Author Topic: Comstar rear brake CB400/4  (Read 662 times)

Offline PaulC

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Comstar rear brake CB400/4
« on: October 31, 2021, 10:42:59 AM »
Morning all, I'm in the process of swapping the comstar wheels on my 75 400/4 for some spoked wheels. The front spoked wheel is missing a few bits, but oes anyone know whether the rear drum brake from the comstar wheel will fit the spoke 400/4 hub?

Thanks Paul

Offline taysidedragon

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Re: Comstar rear brake CB400/4
« Reply #1 on: October 31, 2021, 10:53:07 AM »
I don't know Paul, but I believe the front and rear brakes on a cb250rs are the same as 400f spoked wheels. Their rims are aluminium too which you might want?
I have some front brake parts spare. What are you missing?
Gareth

1977 CB400F
1965 T100SS

Offline PaulC

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Re: Comstar rear brake CB400/4
« Reply #2 on: October 31, 2021, 11:35:09 AM »
TSD - many thanks for prompt reply I'lllook into that.

I think the front forks I have are from a 250N but I can't find any identifying marks/numbers. I've had a look at the parts catalogue and the ones I have  look nothing like the 400/4 forks (different lower mounts where the spindle attaches). Missing everything from the speedo gearing and covers to caliper and mount!


Offline allankelly1

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Re: Comstar rear brake CB400/4
« Reply #3 on: October 31, 2021, 11:39:11 AM »
Hi

If the forks were from a CB250N this has a single front disc so if forks are from this bike then one leg would be missing the caliper mounting points




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Offline allankelly1

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Re: Comstar rear brake CB400/4
« Reply #4 on: October 31, 2021, 11:41:22 AM »
Watch out too as the disc on a cb250n is bigger than a cb400n


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Offline PaulC

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Re: Comstar rear brake CB400/4
« Reply #5 on: October 31, 2021, 12:06:01 PM »
Hi,

Looking at the photo you posted is why I believe the forks and comstar wheels are from a 250N mated to 400/4 stem. I was hoping the rear brake drum would be stamped with a part number.

Cheers
« Last Edit: October 31, 2021, 08:58:06 PM by PX207 »

Offline allankelly1

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Comstar rear brake CB400/4
« Reply #6 on: October 31, 2021, 06:19:05 PM »
Hi PX207

Just a a note I have been told that cx500 lower sliders are a straight swap on the CB400F stanchions if you were looking for a possible donor swap to a twin disc

Maybe a complete cx front end  may suit as I know from experience the cb400n sliders are not compatible with original CB400F stanchions without modifications for the internal bushes

Best wishes Al


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Offline ka-ja

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Re: Comstar rear brake CB400/4
« Reply #7 on: November 01, 2021, 09:38:51 AM »
The 400N front end with twin disks fit straight into the 400/4 yokes with no mods apart from a better master cylinder, but it gives you a 19in front wheel. I don't think the 400/4 rear brake plate is interchangeable with the 250N rear brake, I have had a similar setup since 1985, recently overhauled, but now on 18in front wheel
« Last Edit: November 01, 2021, 09:42:03 AM by ka-ja »
nice bike,nothing in the bank

Offline PaulC

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Re: Comstar rear brake CB400/4
« Reply #8 on: November 01, 2021, 10:21:47 AM »
Just like to thank the forum members for their prompt and suggestive responses, I'm sure it won't be the last time for this mechanical newbie. Al your a life saver, given what ka-ja has just stated 😀  8)

 

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