Burnishing tool for Mezzer

kten

understands stuff moorey doesn't
Seems like the Mezzer is quite a popular fork around here and generally the only real thing some people would like improved is a little more compliance over chatter. Reading up on this thread on mtbr, burnishing the bushings to attain the maximum amount oil thickness and reduce stiction seems to be a good way of improving this.

Specific post #162 in this thread about the Mezzer and burnishing.

Firstly, are the other Mezzer owners interested in getting their hands on a burnishing tool? We could post to each other after use...pay it forward type thing where the only payment is postage to the next bloke/gal.

Second, does anyone have access to a lathe and some stainless and could manufacture the tool? I've also emailed Oliver at Blue Labs about making a tool but if someone here could do it I'd rather give you some $$.
 

gillyske

Likes Dirt
I'm registering my interest, but i dont have the tools or workspace to take the fork apart myself.
I would be happy to pay someone for the service.
 

link1896

Mr Greenfield
I've got the parts to make a burnishing tool. The critical step is measuring stanchions and sizing the tool correctly. The lathe is a must. Maybe we have a burnishing festival at my place soon. @beeb yours still need doing too?
 

beeb

Dr. Beebenson, PhD HA, ST, Offset (hons)
I've got the parts to make a burnishing tool. The critical step is measuring stanchions and sizing the tool correctly. The lathe is a must. Maybe we have a burnishing festival at my place soon. @beeb yours still need doing too?
Indeed, would love to get the 36 done!
 

link1896

Mr Greenfield
Serious question, how hard is the process? I’m keen and may have another mezzer on the way oooppss
Nothing hard as such. A round, smooth lump of metal is pushed through the bushings to shape and size them to the correct size with a huge t bar shaped tool.




Bushings start life as a strip, which is then shaped into a band. But the butt join where the ends meet, like old pinned aluminium rims, is regularly messed up. So the stanchion doesn’t slide though smoothly.

Oil needs to stay on the stanchion surface while it passes through the bushings, to provide a layer of oil for the bushings to ride on. If the bushings wipes it off due to being too tight, it’s plastic bushing on stanchion without a lubricating film. Lube makes everything better according to Poodle.

Conversely, too loose is bad too. Annoying when you apply the brakes and the axle moves 20mm rearwards. Can also cause bind up, where lowers get cockeyed on the uppers and won’t move as well.


Fox states correct bushing tolerance is a diametric clearance of

min: 0.0015" (0.0381 mm)
max: 0.0090" (0.2286 mm)

0.1mm was chosen by Oliver Majewski (aka Blue Liquid Labs) as an easy number to hit.

Challenge is, I’ve seen stanchion diameters all over the shop. I’ve been recording everything I’ve touched. One that comes to mind

2020 Kashima 36mm stanchions at 35.92mm. If you were to use a 36.1mm tool, you’re awfully close to the upper end of the tolerance window. Measuring every time and a suitable sized tool I feel is a must.

The other trick is to make sure the hub pulls the lowers into the right position. If it’s off by much, things will bind.
 

Scotty675

Cable thief
Thanks link.
In my head I had something like honing a bore (I could definitely fuck this up).
Seeing that and reading that makes perfect sense. I think I may still have the brains to do this. Now I shall go forth and measure all my stanchions
 

peanut

Likes Dirt
I'm certainly interested, im happy to pay post & a hire fee to use it, 37.07 is the figure that seems to be used in regards to burnishing the mezzer.
My mezzer has never been as good in regards to hand feel compared to my mattoc pro ( which I no longer have), i often think I got a Friday fork after the user reviews on the mezzer threads...
 

komdotkom

Likes Bikes and Dirt
Link is 100% right on this on two critical points.
There won't be a single size that works for every Mezzer - there will be a single clearance which works but the stanchion size will play a big part in this. Despite what bike companies would have us believe, the manufacturing tolerances from most suppliers are woeful so there is a significant risk of increasing the clearance excessively on the DU bushes because the stanchion sizes could vary from batch to batch.
The other issue is that the installation of the stanchions into the crown is not a particularly precise process and the installation of the axle and hub (the actual hub you are using) will impact on the DU bush alignment and therefore how concentric the bush is in relation to the stanchion when installed.
 

kten

understands stuff moorey doesn't
Can everyone accurately measure their Mezzer stanchions to ascertain the variance? Hoping it's less of a worry than Fox who make Friday specials every other day.
 

yuley95

soft-arse Yuley is on the lifts again
Nothing hard as such. A round, smooth lump of metal is pushed through the bushings to shape and size them to the correct size with a huge t bar shaped tool.




Bushings start life as a strip, which is then shaped into a band. But the butt join where the ends meet, like old pinned aluminium rims, is regularly messed up. So the stanchion doesn’t slide though smoothly.

Oil needs to stay on the stanchion surface while it passes through the bushings, to provide a layer of oil for the bushings to ride on. If the bushings wipes it off due to being too tight, it’s plastic bushing on stanchion without a lubricating film. Lube makes everything better according to Poodle.

Conversely, too loose is bad too. Annoying when you apply the brakes and the axle moves 20mm rearwards. Can also cause bind up, where lowers get cockeyed on the uppers and won’t move as well.


Fox states correct bushing tolerance is a diametric clearance of

min: 0.0015" (0.0381 mm)
max: 0.0090" (0.2286 mm)

0.1mm was chosen by Oliver Majewski (aka Blue Liquid Labs) as an easy number to hit.

Challenge is, I’ve seen stanchion diameters all over the shop. I’ve been recording everything I’ve touched. One that comes to mind

2020 Kashima 36mm stanchions at 35.92mm. If you were to use a 36.1mm tool, you’re awfully close to the upper end of the tolerance window. Measuring every time and a suitable sized tool I feel is a must.

The other trick is to make sure the hub pulls the lowers into the right position. If it’s off by much, things will bind.
Are stanchions generally consistent diameter over their length or can that vary slightly too?
 

Dales Cannon

lightbrain about 4pm
Staff member
Link weird the tool is smooth? Would have expected a matt finish at the very least.as yuley says do you run a tapered tool through first to clean up high spots and even the bushes out?
 

Mattyp

Cows go boing
Link weird the tool is smooth? Would have expected a matt finish at the very least.as yuley says do you run a tapered tool through first to clean up high spots and even the bushes out?
The tool is bigger than the bush will end up being, a 36.1 tool will open the bushing up to about 36.07 due to the hardness (or softness) of bushing material.
You don't remove any material as such, You literally force the tool head through the bushes and this opens them up slightly with a bit of spring back when you pull the tool out.
I've been meaning to make one of these up but don't have access to a cylindrical grinder anymore, and the lathe at work is junk.
 
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