Advice on gearing setup for Bionx PL350
Hi, I'm new to this forum and I'm also new to the electric bike community. I want to build up a Surly long haul trucker touring bike with a Bionx PL350 system and am unsure about the correct gearing to use. I have a 14 mile commute and have some long steep hills. I recently read the following thread about a crankset setup on url=http://www.bikeforums.net and am looking for some further advice for my specific goal of using three chainrings and a 7 speed Shimano freewheel. url=http://www.bikeforums.net/archive/index.php/t-377250.html
The thread discusses a 52/42/26 crankset. I would like to use a similar crankset with a 13 - 15 - 17 - 19 - 21 - 24 - 28 7 speed freewheel on a Surly Long Haul Trucker frame. (The link to the frame specifications for the Surly are url=http://www.surlybikes.com/longhaul.html )
Here are some of my questions that I would be very glad of some advice on:
1) Can a Sugino XD300 or XD600 crankset be setup to use 52/42/26 chainrings? If not, can someone please recommend a brand/model suitable for the Surly frame?
2) What front and rear derailleurs would work for this setup?
3) What shifter should I use (mounted to a flat handlebar)? (would a downtube shifter be more appropriate?)
Doesn't Bionx stop assisting at 20 mph? If so, you may not have much use for 52 tooth front crank. On my bike, which goes 25 on the flats, and faster downhill, I found a 58 tooth front sprocket very usefull. But for speeds under 20 mph, I would think a 48 tooth front crank would be big enough, and maybe even a 44. You can always try it out with the stock crank, and look for what you find you need later.
On my existing bike and without the Bionx system I travel faster than 20mpg as for at least half of my morning commute I am going downhill. So I wanted to make sure that when I setup my other bike with the Bionx system that my gearing allows for a more leisurely cadence, even though the Bionx system may not be assisting much once I go over 20mph.
Morning! I have the Bionx350 and I cannot go nearly fast enough with my gears!! I have a SwissbikeLX ( http://www.greenspeed.us/bionx_montague_swiss_bike.htm ) with a fat downhill tire with stock shimano 24 gears, and I run out of gears on any hill and almost on the flat! I basically hardly ever go out of topgear (as I have the thumb throttle to start off from stationary) and I went to a shop last week to see about getting harder gears. He says change the frontgearing for a bigger set would make it better. I will report on results!
Basically I can go 36km/h on the flat in topgear with gentle peddling and I have got 49km/h out of it down a hill peddling like a dervish! I could easily have broken 50 if I had had harder gears and I really want to cruise on the flat at 40....bring on the new gearing!!!
(Any advice gladly accepted of course!!)
Yes, please follow up with any results... the one problem I see with the Montague/Swissbike BionX setups is the stock gearing that only goes to 42F/14R. On my Paratrooper, the top gear is essentially the only one I ever use with any assist, and I usually only use the top 3-4 when I'm biking without assist. It could easily use either a larger front gear or smaller rear (or both).