8fun conversion story

[mike_j]

Well, after some dithering and advice from here and elsewhere I bought an 8fun kit for my Giant X1500. I was slightly surprised to find the Giant is actually 12 years old, I though it was only about 5. It must have done many thousands of miles over the UK and near Continent, mostly on the bike rack of our campervan.

8fun were very efficient, I ordered about 4pm Tuesday, young lady whose name I didn't get phoned me about 6.00pm to check if it was 700c or 28" (I had missed it on the order). Kit arrived 10:00 Thursday.

So far I have read the instructions, a sure sign of advanced years, put the battery on charge and assembled and fitted the front wheel with only one minor problem. The forks have recesses for the old QR mechanism and the washers supplied would not fit into the recess so I had to take the washer diameter down about 1mm. I'm quite impressed by the overall apparent quality.

Next major job is to remove a crank, a job I have not done for about 15 years. Which way do the fixing bolts turn again?

Anyway SWMBO says dinner is ready and we are out this evening but I'll be ready to do battle at crack of midmorning (no point in being retired if you rush things!).

 

[oigoi]

Hi Mike if you have a square taper crank the bolts on both sides that hold the crank arm to the axle are a normal rh thread so anticlockwise to undo them.

If you are taking out the bottom bracket itself the rh side of the bottom bracket (side with the chainrings on) has a left hand thread and the lh side of the bottom bracket has a right hand thread.

Good luck with the conversion

 

[mike_j]

Thank you. I have found a few minutes to remove the bolts, I had to use my big torque wrench to budge it but I just cannot pull the crank off the taper, I am applying so much force that I am worried about stripping the puller threads and it is a good quality one, not a cheapie. I have left it soaking in WD40 overnight and will try again, with heat from a torch if necessary, tomorrow.

 

[flecc]

A very sharp tap with a hammer on the butt end of each crank arm can help as well, the shock helping to break the seal on the tapers.

 

[mike_j]

Day 2, and battle with the chainwheel continues. The reason that I had so much trouble with the bolts securing the cranks to the axle taper was that the bolt heads are quite shallow and have a chamfer on the top corners. My socket set sockets also have a chamfered lead-in and between the two of them I couldn't get the socket to grip the bolt head at the loads I had to use. I machined off the chamfer on the socket so it sat lower on the bolt head and the job was then relatively easy. Removing the actual cranks just required a little use of a lump hammer to tap the spanner on the puller.

My intention was to remove the two inner chainrings and fit the sensor inside the chain ring. I found that I couldn't get the sensor over the frame bottom bracket and couldn't remove the bearing as it need a special tool which I have no intention of buying so I snipped the sensor ring and stretched it to fit then epoxied it in place. I was suitably careful about getting a good bond to be happy with this solution. It looks very neat.

The triple chainwheel was a problem. It is a unit construction, riveted and swaged, In the end I cannibalised my old 10 speed tourer which has a double chainwheel of traditional design with a central spider and removable rings. At the moment I have left the inner chainwheel on as removing it doesn't give any extra clearance but there is just enough space for the pedelec sensor inside it. I may have to buy a new single chainwheel sometime.

I also had some fun and games removing the front shifter which meant breaking the chain and riveting it back again. I haven't done that for many years and it took me a ridiculously long time, much of it spent searching the garage floor for the lost rivet,

I have removed the old carrier and the front derailleur connected everything up and it works. So tomorrow I have to fit the carrier, sort out the controls and change the front tyre. The one supplied is too big for my mudguards.

With luck Sunday will see the job finished.

 

[mike_j]

Day 3.

started by changing the front tyre. Fitted old tyre with new 8fun inner tyre and started inflating. Got to 4 bar and BANG. I don't know whether it was a manufacturing fault or I installed the inner tube wrongly, though I took all the usual precautions to avoid twists and pinches, anyway the old inner reinflated OK.

After that the job was straightforward except for a long series of minor adaptations and adjustments, the carrier was quite difficult to fit and mudguards had to be modified etc.

One of the biggest jobs was deciding the mounting of the control box and cable management. In the end I cannabalised the old carrier and made a little platform for the control box with the cables stored below. I enlarged the cable entry to the battery box so that the connectors are under cover but will do some more weather sealing. It seems an area that 8fun don't address.

