Sun Tadpole cs vs Bionx
Can someone give me advice as to whether or not a Bionx assist conversion will fit/work with my new Sun Tadpole CX Recumbent. I cannot get a response from BIONX. Direct dealer querys are very vague.
Have any test reports been published or personal test report will be very welcome. I am 86 and need help in the steeper hills, but still want the movement of my legs all possible. Thanks
Murray Fisher firstname.lastname@example.org
I wanted a hub motor on my faired Tad, but it required cutting the fairing and may be a valve problem putting air in. I chickened out, but if the Bionx works easily with a 20" wheel; let me know!
You can do a Bionx on virtually any trike. The limitation is that you cannot use a cassette on the Bionx hub. You have to use a freewheel which come in 8 cogs max. This means you may need to change drivetrain parts if you have 9 or 10 speed specific components. 8 speed freewheel cogs are not easy to find but they are available.
Overall it is arguably the best system available and with the Li-Ion battery option, can be implemented in under 15 lbs. Remember that you will be pushing that 15 pounds around when not in use. Regenirative breaking is nice if you brake on the downhills anyway but don't expect it to do any significant recharging.
One other limitation may be the ability to adapt trailers on the rear axle due to the power cord and the mounting hardware.
In the worst case, for 20" wheels you can use inner tubes with a 90 degree valve stem.
You might also try calling THESE good people at Trimuter for more info.
Bionx with Sun Tad CX
I sure am not able to get any input at all on my query to whether or not I can use the BIONX on my Sun Tad CX. I guess my main problem is that I am brand new at Bents and do not understand the nomenclature and what it does....for example I am told it needs to be a Free Wheeling bike and have the 9 speed cassette. I do not know what those terms mean....I know what free wheeling is and seems like mine would have that, as when I quit pedaling I can coast without the pedals going around. Also I think the Cassette refers to the 9 gears on the rear wheel of the tadpole....what do I need to know before I try to order it? I do not understand why I get no response from either dealers or the BionX company at all....they advertise but don't do any follow up. Help!!
Murray, Don't know where you are located, but you might get in touch with "Murray" at this site.
He sells Bionx and installs them on trikes. He will respond to your questions. Good Luck!
Originally Posted by murrayfw
Murray... I do not mean to be mean at all when I say that this is way over your head at this time. You can do a lot of studying to get up to speed on what is different on bicycles or you can let someone who knows what they are doing make the upgrade for you. I highly recommend the latter.
Here is the what I see in your message so far: You need a "freewheel" gear instead of a "Cassette". These both do ~free wheeling~ as you described it but they are totally different in how they work. You cannot get a 9 speed freewheel. The most you can get is 8 speeds and even those are hard to find.
Isn't the Sun a 24 speed trike already? That would make the change much easier.
Neither SUN nor BionX will deal with customers directly. You need to find a shop that sells AND installs BionX systems and have them give you a quote for installing everything you need for the conversion. Let them explain everything you need and how much they are charging you to do it.
Short of this, you will need to find a competent "friend" on a forum that is local to you who is willing to help walk you through it. It's not rocket science, but some basic bike archetecture is critical in knowing how deep you're gonna get into this conversion. I thought about it for my trike also and decided I had to much to change to make it worth my while. Plan on spending around $1600 minimum for a complete system plus installation costs.
Bionx on SunWEll
You are right, I am in over my head....I am 86 years old, but my mind is still good!! I am an inventor of many things and have an excellent shop, program computers etc. Just never got into these Bents until recently. The Sun Tadpole comes in two versions. The CX has a 9 speed cassette and the SX has an 8 speed cassette which I guess wouldl make them 27 and 24 speeds respectively...my daughter has the SX and I have the CX. We both need the Bionx....she for her MS problems and me for leg problems. I sure cannot find anyone that has ever used one with the Bionx wheel. No dealer responds to me, nor the factory. I know it will be an expensive conversion. I would want the best BIONX version. I need it badly but seem to be butting my head against a brick wall...surely SOMEONE in the thousands of Bent owners know something about this.....all my responses have been just THEORY, which is fine as far as it goes..Still trying.
The Bionx system would work fine for you. There are 13-32 9 speed freewheels now, all the Bionx dealers have access to them. The system is very easy to self install. You can find videos on the internet by going to YouTube and searching "Bionx". The great thing about the Bionx system is that it is light weight; the 250 watt motor is 7.7 lbs., and the 350 watt is 8.8 Lbs. This means the trike can still be lifted by mere mortals. There are many good dealers willing to answer questions and ship kits. Enjoy! Try Electric Cyclery in Southern CA; very into Bionx, and has a fleet of test bikes. Great phone service. 949-715-2345. http://www.electriccyclery.com/catalog/. I have no connection to Bionx or Electric Cyclery.
'01 RANS V2
Thanks Tom, That was a big help....I am getting there. One question. My specs on the Sun CX Tapole shows 9 speed 11-32 teeth. Do you know if this would still be okay with the 13-32 teeth model available. I am wondering what the difference is between the 8 speed and 9 speed....could it be the width of the opening in those rear forks or something critical. Would my 11-32 9 speed work without buying the 13-32 9 speed do you think?
The cassett that you have on your wheel now, and a freewheel for a hub motor are different. Your cassette slides onto a splined ratchet. The freewheel threads directly onto the hub motor, and the ratchet portion is built into the freewheel.
For many years people have not made 9 speed freewheels because there is no bearing at the outer end of the freewheel, as there is in the cassette ratchet. The fear is that with a great amount of force on the chain, the axle, supported only to the width of the motor, would be damaged.
With the advent of hub motors and the demand to electrify 27 speed bikes, one manufacture (Sun, I believe) ha started producing the 9 speed freewheels. Since we recumbent riders do not usually apply the force of a mountain biker standing on the pedals, the rear axle is safe. And because the motor power comes from the wheel itself, no motor force is transmitted through the chain.
The 13-32 will work perfectly with your bike; basically the highest gear will just be two teeth lower. And many people change the cassette to suite their own style , so nothing radical there.