Recent content by JohnH

"It Depends". Sorry, but it does. Many 7-speeds are a simple freewheel - the thing is a unit, and the ratcheting mechanism is part of the cogset rather than part of the hub. There are IIRC some 7-speed cassettes around, and they would use something like what you posted. The common 7-speed...

That makes sense to me. The larger-diameter part of the cone has a higher speed in SFM (Surface Feet per Minute) then the narrower part for a given RPM. What about a stepped cone, much wider I suppose? If you spring it to move away from the tire when not powered, you could drop power to...

More amps, so more heat generated from resistance, so more power lost to heat? That's what I understand the "more volts and gear it down" guys to be saying. I'm assuming that your motor is running the same actual RPM either way, to drive the bike at the same speed, so rpm "sweet spot" is not...

I'm usually quiet here, because while I'm comfy building up a bike from components, I've yet to build anything at all e-bike-like. However, I've done a lot of reading and absorbing, here and elsewhere on these topics, and picked up on a few things. So all this is my interpretation of other...

First let me say: your ability to fabricate and adapt really amazes me. I read the full post on your linked blog, and I do have one observation that may be of some use to you. I own a recumbent bike that uses a mid-drive, and on it (and others I know of) two chains are never allowed to occupy...

FWIW: Shorter cranks make higher cadences easier - it's not so much the RPM per se, as it is "foot speed". You can only move your feet so quickly - so if you reduce the crank length, you reduce the circumference, you reduce the speed your feet are moving to make a given cadence. I run 142mm...

That should be an 8mm hex bolt. You can get self-extractors which will still have the 8mm bolt, but a threaded ring wraps around it so that when you unscrew the bolt the arm is forced off the crank taper. I have those on one bike. Otherwise the crank extractor tool is pretty cheap, sounds...

Mike: First of all, I'm fascinated by your series-hybrid build - I've thought of doing something similar since first reading about a design study done in Europe (Germany?), perhaps a couple years ago. Sadly, I lack the skills to even begin with sourcing the dynamo, let alone building the...

First, Amberwolf gives very practical advice if you have an older, freewheel-type hub. If you have a newer e.g. "9-speed" freehub, you can buy the cogs and spacers separately. You can buy 9-speed or 8-speed cogs and spacers - it matters if you're going to use indexed shifting. Then just stack...

The main assembly will be made of aluminum - the cog itself will be steel. What you have there is a way to turn a more recent/expensive freehub into a single-speed without buying a new wheel. It locks to the splines, and comes with enough spacers to set the chainline pretty much wherever you...

Here's perhaps the definitive gear calculator - easy to use, already knows about DualDrive and mony common (and uncommon) cassettes, etc. http://www.sheldonbrown.com/gears/ Hope this helps, John

How's the chain line? I can't really tell from the pic, but is your final drive cog exactly the same distance from the centerline as the driven cog on the wheel? It's a pain to measure this, I know, but on fixed-gear and SS bikes chain-line issues are common causes of chain loss. In this...

Hi, I've just been lurking for a while, but language and naming is a topic that always gets me going, I like safe's latest pretty well. How about, in order: Motor First Series Drive Single Chain Drive Parallel Drive (could be any combination of chain/belt) Crank First Series Drive (the crank...