Rachael and I enjoyed our overseas trip, visiting Germany and then the USA. The Spezi show in Germersheim continues to grow, and now fills three halls. I believe that it is now the largest and most interesting special bike show in the world. Reports can be found at Bent Rider On Line
And in Velo Vision No. 14
The following weekend we did the New York City Bike Show in the USA. This was completely different, and we found we were the only recumbent manufacturer there. Entertainment was provided by CHUNK, a bicycle club which had a hobby of making fun bikes out of scrap bikes. These consisted of choppers, bikes with excentric wheels, bikes with an extra pivot in the frame, and tall bikes, which were one bike welded on top of another. The tall bikes were used for jousting, with lances make from 3" PVC pipe. Unfortunately Rachael's camera packed up, so we aren't able to bring you any pictures :-( For more info see :-
The hard part about the trip across the USA was getting up early most mornings, taking two plane trips to get to the next city, and carting all our luggage plus the GT3 in a case. Only on one flight did I have to pay for it, when I told the girl behind the counter I had two bags and one oversize case. "Doesn't look oversize" she says and comes up with a ruler. "Yes it is oversize - you will have to pay for that". I had no idea there was a charge for oversize, as we were within the weight limits. Needless to say, I never mentioned it again! We used the "Folding Bike Case" from :-
The best part was was meeting all the great shop owners and staff who took care of us, and who were excited to ride the GT3. It was really special to be able to talk to dealers and customers face to face. We wish we had been able to stay longer, and learn more. Maybe next year!
As indicated in the last newsletter, Jerome Hediger, GreenSpeed USA, and formally of Wicks Aircraft Supply, is our new USA Distributor. We have been working with Jerome since 1999, so we have full confidence in him and his knowledge of trikes. In his own words :- "I am very proud to announce that I have been accepted as the United States distributor for GreenSpeed Trikes and HPV's. I have been involved with the distribution and support of homebuilt aircraft components for most of my life and have been an avid recumbent cyclist for more than 15 years. GreenSpeed trikes have always impressed me as being the best engineered and built trikes in the world, and I am very excited about being involved with a company that will continue to bring new and innovative products to market. I have extensive personal and business experience with the trike market and I look forward to serving all US GreenSpeed dealer needs". - Jerome Hediger.
Jerome is at present building new facilities for the storage and assembly of GreenSpeed trikes. These are now near completion, and will be able to accommodate more than TWO container loads of GreenSpeed Trikes. Furthermore the savings in freight should be enough to pay for the storage and distribution, so that the cost to the shops and the end customer should be no more. Plus shops will now be able to buy their trikes in USD, which should stabilize the prices, and not leave the dealer out of pocket if the currency rate changes before the trike is delivered.
Delivery times will also be reduced with stock held in the USA instead of Australia, and Jerome will be able to answer enquires in normal USA business hours, instead of people having only a narrow time window when they can call Australia. He is now getting weekly production updates from here, the same as the GS factory staff. Rachael and I inspected his facility when we visited him and his wife Nancy on our tour, and we expect them to visit our factories here, later this year or early 2005, so that they are completely familiar with everything that we do.
We look forward to meeting them again at Interbike, and introducing them to our USA Dealers.
In May the pre-production batch of 12 Oz made GT3s were finished and delivered. The next batch 50 GT3s, being assembled here is now nearly finished, with only one remaining to be completed. All these GT3s are now sold, and the next batch of 150 is presently being assembled on the production line in Taiwan. Shipping date for these trikes is June the 10th, so by the time you read this newsletter, they should be on the water. Delivery is expected early in July.
Some years ago I saw a picture in BCQ No. 13 of Frank Lienhard using 110 mm cranks on his low rider recumbent. Whereas after a lot of research, I'd ended up using 185 mm on my personal trikes. This was also confirmed for me by a paper on the Web at :- http://www.nettally.com/palmk/crankset.html
So I dismissed the idea of very short cranks. Then our U.K. dealer Rob Hague, http://www.wrhpv.com started using 150 mm cranks for racing, and found an improvement in his performance over the usual 170 mm, despite the fact he is about 6' tall. Next Mark Mueller, started using 110 mm cranks, and again found improvements in performance, with training, on this size of crank. In fact he even tried 75 mm cranks before fitting the 110 mm to his Greenspeed SLR Race Trike :- http://www.humboldt1.com/~mhp/slr.htm
Then my son, Paul, took the 175mm cranks off his personal GTR, and fitted 100 mm cranks. He found such an immediate improvement in both performance and the stress on his knees and legs, that he announced that there was no way he was ever going back to using normal size cranks, and sent back the 170 mm Rotor cranks he had been testing in the view to using on his own machine.
