legin

Thanks. The bike came with only one tab washer in total which goes on the inside of the dropout in order for it to locate on the flats in the axle. As the axle nut is torqued up, the non tab side of the washer bears on the inside of the cassette but its diameter means that it does not bind on the top gear cog. The tab obviously faces outwards so as to locate in the dropout. I can't recall one being on the other side and, as you say, it would have done nothing because there are no flats on that side of the axle. I've got a torque wrench ( for cars)and it starts at 28Nm so should be fine for the 40-45Nm recommended by Suntour, although I have never used a torque wrench on any bike and have been tightening these rear wheel nuts for the past 3 years with just a ring spanner and have had no trouble up to now. From what you say, I'm just wondering now whether Suntour have modified the axle since I bought mine so that there are now flats on both sides of the axle rather than one and maybe even introduced 2 tab washers each side. There's a post from a guy above which says that there is one tab washer on each side of his Crossfire. Hope this makes sense.

Thanks vfr 400 for the information and particularly the photos. I still have one problem which I haven't managed to find an answer to. My Suntour rear axle has flats only on the cassette side and adjacent to the top gear cog and not extending to the outside of the dropout. So looking at yours, and a video I found somewhere, that's the only side I could attach a torque arm to. The other side of the axle is round so no flats for a torque arm to hold that side. Same with anti rotation washers. Presumably torque arms have to be fitted to both sides in order to equalise the torque on the axle. I am slightly puzzled by this as I would have expected Suntour to put chamfers on each side. The bike is only just 3 years old and so not one of those early ones when manufacturers were experimenting with E bikes. And if they attached just one anti rotation washer to cope with the motor torque, maybe it's not surprising that mine has fractured

Many thanks all. First, I did not know, and I should have- that there are castellated spacers, I'll call them, on each side of the rear wheel. Maybe the bike was wrongly assembled with only the one, which is why it has broken. Interestingly, though, on my bike the rear axle is chamfered only on the cassette side so that the spacer fits neatly over the chamfer, but not on the nearside. Looking up anti rotation washers, these are in fact the "spacers" I have been taIking about, with 2 flats on them to fit over the axle.. The Carrera ones are brittle, so some heavy duty ones would be better. Looks like torque arms would provide a fail safe , but having looked them up, I can't figure out at all how they are fitted.

I have had a Crossfire -E for 3 years now. The bike is presently unusable. Basically, when climbing steep hills where I live ( 15% to 20% or higher) on full power, the hub motor connection to the battery is wrenched loose, thereby losing all power because of rotation of the cover from which the connecting cable emerges from the motor and with it the cable itself. When this first occurred, I thought perhaps I had forgotten to tighten the wheel nuts, but having tightened them "properly" but without a torque wrench, the same problem happened again -and again, the distances travelled before the problem occurring being progressively less each time. I have had the rear wheel off this bike quite a number of times and have reasonable experience, admittedly from years ago, in bike disassembly and reassembly, though of course, not of E Bikes. Just to put a fly in the ointment, there is a lugged washer which fits over flats machined into the axle on the cassette side, , the lug then fitting into the bottom of the dropout to enable the wheel nut to be tightened so that the dropout does not bind on the cassette and to anchor the axle. This washer broke in two within the first year but could still be slotted into place. The cassette still revolves freely round this washer. I decided to mark the axle, axle nut, wheel and motor cable cover to see what was actually rotating and test the bike again. On cutout,, the motor cable cover had rotated 180 degrees anticlockwise as usual from bottom to top, the axle was where it was when I set out, or had rotated 360 degrees and the left hand axle nut had moved from 6 oclock to 8 oclock but had partially unscrewed itself. I am a bit perplexed about the wheel nut because as long retired petrolhead, as well as the bike experience, I know how to tighten nuts and bolts. Looking at whether the (now fractured) lugged washer is responsible for anchoring the axle in place, I find it difficult to believe that this is solely responsible for preventing the axle from turning, given the huge torque which the axle has to cope with on full power up hill. It is brittle poor quality metal. And I am wondering if the internal part of the motor through which the axle is threaded has come loose in some way. I know obviously that the motor in general revolves round the axle. I am sorry this seems a bit complex, but has anyone else had this problem or has anyone any ideas about it? Or is it me, probably, not seeing the wood for the trees?