DF 141 Has a Cracked Boom

The other day, I was messing around with the chain rings on DF 141 when I noticed a long crack in the top surface of the carbon fiber boom. It wasn’t obvious visually, but I could feel it with my finger. I was a bit surprised since I hadn’t detected any movement of the boom while pedaling. Probably a stronger rider would have caused the boom to deflect more. I removed the bottom bracket holder to expose the cracked area of the boom. It appeared that the crack was due to over-tightening the bottom bracket mount clamps. It was about 12″ long.

I emailed Ymte at IntercityBike and purchased a replacement carbon fiber boom. He warned me that swapping out the boom was a lot of work. The old boom was bonded into the DF and I’d have to use a chisel and hammer to remove it. While I was waiting for the new boom to arrive, I decided to see if I could fix the old boom as a learning exercise. I came up with a plan and it seems to have worked so far. Here’s how I went about repairing the crack.

I first found the ends of the crack and ground round holes at the ends to prevent the crack from elongating. I then ground out the crack leaving a beveled groove on the top surface to provide some surface area to add carbon reinforcement.

I also wanted to lay 4 plies of carbon fiber twill on the under side of the top surface. I needed a way to laminate the carbon fiber and hold it in position, fighting gravity. Ideally, I’d also bevel the edges of the groove on the underside, but I couldn’t come up with a solution for that. I came up with a tool to apply the patch. It consists of an aluminum paddle of the correct length and width and an old bicycle inner tube. I covered the paddle with some pvc tape as a mold release. I then saturated the 4 plies onto the paddle forming the patch. After cleaning out the boom with Acetone, I ran the paddle into the boom, positioning the patch under the ground out crack. I slid the deflated inner tube under the paddle with the valve stem still accessible outside of the boom. I then inflated the tube which forced the patch upward to bond to the underside of the top surface of the boom. The pressure of the inflated tube force some resin out of the patch, filling the ground out crack.

While the resin filling the ground out crack was still in the uncured state, I filled the crack with long strands of carbon fiber. On top of the strands, I filled the ground out beveled area with chopped carbon fibers.

When the resin had cured, I deflated the inner tube, removed the paddle tool and ground the exterior patch flush with the top surface of the boom.

I’ve got about 50 miles on the DF since I made the repair and it seems OK. There are no re-appearing or new cracks. Also I can’t feel any flex in the boom so far. I’m hoping that I can leave the new boom on the shelf and live with the repaired boom for a while.

DFXL Sold

I’m back down to owning 2 velomobiles again. My friend David L has bought my DFXL. The DFXL was my first velomobile and the test bed for all of my custom parts. I decided to sell it after determining that I could comfortably squeeze into my recently purchased standard DF. It just so happens that David was in the market for his first commercially produced velomobile and the deal was done quickly. I’m so glad that there will be another velomobile rider in town to share this strange hobby with.

David is the grand daddy of recumbent trike riding in Santa Barbara. He’s the guy that got me interested in trikes. He was one of Wizwheelz’s first customers in the 1990s when he bought one of their first generation TerraTrike recumbent trikes. David is no stranger to velomobiles. He’s been tinkering with home made coroplast bodied Terratrikes since those early days. Now he’s finally got the velomobile that he’s been wanting for all these years.

Greenspeed X5 – SOLD

I recently met a fellow retiree at the local dog park. During a short conversation, he mentioned that he has had a tricycle hanging in his garage for years. He had bought it from Dana at Bent Up Cycles to use to walk his dog. It seems that idea didn’t work out very well so he put it away and never used it again. I went by his place to have a look and was surprised to find a pristine Greenspeed X5. It looks like it just rolled off of the Bent Up Cycles showroom floor. There’s not a scratch or sign of any wear. It looks like it was never used. The tires still have the center seam.

I failed to convince him to take it back out on the road. He was more interested in getting the trike in the hands of someone who would make good use of it. So I offered to help him find a new home for the X5.

Price: SOLD $1800 plus Shipping via Shipbikes to Continental USA. Expect $100 – maximum $150 depending on destination. (We will pick up anything over $150).

