Getting the best chainline with the bbshd

Ykick said:
Holy cow Robo that is a crazy chainline but if it works for you, rock on!

I’m still very pleased using 3 wide range cogs and hardly any angle to the chain.

I wish there was an easy way to do that with a freewheel hub. With a cassette, I can see it would be not hard.

Do they make a cassette to freewheel adapter?
 
Most of the freewheels I've messed with are built basically like a cassette, in that they have a lockring (that is usually also the smallest cog). Just like with a cassette, you can use two chainwhips to undo the lockring, and then take off whatever cogs you want, respacing them either with rearranged cogs or with more spacers off other old freewheels, or rings cut from the right sized PVC pipe or plastic sheet, etc.
 
amberwolf said:
Most of the freewheels I've messed with are built basically like a cassette, in that they have a lockring (that is usually also the smallest cog). Just like with a cassette, you can use two chainwhips to undo the lockring, and then take off whatever cogs you want, respacing them either with rearranged cogs or with more spacers off other old freewheels, or rings cut from the right sized PVC pipe or plastic sheet, etc.


Oh, I want to try that. Thanks!
 
You're welcome. :) FWIW, the sprockets I used to convert my IGH to a frame-mounted unit rather than wheel-mounted came off some old freewheels:
https://endless-sphere.com/forums/viewtopic.php?f=2&t=67833&hilit=igh&start=350#p1227692

I used just one (homemade) chainwhip, and clamped the freewheel body down to the bench. Sometiems I hae to clamp it and also put screws into the benchtop in the spaces between sprocket teeth in several palces aorund the largest sprocket.

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robocam said:
I've been waiting to make this post because I wanted to put some miles on my 30T Mighty-Mini first, and I'm thrilled to report that all the chainline issues that I was worried about are all wiped away. Look at that crazy chainline! I'm running a KMC 10.93 chain to a 10-speed Shimano XT 11-36T cassette with a 42T Wolftooth expander cog.

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I am now a firm believer in narrow-wide chainrings. They are amazing at guiding a chain onto the teeth even at crazy angles! And look at how many spacers I used to push the BBSHD out! My bottom bracket is 68mm.

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Those spacers were necessary for the 42T Luna Eclipse to clear the chainstay. So does it work? Yes! At first, it made a little noise in the first two larger cogs and skipped a little under load, but after a few miles, it's all quiet and smooth now. Now here's the bad part. Look at all those aluminum shavings from the chainring! I wish a steel version was available. It would last a lot longer and be a lot stronger. I've seen people break teeth on these things. Please Luna, make a steel version someday =)

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For now, this will do. I'm thrilled that I can use this chainring because I wanted a 1x setup. I've purchased a 50T OneUp Shark extender cog that I will install very soon (I'm going to an 11-speed setup).
You can take out all of those spacers and mill down the BBSHD gear cover. It is very strong.

I did mill down 7-8mm for clearing the Chainstays without any issus.

If you keep the spacers the chain will eat your mighty mini in no time.

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fechter said:
amberwolf said:
Most of the freewheels I've messed with are built basically like a cassette, in that they have a lockring (that is usually also the smallest cog). Just like with a cassette, you can use two chainwhips to undo the lockring, and then take off whatever cogs you want, respacing them either with rearranged cogs or with more spacers off other old freewheels, or rings cut from the right sized PVC pipe or plastic sheet, etc.


Oh, I want to try that. Thanks!

Good one Amberwolf! I'll definitely be trying that soon as my Fat bike is threaded freewheel but I would love to move the shifter to a 3sp trigger on the LH grip and just do wider range cogs.

I suppose I should've figured that out when I tried boiling a badly rusted freewheel in oil and the plastic separators melted. Oops.... Oh well, it was a hail Mary attempt to free it up.
 
Thanks =) Yeah, I wasn't expecting it to work at all after reading about how people needed to make custom chain guides to use the Mighty-Mini. Now I'm wondering why those people are having trouble at all. Maybe I just got lucky.

I wanted to keep the full range of gears so that I could still use it like a regular mountain bike on the trails, but it's great that you don't have too much of an angle to the chain.

Ykick said:
Holy cow Robo that is a crazy chainline but if it works for you, rock on!

I’m still very pleased using 3 wide range cogs and hardly any angle to the chain.
 
Thanks for the idea. I was wondering how far you could go before exposing the gear. So you removed 8mm of material and still didn't go all the way through? Could you show me some pictures of what you did?

