 mm on this 175 mm crank. The downside of crank shorteners like this is they increase the space between the pedals (sometimes referred to as Q-factor) by an inch or so, which might make it harder for small legs to pedal.

My bike came with SRAM's DualDrive system, which pairs an internally geared 3-speed hub with a 7-speed derailleur (newer models are 8 speed, but my bike is over 10 years old). For tandems, this makes it possible to put the drive chain and timing chain on the same side of the bike.

This gearing system actually makes it possible to use a less expensive solution for short cranks, which I hadn't considered at the time I bought the crank shorteners. BMX products maker Sinz makes a crankset for square taper bottom brackets that comes in a huge range of sizes from 125 to 180 mm. They retail for around $60, but I've sometimes seen them available for less. They have a 110 mm bolt circle diameter, which fits a large range of road chainrings these days, including the ones on this bike, and they allow for the installation of two chainrings. I've read that the spacing of the chainrings on Sinz cranks will put them too far apart to work properly with front derailleurs, but this is not a problem for the DualDrive system.

Had I bought the bike directly from Bike Friday, they would have customized the size to fit me exactly. By buying used, I had to figure out how to make it fit. One problem that became clear after a couple of rides that the handlebars were too low and too close. I found this stem which seems to fit me well, and is adjustable, making it fairly easy to modify the setup to suit another rider.

At one point I decided to get a pump and a traingle cargo pack for tools for this bike. As it turns out, neither fit without modifications. The Park frame pump, which is adjustable to a wide range of frame sizes, was a quarter inch tool long at its shortest setting for the pump peg on this frame (I hope newer versions of this bike have fixed that). I eventually was able to modify the pump to fit. Likewise, the triangle pack was a little too tall for the frame, so it took some modification on a sewing machine to take the lowest 1 inch off.

Below is the bike in its current setup. Note that my kids have got taller in the last 2 years, so the rear seat is higher. I have moved the rear water bottle cage to the handlebar. My kids found it was a long reach down to the top tube of the frame, especially with the horizontal orientation of the bottle. I've also added the luggage rack and bar ends. Even for a 10 mile ride (most of our rides with the kids are in the 10-20 mile range), I need to be able to change hand positions. I may eventually try to install a drop handlebar, which is what I would have got if I had ordered a new one of these custom.

As noted in my last entry about the tandem trailer, I think I should have bought one of these earlier and never bothered with the tandem trailer. This is a much more significant investment, so it's not for everyone, but if you want to do bike rides as a family, I think the Bike Friday tandems are an ideal solution for kids who aren't yet big enough to keep up on long rides. This is also a good option for larger families because you could theoretically pull a child trailer behind one of these (up to 3 children per parent!). I do have a friend who has pulled a child trailer behind a tandem trailer, but I've been soured on tandem trailers enough that I don't think I'd recommend that to anyone.

WeeRide Co-Pilot Bike Trailer: don't waste your money!

We did family bike rides with both kids in the trailer until our oldest was about 5, at which point she was simply getting too tall to fit inside (she's taller than average). At that point, we knew it was time for her to graduate to something else, so we looked at our options in "tandem trailers", i.e. trailers where the child pedals. One of the most well known products for taking a child along on a ride is the Adams Trail-a-Bike. They seem to have a good reputation, but they are also one of the more expensive options (suggested retail is over $200, but it looks like Amazon has it for $160).

At the time, we decided it was important to be able to fit it into the trunk of our car. Most newer tandem trailers have some kind of folding feature which makes this possible, but I passed on a chance to by an older Trail-a-Bike because it lacked this feature. In the end, we chose the WeeRide Co-Pilot, which typically sells for less than half the price of the Trail-a-Bike.

Here is a closeup of the hinge in the middle that allows it to be folded over for transportation.

The rear 90% of the bike is solidly built and I have no complaints about it, especially for the price. The part that has turned out to be huge problem is the front part. Here is a closeup.

The hitch mechanism attaches to the seat post of the adult bike. It's not a particularly elegant design, but it works. Behind the hitch are two joints, designed to allow the trailer to move both horizontally and vertically with respect to the bike. The first problem with the joints is that the weld connecting them to the rest of the trailer is not straight. When the hitch is held perfectly level, the trailer bike leans a couple of degrees to one side.

This is not a one-time anomaly. While this trailer has generally received positive reviews on Amazon, there are a number of 1-star reviewers (full disclosure: I am one of them) who have described this same problem. I don't know how common this is, but there are clearly some quality control problems.

