Trek Rail headset bearing

[Hamina]

After 1200km and mainly stored and washed outside the headset bearings of my Trek Rail has come to an almost end. The lower bearing doesn't seem to have any protection from weather. When I bought the bike I opened all bearings and filled them good quality grease.

I think I'll clean the headset bearings and put new grease when I service the front forks.

Will update the bearing details here for future use. Here's just an example picture outside the lower bearing

UPPER
TH MR122 1 1/8" 36'x45' R9
41mm x 30,2mm x 6,5mm
TREK OEM-CODE W531676 11,99 EUR


BOTTOM
TH MR127 1,5" 36'x45' F9
45mm x 38mm x 6,5mm
TREK OEM-CODE W532843 13,99 EUR

 

[Josh1988bmx]

Hi did you find a size for these as removed my knock block abs want to use another brand headset? Thanks

 

[Hamina]

I updated the sizes to the first post.

I just relubed it went riding. The local Trek dealer was able to order them if needed but I'll change them later when I service the fork.

The problem here is, that the OEM front fork was Rockshox Gold 35RL and it has much more coverage for the lower bearing than my current Cane Creek Helm MK1 coil.

 

[Stanpipe]

I’m thinking of changing my fork to a non-OEM (Marz Bomber Z1 Coil). Does anyone know if there are any other headset options other than the FSA that Trek Spec’s?

 

[Tonycube]

Superstar components might have what you need

 

[coregrind]

Does anyone know if there are any other headset options other than the FSA that Trek Spec’s?

Cane Creek Hellbender 70 headset bearings (41mm & 52mm) can be used with the other stock headset parts if you’re just looking to upgrade that aspect of the system. Otherwise, I know Wolf Tooth Components produces a Knock Block specific upper headset that can be matched to their standard IS lower headset.

 

[JC-Cali]

Cane Creek Hellbender 70 headset bearings (41mm & 52mm) can be used with the other stock headset parts if you’re just looking to upgrade that aspect of the system. Otherwise, I know Wolf Tooth Components produces a Knock Block specific upper headset that can be matched to their standard IS lower headset.

Apologies (I am a future Rail owner), can the Rail head tube accept different sized bearings? I have not been able to find any info on head tube measurements and whether or not it uses bearing cups. Thanks in advanced for your help!

 

[coregrind]

Apologies (I am a future Rail owner), can the Rail head tube accept different sized bearings? I have not been able to find any info on head tube measurements and whether or not it uses bearing cups. Thanks in advanced for your help!

The headset is an IS-type (no cups) with the following bearing requirements:
Upper - OD 41mm 36° x 45°
Lower - OD 52mm 36° x 45°

 

[JC-Cali]

The headset is an IS-type (no cups) with the following bearing requirements:
Upper - OD 41mm 36° x 45°
Lower - OD 52mm 36° x 45°

Thanks!

 

[Doug Stampfer]

Would a normal bearing supplier carry these type of bearngs or are they mtb specific?

 

[T8COH]

Just as a heads up really the shop I purchased my bike from as part of the pre delivery inspection removed the head stock and greased it , he said all to common they come from the factory with not enough grease in the headstock and a few other pivot points etc.

 

[Peaky Rider]

Just as a heads up really the shop I purchased my bike from as part of the pre delivery inspection removed the head stock and greased it , he said all to common they come from the factory with not enough grease in the headstock and a few other pivot points etc.

Are these not sealed bearings?

 

[coregrind]

Are these not sealed bearings?

The stock headset bearings are not full sealed. A coat of grease when new, specifically on the ID of the bearing, keeps them fresh longer.

 

[Peaky Rider]

The stock headset bearings are not full sealed. A coat of grease when new, specifically on the ID of the bearing, keeps them fresh longer.

That's disappointing, I thought they might have been better quality than that.

 

[Doomanic]

Trek's, or head bearings in general?

 

[Peaky Rider]

Trek's, or head bearings in general?

If your question is aimed at my point then I was specifically thinking about Trek and wondering if they had bucked the trend.

 

[Doomanic]

If your question is aimed at my point

It was.

I was specifically thinking about Trek and wondering if they had bucked the trend.

No, they haven't. It's down to the type of bearing used.

 

[Philly G]

I checked my headset recently, they look like sealed bearings to me...a bit different to the frame bearings since they're angular contact, but still sealed...I use grease as a barrier to keep the water out. Bearings still felt smooth after 2 years of riding.

