tR1x

[cobbadiggabuddyblooo]

What was the 17mm axle from Dave?????
Did you machine off the section on the fork that housed the thread for the original R1 axle????

[Killerwhale]

What was the 17mm axle from Dave?????
Did you machine off the section on the fork that housed the thread for the original R1 axle????

Think there are pics of my conversion on here somewhere, bought it ready for TRX wheel so quite clever stuff....

[davamb]

What was the 17mm axle from Dave?????
Did you machine off the section on the fork that housed the thread for the original R1 axle????

Nope, no thread at the bottom of these fork legs Brian. This is a late model R1 fork; 2002 - 2008 model I think was it's production run. Bit different than the earlier forks to adapt. I don't like doing mods that can't be reversed, but to use the original TRX axle unmodified meant that I had to have a couple of mm taken off the boss on the inside bottom of the R1 LHS fork leg. (Could always make this up again with a spacer if needed I s'pose, but the idea is that the stock TRX front end can go back on.) The axle for the R1 is 22mm OD and is clamped at the bottom of the fork legs each side, so my mods mean a clamped threaded piece one side to take the TRX axle and plain bush the other.

All good so far, just the disc-to-disc centres are 131mm (R1) and 128mm (TRX) so either need to space out the discs by 1.5mm each side or space the calipers in by 1.5mm. To my mind, spacing the discs is intrinsically a better option, if for no other reason that it offers greater redundancy. I've managed to remove 4 of the 6 screws on one side, but that's as far as I could go yesterday - scared of damaging the screw heads yesterday so stopped. Poured on some CRC and left to soak overnight. Will try some heat today and If I can adapt an Allen piece to my old impact driver I'll give that a go.

[Killerwhale]

What was the 17mm axle from Dave?????
Did you machine off the section on the fork that housed the thread for the original R1 axle????

Nope, no thread at the bottom of these fork legs Brian. This is a late model R1 fork; 2002 - 2008 model I think was it's production run. Bit different than the earlier forks to adapt. I don't like doing mods that can't be reversed, but to use the original TRX axle unmodified meant that I had to have a couple of mm taken off the boss on the inside bottom of the R1 LHS fork leg. (Could always make this up again with a spacer if needed I s'pose, but the idea is that the stock TRX front end can go back on.) The axle for the R1 is 22mm OD and is clamped at the bottom of the fork legs each side, so my mods mean a clamped threaded piece one side to take the TRX axle and plain bush the other.

All good so far, just the disc-to-disc centres are 131mm (R1) and 128mm (TRX) so either need to space out the discs by 1.5mm each side or space the calipers in by 1.5mm. To my mind, spacing the discs is intrinsically a better option, if for no other reason that it offers greater redundancy. I've managed to remove 4 of the 6 screws on one side, but that's as far as I could go yesterday - scared of damaging the screw heads yesterday so stopped. Poured on some CRC and left to soak overnight. Will try some heat today and If I can adapt an Allen piece to my old impact driver I'll give that a go.

For sure the R1 got radial calipers in 2004?

[davamb]

Must be earlier than that then KW as they're not radial. I know they're not from the first USD forks as the earliest front mudguard didn't fit.
Aywho, have elected to space the disc, but danged if I can get a couple of the retaining screws to budge. Tried heat and impact driver, but no joy - just damaged the engagement, think I'll have to get some bits welded on to each remaining screw head so I can get enough leverage. No shortage of Loctite on each thread.

[davamb]

Success!

Finally, after a fruitless week of still trying to get some joy out the allen heads.
I bought a new impact hammer, but that did bugger-all and then later the same day found my old one, lost since the move to my current digs. Don't ya just hate it when that happens.
I'd tried drilling the hex hole deeper and using an easy-out. Snapped the easy-out. Was lucky to get the busted bit out.
Thought about drilling the heads off, but if I had, there would only be about 3mm of protruding screw to get a grip on , so I really didn't want to chance it. The LocTite would have made it impossible.
Had also tried heating the hub with the propane torch, but too much mass and not enough heat energy.

