Cafe Racer Forum banner

41 - 60 of 86 Posts

·
Registered
Joined
·
112 Posts
Discussion Starter #42

·
Registered
Joined
·
112 Posts
Discussion Starter #43 (Edited)
Me and the dog been jiving with Bowie...'I can't explain..I'm going outa my mind...dizzy in the head... I can't explain.. I'm a worried guy..'. This is what the exhaust will look like. I just get it adjusted so, then Biscuit rocks through and smashes everything with his tail, you gotta love him.
P_20170117_145001.jpg
I'm trying to keep large radius bends, 145mm on the rear, I have to go down to 125mm on the front, and both headers are 90cm, amazing, pure luck.
P_20170117_144504.jpg
Next step is to go from cardboard to ply.
 

·
Registered
Joined
·
112 Posts
Discussion Starter #44
A man has got to know his limitations, well that's if he wants to do himself a favour. There is no way I could have welded this tank, the metal is just too thin for me. My son's mate is doing the welding, I'm just happy to fit and tack it together, and my tacking is improving. As mentioned earlier, I messed up the slicing and dicing a bit, but it's coming together OK. I think the secret is to keep the original cuts to horizontal, vertical and perpendicular. Having said that, I will most probably make a right balls up of the 2nd tank.
P_20170130_133237.jpg
 

·
Registered
Joined
·
112 Posts
Discussion Starter #45
I've bought the brake calipers, 1 off a GSX-R 600 and the other off a GSX-R 750, different makes but otherwise identical. This is roughly the mounting position.
P_20170201_184328.jpg
Due to the 5mm dish in the disc, there is a corresponding offset in the caliper mounting, a pain in the butt, but because the disc modifications were pretty simple, I think this disc was the right choice. I'm not sure that this caliper is the best choice though. Another caliper with closer mounting points would allow moving the caliper closer to the forks. I think I will re-visit the re-cycle man tomorrow.
I'm thinking of making the adaptor plate out of 10mm and 5mm stainless plate. I suppose it could be made out of aluminium, but I prefer stainless.
 

·
Registered
Joined
·
5,959 Posts
Those zip ties are never going to hold ;)

You're attaching a cast aluminum part to a cast aluminum part and aluminum is a lot easier to shape and work with, none of it has to move around once you bolt it all up because your disc is designed to float and I'm pretty sure that calliper has pistons that push against each other, yes? ... I'd go with aluminum. Stainless looks nice in raw form but unless you have to make the parts super thin I'm not sure what the motivation would be.
 

·
Registered
Joined
·
7,014 Posts
Those zip ties are never going to hold ;)

You're attaching a cast aluminum part to a cast aluminum part and aluminum is a lot easier to shape and work with, none of it has to move around once you bolt it all up because your disc is designed to float and I'm pretty sure that calliper has pistons that push against each other, yes? ... I'd go with aluminum. Stainless looks nice in raw form but unless you have to make the parts super thin I'm not sure what the motivation would be.

The zip ties are in compression so they should be okay. You should swap them for the stronger Green zip ties though.:D
 

·
Registered
Joined
·
7,014 Posts
Just be aware of where your stresses are.

View attachment 50225
I wish there were some numbers to work with here. We know moving it makes the forces change by 2.67 times, but is that enough to make it unsafe , or just one better than the other?
 

·
Registered
Joined
·
2,347 Posts
I wish there were some numbers to work with here. We know moving it makes the forces change by 2.67 times, but is that enough to make it unsafe , or just one better than the other?
I guess the question should be: what are the max forces (to the point of failure) that the mounting points are able to withstand under the new force vectors? After that you'd need to figure out the max forces exerted by the new setup, and determine if you are under an acceptable safety margin.

that's not even factoring in the effects of those forces over time though.
 

·
Registered
Joined
·
7,014 Posts
I guess the question should be: what are the max forces (to the point of failure) that the mounting points are able to withstand under the new force vectors? After that you'd need to figure out the max forces exerted by the new setup, and determine if you are under an acceptable safety margin.

that's not even factoring in the effects of those forces over time though.
While one may be weaker than the other, the weaker one may be sufficient for the life of the application.
 

·
Registered
Joined
·
112 Posts
Discussion Starter #55
Thanks for all the replies, 'changes like this need to be considered' is an understatement. I'm going from a 295mm disc to a 320mm disc, so the braking force is moved 12.5 mm up the leg, increasing the load on the top mounting point and decreasing the load on the bottom, even perhaps changing it from compression to tension. One thing for sure, understanding the forces is complex. Another thing for sure is the closer I can get the caliper to the fork the better. For example, consider the forces involved if the caliper was mounted at the bottom of the disc, the mind boggles.
 

·
Registered
Joined
·
112 Posts
Discussion Starter #57 (Edited)
Just make a strong enough adaptor plate and you'll be fine...

Thanks Hillsys, this photo gives me confidence. I've got another couple of calipers. I like this one, but it's pretty light weight, the mounting holes are only 8mm. But that should be OK, the forces at those points have not changed.
P_20170202_163844.jpg
And then there is this one, I think it would be OK too.
P_20170202_164605.jpg
The man also had a 6 piston caliper, but I dismissed it without really considering it. But bugger it, I will see what it looks like, it could be awesome.
 

·
Registered
Joined
·
6,587 Posts
You'll be having to use an adaptor plate, so really the holes lining up (or even being that close) is a non issue. It's actually probably better that they don't line up - that way you won't have the holes on the same plane so you'll have more metal between the holes if you know what I mean.
 

·
Registered
Joined
·
112 Posts
Discussion Starter #59
I think the 6 pot is a goer. I will use the little Tokico for the other bike. I'm off to the scrap metal man for some plate for the adaptors.
P_20170203_133234.jpg
 

·
Registered
Joined
·
7,014 Posts
I had the same issue mounting Tokico calipers to mine. I was fortunate in that the lower legs on a triumph are steel so it only required a single bracket made and welded on. In your case just put the caliper on the rotor where you want it and pressurize it to hold it in place while you use a piece of card board to mark your 4 hole locations. It's a piece of cake from there making a bracket and spacers.



My calipers are Tokicos that I shaved the name off and put the Triumph logo on them. I was going to use the same 6 pot caliper you have, but they are too wide on the backside and would have hit the spokes.
 
41 - 60 of 86 Posts
Top