Hitchcocks Forum

Hello everyone.
I am fitting one of our hosts disc brake conversions. I have attached the supplied bracket to the fork leg, and fitted the caliper bolts finger tight everything ok. When I tighten the caliper bolts properly the brake binds on and the wheel cannot turn. I think the supplied bracket is not parallel to the disc. Should I file the supplied bracket to try and get it parallel to th disc?
Has anyone had this issue?
I would be grateful for any help, thanks.
Philip.

Quick sanity check. There isn't a lot of clearance between the mounting and the disc. Check you aren't fouling the disc rotor with the end of a bolt.

It's most likely the lugs on the fork leg aren't paralell and square. Not totally surprising since they were originally designed as a mudguard stay mount. I wouldn't be surprised if the holes have been drilled on the piss too. Conversely, I'd expect the bits supplied in the kit to be pretty squared-away, it's putting the two together that's the issue.

I'd suggest shimming either between the lugs on the fork and the mounting plate or the plate and the calliper so it is paralell to the disc and the disc is roughly central in the calliper (it's a sliding calliper so there is a fair degree of leeway here).

In fairness, I had to do this with the very expensive aftermarket callipers I fitted to my Honda VFR750 where both the bike and calliper are made to very prescise tolerances and they were attaching to a purpose-designed calliper mount. That was using 0.1mm hardened steel shims and a feeler guage though. I suspect a selection of thin-ish washers and a mk1 eyeball will suffice here.

If they are a long way off-square, it would probably be easiest to file the alloy fork lug carefully with a hand file and a try square. In an ideal world, you'd put the fork in a milling machine and mill the facings so they are perfectly perpindicular to the axle.

Thanks for the reply Stinkwheel.
I checked and the disc isn't catching it is clear.
You are right in that it seems as though the lugs on the fork are not parallel to the disc.
If I shim between the fork lugs and the mounting plate then wouldn't the shims have to be tapered to bring them parallel?
Expecting mudguard mounts to line up perfectly is perhaps a big ask, and some persuasion was always going to be necessary.
On the positive side I have been furloughed so have some to investigate, every cloud and all that.
Take care, Philip.

The alternative is to use the fork sliders off an Electra-X or Electra EFI which are intended for disc brake use, though this would need a change of mudguard, you also would have to lose the fork shrouds and run the bike with bare fork legs or fit a pair of gaiters.

For anyone else considering a disc brake conversion, the complete forks for a 2009-2011 C5 EFI Bullet will fit the earlier headlamp casquette or top yoke.

A.

Depends how faer oiut it is and what angle. If it's out in the vertical axis (along the fork), you can use shims under just the top or the bottom bolt. If it's rotated horizontally, you're probably looking at filing the lugs square.

Thread revival!

I have just been researching the disc brake conversion for an iron barrelled Bullet like mine, presently fitted with a TLS. I’m not about to do this right now but might in the long term. The bike is a home market Electra and the front end seems to be something of an interim type. The existing sliders don’t have lugs for separate mudguard stays/ brackets; the later type, short mudguard is used and this has two mounting screws at the inside top of each slider. The lower ends are plain.

Our hosts do a conversion kit and these are also available elsewhere. Unfortunately because there are no lower mudguard stay lugs on my sliders, I would need to change them, too because the kit uses them to mount the caliper bracket.

I’ve done a previous thread search but what I’m still not certain about is this:

Do the lower sliders for a disc braked bike, such as for the Electra X, fit straight onto the existing fork stanchions of a TLS bike? Reason for my question is that the disc brake stanchions I’ve seen, for example for the Electra X, don’t have the threaded top for the “casquette” and use a different top bracket. If so, the conversion would be relatively straightforward. If not, it’s a different ball game!

The top fastening might be the only difference, but then again, this is Royal Enfield we’re talking about….

Thanks in advance!

You've been looking at the eBay Electra forks haven't you?

The Electra-X forks DO have the threaded stanchion tops, mine certainly did! Most Indian eBay suppliers have never seen an Electra-X, only the home market Electra 350s which come in about a dozen variants if you include pre-unit and UCE versions. AFAIK the later AVL 350 Thunderbird models were the first to use the plain-top stanchions with the updated internals. If your 350's forks have the long hex cap nut at the bottom of the sliders like most of the other pre-2008 Indian Bullets, they've the traditional style internals.

The Electra-X and Electra-EFI still have the old-style damping so I'm fairly certain you'd get away with swapping the sliders, a check of the parts books ought to help. You can of course just screw in a complete set of forks.

A.

Thanks Adrian, a mine of information as usual.

Actually, this all started because I took the front wheel out to service the front brake and thought that I might need to fit new shoes in the not too distant future (or get them re-lined by Villiers as an alternative). Whilst doing that, I noticed that the fork steering bearings feel like they need replacing because they are slightly notchy, with a definite straight ahead detent. I have obtained a new set of cups, cones and ball bearings ready to fit. Then I thought if I have to drop the forks, what else might need looking at…. Possibly fit a disc brake rather than new linings (although to be honest, the existing TLS drum is pretty good as is. Strange how these jobs develop, isn’t it? I searched this forum for further info, found this thread, looked at the picture that you posted above, then tried to find stuff for sale - as you rightly guessed!

Yes, my bike has the long hexagon screw/plug at the bottom of the leg.

Another thing that crossed my mind…are the wheel spindles the same diameter and the hubs the same width, because the later bikes have “pinch bolt” fixings, rather than the separate caps of the older Bullets?

My front mudguard is exactly the same as the one on the photo of the Electra X above., btw.

The Indian TLS front hub and the disk brake hub both use 6203 bearings, but it's not the same spindle arrangement, it's a Q/D knock-through affair for the disc brake with different spacers. A quick blast of parts book will show you what's needed. You might have to change the speedo drive too, the disk and drum variety are allegedly different besides the disc brake version usually being plastic - bore perhaps?

A.

Looks like the best option is to buy the whole front end as a complete setup.

I’d probably want a 21” front wheel rim at the same time but then that gives a problem with the headlight beam being too high with the OE casquette. I’ve already seen this to some extent when I fitted shorter/softer rear shocks and there is but a very small amount of adjustment available at the rim. So it would have to be fitted with separate brackets.