I thought if I couldn't crack it this weekend, I was about to give up and go with my brother's offer of drilling-out all the remaining screws (5 from 12) and re-tapping. I spent a lot of time thinking about it and a bit of time experimenting. For a start, the remaining (5 out of 12) hex holes were all damaged, so I got my Ozito (Dremel copy) out and cut normal screwdriver slots in one screw head. I had a suitable broad tip from the new impact driver set, so although it didn't work with the hex tip, at least I thought I'd give it a bash with that. No good though.

Next up I tried my rattle gun and this just jumped out and gouged the alloy a bit. Great. Cosmetic damage only though. Heat next, took the torch to the bolt heads to see if it would soften or denature the threadloc. While still hot, hammered the screwdriver tip into the slot I'd cut, put the wheel on the ground and used adaptors to couple to my large ratchet with a 10cm extension. I was finally able to free it by pushing down with all my weight while working the ratchet.

The rest went the same way, about 5 minutes on each screw. Cleaned-up the discs in the dishwasher and took a tap to the threads to remove the residual crap. Spaced the discs with 1.5mm high tensile washers and put in new high-tensile screws. Fitted the wheel up and it seems to run true and the brakes operate properly.

I'll tighten, re-tighten, check and re-check during the week and should be good to test next weekend.

I'm a happy man tonight, was beginning to think I'd be stuck with the R1 wheel and no speedo.

I'd like to know exactly what the details of the R1 front end are though, it needs new brake pads soonish.

[dicky]

I'd have spaced the calliper and would have been done with it all two weeks ago
Still can't figure out why you'd want to move the disc and risk getting some distortion by having to use so many washers.
I may be wrong about this bit I'm pretty sure that all the R1/R6 callipers use the same pads up until they moved to radial. I've never seen a part number, just look up the manufacturer you want and put in any year that's pre-radial.

[davamb]

The washers are just an interim to see how it all fitted-up Dicky. I'll make a couple of 1.5mm Aluminum shims when I get a moment. Why this way? I just can't convince myself that spacing the calipers is going to be more robust than spacing the discs. Always prepared to see the other side of the coin though...

Thanks for the advice on the pads, I'll have a search.

[cobbadiggabuddyblooo]

You can lead a horse to water dicky...
but each to their own..
Either way will give you the same result..
Thank god you finally got the job done Dave.
The full shim as your planning would give a larger surface area at dispersing heat than just the washers behind the disc ..

[Overlord Neil]

I could very well be wrong, but; don't the disc's locate on the hub? I'm pretty sure the rotor spigots to the hub and the bolts just resist the rotational sheer of the braking forces. I'd be very wary of moving away from that; a couple of spacers to pack the caliper will have far less detrimental effect than taking the back of the disc off of a datum face.

The caliper bolts are way way over specced, a high-tensile M10 will take something in the region of 8 Tonnes to fail, as long as you have some good machined [matched] spacers so the bolt doesn't see any bending you won't over load the bolts.

The disc bolts are more likely to be A2 stainless because they are normally spigotted so don't have to locate the disc so doing less mechanical work, even if they were hi-tensile they will still pop closer to <3 Tonnes [assuming they are M6]. Add to that some bending from the spacer washers behind the disc rotor (though this will be mitigated by the floating disc) and a bit of heat, you are far more likely to pop the heads off the disc retaining bolts.

I'm an engineer, so factors of safety are a fundamental requirement, chances are you will be fine but if you actually went through the numbers properly (rather than the man better looking/dressed than me-packet maths above) you might be disturbingly close to the limit that one time you REALLY need the brakes to work. Personally, I wouldn't risk it.

[Rich]

M8 high tensile for the disk bolts, 6 of them.

[davamb]

Thanks guys, appreciate the input.

[bagmaker]

you will need to get them plated with something Dave, the HT ones rust pretty quick...........

[M.V.]

you will need to get them plated with something Dave, the HT ones rust pretty quick...........

I used stainless, but with a very big dob of this: https://tefgel.com.au/ to stop the galvanic corrosion & some loctite to stop them falling out.

Haven't failed yet & I haven't needed to remove them to see if the Tefgel works, but I'm hoping! The standard ones were a nightmare to remove.

[bagmaker]

I always worry about stainless that gets heated, cooled, heated, cooled..............
Are there non-corrosive options anyone?