Ribiero said:
Off topic to the op and directed to Furcifer. At the point you chose to assemble a hard tail did you already have the knowledge and opinion you hold now? This is the part I cannot capiche. Why did you design something you understood wouldn't work. Could you tell us more about the components you used, specifically frame, forks, rims, hubs, tyres, tyre pressure, battery weight and position. Would you elaborate on how the frame is getting beat up, or the ride characteristics you find sub par. Finally could you give a short précis of your cycling experience.
I was under the assumption that a good hard tail would be able to withstand the rigors of city streets. I purchased an older Oryx (made in Canada) that had been modestly upgraded. A Manitou Minute through axle front shock, DT Swiss 2300 wheels with double walled rims and Avid Juicy 7 hydraulics (203 front and 160mm back discs) Right now I'm running Bontrager Elite 1.5" slicks @65psi. I have the battery in a soft pack that fits in the triangle, but also fits the on the rack. I'm pushing 200lbs, plus BBSHD 14lbs and a 21ah 52V that's about 10lbs. So probably 260lbs. GVWR
It's too much weight on the back wheel, especially with tires at 65psi. Moving the battery from the rack to the triangle doesn't seem to change much. It's better running a 2" tire at 40psi, but I've hit a few potholes where you cringe and listen for that pinch flat. I'm looking for a tire with a good sidewall and better wear. I think the Schwinn Cruiser 2.12" bike tire with kevlar looks like a much better tire for my needs.
The front shock works pretty good. I've got it tuned in now and it doesn't dive too much on braking, the rebound is fast enough for most road conditions and it doesn't bottom out. There's still a little too much flex in it for my liking.
This frame has fat chainstays, the main gear housing limits the offset, right now there's a 5mm spacer on the non-drive side. I had to glue a piece of nylon webbing to the frame to keep it from rubbing. If I forget to down shift enough, or I just can't, it will flex the chainstays enough to make it flex and squeak. And that's a couple inches from the motor, at the axle it's more, how much I can't say. If I had to guess I'd say 1/8". I check the QR skewers every other ride because I've had them come loose once.
On "good" pavement, where you might have a crack every 10 feet it's perfect. It's when you get imperfections every couple feet and you're at 25mph, the front is fine but the back end starts to bottom out. I think most riders know that feeling and sound when your bike bottoms out. Whether you're riding FS or not you can feel when you've hit the elastic limit and there's no more give. That's when you need to ride the bike with both hands and your body. It's no big deal coming down a hill or if you're by yourself, but if you're in traffic it's sketchy. I'm finding that in my area the pavement near stop lights and stop signs tends to be worse than other areas. Asphalt that's used by trucks a lot is terrible. There's a truck driving school near me and the pavement a block in either direction from it is terrible.
I don't know how much torque the BBSHD is putting onto the frame. To get an idea you can hold the back brake and stand on one pedal. You can feel the frame flex and see the bottom bracket move. Then try to pedal on the third cog, it takes some serious pedaling to get a bike to move from a dead stop. Then hit the throttle, that little motor doesn't even hesitate.
When you get a feeling for the torque it puts out you can kinda compare it to normal riding. I've broken plenty of chains riding and probably not with same amount of torque. I think the ramp up from the controller does a good job of rolling on power, and between the chain stretch and frame flex since I put a new chain on it hasn't broken. I think it would be interesting to put one on a BMX with the same chain and see what happens. BMX frames usually don't flex like mountain bike frames I my bet would be the BBSHD would snap chains quite frequently.
I've ridden old chromo 10 speeds, and mountain bikes as well as aluminum. Not much carbon fiber, I've never owned one myself but I have had one from the shop I worked at. Based on my experience riding I'd say if you're going to ride a rigid frame get something chormo. They don't flex anywhere near as much as aluminum, and flexing aluminum is not something you want to do very often. The only problem with that is you tend to give up the disc brake option. That's a tough call, but v-brakes are actually good and snapping a frame is very bad. If you are going to ride a rigid frame aluminum make sure you have downhill rims and fully adjustable front suspension. A wire bead tire with a thick sidewall and good tread at 30-40 psi is probably the only way to go. If you're going to be a road warrior and take on traffic for an hour or two every day go full suspension. I'm only doing a few miles a day right now, but I don't see this hardtail lasting very long. My gut feeling is if I would have went with a full suspension I wouldn't have to worry about taxing the bike as much and having to keep an eye on the frame and wheel true etc. By far the biggest shock I've had riding an ebike is finding out how crappy the roads are. The same roads I've ridden a bike on 100 times.