[WR304]

In the Cotswolds (South West England) it's usually possible to ride outdoors year round. There may be a few days or weeks with some snow and ice but they're a rarity. Winter here is mostly just cold (slightly above freezing 0c to +5c), wet and very muddy.

I had an odd one on Sunday's ride. The bike was fine when I set off, I did a 4 hour ride only when I got home there was a load of free side to side play in the rear triangle. The back of the bike was waggling all over the place. When I checked the bolts the 10mm allen key main rear suspension pivot bolt had worked loose, which is where the play was coming from.

I tightened the suspension pivot bolt back up, and it seems to be ok again. What I'm still trying to work out is why the pivot bolt would choose that particular ride to come loose after a year of riding, rather than one of the previous rides.

 

[Lahrs]

Raw carbon finish now available, 80-100 grams lighter! Looks fast.

Orbea Launches Raw Carbon Frame Finish on Select Models

Introducing the new Carbon Raw finish, available for Orbea’s most exclusive models. Now when you design your new Oiz, Alma, Orca OMX or Rise, you can choose the lightest and most dramatic finish. Have you ever given carbon a close-up look? The...

m.vitalmtb.com

 

[WR304]

Raw carbon finish now available, 80-100 grams lighter! Looks fast.

Orbea Launches Raw Carbon Frame Finish on Select Models

Introducing the new Carbon Raw finish, available for Orbea’s most exclusive models. Now when you design your new Oiz, Alma, Orca OMX or Rise, you can choose the lightest and most dramatic finish. Have you ever given carbon a close-up look? The...

m.vitalmtb.com

The new 2021 Orbea Oiz OMX carbon frameset is claimed to be 250 grams lighter than the previous 2020 Orbea Oiz OMR carbon frameset. If you opted for the raw carbon finish as well to save an additional 80 grams that would be a weight saving of 330 grams over a 2020 Orbea Oiz OMR carbon frameset. That is quite a big saving.

On the Orbea MyO configurator you can choose the raw carbon frame finish with your choice of lettering colour also, not just the gold that's in the pictures. I'm writing this 30 December 2020 and the listed UK delivery date for an Orbea Oiz is 02 August 2021.

The potential drawback of a raw carbon frame is that the bare carbon fibre is visible under the clear coat and every bike is unique. You don't know what it's going to be like until it arrives.

If they're finished carefully raw carbon can look good but they can also look patchy and uneven, which would be hidden on a painted frame. eg: pictures of a 2018 Specialized Stumpjumper here

2018 Expert Stumpjumper - "Raw carbon&quot...

Hello all. I just got my first mountain bike, a 2018 Expert Stumpjumper: https://www.specialized.com/us/en/men/bikes/mountain/stumpjumperexpert296fattie/128892 It is the "Satin Silver Tint Carbon/Black" variety. I stopped by the store after I was called telling me that it was in and would...

www.mtbr.com

2018 Specialized Stumpjumper raw carbon picture for illustration of what this could look like. This picture is NOT of a raw carbon Orbea Oiz frame.

 

[dundundata]

looks cool, and the black and gold are the colors on my occam. i'm wondering if the paint helps protect the carbon at all? and what would the carbon look like with frame protection?

 

[WR304]

looks cool, and the black and gold are the colors on my occam. i'm wondering if the paint helps protect the carbon at all? and what would the carbon look like with frame protection?

A raw look carbon fibre frame like this Orbea MyO option isn't completely unpainted. It has a UV resistant clear coat lacquer (the matte or gloss option in the MyO configurator) applied to protect it from sunlight. The raw look carbon fibre frame should last as long as a painted carbon fibre frame would.

Apparently it's the epoxy resin that binds the frame together that can be degraded over time by UV rays. Over time when exposed to UV light the epoxy resin degrades and turns into a chalky layer that can fall off if it doesn't have a protective coating. Even without a protective coating this degradation can take many years to occur.

