BBSHD mounting questions

saukit · Apr 13, 2019

Hi all,
I am hoping to mount a BBSHD on a 2018 Kona Honzo steel hardtail frame. The bottom bracket shell is 73mm wide and points towards the standard 68/73 BBSHD. However, the bike is boost spacing and the chainstays move outboard significantly not too far back from the BB. If I just use the standard 2.75" measurement from the center of the BB (measured from the face of the BB shell), I don't think the gear housing of the BBSHD will clear the chainstay.

My question is related to the BBSHD spacers and how they relate to the spacing created by a standard bottom bracket. In my situation, the bottom bracket pushes the sprocket out another 12mm or so from the face of the shell. It does so on both sides. So if I include the 12mm of bottom bracket on both sides, the spacing is more like 97mm.

So should I be using the 68/73 BBSHD and planning to clamp it down with maybe one spacer or so? Or am I going to have to use enough spacers with the 68/73 that I won't be able to tighten down the motor? Any detriment to just using the 100MM BBSHD version and using spacers to get it aligned how I want?

Hopefully this makes sense, thanks for any input!

Chopcat · May 8, 2019

That is a really good question.
Can someone help us here

CC

furcifer · May 8, 2019

saukit said:
Hi all,
I am hoping to mount a BBSHD on a 2018 Kona Honzo steel hardtail frame. The bottom bracket shell is 73mm wide and points towards the standard 68/73 BBSHD. However, the bike is boost spacing and the chainstays move outboard significantly not too far back from the BB. If I just use the standard 2.75" measurement from the center of the BB (measured from the face of the BB shell), I don't think the gear housing of the BBSHD will clear the chainstay.

My question is related to the BBSHD spacers and how they relate to the spacing created by a standard bottom bracket. In my situation, the bottom bracket pushes the sprocket out another 12mm or so from the face of the shell. It does so on both sides. So if I include the 12mm of bottom bracket on both sides, the spacing is more like 97mm.

So should I be using the 68/73 BBSHD and planning to clamp it down with maybe one spacer or so? Or am I going to have to use enough spacers with the 68/73 that I won't be able to tighten down the motor? Any detriment to just using the 100MM BBSHD version and using spacers to get it aligned how I want?

Hopefully this makes sense, thanks for any input!

Yikes, adding Boost to the mix is confusing.

I think it's going to be a hard question to answer because you really need to see how much offset you're going to end up with when the housing hits the chainstays. If I'm reading you right the 12mm doesn't matter, the crank arms should clear the chainstays regardless.

The only problem with a 100mm is getting the torque plate to grab and spacing the bolts to the stator housing. That and if you don't need that much spacing to the right, you're left crank arm is going to be wicked offset.

saukit · May 8, 2019

furcifer said:
Yikes, adding Boost to the mix is confusing.

I think it's going to be a hard question to answer because you really need to see how much offset you're going to end up with when the housing hits the chainstays. If I'm reading you right the 12mm doesn't matter, the crank arms should clear the chainstays regardless.

The only problem with a 100mm is getting the torque plate to grab and spacing the bolts to the stator housing. That and if you don't need that much spacing to the right, you're left crank arm is going to be wicked offset.

Thanks for the input. I ultimately decided not to go with the Honzo frame as the small front triangle also presented some serious challenges in mounting a battery. It also had no rack mounts. So I sold the Honzo and bought a Kona Unit which seems to have a lot more clearance for the chainstays and room in the triangle for a jumbo shark. Hoping the kit gets here soon and once I have it built up I'll post a thread. Appreciate the help!

Chopcat · May 9, 2019

Thanks , so if there is a small offset it should be able to be taken up with the standard BBSHD. Does anyone know what the MAXIMUM offset the 73mm unit allows?

I am about to try to convert my specialized stumpjumper and will do a careful measure before ordering. Likewise battery position will be a challenge and I am planning to print some top tube mounts initially. Which might or might not work. That the fun of it !

CC

Wags · Jun 16, 2019

Following. I had to give up on my Honzo dreams too lol. Are you converting a unit to gears or buying a unit x?

BBSHD mounting questions

saukit

10 mW

Chopcat

1 mW

furcifer

10 kW

saukit

10 mW

Chopcat

1 mW

Wags

10 µW

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