Wattsup

Ok, so I just removed my first bottom bracket ever. My Vaya has a 68mm threaded BB shell, and I removed a Shimano MT800. Here's the thing. I only see two 2.5mm spacers, both were on the right side. I see nothing on the left side. According to Shimano's manual, for a 68mm shell, you need one 2.5mm on the left, and two 2.5mm on the right. So what does this mean??

The crank is Shimano XT Hollowtec II. I have noticed no shifting issues since I bought the bike used. It's a 1x11 with an XT 11-46t cassette. The previous owner had the bike built from a frame kit.

Thanks!
PS. I'm a little confused now as to what Shimano recommends. They have like 4 different dealer manuals listed. This page from one of them suggests a slightly different arrangement.

fietsbob

You're Putting a 73 type (MTB crank (spindle part of the crankarm now), in a 68 frame..? you have a 5mm difference...

use it for tweaking chainline Rt or left end or as you read? split the difference equally 2.5 a side

DrIsotope

I have a "normal" PF30 in a BBRight frame, so I think I have like 11-12mm of spacers on the driveside. The factory spacer is the size of a mid-height headset cap.

For your situation, just use whatever combination of spacers gives you the best chainline.

Wattsup

I understand you're math, but I don't understand why Shimano recommends three 2.5mm spacers. Take a look here. This guy does the same thing. Two 2.5mm on the drive side, one 2.5mm on the non-drive side. Scrub to the 6:00 minute mark.

Slightspeed

I have two cassette spacers on my Super Course to move the Sugino AT triple out so the inner chainring screws clear the frame. Never gave chainline a thought, but it rides great. The BB shell is 68mm, and I think the spindle is 126mm.

Dan Burkhart 

One of the two drive side spacers is eliminated when an E type derailleur is used.
The spacers are provided to correct spacing from 68mm without E type derailleur up to 73mm with E type. Thats why 3 spacers.In the latter case, all spacers are eliminated.

fietsbob

[QUOTE=Slightspeed;20781320]I have two cassette spacers on my Super Course to move the Sugino AT triple out so the inner chainring screws clear the frame. Never gave chainline a thought, but it rides great. The BB shell is 68mm, and I think the spindle is 126mm.

Ok, but you have a older bike,loose ball BB , and nothing like the OP..so not applicable, . but at least it's a nice picture..






....

Wattsup

Thanks everyone for the advice. I also decided to call Salsa themselves and also called Shimano and asked them. For my 1x11 configuration, Shimano tech support says to use THREE 2.5mm spacers, two on the drive side, and one on the non-drive side. That's for fitting the 73mm bottom bracket to a 68mm shell. (They recommend one spacer for fitting their MT800 BB to a 73mm shell.). Salsa on the other hand recommends using only two spacers in total, one on either side. Now I think the guy who built the bike used two spacers, but he put them both on the non-drive side!

The Salsa guy said that the original builder may have done it the way he did because the end result, the shifting was better. Shimano said that it's possible that Salsa's directions differ from theirs because Salsa has learned through experience that one spacer on either side just works better on their Vaya frame.

The Shimano rep told me that 1x11 systems can be tricky, and it occurs to me that the cassette the original builder used, (11-46t) with that huge 46t cog may make it even tricker.

So where am I left? I have a much better understanding, thanks to all the advice I've received, but I'm still not sure what configuration I'm going to use!

fietsbob

A 1 by, you center it in line with the center , the middle cassette cog , use Low a lot bias it off center tn that direction, High gear bias it to the smaller end

but that's , .. minimal chain has to bend sideways for most gears anyhow..







....

Wattsup

Thanks...I guess I'll just have to experiment. It just seems rather extreme for the builder to have installed 2 spacers on the non-drive side. I guess I'll just start with Salsa's recommendation, 1 spacer on each side, and then take it from there.