But the main reason I had to space it out was because the 42T Luna Eclipse chainring was contacting the chainstay. I thought about just spacing the chainring out, but the spacer they sell isn't thick enough. I wonder if I can use 2 spacers (can I just use washers?) and get longer bolts. I hope that's strong enough.

If I don't have any fancy tools, can I just use a grinder or Dremel to "mill" the cover?

--freeride-- said:
You can take out all of those spacers and mill down the BBSHD gear cover. It is very strong.

I did mill down 7-8mm for clearing the Chainstays without any issus.

If you keep the spacers the chain will eat your mighty mini in no time.

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so here's the best possible chainline you could get 8)

top gear is 14t because 11t isn't really usable at full power (tends to jump and wears quickly). unfortunately the 14t doesn't the micro-teeth that's needed to retain the lockring so i welded on the micro teeth that was cannibalized from and old worn-out 11t :shock:

so there the 14t now occupies the outermost position

and all my cogs are now steel. no more worries about breaking my aluminum 42t
 
I asked my local bike mechanic about the micro teeth on the smallest cog used to "lock" the lockring. He said it was ok not to have them, so long as it was torqued down. Going to do this in the next day or two, see what happens!
 
nadair20 said:
I asked my local bike mechanic about the micro teeth on the smallest cog used to "lock" the lockring. He said it was ok not to have them, so long as it was torqued down. Going to do this in the next day or two, see what happens!

well that might work, but how reliably under extreme conditions? i just didn't want to take the chance

HpYMtG2.jpg
 
Really, the cassette only needs to be tight. The serrations are just a way to keep things from disassembling when they're not very tight.

The welded serrations are a clever workaround, but no doubt removed some of the hardening from the 14t sprocket.
 
Overclocker said:
top gear is 14t because 11t isn't really usable at full power (tends to jump and wears quickly). unfortunately the 14t doesn't the micro-teeth that's needed to retain the lockring so i welded on the micro teeth that was cannibalized from and old worn-out 11t :shock:

so there the 14t now occupies the outermost position
Do you mean 13T? The CSM680 specs shows cogs of 11-13-15-18-22-28-34-40T.

Either way, it looks like a very promising cassette. Inexpensive, plenty of range, pure steel, and easy to mod. I'm all about having fewer speeds! Less time wasted shifting -- especially since the GearSensor does not handle double-shifts very well.

Plus you get to use 7/8 speed chains, which are wider (stronger) -- 3/32” vs 11/128” for denser cassettes. KMC does not make an ebike-specific 7/8spd chain, sadly, but they assured me the X8-EPT was comparable in strength to the X10e series, not to mention way cheaper.
 
Chalo said:
Really, the cassette only needs to be tight. The serrations are just a way to keep things from disassembling when they're not very tight.

The welded serrations are a clever workaround, but no doubt removed some of the hardening from the 14t sprocket.
I wonder if the best solution wouldn't be to steal the micro-toothed top gear from a narrow range cassette -- for example, the 13T from a Shimano HG50 13-26. Then you'd preserve 7 usable gears (13-40) even after moving the Sunrace 11T behind the granny.

(thank goodness 7spd steel parts are cheap)
 
Richard Berg said:
Do you mean 13T? The CSM680 specs shows cogs of 11-13-15-18-22-28-34-40T.

Either way, it looks like a very promising cassette. Inexpensive, plenty of range, pure steel, and easy to mod. I'm all about having fewer speeds! Less time wasted shifting -- especially since the GearSensor does not handle double-shifts very well.

Plus you get to use 7/8 speed chains, which are wider (stronger) -- 3/32” vs 11/128” for denser cassettes. KMC does not make an ebike-specific 7/8spd chain, sadly, but they assured me the X8-EPT was comparable in strength to the X10e series, not to mention way cheaper.

14t. from another cassette. you might notice the difference in color

well there are 3 ways to make a stronger chain: 1) better metallurgy 2) thicker plates 3) stronger rivets

8spd chain don't have those 3 8) anecdotally i find it much easier to push out 8spd pins w/ a chain tool than the higher speed chains

you could make a 1-inch wide chain but if the plates aren't any thicker then the chain wouldn't be stronger

but 8spd has wider cog-to-cog spacing so is more forgiving, so it tends to shift better. and the chains are super cheap. so even my 100% human powered bike is on an 8spd system w/ one cog removed:

[youtube]MRaIMriVHWE[/youtube]
 
robocam said:
I'd just grind in some serrations or use a threadlocker.

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tried doing that but the splines on the freehub body don't go all the way to the edge. the whole cassette stack has to extend past the edge in order to be cinched by the lockring
 

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