 

[Doug Stampfer]

Headset bearings suck. Having a bike with a munted headset bearing sucks. Having 3 guys in a bikeshop trying to find the part number for a headset bearing on a computer at 4pm on a Saturday sucks. Having to wait till Monday to order one knowing that there is probably one in the workshop if they'd let me have a look sucks.

I've had lots of trouble with the bars twisting after coming off & have tightened the stem bolts & topcap quite a few times. as well as that I've checked the top bearing a few times as the seal came off eary on.
What would munt the top bearing? What can go wrong with the install? For something so simple should I just get the bikeshop to fit it?

 

[Philly G]

That's extremely odd the seal came off your top bearing...no idea at all what could cause that...being an integrated headset the bearings just drop in, I then just slap some marine grease around to weather proof...the bearings used are a common headset size, (identical to those used on my 2017 Remedy, so I'm guessing Trek use them on lots of their bikes)...it's important to leave the stem bolts loose, torque the top cap then tighten the stem bolts, otherwise the bearings won't be preloaded correctly...otherwise not much to go wrong really

 

[Stihldog]

Maybe I missed it but is this the upper sealed bearing?

Most of our Rails (2020) came with the open bearing, upper only, and needs regular greasing.
Marine grease also seems like a good idea as a barrier to water ingress.

 

[Doug Stampfer]

Thats what mine looks like except in a million pieces. I found the broken seal when I took the headset off for painting. Mechanic said just keep grease in it & it'll be ok, which it was till it wasnt.
Not having a torque wrench I can only surmise that I overtorqued it.
I know there would have been a few bearings in the shop if they'd let me into their workshop. I wish they were $12 over here - I got quoted $47NZ

 

[Philly G]

Yes you must have overtorqued it, it's only 4nm on the top cap, just enough to preload the bearings...maybe time to invest in a small torque wrench?

 

[Doug Stampfer]

Yes you must have overtorqued it, it's only 4nm on the top cap, just enough to preload the bearings...maybe time to invest in a small torque wrench?

Only 4? I was trying to make out the markings which a re faded & thought 9NM. Good to know thanks. I'll prob get the shop to torque it up for me
The top ball bearings were all cracked in half. I carefully picked the seal off the bottom one & regreased. There was a bit of grit in there but running smooth now.

 

[RustyIron]

Not having a torque wrench I can only surmise that I overtorqued it.

Hey, Doug.
Don't beat yourself up. The preload on those bearings isn't super critical. Think how much leverage there is on the fork that is being transmitted into those tiny little imported bearings. Every time you bang that front tire into a rock, the bearings take a beating. It's a wonder they hold up as well as they do. The best we can do is to slop them up with grease to repel the water, and then service that area once or twice a year. Once the bearings start getting grumbly, it's time to start shopping for replacements.

 

[coregrind]

I checked my headset recently, they look like sealed bearings to me...

There is a seal but the stock bearing is not totally sealed.

In the pic below, the individual balls are just slightly visible.

This is why I suggest packing grease into the ID of each bearing. Or, replace the bearings with something like Cane Creek Hellbender.

 

[Philly G]

There is a seal but the stock bearing is not totally sealed.

Yes you're right, there is a small gap, and the balls are visible. Packing with grease definitely does a good job of protecting them though.

 

[NETTA17]

After 1200km and mainly stored and washed outside the headset bearings of my Trek Rail has come to an almost end. The lower bearing doesn't seem to have any protection from weather. When I bought the bike I opened all bearings and filled them good quality grease.

I think I'll clean the headset bearings and put new grease when I service the front forks.

Will update the bearing details here for future use. Here's just an example picture outside the lower bearing

UPPER
TH MR122 1 1/8" 36'x45' R9
41mm x 30,2mm x 6,5mm
TREK OEM-CODE W531676 11,99 EUR


BOTTOM
TH MR127 1,5" 36'x45' F9
45mm x 38mm x 6,5mm
TREK OEM-CODE W532843 13,99 EUR


View attachment 46358

Hey, even if it's an old thread....
Which

Does Crown Race & Compression ring go with those bearings?​

Cheers!

 

[paquo]

i was thinking of switching out my fork and i looked everywhere for a 1.5 crown race with no luck