Built my bike at last

[bogmonster]

Pictures:

Now, I know the wiring is, ummm, a little poor shall we say. This was jury-rigged. I was still deciding what to do, was thinking of putting the controller on an IP rated box. Think I will leave it as it is and solder and heat shrink all the cables. I will get some trunking to run down the frame I think. I think all the control wires will be soldered as they are now, just MUCH tidier


Does not look like there are any brake levers in the pictures but there are!

Also, very pleased with the bag. Fits very secure and has fold out paniers that are large enough to take a laptop. Kind of need this for work.

Cheers, BM.

 

[Beeping-Sleauty]

Did another run this morning. Like a muppet I didn't note my time of departure accurately but my wife assures me she looked at the clock before I left so I have a rough idea. I was out for no more than 1 hour 15 and probably about 1 hour 5. I managed 21 miles with a downhill from the Mendips into Wells, along the bottom to Cheddar and up Cheddar Gorge and back home. For those interested here is a profile of the gorge.

profile of the Cheddar Gorge

I only managed 30mph on the downhill, still getting used to the butterfly bars, the new weight disrtibution, the new brakes and paranoia about the modified dropouts.

Given the 1 hour 15 time that would be about 17mph average and I am happy with that. I suspect it was a bit faster but due to my dodgy time keeping would not want to set false expectations. I found I was down to under 10mph at one steep section but was going 16+ on the long shallow hill at the top.

Overall I am happy with the result. Note however that I put a fair degree of effort in cycling up the gorge. This was not a sit back and let the bike do all the work experience. That is what I wanted from the bike but may not work well for everyone.

Cheers, BM.

Nice one, well done BM, glad you are pleased with the fruit of your labours,

to steal a phrase 'the sweetest breeze in the world, is between some butterfly bars....'


i PM'd you,
beeps

PS: whoa... just saw those bars, now we're talkin' serious leverage... that'll make a six pack from a party seven barrel in about a week....LOL

 

[frank9755]

Looks very good, and sounds like you are getting good performance from it!

I think you are wise to leave the controller in the open. Mine and others experience has shown that the main risk is over-heating, not getting wet. They do get quite warm and need as much air flow as possible to stop them blowing. However, the resin they are potted with seems to make them impregnable to water.

Frank

 

[andyh2]

Nice conversion BM.

It sounds as though the tongxin kit side went together quite easily and there was actually more difficulty from changing parts a bike that'd been stored for a long time.

How do you find the thumb throttle, is it quite easy to moderate input and does your thumb get 'fed up'?

Am I right in thinking that the 175rpm motor would push a 26" wheel with a bit less top speed (15mph?) and a bit more pulling power and if you went right down to a 16" or 20" wheel you'd have lots of power for hills or heavy loads but no assistance above about 10mph?

 

[frank9755]

Am I right in thinking that the 175rpm motor would push a 26" wheel with a bit less top speed (15mph?) and a bit more pulling power and if you went right down to a 16" or 20" wheel you'd have lots of power for hills or heavy loads but no assistance above about 10mph?

That's right. The 175 is actually the motor that Tongxin recommends for a 24" wheel, so may do a bit more than 15mph in a 26" and, as you say, would climb well but have low top speed in a smaller wheel.
FYI - these are Tongxin's range of motor speeds and suggested wheel sizes, with the UK/EU speed limit in mind

inches rpm
16 260
18 230
20 210
22 190
24 175
26 160

 

[andyh2]

That's helpful thanks Frank. Do you know if any of the different motors has an especially good or poor reliability record? or is it that provided each is used for its intended wheelsize then reliability is even?

 

[frank9755]

I remember there were reports of problems with the 160 about a year ago, which led some people to go for a 175 in 700c wheel. What the issues were or how extensive they were or if and when they may have been sorted out, I don't know. I've not heard anything else.

In general the Tongxin motor is more fragile than other hub motors and needs to be handled with care. In particular two aspects of its construction are worth noting.
1. The roller drive - it works on friction alone rather than toothed gearwheels in other motors, hence its best not to put it under too much strain or the drives can start to slip
2. Two piece axle - the Tongxin axle is not a solid spindle right through the motor, but two separate pieces of steel which need to stay in near perfect alignment. Therefore bunny-hops and bumping up kerbs are not a good idea.

I think its fair to say that most people have found the motors to be more robust than the controllers - although the evidence from Cytronex owners is that they may have been fixed now.