Bolts to mount flat mount calipers to frame and fork

[NHAero]

My incoming Strong frame is at Dark Matter, and I'm trying to envision what little parts am I going to be missing when it arrives and I want to build it up. One thing I don't see are bolts for the Shimano Dura Ace flat mount disc calipers. I have a WHISKY No.9 Road Plus fork and it didn't come with bolts, and it looks as though neither did the calipers.

So - how do these calipers mount, and what bits do I need to get that I don't have?

160mm rotor front, 140mm rotor rear, if that helps!

[batman1425]

For the fork you'll need one of these:

https://www.backcountry.com/shimano-...xoCAvEQAvD_BwE

They don't come with bolts, you'll need a set of short bolts to mount the plate to the caliper, and another set of bolts to mount the plate to the fork. Your LBS should have some in their spare bin they can give you for free.

If you need some for the rear, those are available as well, but length is variable depending on the frame. LBS might have these, might not, but they are reasonably easy to track down if you know what length you need. If your frame is set up for 140 rear, shouldn't need any adapters, just bolt and go.

[joevers]

For the rear, you bolt right on without an adapter. For the bolt length you measure the thickness of the flat mount part of the frame that the bolts go through, add ~7mm and get the nearest length bolt from Shimano. I don't think the rear comes with them but IIRC the front should if you got it in retail packaging.

Originally Posted by batman1425

They don't come with bolts, you'll need a set of short bolts to mount the plate to the caliper, and another set of bolts to mount the plate to the fork. Your LBS should have some in their spare bin they can give you for free.

You shouldn't need to buy one, should be included with the caliper and come with the hardware. Also, for whatever reason disc caliper mounting bolts are hella expensive even for shops, I wouldn't expect it for free.

[elliott]

Shimano part number Y8N204000 for the front which will pass through the adapter posted above and thread into the fork. The rear can vary quite a bit on the dropout design. Contact your framebuilder.

[elliott]

Originally Posted by joevers

For the rear, you bolt right on without an adapter. For the bolt length you measure the thickness of the flat mount part of the frame that the bolts go through, add ~7mm and get the nearest length bolt from Shimano. I don't think the rear comes with them but IIRC the front should if you got it in retail packaging.

If the rear rotor is 160mm it will thread into an adapter, but that won't change the math you mentioned above.

[joevers]

Originally Posted by elliott

If the rear rotor is 160mm it will thread into an adapter, but that won't change the math you mentioned above.

Only said it that way because they mentioned rotor size.

[Hellgate]

Whatever you get make sure they are Ti for that bike. Nothing but the best!

[NHAero]

Thanks very much!
I thought the point of flat mount was that they were directly mounted? Now it's even less clear why these are an improvement!

Originally Posted by batman1425

For the fork you'll need one of these:

https://www.backcountry.com/shimano-...xoCAvEQAvD_BwE

They don't come with bolts, you'll need a set of short bolts to mount the plate to the caliper, and another set of bolts to mount the plate to the fork. Your LBS should have some in their spare bin they can give you for free.

If you need some for the rear, those are available as well, but length is variable depending on the frame. LBS might have these, might not, but they are reasonably easy to track down if you know what length you need. If your frame is set up for 140 rear, shouldn't need any adapters, just bolt and go.

[unterhausen]

that plate is so they can use the same caliper front and back. I think they were right not to have bolts come through the fork. I have always thought the front made a lot more sense than the back. Post mount always results in the caliper being too far from the fork blades for no good reason.

[NHAero]

Are the Shimano calipers 74mm calipers? On Universal Cycles web site they have a series of fixing bolts of different lengths that are for 74mm calipers. When I measure center to center distance of the bolt holes, it looks like 70mm.

Carl responded that I need 28mm bolts on the rear. How much +/- is that length? I notice on the Universal web site they have a 26.8mm and 31.8mm.

[Likes2ridefar]

Should you have received the bolts with the calipers? I bought my dura ace calipers new and both came with the bolts needed to mount on the frame...adapters for 160/140 as well.

[NHAero]

What's interesting is that I bought the shifters and calipers as a package without original boxes from Hong Kong. It was a real bargain, and maybe now I know some of the reason why!

[prototoast]

I've traditionally received bolts with the calipers but, particularly in the rare, they are rarely the right length for the frame. Given how cheap bolts are to produce, Shimano would really be doing us a service to include multiple lengths with the caliper. On the other hand, they can sell aftermarket bolts for 25% the cost of the caliper, so good for them.

[NHAero]

I'm waiting to hear back from Whisky exactly what I need for the fork then will order all the bits.
I wonder what else I've overlooked that will leave me groaning as I build the bike up - every new technology is another challenge to make sure one has all the bits and the proper tools!

[ryker]

Originally Posted by prototoast

I've traditionally received bolts with the calipers but, particularly in the rare, they are rarely the right length for the frame. Given how cheap bolts are to produce, Shimano would really be doing us a service to include multiple lengths with the caliper. On the other hand, they can sell aftermarket bolts for 25% the cost of the caliper, so good for them.

Thanks Shimano indeed.