CST Composites | How To Care For Your Carbon Fibre Products

www.cstcomposites.com

.

 

[dundundata]

good info, I would probably go for it with the gold logo, though their paint looks really good too, and so many choices on MyO...but since I like black anyway

 

[WR304]

I had an odd one on Sunday's ride. The bike was fine when I set off, I did a 4 hour ride only when I got home there was a load of free side to side play in the rear triangle. The back of the bike was waggling all over the place. When I checked the bolts the 10mm allen key main rear suspension pivot bolt had worked loose, which is where the play was coming from.

I tightened the suspension pivot bolt back up, and it seems to be ok again. What I'm still trying to work out is why the pivot bolt would choose that particular ride to come loose after a year of riding, rather than one of the previous rides.

The weather was grim so I spent most of last week on the turbo trainer. I did finally get out for an outdoors ride on Sunday though. By the end of the ride the main rear suspension pivot bolt had come loose again.

This diagram shows how the 2020 Orbea Oiz main pivot goes together. Part 1 is the pivot bolt and Parts 4 are the two pivot bearings that the rear suspension rotates on.

This picture shows the main pivot bolt (Part 1 in the diagram) from my bike.

After snapping that lower shock bolt previously I was concerned that I might have snapped this bolt too or stripped the threads for it to be coming undone. The bolt doesn't appear to cracked and the end threads that fasten the bolt into the swingarm look ok.

This is a close up of the drive side end of the bolt. The red line shows where the drive side bearing sits when installed. Rather than sitting on the solid metal portion of the bolt the drive side bearing sits on the aluminium threads instead. Over the course of a years riding the threads underneath the bearing have been worn and ground down so that there is no longer a good fit between the bearing and pivot bolt on that side resulting in free play.

In the same picture there's visible wear of the anodising inboard of the axle. What I think has happened is that as the pivot bolt has gradually worn down underneath the bearing the free play has increased until the slop was so much the pivot bolt has begun binding on the edge of the frame or the spacer inside, which has then caused the bolt to come loose over the last few rides.

The fix looks to be a new pivot bolt and new bearings. Whether I can actually get hold of a replacement Orbea pivot bolt is the big question!

 

[WR304]

I took the bike fully apart today to look at the state of the bearings and swingarm threads. I've attached some additional photos showing the fully disassembled drive side bearing and threads of my 2020 Orbea Oiz.

The rear view picture shows that when the main pivot bolt is fully tightened the drive side bearing sits on the threads of the pivot bolt, rather than on the solid metal part of the pivot bolt. There is no spacer on that side. With the bolt installed all the wear on the anodising is at the bottom of the bolt.

The drive side bearing is gritty but not completely seized with the swingarm removed. The non drive side bearing is also a bit gritty but in better condition than the drive side bearing. When assembled with the swingarm in place and the worn pivot bolt it looks like there is a lot of slop exerting uneven pressure on the bearing however. When riding it would most likely be seizing up fully as the swingarm twisted to the side.

The threads into the swingarm aren't great but aren't completely stripped as once cleaned out the bolt would thread back in. The threads are worst at the bottom of the swingarm where it has been sitting at an angle instead of square with the drive side bearing. It looks like the swingarm has been rubbing on the frame/ edge of the bearing.

 

[Daniel Thomas]

😱 How is that possible? I can't imagine how it is possible to make such a huge design flaw, and take it to full-scale production! That looks like the bolt was made for a different bike. 😖 I can take mine apart and check it out. Doesn't say anything about thread locker in the blue paper. Did you use any?

Now for something positive, I did some base miles on the Oiz yesterday. It was a bit weird riding a full-suspension bike with Mazza tires on a paved cycling route. The new shifting is great! Super smooth and requiring much less force than before.

 

[dundundata]

Do you have all these parts?

 

[WR304]

Do you have all these parts?

