BB of Isaac Proton FW - 42mm shell?

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androidavies
Posts: 74
Joined: Sun Sep 29, 2013 4:34 pm

by androidavies

BB30 bearing is a 6806, dimensions are 42mm outside diameter, 7mm wide, 30mm inside diameter. If the diagram in the original post is accurate, then it looks like this bearing will press directly into the BB shell and sit flush with the outer face. This is like the bearings on a lot of Trek carbon frames, BB90(?), although Trek use a different bearing size.

Once the 6806 bearings are in, could a Wheels BB30 to 24mm adaptor be used to allow fitting the Shimano crank?

In the UK, Stif Cycles, Stif.co.uk are advertising the frame on sale. Would be worth contacting them as well to confirm. I may even do that to get to the bottom of this!

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bikerjulio
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Location: Welland, Ontario

by bikerjulio

Looks like you didn't read through the thread. I already suggested this.

If this is really Isaac's intention, then I don't see how they can possibly describe this as "Shimano pressfit" though.
There's sometimes a buggy.
How many drivers does a buggy have?

One.

So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.

http://www.youtube.com/watch?v=GekiIMh4ZkM

Krull

by Krull

a friend of mine had a storck-frame, although with shimano pf-bottom-bracket. after less than a year in use, the bb-housing had widened, and bottom-bracket could be removed and installed by hand, no more press-fit with tight fit. housing simply had become to wide for 41-mm-bb.
the frame had to be changed.
could this possibly have been happened in this case as well?

androidavies
Posts: 74
Joined: Sun Sep 29, 2013 4:34 pm

by androidavies

Ah, sorry Bikerjulio.... I wasn't concentrating! Was already thinking how to machine one of the cups down!

You're correct! I called Stif cycles, and they said it looked as you describe in your post. They had a built up bike with a Shimano crankset fitted sat in front of them.

They said that Jungle Products handle Isaac in the UK, and may have parts, and I think it's a company called Tehava(?) in mainland Europe- for the OP...

I have two Isaac frames, but they're a bit older, and both have threaded BB's.

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bikerjulio
Posts: 1900
Joined: Fri Dec 11, 2009 10:38 pm
Location: Welland, Ontario

by bikerjulio

I don't like the idea of pressing BB30 bearings directly into a carbon frame. Just seems to be asking for trouble. I think OP would get a more satisfactory result if he is able to machine the Shimano cups he has and loctite them into the frame.
There's sometimes a buggy.
How many drivers does a buggy have?

One.

So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.

http://www.youtube.com/watch?v=GekiIMh4ZkM

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Frankie - B
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by Frankie - B

The parent company for Isaac is indeed Tehava. I'm visiting them next week I'll ask what their solution for this specific frame is.
'Tape was made to wrap your GF's gifts, NOT hold a freakin tire on.'
If you want to see 'meh' content of me and my bike you can follow my life in pictures here!


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bikerjulio
Posts: 1900
Joined: Fri Dec 11, 2009 10:38 pm
Location: Welland, Ontario

by bikerjulio

Not sure your point, but I posted that already. I think we moved on.
There's sometimes a buggy.
How many drivers does a buggy have?

One.

So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.

http://www.youtube.com/watch?v=GekiIMh4ZkM

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Frankie - B
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Joined: Mon Jun 02, 2003 8:17 am
Location: Drenthe, Holland

by Frankie - B

@Bikerjulio, I'm not sure why you are pushing so hard to get the frame machined when this is clearly not needed.

@ the OP. I went ahead and contacted Tehava, the parent company of Isaac for you. The solution might be super simple.

The BB used in the frame is a press fit BB91 with a diameter of 42mm. This 42mm diameter is either for BB30 bearings or MTB press fit use. You went ahead and installed a MTB preset BB in the frame, witch is perfectly fine. The reason why you BB may appear to be too wide could be:
-The BB isn't pressed in thoroughly.
-The spacer that sits in the BB is made for MTB spacing and should be left out in this case. (or replaced with a road version) The spacer is the black plastic cylinder that is placed between the bearing housing.

Please make sure this is done before you try to install that DA crankset again ;)
'Tape was made to wrap your GF's gifts, NOT hold a freakin tire on.'
If you want to see 'meh' content of me and my bike you can follow my life in pictures here!

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bikerjulio
Posts: 1900
Joined: Fri Dec 11, 2009 10:38 pm
Location: Welland, Ontario

by bikerjulio

You misunderstand me. I have been suggesting machining the cups in order that they can sit 2.5 mm closer into the frame.

They cannot go in any further than they are in the original photos, because those cups have a shoulder on them, and the shoulder is seated against the frame.

A MTB crankset has a spindle that is 5mm longer than a road crankset, and those cups are intended for MTB use.

Hope that explains it better.
There's sometimes a buggy.
How many drivers does a buggy have?

One.

So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.

http://www.youtube.com/watch?v=GekiIMh4ZkM

Krull

by Krull

Frankie - B wrote:
The BB used in the frame is a press fit BB91 with a diameter of 42mm. This 42mm diameter is either for BB30 bearings or MTB press fit use. You went ahead and installed a MTB preset BB in the frame, witch is perfectly fine. ......


ah, ok, i see. considering this aspect, the term "BB Shell Hybrid: Integrated Shimano Press Fit" makes sense. interesting idea.

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dino0204
Posts: 52
Joined: Tue Feb 24, 2015 5:31 pm

by dino0204

I'm pleased that so many people want to help :) Thank you for that.
The problem was solved. I didn't buy anything. I polished up only backs of BB cups, not frame! Each 2.5mm. Now Shimano cranset can work with this frame.

Image

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bikerjulio
Posts: 1900
Joined: Fri Dec 11, 2009 10:38 pm
Location: Welland, Ontario

by bikerjulio

Cool - I'm glad my suggestion worked out for you :)
There's sometimes a buggy.
How many drivers does a buggy have?

One.

So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.

http://www.youtube.com/watch?v=GekiIMh4ZkM

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