For the 24 hr race, mentioned in the last newsletter, he decided to use 150 mm cranks, as none of the rest of the team had trained on Ultra Short Cranks. The fact that they won the 24 hr race seemed validate their use, so then Paul did some testing on our Computrainer dynameter. He tried four different lengths - 175, 155, 125, & 100 mm. Over the 4 lengths, power output was virtually constant, with a slight reduction of max. power for the 100mm. See Test Results.
So if the power is the same, then what are the benefits? Mechanically it reduces the need for high gearing, eliminating the need for oversize chainrings and extra small rear cogs. Even by going down to only 150 mm cranks for his race trike, Paul found that he only needed a 12/25 rear cluster with a 75t chainring, and furthermore the 12t was not used in the race. And this was with a 16" rear wheel. Thus the top gearing used was only 75/13*16.5 = 95 inches. With a 20" rear wheel the standard 52/11gearing gives 95 inches, so with 110 mm cranks one could go even lower.
This is due simply to the higher cadence one automatically achieves with the shorter cranks, and the higher cadence (crank revolutions per minute) is what gives the benefits to the legs. This was brought home to me when I fitted a new customer, Irene, for her trike. She had hired a demo trike for a couple of months, to see if it would solve her transport problems, as she had never driven, and her husband had suffered a stoke. Measuring her short legs, I found that according to Palm (above) she would need 150 mm cranks, so these are what I fitted to her new trike, whereas she had been using 165 mm on the demo trike. Latter I got an email saying how much smoother the the new trike was, which did not make any sense to me. Then she told me that she was not getting the cramps in her legs that she had suffered on the demo trike, and the penny dropped. The shorter cranks had made the difference!
Another mechanical benefit is with faired trikes. The smaller circle that the feet move through mean that the cranks can be set lower, as on our SLR race trike, and because the knees do not move as much, the front of the fairing can be lower again. This is very useful for head out fairings, as it means the seat can be more laid back, reducing the whole frontal area and making the whole machine more efficient. This is possibly what accounts for performance increases with bare trikes - moving the feet less would have less disturbance on the air stream, giving less drag.
Yet another benefit for the legs seems to be that moving through a smaller angle is easier on the knees and the hips.
Both Rob and Mark are now training on 75 mm cranks and have 110 mm cranks on their race trikes. These short cranks are simply made by shortening existing cranks, and we can do this work for anybody who wishes to try a set.
Having spent many years testing all the tyres available on the market for trikes, and even some which are not, I believe I now have a good idea of what is needed to make a superior Trike Tyre. Unfortunately the most frustrating thing has been trying to find a tyre company which is capable and willing to make something a bit different. Now after talking to a tyre company for two hours at the Taipei show, and countless emails back and forth, I am finally waiting for a quote. IF it is satisfactory, and IF the samples come up to expectations, we should have some better tyres for both our 20" (406) wheels and 16" (349) wheels. The sizes will be 40-406 and 40-349.
And for those people who have punctures too often, we are also working with another tyre company who makes airless tyres. Together we have developed an airless tyre which rolls as easy as some pneumatic tyres. These are currently undergoing field trials in Germany and the USA.
Thanks to the many people who provided feedback on the four tailbox designs that we had sketched by a design company. They are now working on integrating this feedback into a new design, and we will get quotes for that.
The timing chain on our tandems needs to keep fairly tight to prevent derailment when the captain is pushing hard, over rough roads, so we investigated adding chain tensioners to the timing (front) chain. However even the best added an un-acceptable amount of drag on the chain. We also searched for a long time, unsuccessfully, for some decent looking chain ring guides. Now at last we have been able to get some good looking chain ring guides from the French company, Specialites TA. These do a brilliant job of keeping the chain on with less tension. These will suit chain rings up to 54 t on a 130 mm PCD, so they will fit the Standard Sugino RD 7000 Tandem crank sets, we have been fitting to our GTT Tandem Trikes for some time, and even the Shimano RX 100 cranks before that.
So if you are having any problem with chain derailments, please contact Rachael letting her know the serial number of your Tandem Trike, and she will be happy to post you out a set cost free. We also have a limited range of TA guide rings in other sizes for other applications. Please contact Rachael for details and prices.
As indicted in Newsletter 1, we changed from fitting the Hope disc brakes on the GTT to fitting to Magura BIG disc brakes, as they performed better under extreme conditions, like descending a mountain with a camping load and a trailer. We have now been fitting a rear disc brake mount to all tandems as standard equipment, and have changed over to fitting the much larger 210 mm rotors, at the front, and at the rear when the optional rear disc brake is ordered.
This newsletter is produced for your information, so I'd like some feedback on the sorts of things that YOU would like to read about :- GS News? Technical Stuff? Owners' travels? Owners' letters? Repair tips? Accessory reviews? Other stuff? Please drop me line - email below.