Yes, the main suspension pivot assembly was complete with all the parts. I'd never actually taken that main pivot assembly apart from new until I began having these recent issues. It was only the last few rides where the bolt was coming loose whilst riding. You can see what I think is the remnants of the thread locker (the white residue in the close up bolt pictures above) that Orbea used in their original factory build on that bolt.

The bike is getting a new set of pivot bearings and main pivot axle under warranty, hopefully next week.

 

[Daniel Thomas]

Good news! Please keep us updated when you get the new bolt!

 

[WR304]

There's still no news on when my Orbea Oiz will be working again. I suspect it's going to need a custom bolt making, as with when I broke the lower shock mount bolt.

I did have an Orbea Rise ebike demo to try for a bit so haven't been stuck completely on the turbo trainer.

The Orbea Rise is basically an Orbea Occam full suspension trail bike with a Shimano EP8 RS motor added. I really liked the mountain bike aspects of the bike - handling, suspension etc but the Shimano EP8 RS motor doesn't work for me at all. Because I pedal with my right leg and can only add a minimal amount of force with my left leg, somewhere around a 95% Right leg / 5% Left leg split with the left leg out of phase, that pedalling imbalance was tricking the torque sensors of the motor. Instead of a smooth pedal assist throughout each pedal stroke imagine a misfiring car with stuttering power coming and go midway through each pedal stroke. It wasn't quite pogoing up and down but not far off!

It was actually smooth pedalling purely on the right leg with the left leg off the pedal, or with the motor turned off, but my normal pedal style doesn't work at all. That's purely down to how I pedal. Anyone pedalling the bike with two equally working legs wouldn't have a problem.

The motor has an internal clutch so it was also super noisy and rattly, particularly when freewheeling. It sounded like a handful of bolts were rattling loose in the frame. It's a known issue with the Shimano EP8 motor apparently. Compared to that Specialized Turbo Levo SL I had to try last year this bike was more powerful (not always a good thing) but that torque sensor response to my uneven pedalling style makes it not an option.

From an Orbea Oiz point of view what was interesting about this bike if you look at the picture above is that it has my DT Swiss XRC1200 carbon front wheel / Specialized Ground Control tyre and XTR RT-MT900 180mm rotor fitted from my Orbea Oiz. The Shimano Deore XT M8120 4 piston brakes are also the same as I have on my Orbea Oiz. I couldn't fit the DT Swiss XRC1200 rear wheel as the rotor sizes were mismatched. The original front wheel of the Orbea Rise appeared to be made of lead so I put the XRC1200 wheel on to lighten it a bit.

The front fork on the Orbea Rise is a 150mm travel Fox 36 fork whilst I've got a 100mm travel Fox Stepcast 32 fork on my Orbea Oiz. With the same front wheel and same brake it gives a fairly direct comparison between the two. What was very noticeable was just how much more composed, particularly under heavy braking, the front end of the Orbea Rise was with the heavier duty Fox 36 fork on there. It wasn't even close. I think there must be a ton of flex in the lightweight Fox Stepcast 32 fork, making more of a difference to the bike's handling than perhaps I'd appreciated.

 

[Rasmazzer]

I have to replace the two bearings in the headset of my OIZ OMR 2020 frame. I've ordered new bearings from the Orbea website and they will arrive today.
I was wondering what product you should use when installing the bearings into the carbon frame. Do you put the sealed bearings dry into the frame or add some grease or anti-seize or some kind of assembly paste between carbon frame (the fitting in the head tube) and the bearing? It seems that there was a sort of black paste used between the old bearings and the frame. Maybe black assembly paste?

I'm planning to grease up the outside of the bearing when installed back into the frame before installing fork and stem to keep the moisture/dust out.
I'm just not sure what to use when installing the bearings itself into the carbon frame. Too much contradictions when googling for a solution.

tx.

 

[Rasmazzer]

Another question about the bottom bracket and crank. I've removed the crank arm (Standard Shimano M8000 XT crank that comes with the M10TR). The Bottom bracket is the standard Shimano BB-MT800-p that comes with the M10 TR.
Between the crank and the bottom bracket are these plastic rings (spacers?) like in these pictures below. I can't find any reference to those spacers and why they are used?

