Recent content by BMX

Most BMX hubs these days are cassette type hubs with the freewheel mechanism built into the hub like MTB hubs, however there are probably still a lot of dual threaded hubs available out there. BUT they come in several types. Some are for "race" use and have a right hand thread on both sides...

Google Cahe (wont last forever so I've copied and pasted, hope that isnt out of line):- Here is my custom built HPM5000B Bike, my inspiration was the Jackyl. The city of Phoenix has canals that spider web all over the city, keeps me off the roads Custom Built dual suspension frame - steel...

24" rims and tyres are relatively common, there are two sizes. BMX ones where a 1.75-2.0" tyre gives you 24" and 1,3/8" ones where the rim is slightly larger such that a 1,3/8" tyre sits at 24". http://sheldonbrown.com/tire-sizing.html 22" BMX wheels do exist, Faction are pushing this standard...

I expect you realise that the suspension movement will shorten and lengthen the BB to rear wheel length with that set-up? That will require a pretty flexible chain tensioner. Mounting free spinning sprockets to the crank axle is also a bit of a problem. Instead, how about mounting the free...

That seems reasonable. Regenerative braking always seems attractive but whenever I try to estimate yield and weight (compared to adding extra battery capacity) it seems way too marginal to be worth the effort. My intention with the bracing suggestion was that you go to a thicker wall but...

You are going to get us all thrown in jail... :) George

Just found this thread, nice stuff. Just a few questions: Is the clutch really worth the effort? My guess is that the energy you can hope to recapture by regenerative braking isn't worth the extra weight and complexity, have you done any kind of calculations on it? Seems a shame to...

Alignment is very often the cause, but if that is good also check the chain for stiff links, if you joined the chain with a chain breaker then you may well have a stiff link somewhere and when that hits the sprocket it may climb out rather than flex. The chain breaker can be used to loosen off a...

That would be great thank you. I will PM you my email. in the mean time I will play about with the other motor and see what it can do, at this stage I am trying to learn all I can so it is all valuable (if expensive) experience... George

Well that about wraps it up for the motor. Tried another little test run and almost immediately had a nasty sound, turned out that the outer part of the can had moved even more off centre and was now rubbing. Took it off to find the typical loose magnet/ chuff all epoxy scenario as well and at...

Thanks Matt, The Turigny motor has a slightly oversize hole in the outer can for the axle to fit into. The result of this is that the can runs slightly eccentric (0.2-0.4mm at a guess). I could potentially shim this somehow, but I doubt it would be very satisfactory. I also wonder if the...

Thanks for the help. I put the timing back to 8kHz and left the brake off, also put the timing to low. Definitely the best it has been, less heat build up in the ESC but still very bad cogging followed by a screech and nasty beeps from the motor, only possible to remedy by disconnecting power...

Thanks, Bit difficult to go back top the short wires as there is no way to get the setup on the bike that way. Took the brake off and put the PWM up to 16kHz bike seemed a little less inclined to cogging, but still very problematic, speed controller got pretty hot. I guess I will try going...

So I extended the ESC cables by about 10inches and strapped everything to the bike to try. Almost immediately the ESC seemed to lose sync. So I stopped and picked up the back wheel of the bike and the motor was "freaking out" trying to run, then stopping suddenly. Servo tester was fully "off"...

Hi, Discovered this board a few months ago and its a gold mine of helpful info, thanks so much to all those who have contributed so much. Sorry to start with what is probably a ludicrously simple question, but I cant seem to find the answer elsewhere. I am on my first build using an RC...