Ash21014

The cable didn't snap and the disc didn't shear, when the brake lever was pressed the brake gave no stopping power at all. The cable moved normally and the calipers appeared to be contacting the disc as normal. Upon further testing I found that the issue was intermittent, sometimes the brake gave full stopping power and other times zero, I believe when this happened there was a bit of a clunking/clicking noise. Not having the expertise or desire to investigate what the failure was I decided the safest thing to do was replace it was a Shimano brake set.

The bike has only been used on road. The only impact that I can possibly think of was when I received the bike back from Woosh after they had repaired the failed battery and pedal sensor. The end of the battery rack was bent downwards so I couldn't even remove the battery from the bike, which suggests that it was dropped on its back during the repair... Can you please explain how cleaning the bike of some cosmetic rust would have revealed microscopic metal fatigue and prevented the catastrophic failure of the first metal strut? Both sides presumably did not snap at the exact same moment, but clearly if one snapped due to fatigue the other one was already dangerously compromised and could have broken at any moment regardless. Obviously a bike should be well maintained, however, any lack of maintenance does not excuse an unrelated manufacturing problem. The above poster saying their seat post sheared off suggests a materials issue common to this bike. After all there's no smoke without fire. Furthermore this is not the only dangerous maintenance-unrelated failure I've experienced with this bike, the front disc brake had to be replaced after it failed without prior warning down a hill, and the throttle lever separated in two resulting in it detaching from the handlebar and me falling off the bike in the middle of the road. More evidence that points to a general lack of poor quality. d8veh Thanks for your suggestions, but as this is my older backup ebike I will be selling it off for parts after this, I now consider it to be too dangerous to use and after having spent a couple hundred on replacement parts already, I feel spending more money and hours repairing it would be a fools errand. I guess the lesson learned here is, "buy cheap, buy twice".

It's rarely used anymore so hasn't had tlc in a while, not sure what that has to do with the metal shearing though? He said to me that it started rattling a bit near the start of a ride which was around 100miles, but because the screws become loose and need tightening up periodically it was assumed to be that, but yes I'm assuming one side broke a little before the other.

So the other day when my mate was riding my old sirocco CD the metal connectors on the battery rack sheared off, the weight of the battery rack presumably pulling all the wires out of the back which then caused it to fall back hitting the ground, pictures attached. How on earth does this happen? Metal fatigue? How can a solid piece of metal just break off?

Clipless pedals though?

So would you recommend this bike then? There's so much choice lol.

Brakes aren't a problem, I already have a pair of Shimano hydraulic brakes.

What do you guys think of this model? http://www.evanscycles.com/products/cannondale/trail-6-29er-2015-mountain-bike-ec071451 It seems to get good reviews.

Well I just prefer a new bike from a proper shop. And I've got the money for it so it's not a problem. So to quote Any of those bikes from that site I linked would be fine as long as they met that criteria? With preferably a suspension.

I'd prefer to have a new bike, not just for warranty reasons but because I know that it hasn't been put under a lot of stress and suffered metal fatigue or has hidden problems waiting to happen. For me it's a small price to pay, these bikes aren't expensive relatively.

So many to choose from http://www.evanscycles.com/categories/bikes/mountain-bikes/f/unisex#!Brake+Type=Hydraulic+Disc!price_from=300;price_to=590;on_sale=;sort=asc; is there any particular bike that stands out here for an ebike conversion with a 350W or 500W rear motor? I think I'd like large tyres because I feel they give me more stability when maneuvering.

Crank drive is what I had before but it was not highly reliable, if there was a problem with the chain or gearing system I was dead in the water whereas a hub motor would continue to work on the throttle no problem.

Thanks for the suggestions, I should be able to make a choice from those. As far as batteries go, I can build my own, or use one off the shelf, I've even got my old Sirocco CD one, claimed to be 15Ah. Incredibly slow charge rate though, and god knows what the capacity is after all this time, if I'm using a 350 or 500W at full power up hills I need to figure out what capacity I'll need anyway.

Ok then, so let's swap out what I said in my op for rear hub.

Well I just thought I might see some handling benefits mounting on the front with the two-wheel drive effect.

Sorry I don't mean frame, I mean bike, there doesn't seem to be any way to edit thread titles on this forum! Now that I've got a full time job I can finally afford to start buying components for this custom build. Don't have an exact budget in mind but I'm looking for a mountain bike that's less than £500. The bike must be able to fit disc brakes on the front and rear wheels, the more heavy duty the bike the better. I would like to fit a 350W/500W 36v/48v hub motor kit on the front wheel for a lot of hill climbing, up to about 20% gradient, throttle is essential. I can build any battery to supply the power, from my experience of a 10 mile round trip it will need to be >500Wh. I don't intend on de-limiting the bike past any 25mph limit the controller may have programmed into it. So any suggestions would be welcome, I know I created a similar thread to this in the past, but reading back through it started to get confusing and I'm more sure of what I need now.

Thanks that's a really useful suggestion, I already have lights and hydraulic disk brakes that I can use because I bought them for the Sirocco CD. With regards to the beavertails how good are they relatively? Obviously mud and water is something I encounter a lot in the winter, yet I've had to remove previous mudguards because they ended up touching the Tyre at some point. Now with respect to tyres, which ones to get? I guess tyres with a large diameter would give better stability and traction?

Thanks. And yeah I could have done without the thread hijacking... makes it difficult to find answers to the questions I'm asking. That's something interesting to think about as there are a couple of gravelly paths I have to go down on my commute.

So err, any recommendations on frames?...

Ok, so that's some idea of motors then, now does anyone know a decent frame I can buy considering I'm 5'8" and 65kg, I think I'd like large diameter tyres because of the bad road surfacing etc, what do you think? And does having both rear and front suspension make a difference?

How much are these higher power motors going to affect battery life though? I realise battery life will be disproportionately reduced because at higher speeds the bike is less aerodynamically efficient, and the higher current use will cause vdrop to occur faster, and I'm guessing more power from the motors will also be lost as heat, unless the higher power motors are more efficient? With the 250W motor on max power for say 16 miles on the Sirocco CD there is a noticeable drop in power output, so maybe I should add a couple more cells to my battery? On that note how does hub vs crank compare on power usage to obtain a given speed on the flat or a hill? As to the earlier comments about me having problems with gearing, to be fair as you well know the Sirocco CD uses the cheapest components on the market, I would be using a much better group set if I went for a crank drive motor again.

Well the 250W CD motor is fast enough on the flat at about 22mph and would be even faster for me if there was a harder gear. On steep hills I get about 11mph, but 15mph or more would be nice.

So what would you guys recommend as a rear hub motor for my use case then?

How does having a hub motor effect the wheel that can be used and changing a tyre?

You see the thing is I don't think I need that much power, the 250W motor was perfectly adequate, it'd be nice to have a bit better performance like a 350W motor but I think that 500W is pushing it. I only weight 64kg after all!