 

[dundundata]

The ebike is pretty sick, suppose I could strap a motor onto the Occam, but I'll keep the electric for commuting.

You might prefer something with a cadence sensor.

 

[WR304]

I have to replace the two bearings in the headset of my OIZ OMR 2020 frame. I've ordered new bearings from the Orbea website and they will arrive today.
I was wondering what product you should use when installing the bearings into the carbon frame. Do you put the sealed bearings dry into the frame or add some grease or anti-seize or some kind of assembly paste between carbon frame (the fitting in the head tube) and the bearing? It seems that there was a sort of black paste used between the old bearings and the frame. Maybe black assembly paste?

I'm planning to grease up the outside of the bearing when installed back into the frame before installing fork and stem to keep the moisture/dust out.
I'm just not sure what to use when installing the bearings itself into the carbon frame. Too much contradictions when googling for a solution.

tx.

What I do with headset bearings is to use the heaviest duty marine grease I can find and cover the entire bearing, the carbon frame bearing seats and fork crown where the bearings come into contact. If you don't grease the part of the bearing that goes next to the carbon frame the bearing will go rusty there so the whole thing needs covering really.

With the current drop in design of headset bearings on mountain bikes there isn't much protection from water ingress, particularly for the lower headset bearing as there are no additional o-ring seals to keep water out of the lower headset bearing on a typical Fox or Rock Shox fork. They rely purely on the bearings seals and whatever grease you apply.

eg: Liqui Moly marine grease:

Liqui Moly P003656 Marine Boat Grease, 400 g: Amazon.co.uk: Car & Motorbike

Buy Liqui Moly P003656 Marine Boat Grease, 400 g at Amazon UK. Free delivery on eligible orders.

www.amazon.co.uk

 

[WR304]

Another question about the bottom bracket and crank. I've removed the crank arm (Standard Shimano M8000 XT crank that comes with the M10TR). The Bottom bracket is the standard Shimano BB-MT800-p that comes with the M10 TR.
Between the crank and the bottom bracket are these plastic rings (spacers?) like in these pictures below. I can't find any reference to those spacers and why they are used?

A Shimano BB-MT800-P bottom bracket has a press fit cup, a bearing and then there is a plastic sleeve that pushes in on either side and sits flush to cover the bearing as a protective seal.

It looks to me like your picture is the back of those plastic sleeves that would normally sit flush? There shouldn't need to be additional spacers in there when using a Shimano bottom bracket and Shimano crank together.

 

[Rasmazzer]

Those sleeves you mention are still there in the bottom bracket. They are marked with the text “do not disassemble”.
The pictures are from other kind of spacer/seal between crank and BB. Maybe the LBS put them there...

 

[WR304]

Those sleeves you mention are still there in the bottom bracket. They are marked with the text “do not disassemble”.
The pictures are from other kind of spacer/seal between crank and BB. Maybe the LBS put them there...

If you look on the Shimano crank arms the version type should be printed onto it on the inside next to the pedal hole.

I went and had a look in my garage at a new boxed Shimano Deore XT M8100 crank and it doesn't come with those spacers. The Shimano bottom bracket doesn't come with those spacers either.

There are a few different versions of the Shimano Deore XT crank arms with different q factors. The M8100 being the narrower version 172mm q factor, 52mm chainline and M8120 being the wider version 178mm q factor, 55mm chainline. The M8100 doesn't have spacers but I'm wondering if the M8120 might have a longer axle and then spacers added on each side to achieve that 6mm wider q factor? That could explain why your crank has spacers on perhaps if it's the wider M8120 version.

Shimano XT 12-Speed Cranksets

Reviews, ratings, specifications, weight, price and more for the Shimano XT 12-Speed Cranksets

www.vitalmtb.com

I don't have an M8120 crank on hand to check for sure.