1981 GS750E (GSX750E) Rat Cafe Racer

LKS

Member
Well.. I've been drilling some holes and the "corner"-holes on the nuts are a pain to drill. The bolts are OK, I drill them at a 90 degree angle, but the nuts.. I've given up on them. Mostly because I dont have any 2mm drill bits left :/ 3mm drill bits hold well, and I'll use 2,5mm drill bits for the rest of the perpendicular holes (it's a national holiday today in Norway, and I can't get new drillbits). I think the problem is that the bits snag on the hardened surface when you push through on the other side. I've heard that drill bits for drilling circuitboards are cheap and work great for this. Maybe I'll try them later.The bolts for the brake discs will be OK when they are drilled and wired. I'll buy titanium bolts for the brake conversion later.

For the sprocket bolts I've ordered these Pro-bolt pre-drilled aluminum nuts with steel core. They are very popular in MX competition and should hold up well. They also make them in titanium, but these were in store, and I don't want to wait.
lspn10dbk_7 by Lars Krogh-Stea, on Flickr
 

LKS

Member
Perseverance has turned frustration into joy once more :) I googled around on how to drill bolts and got some tips on drill-speed and pressure on drillbit. I've read before that small drillbits require high speed, but this guy said to use slow speed, max 1100 rpms. Geared mine to the lowest, wich is 550 rpm. He also said to oil the bit every 30 seconds :0 That told me I was way too impatient! I can now drill the bolts by listening to the sound the drillbit makes. If it makes a kind of crackling sound, the bit is either about to pack full and overheat or about to brake through the hardened surface on the other side. If the first is true, I back the bit out and clean it and reapply oil. If the bit is about to break through I'm very careful with how much pressure I apply. This was a bit tideous, but I didn't breake anymore drillbits. Took me about 1.5 hours to drill all the bolts for the front and rear discs. I also painted the center of the rear brake rotor. Pictures included as usual:

Rear rotor, painted and drilled bolts torqued down, The one odd bolt is the magnetic one. Should have drilled it last, as it made the drillbit magnetic and a pain to clean.
IMG_20200521_222827 by Lars Krogh-Stea, on Flickr

This is how it was before:
IMG_20200520_210733 by Lars Krogh-Stea, on Flickr

This is how the safetywiring looks now. I went with connecting two in pairs instead of three. I watched a youtube clip of an older guy wiring a propeller for a small plane, and tried to copy what he did. He had several very good tips on how to twist the wires to keep them tightly in place.
IMG_20200521_180148 by Lars Krogh-Stea, on Flickr
 

LKS

Member
I'm sure you're pretty tired of me posting pictures of safetywire by now, but I recieved the new nuts today. Must have been an older version as they were NOT drilled :( Anyhow, as they do look much nicer than the ones I that are on now, I drilled them myself and put on a couple of nuts to see the results. Pretty satisfied :)
2020-05-25_11-12-34 by Lars Krogh-Stea, on Flickr

I also put together the GSXR fork to get a bether view of how it all fits together, and I must say I'm sceptic as to how I'm supposed to fit a spoked wheel between those calipers? The angle is little off on the picture where I measure. The more correct measurement is about 47mm (1.85inches). As they are radially mounted I could get some 320mm discs but that would only move them 1cm towards the narrower part of the wheel.
2020-05-22_09-15-19 by Lars Krogh-Stea, on Flickr

2020-05-22_09-15-57 by Lars Krogh-Stea, on Flickr

2020-05-22_09-15-43 by Lars Krogh-Stea, on Flickr

I checked the Cognitomoto wheel and they have laced it with all spokes on the inside. Mine are the usual inside/outside. If that's how it's done I'll need another set of spokes to get all of them in the correct angle, and then I might as well get a wider front rim/tire. then it starts to get expensive.. If I have to do the front wheel all over again, I will have to wait for the winter to do the fork swap :/
cognitomotowheel by Lars Krogh-Stea, on Flickr
 

50gary

Under the Limelight
You have the brake calipers mounted upside down. The witness is the bleeder nipples should be at the top of the caliper to vent the air.
Flip the calipers and right side up to gain more clearance. Can happen to anyone.
Cheers, 50gary
 
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cb250nproject

If you can make it better do so
I have done the same thing on my bike, rim goes on first then the calipers, then when you remove the rim, calipers off first then rim comes out.
IMG_9416.JPG
it should work


Sent from my iPhone using DO THE TON
 

pidjones

Well-Known Member
GL1800s require calipers (or at least one) off to get the rim off. But yes, make sure calipers mount with bleeder at top, or you are doomed forever to spongy brakes.
 

50gary

Under the Limelight
That's a given, removing calipers before wheel.
But the point in question is that the wrong way mounted calipers creates the problem situation I.E. that the wheel (hub) won't fit because of the offset of the calipers when mounted incorrectly.
Cheers, 50gary
 

LKS

Member
That's a given, removing calipers before wheel.
But the point in question is that the wrong way mounted calipers creates the problem situation I.E. that the wheel (hub) won't fit because of the offset of the calipers when mounted incorrectly.
Cheers, 50gary
I, can't see how this comes into play.. When I flip the calipers, they also need to swap left/right between fork-legs, or else the brake pads will end up on the outside of the caliper mounts. Or am I not understanding you correctly? I will mount both the calipers and the triples correctly later, but I can't see that it will make any difference with regards to clearing the spokes.
 
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LKS

Member
I have done the same thing on my bike, rim goes on first then the calipers, then when you remove the rim, calipers off first then rim comes out. View attachment 226098 it should work


Sent from my iPhone using DO THE TON
That is an awesome setup, but I've set my mind on trying to make it work with the original hub/wheel. The Cognitomoto wheel is laced with all the spokes threaded from the outside of the hub. You can se it in this video;

This means that I would have to source other spokes, because the original spokes won't do. First off, the outer spokes would have the wrong angle. Secondly, a double set of inner spokes wouldn't work either, bacause, as you can see in the video, half the spokes need a longer neck at the bend to get behind the other spokes. I don't know if I explained that clearly enough, but it' in the video. The Cognito hub is by far the best solution of course, but I've set my mind on the challenge. But.. as I've said earlier; if I have to relace the wheel and figure out the dimensions for the new spokes, I will probably go the CognitoMoto route myself :)
 

LKS

Member
I have mounted the hoodlatches for the "quick-release" seat:

IMG_20200530_210232 by Lars Krogh-Stea, on Flickr

Cut the bolts to length, drilled and tapped them. Then I mounted them on flat piece of steel:
IMG_20200530_210210 by Lars Krogh-Stea, on Flickr

IMG_20200530_210059 by Lars Krogh-Stea, on Flickr

I will cut this plate to size and screw it on to the frame of the rear seat:
IMG_20200530_210104 by Lars Krogh-Stea, on Flickr

This is how it looks underneath the rear fender when the seat is locked in place:
IMG_20200530_205935 by Lars Krogh-Stea, on Flickr
 

LKS

Member
Did a test run with a GoPro mounted to the swingarm to check how the shocks work after rebuild. These are vintage Koni 7610 with the preload set to the lowest out of 3 (twist sleeve) and rebound set to 2 out of 4 (twist dial on top). They're filled with 5W fork oil. The short videoclip is from passing over a speed bump at moderate speed. You can also spot one of the hood-locks. The seat stays well in place.

 

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