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Need Opinions On Rear Disc Mounts


Chris

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hey there...

I just got my custom frame. A few things didn't turn out the way I ordered it... so it's going back --> Chance to redesign it.

I just wanted to get your opinions on that disc mount. The dropout is 10mm thick, cnc'ed I guess. And there's a gusset, about 10mm thick. So what you think? Is the gusset strong/big enough? Could it be placed better?

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There are several disc mount designs out there, which one do you consider the best? Not just by the looks of course :) More from the technical side! Also, what's the best place for the gusset?

Simtra

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MKB

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Megamo

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Edited by Chris
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I duno, if you think about the forces coming from the disc brake, i'd imagine the MBK has got it right, in that if you imagine a straight line coming from the disc, through the caliper, and to the frame. With the simtra, i'd imagine the seatstay's will also have to deal with some of the forces before the re-inforcing bar does......

With the MBK it might just go straight through the bar to the chainstay, which might not be the best thing either.....

It's a hard one.....

Edit: the one in the first picture seems alright, is that what you've got at the minute?

Edited by jake1516
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that mount will crack on the weld

the disc mount needs to over lap the chain stay like the mbk and simatra, no need for it to be 10mm wide as mine ner broke, it just cracked on the weld joining it and it was about 5mm wide

id go for a mount that goes up the stay more

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Dave speaketh the truth. If you look at it, the force from the disc is going to be going straight onto the join between the dropout/discmount and the seat-stay weld, which ain't great. When you move the mount to the right place I guess that might cover it, but a little bar going from the disc mount to further up the seat-stay like the other frames have might be a sound idea?

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that mount will crack on the weld

the disc mount needs to over lap the chain stay like the mbk and simatra, no need for it to be 10mm wide as mine ner broke, it just cracked on the weld joining it and it was about 5mm wide

id go for a mount that goes up the stay more

So you mean the part of the disc mount I've marked in the pic, should overlap the chainstays? Which it does in the pic...

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Problem is, my disc mount was placed totally wrong. The one in the pic here is a standard IS mount, but it should be a +40mm. When the mount is further left, it overlaps the chainstay - then it will be fine?

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So if I got it right, the best solution would actually be to make a massive dropout/disc mount like on the pic?

I know it looks shit and would weigh a ton... but it would be the strongest?

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Edited by Chris
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I'd go for the Simtra design. I wouldn't say that having a huge block of metal act as the adaptor and dropouts is a good idea. It won't help much. My friend had a Megamo Equip Pro with 2 disc brakes (8" rear) and it took 4 years of constant abuse before it cracked. His mount was slightly different to the picture you put up.

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yea thats just quickly drawn up but id say that you need to have the top bolt on top of the stay, the dropout its self isnt gonna break if its gonna break its gonna be the weld

ll draw a decent one up tomoro

past my bed time

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