Swiss Cheese Crankarms

[MartsEbike]

My pedal felt strange this evening when I noticed it was almost about to fall off. Luckily I was only 5 miles away and throttled it all the way back home.

It's now half out and twisted at an angle. The threads are clearly damaged. I don't have much faith it will tighten properly again.

Probably a good time to upgrade. Does anyone have any suggestions? Are Miranda crankarms any good, or would Hope crankarms be the best bet? Or something else!

 

[MartsEbike]

So I've already been ordering new parts

I opted for the Hope E-Bike Crankarms over the Mirandas. Hopefully the build quality justifies the extra cost! Slightly shorter than the standard ones at 165mm.

Also got myself a new set of pedals, keeping with the Hope theme I went with the Hope F20's in silver...

If anyone is thinking of doing the same, I'll let you know how I get on with them

Now just to wait for delivery!

 

[MartsEbike]

A few shots of the damage. Cross threaded a bit and at an angle, it didn't want to come out easily!

Lots of debris, threads heavily worn away

Turned the Camera flash on - shows up the threads better. Still some definition, but shallow ridges, no depth in cut. I doubt they'll hold out for long, if at all.

That has not stopped me applying plenty of blue Loctite and having a go at a temp fix. It actually tightened up more than I expected it too but I didn't use a torque wrench on it - I don't have that much faith in it.

No real damage to the pedal threads. A wire brushing cleaned them up fine.

Anyhow, hopefully tomorrow replacement parts arrive!

 

[MartsEbike]

They've arrived!

Will try fit them this afternoon if possible

 

[MartsEbike]

All fitted. I don't think they look too bad!

I might even have to clean my bike to make it as shiny as the pedals

Amazing how much you notice just 5mm difference, these new crank arms are 165mm, the standard bafangs are 170's. Slightly different offset, about 27.75 compared to 30.

Not a perfect fit! These crank arms rub slightly against the motor casing. You'll need a washer/spacer to gain that extra millimetre of clearance.

Tbh I couldn't actually feel any rubbing when riding it, seems to have just taken off the paint, but better to add a spacer anyways.

The weight of these parts was virtually identical, no real weight savings. 433g for the old pedal and crank, and 437g for the new one. Look so much better though!

 

[greeno]

Good job on the rework and not having had them fail on a steep climb like mine did a few years ago. Shorter crank arms a digits bonus. Been using 160's for awhile now and love em no more pedal strikes. Was using the Mirand'as but I couldn't find any 160's so I tried out a company called Praxis out of Santa Cruz Cali and they were reasonable and they work fine. The Q factor worked out great and fit perfect with motor and frame I'm using. Still running my old Spank pedals as they haven't let me down yet. Again good job.

 

[MartsEbike]

Thanks greeno! I'm really liking them! They had them in 160's too but I wasn't sure whether to go for them or not. I didn't think you'd feel that much of a difference having cranks just 5mm shorter, but you really do! I use to get quite a few pedal strikes so I'll see how these fair. I might opt for 160's in future!