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View Full Version : A Little More on Bushings and Store Bought Tadpoles



trikeman
05-28-2008, 06:16 PM
I didn't want to hijack the other Tadpole thread anymore than we already did, so thought I would bring this here. I decided to stop in to my local bike shop today and drool over the store-bought tadpoles.

They had a Greenspeed, a Cattrike, and a a Terra Trike on display. All had the 20" rear wheels, and I was struck by how small these bikes are. I could probably carry one on the back of my DW :) The Greenspeed had a folding boom. I believe it would fit in the trunk of my car folded up.

Anyway I told the guy I was just browsing, which is about all I could do since the prices were $1,500, $2500, and $3,000 on them. They were beauties for sure. Nice and shiny and new, with that new-bike-smell.

What was interesting (to me anyway) was that the Terra Trike had bronze bushings in a set up a lot like what Brad showed as his first try. The Cattrike had Cane head stock king pins, and the Greenspeed (at $3,000) had bushings, as well. I asked the guy who owns the place if people liked the bushings. He said, "They do have a bit of play in them." I smiled.

Then, I looked at the cross members. All of them were in the same plane as the main boom, where they came across. I remembered Brad saying that he put the crossmember above the boom to give him more chain clearance. Sure enough they all were having to bend the chain more to get under the cross member. I asked if those pulleys were noisey, since all were smaller (like 2" or so) than the ones on our creations. He said they made a bit of noise. I smiled again.

With the 20" rear wheels, the rear derailer on the Greenspeed was almost touching the ground. It had maybe 1.5" of clearance. I also noticed that the Cattrike only had a Sora derailer. That seemed kind of low end for a $2.500 bike. I asked about top speed with those tiny 20" rear wheels. He said the Greenspeed had a 9 tooth sprocket on the rear for top end. Nice bar-end shifters though. They seemed as nice as the down-tube indexed shifters on my road bike, but they are at least Shimano 105s.

Anyway, I didn't buy anything. They were all pretty bikes, but for the price I could build 5 Street Foxes with really nice new equipment. I didn't examine the paint jobs critically (or the welds). I didn't want to appear too nosey. Maybe next time.

TheKid
05-28-2008, 07:51 PM
You mentioned how small they are, which made me chuckle. The first attempt I made at a tadpole was with a standard 20" rear, and had a wheelbase of 37". It was 30" wide and way too low for me. It was 69" long.
I raised the seat, then made the crossmember wider for more stability. I also increased the wheelbase to 43". Then I found a 20" suspension rear. I didn't want to extend the boom, so I started from scratch.
After rebuilding and finally going to a 26" rear, I now have an overgrown Streetfox with the crossmember mounted under the boom. I made the boom longer to mount a fairing, the crossmember is even wider, and the seat is higher. Total width is now 40", the wheelbase is 52" and it's over 7' long.
The first one made me feel unsafe in traffic, because it was so small and low. I was looking up at little kids riding 16" bikes. Now it has a nice smooth ride, I sit at the same height as my Saturn, and I don't feel like Baby Huey on a 12" unicycle.
I don't understand why the makers of expensive trikes use bushings knowing there's play in the steering. As you mentioned, the deraillers are sometimes too low on 20 inch wheels, which is one reason why I went to the 26" rear wheel. (I would have like a 24", but I found a 26" suspension bike.)
$1500 -3000 is a bit steep for a machine you may not feel 100% comfortable on. I'll stick with building my own, and making mods until I'm 100% satisfied with how it feels, how it rides, and how it looks.

wretched_hyena
06-10-2008, 04:08 PM
Ah, come on. Go back and pretend to drop something. Get down on your hands and knees ("Now where the hell did that thing go!") and take a good look at the welds and paint!

savarin
06-10-2008, 07:03 PM
2 of my friends own greenspeeds. 1 a younger model than the other by quite a few years. (both friend and bike:))
Both frames are immaculate in the welds and paint.
Both have 20" wheels, one with disks and the other with sturmey archer drums.
They are both very low but handle very well.
I must say I couldnt hear the chain on the pulley whilst riding and the cross member is welded to the main boom in the same plane.(neither top or bottom)
These models were built in Australia and feature top end components.
The rear dérailleur on the older bike is married to a 6 speed internal hub and has at least 6" ground clearance (cant remember what it is on the newer bike)
I had to shim the bushings on the older the other month for him although the play was hardly noticeable, I dislike any play in a bearing. He said it felt a lot better.
I would suspect that the $1500 price on the greenspeed is more than likely for the new frames Paul is having produced in china so he can bring the price down.

Would I pay that? Uh uh! way out of my league so I'm sort of copying the frame geometry for my tadpole. I like the riding position.

trikeman
06-10-2008, 07:37 PM
They were beautiful machines for sure.