Well, I've stripped all the unnecessary stuff from my old Marin and am ready to start installing the Woosh kit.

 

No major problems so far, apart from the bottom bracket cartridge which was a bitch to remove. But the cheap Halfords remover tool did its job eventually, aided by a big spanner and (not least) a 10 lb sledge hammer.

I've found a minor snag when offering up the motor for the first time: the gear casing on the right hand side of the unit clouts the bike's right-hand chainstay before the unit sits fully home in the bottom bracket. But the old bottom bracket cartridge has a washer (40x35x2.33 mm) which I propose to use with the Bafang - it offsets it slightly to the right and gives about 1.5 mm clearance to the chainstay.

that's a good idea. Which bike do you use as a donor?

just re-read your post, its a Marin. The last time I saw a Marin with the BBS01, I did not notice the gearbox casing fouling the chainstay. Can you post some pictures?

Edited March 1, 201511 yr by trex

Can you post some pictures?

Sorry, I'm struggling to attach a pic. Trying to "upload a file" (on my iPad) but it won't let me choose anything...

 

Hopefully that has worked - view from underneath, without spacer.

Here's another pic, with the spacer fitted so a bit of clearance.

Many makers put an indent on chainstays at the contact point for chainwheel clearance, and you can do the same in your problem position without weakening the frame.

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Many makers put an indent on chainstays at the contact point for chainwheel clearance, and you can do the same in your problem position without weakening the frame.

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But wouldn't they do that before welding the tubes together? I don't want to risk cracking or distorting anything (mind you, I used a sledgehammer on the bottom bracket cartridge so I'm a bit inconsistent!)

The tube is quite thin so it only needs a quite light tap to indent. I've done this twice when fitting a much larger chainring which fouled the frame. Either a soft mallet or a layer of softer material like hard rubber or leather between hammer and frame does the trick and it's easy to gain 2 or 3 mm.

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But wouldn't they do that before welding the tubes together? I don't want to risk cracking or distorting anything (mind you, I used a sledgehammer on the bottom bracket cartridge so I'm a bit inconsistent!)

 

I agree you need to proceed with caution.

 

The required indent is between the bottom bracket weld and the chainstay brace, so the area is well supported.

 

I would be inclined to give it a go.

 

I've no idea what the thickness of the tube will be at this point, but you might be lucky and be able to create a suitable dent with no more than a sharp tap with the ball end of a ball/pein hammer.

That tube is normally very thin and won't need much of a knock to indent.

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Whack it! You're a bunch of girls' blouses.

Oy it's Mr big girls blouse to you matie

Ok, ok, I'll give it a gentle tap...

I gave it a good clout, with a biggish hammer via a piece of round bar, but made almost no impression. The wall of the tube must be quite thick. So I think I'll stick with my previous plan of a spacer. The downside of this is that there's less of the Bafang spigot protruding through the bottom bracket, but still just about enough to get both nuts on it. Also the triangular support plate needs spacers, so its two 6 mm cap screws don't engage quite as far as they should, but still just about enough. I might get some slightly longer screws to be safe.

I had to do that on my Haro escape Took some good hard whacks on the alloy frame. Now the chainwheel just clears the chainstay (the chain wouldn't fit, if it had to pass there), though I'm going to a smaller chainwheel and adapter soon anyway (this is my towing bike).

 

Just have to work out if it small rear wheel I fitted (17" moped rim and tyre) is going to make the pedals way too close to the ground when cornering

I gave it a good clout, with a biggish hammer via a piece of round bar, but made almost no impression. The wall of the tube must be quite thick. So I think I'll stick with my previous plan of a spacer. The downside of this is that there's less of the Bafang spigot protruding through the bottom bracket

Another downside is it puts the chainline further out. The chainline on these is quite far out already (away from the frame) and can prevent usage of the lower geared sprockets at the rear. You might find you need to use a chain retainer to prevent the chain coming off the inside of the front sprocket (you can often use the original front derrailleur for this).

 

Michael

This pic shows the motion sensor installation on the left-hand brake lever. The right hand is the same. Bracketry cobbled from 22 swg ali sheet. Sensors bought from Eclipse.

would it be better if the aluminium bracket was bigger and sandwich in the sensor?

would it be better if the aluminium bracket was bigger and sandwich in the sensor?

I think a single bend is the limit of my fabricating ability! It actually feels pretty stiff and secure, and weighs next to nothing. If the double-sided foam tape fails with age, the sensor would still be retained by its cable.

I thought your bracket has a very nice shape.

could you have used the smaller sensor from the brake levers with the same technique? the sensor can be unscrewed easily, cylindrical in shape, about 4mm diameter and 10mm long.

Didn't think of that, do they work on the same principle? Would have save me some cash.

they work on the same principle. I am thinking of borrowing your idea of making ali brackets to add sensor to my Auriga brakes. How did you cut your sheet? the edges look quite neat.

How did you cut your sheet? the edges look quite neat.

Gilbow tinsnips.