Chain Ring spider offsets?

[Nvreloader]

I went to change the chain ring gear/spider on the WH to 42t.

While attempting to fit the new 130 BCD/42T CR and spider,
I found out that there was NOT enough off set on the spider arms/CR to clear the tire, on the chain.

The WH OEM Bafang 44T spider offset/depth is approx .950" deep, measured across the flat face to the inside lip of the spider hole.

The 42T CR spider/gear, I just bought measures .400" deep, measured the same way.

So it appears I have to find a .950" deep, 130 BDC, 5 arm spider,
any thoughts or suggestions on where to find one, as I have had NO success finding one,
so far.
Tia,
Don

 

[fooferdoggie]

I went to change the chain ring gear/spider on the WH to 42t.

While attempting to fit the new 130 BCD/42T CR and spider,
I found out that there was NOT enough off set on the spider arms/CR to clear the tire, on the chain.

The WH OEM Bafang 44T spider offset/depth is approx .950" deep, measured across the flat face to the inside lip of the spider hole.

The 42T CR spider/gear, I just bought measures .400" deep, measured the same way.

So it appears I have to find a .950" deep, 130 BDC, 5 arm spider,
any thoughts or suggestions on where to find one, as I have had NO success finding one,
so far.
Tia,
Don

can you use washers behind it to push it out? though thats a lot of distance to make up.

 

[juggernaut]

Why do you need to change the spider? Just change the chainring.

 

[Nvreloader]

Why do you need to change the spider? Just change the chainring.

Because I want the chain Ring guard on, to prevent the CR from grabbing my pants leg.
The OEM 44T CR does NOT have a guard, the 42T does, and the parts can NOT be interchanged.

 

[m@Robertson]

BBS02 or BBSHD? Sounds like a BBS02. California-ebike.com has BBS02 and BBSHD offset rings and spiders.

If you are limited on space, one trick you can play is to set your chainring on backwards, which will not affect the drivetrain. This will put the chamfered openings on the inside. From there you put the chainring bolts on backwards as well, and since the 'outside' bolts are flush-fit, you gain back some space. Once that is done you bolt the spider to the motor.

 

[EMGX]

Because I want the chain Ring guard on, to prevent the CR from grabbing my pants leg.

This might work well for that purpose, it does for me anyway.

 

[Nvreloader]

BBS02 or BBSHD? Sounds like a BBS02. California-ebike.com has BBS02 and BBSHD offset rings and spiders.

If you are limited on space, one trick you can play is to set your chainring on backwards, which will not affect the drivetrain. This will put the chamfered openings on the inside. From there you put the chainring bolts on backwards as well, and since the 'outside' bolts are flush-fit, you gain back some space. Once that is done you bolt the spider to the motor.

Thanks Guys,
Matt
This is on my Ultra 620/510 motor, there is lots of 4 spoke CR spiders,
but very few 5 spoke 130 BDC, and the few I found don't list any spec's for the offset,
I have to have 1" to clear the tire rubbing issue.
This spider also has the splined hole, like this one, but needs to be 130 BCD spec's with 5 arms.

 

[m@Robertson]

Thanks Guys,
Matt
This is on my Ultra 620/510 motor, there is lots of 4 spoke CR spiders,
but very few 5 spoke 130 BDC, and the few I found don't list any spec's for the offset,
I have to have 1" to clear the tire rubbing issue.
This spider also has the splined hole, like this one, but needs to be 130 BCD spec's with 5 arms.

Yeah that piece is not reversible thanks to the offset its using. I didn't realize the Bafang motor we're talking about is one of the frame-specific motors. Christini sells two different pieces like this specifically to clear their fat bike frames. You might check their site to see if thats going to do you any good. One of them offers more offset, the other one offers a LOT more. Karl Gesslein reviewed that latter one quite awhile ago. And nobody gives specs of course. But both of the Christini options offer increased offset from factory stock. You can see at least the smaller offset version installed here. This guy may give you some ideas.

Out of my element on this as I haven't worked directly with this motor.