Help! Fork problems

[Geoff_L]

Nothing seems straightforward with this conversion. I'm trying to convert a 1990s Giant Cypress SE using a Cyclotricity front wheel kit. I've already had to hack some metal off one of the cranks to get the PAS rotor to fit and remove the disk brake securing screws and spacer from the hub. I thought I was on the last lap until I tried to fit the wheel! (I'd already ensured it would fit into the dropouts and worked out I needed to add an M12 washer behind the each torque washer to ensure the hub cleared the forks). It wasn't until I tried fitting the (flanged) axle nuts that I realised I'd missed something. My forks have QR dropouts with a recess to retain the skewer should it slacken slightly; and the flanges of the axle nuts are too large to fit those recesses. Specifically, the recesses are 21mm dia and the flanges on the axle nuts are 25mm dia. I've attached photos.

I thought of fitting M12 washers on the outboard side of the dropouts, but the standard form A and form B washers are 24mm OD, so won't fit, and I haven't managed to source M12 flat washers with 21mm OD. Another approach might be to turn down the axle nut flanges to 21mm dia to fit the dropouts; but is that safe? Perhaps flanged M12 x 1.25 (i.e. fine) nuts with 21mm flanges might exist?

All help gratefully received. Thanks for looking, Geoff

 

[vfr400]

You have two choices:
1. Buy a couple of C-washers. They should cost pence if you can find the right ones. This is what they look like:

2 x 'C' Washer for e-bike Front Hub Motor 12-14mm Axle Stainless Steel ebike | eBay

Find many great new & used options and get the best deals for 2 x 'C' Washer for e-bike Front Hub Motor 12-14mm Axle Stainless Steel ebike at the best online prices at eBay! Free delivery for many products!

www.ebay.co.uk

2. File or grind down a standard 12mm washer until it fits. You'll probably need to make the OD eccentric.

 

[Geoff_L]

Many thanks. From the description on eBay, I guess that this is a common issue and these C washers are made specifically to address it. That's three out of three issues you've given a solution for -- again, many thanks. Geoff

 

[vfr400]

Many thanks. From the description on eBay, I guess that this is a common issue and these C washers are made specifically to address it. That's three out of three issues you've given a solution for -- again, many thanks. Geoff

Hopefully, you'll be able to pass on the knowledge in the future.

 

[Geoff_L]

A pair of C-washers arrived yesterday and I fitted the wheel. However, the flanged axle nuts still (slightly) foul the lawyer lips at the extreme end of the forks (the bit that's showing compression marks in the first piccy of my OP). Instinct says that I can file these down the 1/32" or so necessary to reduce the blade thickness at the lawyer lips enough prevent the fouling. However, I thought it wise to check with the forum before taking a file to them...

All help gratefully received. Geoff

 

[vfr400]

There are two ways to deal with Lawyers lips. You either reprofile the drop-outs so that the axle becomes central again so that the nut fits within the lips, or you use eccentric washers to space the nut above the dimple.

As I said before, you can file normal 12mm washers into eccentric ones. It takes a couple of minutes and costs nearly nothing.

It's important that the nut doesn't overlap and rest on a part of the metal above the dimple because it'll squish it in use, then come loose with disastrous consequences.

 

[Geoff_L]

Thanks again. FWIW, I'm not sure what you're telling me here. For info, the C-washers are 19mm OD -- the same OD as an M10 form A or form B washer. So, I could elongate the hole of an M10 washer to 12mm long x 10mm across (same as the axle cross-section). However, that would introduce another layer. The C-washer (shaded yellow below) sits in the recess and projects above the dropout except for the 'lips' (shaded blue). What I proposed was to file down the 'lips', removing them and leaving a 'clean' recess that the C-washer would project beyond. Thus, the flanged axle nut would bear entirely on the C-washer rather than partly on the 'lips' as it now does. Is this one of the options you meant?

Thanks again, Geoff.