Another difficult job was deciding on the handlebar layout. Initially I was going to modify the Shimano control so that I could mount the throttle horizontally in place of the gear selector. I would have meant making a few bits on the lathe and in the end I took the easy way out and cut away much of the old Shimano controls and fitted the throttle in the resulting space. It has worked quite well, I will fair it all in with some body filler later on.

So - some jobs to do still, new chainwheel being the major one, otherwise tidying up minor details and fitting a brake cut out. I'm going to fit a simple swtich on the rear brake caliper to do that, should be quite adequate and only needs a simple braket and microswitch.

I had the first run this evening, 20 years off my legs, hills just were no problem Both throttle and pedelec worked fine. Only downside is that the bike is slower on freewheel downhill, motor drag is noticeable. Unfortunately the bike hasn't lost its old habit of stopping at the pub on the way home but at least the final climb up the hill has lost its venom.

Not as easy a job as I had hoped but well worth the doing. Hope I haven't bored you all.

 

[kitchenman]

Not bored at all! .... Thanks for sharing Mike. more photos will be good .. and I'll be back with the really boring detail questions later! ...

 

[mike_j]

this is the missing image from my previous thread, shows the handlebar conrols and converted Shimano brake

 

[Caph]

Looks like a job well done to me Mike. Congratulations. Someone at my work has just recently bought an 8FUN and he is very impressed with it.

I also had some fun and games removing the front shifter which meant breaking the chain and riveting it back again.

Mike, it's not a Shimano chain is it? If so you can't replace a removed pin, it will give way sooner rather than later as someone at my work found out recently. If you remove a Shimano pin it widens the hole and so you need to replace with a special wider pin.

I now buy SRAM chains which use a powerlink connector which allow you to remove the chain without removing a pin. They're fantastic.

 

[mike_j]

Thanks for telling me, it probably is a Shimano. I'm going to change it in a few days anyway when I get the new chainwheel. I hope that it will serve till then.

 

[mike_j]

One last job was the brake cut off. 8fun supply new brake levers with switches built in but I have modified my Shimano brake and didn't want to use their rather cheap and nasty black paint levers.

The switch 8fun use is a simple n/c (normally closed) switch held open by the brake in its normal position. When you pull the lever the switch is released and closes. Good design being fail safe. However I wanted to use a n/o (normally open) switch which would close when pressed and I managed to find one in the scrap box.

It is fitted on a simple adjustable bracket and is operated by the rear brake to save cabling, the wires are only a few inches long.

I think it has been worth fitting though I know some people haven't bothered. One advantage I have found already that just by holding the rear brake on lightly I can manoeuvre in car parks at low speed without the motor cutting in at an awkward moment. If the cutout proves a nuisance I can easily disable it.

 

[IanA]

Nice job Mike. I particularly like your brake switch mount - very neat.

I'm also interested in your control box mounting position. My next door neighbour bought a complete 8fun shopper bike and the control unit is somehow located within the white plastic box that the battery slots into. Was there not enough room or do you simply prefer it to be out of the box? I'm a little worried about the possibility of overheating as mine is crammed into a small black box with all the cables and exposed to the sun (sun? - what's that?) and there's no room for air to circulate.

Ian

ps I was out yesterday with my wife and have found my bike has also developed steering problems when passing pubs and I haven't a clue how to fix it.

 

[mike_j]

I'm glad you like the brake switch. It works well so far.

I couldn't mount the control box inside the battery case, 8Fun must use a different battery or controller enclosure on their own bikes. They do warn against enclosing the control box as it gets hot so I opted for my arrangement. The moulded in box at the end of the battery case holds the assorted connectors quite well but I would like to have been able to conceal the whole control box.

Re steering problem. There is no cure - just grin and bear it!

Nice job Mike. I particularly like your brake switch mount - very neat.

I'm also interested in your control box mounting position. My next door neighbour bought a complete 8fun shopper bike and the control unit is somehow located within the white plastic box that the battery slots into. Was there not enough room or do you simply prefer it to be out of the box? I'm a little worried about the possibility of overheating as mine is crammed into a small black box with all the cables and exposed to the sun (sun? - what's that?) and there's no room for air to circulate.

Ian

ps I was out yesterday with my wife and have found my bike has also developed steering problems when passing pubs and I haven't a clue how to fix it.