The second problem with the joints is that the bushings get looser over time. After 4 summers of regular 10-20 mile bike rides, there is now enough play in the joints that the trailer can flop back and forth several degrees. This is particularly challenging for the adult rider trying to keep the whole rig upright. A few weeks ago this finally resulted in a crash, and we have decided that it's time to retire the Co-Pilot and find a better solution for family cycling. WeeRide's web site says they now have a new hitch design, so it's possible they are aware of this problem.

The lesson learned from all of this was that if you want to buy a tandem trailer, you really need to spend the money on one of the more expensive models. A year after buying the Co-Pilot, I acquired a true tandem, and we have been using both for the last two years. After using both, I've concluded that the only real advantage of a tandem trailer is cost, and that anyone serious enough about riding to make the investment in a tandem is better off skipping the tandem trailer entirely and going straight from a trailer to the back of a tandem. The advantages of this are:

• Better handling and balancing characteristics than a standard bike pulling a tandem trailer.
• The child can actually help pedal no matter what gear you're in. Above a certain speed, a child on a one-speed tandem trailer can't pedal fast enough to actually contribute, so they end up just coasting and (in my experience) goofing off in ways that can make it a challenge to keep the bike upright.
• A tandem can grow with the child past the age where they might be too big for the trailer.

Schwinn bike trailer

My last post was on a bike project, and now I've acquired yet another bike, this time a tandem for the purpose of cycling with my kids. There are other blogs out there where people have documented their experiences cycling with their children, and I've found them quite helpful. So, before I put up pictures of the new bike, I've decided to start from the beginning documenting my experience cycling with kids, the equipment we've used, what has worked and what hasn't, in case it's of interest to anyone out there.

The first piece of gear we got was your basic 2-child trailer. This would have been in 2005 when our oldest daughter was 1. This is a Schwinn, bought at a local big box store for around $160, if I recall correctly. This picture shows it with its "stroller" handle attached. We never used it that way, but I'm sure would do the job well.

There were (and still are) other options made by manufacturers who specialize in bike trailers (like Burley), but they cost considerably more. There are also cheaper options. After pulling this for hundreds of miles, many of those miles with friends pulling a smaller and cheaper trailer, I'm glad I spent the money on this one, and don't feel like I needed a more expensive one. The large wheels (16 inch) roll more easily than the 12 inch (or smaller) wheels common on many other trailers, and they use standard quick-release levers to attach, which makes it easy to break it down to go in the trunk of a car. This trailer also has a fair amount of storage space behind the seat, which we put to good use more than once on some longer trips.

The trailer after being folded for transport or storage.

The trailer hitch that goes on the bike looks like this (picture borrowed from Amazon without permission):

We bought an extra one so both parents' bikes so the trailer could be switched between us easily. The small hole in the hitch attaches to the rear axle of the bike. It adds probably 2-3 mm of additional stuff that have to fit inside the nut or quick release skewer. One of our bikes required a longer quick release skewer in order to make it fit, but I happened to have an old one. The other bike (a Giant OCR3 from about 2005 or so) has a rear dropout that looks like this:

It might be hard to see in this picture, but the recessed area around the end of the quick release skewer is nearly 1/2 inch deep, and not wide enough for the top of the trailer hitch to fit. As I see it, there are basically two possible solutions to this. The first is to get a really long skewer and some kind of spacer to get the trailer hitch outside of the recessed area. I did some research on skewer lengths, and it appears that there might be some out there designed for tandems that might work, but they are hard to find and expensive. The second option is to find a way to attach the hitch to the frame, which is what I opted for. I don't have a picture of it, because it's been disassembled now that we're not actively using the trailer any more, but basically I used electrical conduit clamps to bolt a plastic plate to the rear triangle of the frame, and bolted the hitch to the plate. It was ugly, but it did the job.

I don't have experience pulling other trailers, so it's hard to say how pulling this trailer compares to anything else. The one thing that took some getting used to was that it really forces you to pedal smoothly. There's enough flex in the hitch mechanism and the long bar that attaches to the bike from the side of the trailer that any hard acceleration feels like pulling on a bungee cord and wastes energy. This is probably the case for most trailers that mount on one side (as opposed to some cargo trailers which attach to both sides of the rear axle of the bike).

I never required my children to wear helmets in this trailer, in part because we just hadn't bought them yet at the time. I can say from experience that these trailers are extremely stable, and would be difficult to knock over (I have crashed once while pulling this trailer and it remained upright). This is a fairly roomy trailer, and it worked well for our kids up to the age of about 4. By the time our oldest was 5, it was getting clear that she just didn't fit, so we took the next step and bought a trailer bike, which will be my next blog entry.