[spa2036]

Hi,

I am new to this forum, live in France and I am desperate in need of some help.
At this moment I am trying to design a rear dropout with ISO mounts for an hydraulic disc brake.
It is hard for me to find the information I need.
Maybe one of you can help me if I am going in the right direction.
Please find attached an illustration of what I came up with so far.
I would like to use a 180 mm disc rotor.
Am I on the right track?
Can I use another offset to avoid the need of bracket supports for the 180mm rotor?

Thanks in advance,
Robert

 

[spa2036]

Better image of my design..

* EDIT * found a way to modify the post..

 

[spa2036]

A .png does not show a white background so I am trying it now as .JPG. Sorry for making a mess. I did not find an option to modify my post..

* EDIT * found a way to modify the post..

 

[phlegm]

I think the Beginner's forum isn't the right fit for this question. I'd try frame building:

Frame Building

www.mtbr.com

 

[JackOfDiamonds]

If you build it with offset, then it's not ISO anymore. You should stick to the ISO design, which is intended to be used always with an adapter. If you don't want to use an adapter, then you should just change to post mount or flat mount, and not invent something new.

 

[spa2036]

@phlegm thank you for placing my question in the right forum.

@JackOfDiamonds I think ( feeling) that an ISO mount offer more strength than a post mount. I am not sure yet which one is better but in the fabrication process ISO mount seems easier. You are right. If I stay to ISO that I will have more options for modifications in the future. So back to my question, the drawing I showed in the first post, is that correct or not?

 

[JackOfDiamonds]

I don't have access to any official standards document. Last time I did an ISO rear dropout, I just drew a 40mm radius and a 78mm radius from the axle. Then I construct a 51mm line between the two circles, and drill the holes at the intersections, and that's the standard IS mount.

 

[dr.welby]

Disc brake mounting systems | Peter Verdone Designs

www.peterverdone.com

 

[spa2036]

@JackOfDiamonds Yes that is about the approach I was using to come up with the drawing. I do not understand that it is so hard to find the standard ISO dimensions/angles.
Or I do not use the right words in the search engines or it is a well kept secret of the bicycle industry.

@dr.welby, thank you for the link to the disc mounting system drawn up by Peter Verdone. That is a lot of usefull information.
When I get it right, the ISO standard is in fact defacto for the 160mm disc brakes without any adapter and you need to use adapters when using another size of disc?

So now I need to figure out if there is an offset between the disc brake caliper and the disc itself.

 

[JackOfDiamonds]

@JackOfDiamonds Yes that is about the approach I was using to come up with the drawing. I do not understand that it is so hard to find the standard ISO dimensions/angles.
Or I do not use the right words in the search engines or it is a well kept secret of the bicycle industry.

@dr.welby, thank you for the link to the disc mounting system drawn up by Peter Verdone. That is a lot of usefull information.
When I get it right, the ISO standard is in fact defacto for the 160mm disc brakes without any adapter and you need to use adapters when using another size of disc?

So now I need to figure out if there is an offset between the disc brake caliper and the disc itself.

Je fais un nouveau cadre avec ISO mount actuellement. J'ai trouvé ce document de Magura:

https://www.magura.com/media/1997/is_e_09-12-02_11.pdf

phrase de recherche google: "iso brake mount specification", 2e resultat. Elle n'est pas la spécification officielle, mais je pense qu'elle servira assez bien pour moi.

À noter que la fixation avant est déplacé lateralement 4mm versus la fixation arrière. Ça c'est parce que la distance laterale entre le disque et le cadre est établi differement par le moyeu avant (11mm) que le moyeu arrière (15mm).

hth