Here are the details:

  • Frame Color – dark metallic gray (unusual color for a Greenspeed)
  • Seat Color – dark blue
  • Crankset – 165mm Shimano 105 triple
  • Brake Calipers and Levers- Gatorbrake hydraulic (mirrored)
  • Brake lines – stainless braid shielded
  • Front Derailleur – Shimano 105 9 speed
  • Wheels – 349 Greenspeed (unmarked)
  • Tires – Scorchers
  • Shifters – Shimano 9 speed bar end
  • Chain – stock 9 speed
  • Idlers and Chain Tubes – Greenspeed factory set up
  • Rear Derailleur – Shimano 105 9 speed long cage
  • Rear Hub – Shimano Capreo 9-26

Additional Features

  • Greenspeed factory headrest
  • Greenspeed factory rear fender
  • Cateye Wireless computer

DF vs DFXL Size

While I’ve got both a DF and a DFXL in my garage, I thought I’d post some photos that show the size difference between the two models for reference.

Here are the dimensions.

Check out how Daniel Fenn derived the pattern (buck) for the DFXL from an expanded DF. Notice how he avoided expanding the wheel wells, derailleur hatch and front cover to keep the changes simple… Very clever.

The DF (blue) and the DFXL (red) currently residing in my garage. BTW… one of these will be for sale after a brief evaluation period,

Good Bye to the Catrike 700 and Hello to DF 141

I’m once again a 3 velomobile owner. I’ve just completed a trade of the black Catrike 700 plus cash for a crashed standard DF velomobile. DF 141 had been involved in a crash about a year ago when it ran into the side of a car that turned into its path. The owner had repaired the resulting cracks and ridden it for the last year. The repairs were structurally sound but not pretty.

So why would I do this deal? Ever since I managed to squeeze into the tiny Milan SL, I wondered if I could downsize from my DFXL to a standard DF. A standard DF would have a smaller frontal area which could potentially be faster. My 700 spent most of its time hanging in the garage so it was time for it to go. The plan is to spiff DF 141 and see if I can comfortably ride it. If so, I’ll sell my DFXL. If it’s not comfortable, I’ll sell it and keep my DFXL

Carbent Raven (Sold)

I’m pricing this Carbent Raven for a quick sale. I am the second owner of this bike. It has a fairly large frame. I would guess that it would fit a rider with 43″ to 47″ X-seam. It weighs 21 lbs with pedals. It shows that it has some miles on it but is in good mechanical and cosmetic shape. There is one exception – the carbon fiber seat has been patched on the face surface which is covered by the seat foam. (See the photo below). The seat seems structurally sounds but that hidden patch is not pretty. This bike is ready to ride today.

sold!

  • Some Details
    • FSA double crank with Q-Rings
    • Terracycle Idlers
    • SRAM chain with little elongation
    • Mavic 700c wheels and hubs
    • Bacchetta long handlebars
    • New foam seat pad
    • X-Eyed front brake, Bacchetta (?) rear brake
    • Avid brake levers
    • Shimano SPD pedals


Another Bike!

Only days after I picked up the Carbent, I noticed a posting in Craig’s List for a Bacchetta Carbon Aero for $1000. It looked to be in near new condition. I had to check it out. So, I made the trip up to San Luis Obispo and bought it on the spot. It has some pretty high end components like a carbon fiber crank, Q-Rings and a carbon fiber seat. It is pristine.

I’ve ridden both of my high racers and have decided that the Carbon Aero is staying and the Carbent will be put up for sale soon.

Getting Back On A Bicycle

It’s been a year or two since I’ve owned a recumbent bike. Recently my friend, Gregory, bought a used Carbent high racer. We get together from time to time to ride trikes or my velomobiles so I thought it would be fun to get a similar bike so that we’d have another option on our rides.

I began looking for used Bacchettas and Carbents. I even considered buying a new Schlitter Freestyle. But, since I don’t anticipate riding a bike very often, I decided to spend as little as possible. I was able to pick up this used Carbent Raven on eBay for a very low price. Carbents are built to fit the buyer. Boom length and seat recline are not very adjustable. So, I hope that I won’t need to do any surgery on this bike. I’m sure that I’ll need to refresh some parts before I take it on the road.

Update: I picked up the Carbent and it was in much better shape than I had expected. It fits me well. It will need a new chain and some cleaning but that’s about it.