Are carbon all mountain frames up to ebike use

[Binhill1]

Break anything without trying too hard . Amazing there's not a lot more breakages the things these bikes get put through.

 

[Mikerb]

Its all down to design, U tend to see lots of pictures of failures in Alloy frames around the welds either down to poor heat or fatigue around the welds. Carbon if done properly you shouldn't see fatigue failures that often. Hitting a tree in any material means your bikes fubar anyway.

Always look for lifetime frame warranties.

well the one in the photo is carbon (you can see the frayed fibres at the fracture) and looks like it snapped the downtube.

 

[Montana St Alum]

As I do all my own maintenance, what about the mounting points for head bearings, frame bearings and wheels?

If these are issues that you really are concerned about, you should get alloy for peace of mind. There's a whole lot of carbon frames out there that are doing just fine, they're not falling apart and they're sturdy, but there are always stories.

 

[Canyon Shawn]

As I do all my own maintenance, what about the mounting points for head bearings, frame bearings and wheels?

If you have this much paranoia and anxiety about a material that’s been used in the bicycle for over 30 years, you should definitely choose a different material. Perhaps steel is more your speed.

 

[maynard]

Have u got photos of these abused bikes? And I'll give my expert opinion

 

[Canyon Shawn]

Val di Sole Practice ... (Photo by Nathan Hughes)

View attachment 119389

Are you sure that’s not the new long and slack geometry?

 

[DS.]

You won’t get peace of mind from a alloy frame I’ve just cracked my Levo frame been waiting 3 weeks now and still haven’t had the bike back

 

[B1rdie]

As I do all my own maintenance, what about the mounting points for head bearings, frame bearings and wheels?

Did I hear headbearings??

This is how my 2014 stumpjumper looks. Just cosmectic I guess, will try to fill with putty someday

Bottom bracket looks ok, but the rear triangle would be looking worse if it wasn’t alloy…

 

[Montana St Alum]

You won’t get peace of mind from a alloy frame I’ve just cracked my Levo frame been waiting 3 weeks now and still haven’t had the bike back

I'd say just go for a walk, but there's always the danger of being run over by an E-biker! On a heavy alloy frame.

 

[Zimmerframe]

The good thing with carbon is that some minor blemishes can be fixed up, by those in the know, quite easily ..

Tour de-France today (Fabio Jakobsen) - ok, it's not an MTB .. but we often push our bikes beyond their intended use ..

 

[Binhill1]

The good thing with carbon is that some minor blemishes can be fixed up, by those in the know, quite easily ..

Tour de-France today (Fabio Jakobsen) - ok, it's not an MTB .. but we often push our bikes beyond their intended use ..

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Same as fiberglass then

 

[Plummet]

Carbon is me preferred frame material. Its lighter for the same strength or stronger for the same weight. Carbon ebikes are about 1.5 to 2kg lighter than their alloy equivalent.

Ss others have said design and quality control is everything, regardless of frame material.

You can gave strong and week carbon frames.

The enormous plus for me is that I can fix carbon myself in my garage with basic hand tools some know how and a bit of epoxy resin and carbon cloth.

You cant practically fix an alloy frame. Sure you can weld them back up but then you normalize the heat trearment by doing so and the frame keeps cracking.

 

[Ark]

if you fall and your frame bashes on a rock what would be just a bit of scratched paint on an alloy frame surely ends up much worse on a carbon? like a big crack.
yea you can fix your own carbon frame, it's not hard but unless you have an xray machine or whatever you don't know if its safe to repair it or not

 

[RiderOnTheStorm]

Here is a great video imo that recaps the Alloy vs Carbon frame pros & cons:
Answer to the OPs question: yes, definitely with some trade-offs, as with everything

 

[Plummet]

if you fall and your frame bashes on a rock what would be just a bit of scratched paint on an alloy frame surely ends up much worse on a carbon? like a big crack.
yea you can fix your own carbon frame, it's not hard but unless you have an xray machine or whatever you don't know if its safe to repair it or not

If you crash and scratch the paint on an alloy frame and subject the a carbon frame to the same crash and damage the same result will occur. A scratch. The type of damage that would delaminate a carbon frome will dent and damage an alloy frame. The other reality is that a carbon frame if designed and manufactured well will hold up to more abuse than the equivalent alloy frame. IE it will not fail where the alloy one will.

Regarding repairs. You do not need an xray to know that the repair is good. It is very easy to add more material and make the frame at that point stronger than what it was originally. Weight gain is minimal, The old failed structure is essentially used to hold the shape. The new carbon wrap provides the reinforcement. The key is to taper in and out of the repair to limit the creation of stress risers. If you look closely you can see that tapering in the repairs.

Here's some of my repairs. Zero Failures thus far. I broke the Rocky Mountain in 2019, fixed and have been riding it since as my send it machine off anything that I might brake a bike one. 4 years later and many many silly sends later its still going strong. No xray in site and not failure.

 

[Mikerb]

The primary difference between a carbon composite and aluminium is that aluminium can deform ( dent) whereas Carbon composite is brittle. A carbon composite can be made to be flexible ( fishing rod/windsurf mast etc) or stiff ( typically in a bicycle frame) but either way the composite does not deform/dent on impact. It may be strong enough to withstand the impact and that depends on the how the composite is constructed in terms of both materials used ( carbon,glass, kevlar etc) and the fibre layout ( unidirectional or matrix). For whatever element of the composite is carbon fibre ( not everything descibed as carbon is a 100% carbon composite!), the modulus of that fibre also influences impact resistance. The main issue with impact damage on a carbon composite is that any damage incurred is often invisible because the shock is tranferred through the composite layers often delaminating one or more underlying layer from the composite, or in some cases fracturing the fibres. That is why catostrophic failure is often the result of a previous impact that was either not known about or ignored because there was no surface damage.
A well designed bicycle frame constructed as a carbon composite should deliver the correct degree of both stiffness and flex reliably, but to be strong enough in key areas ( bottom bracket/headset and seat tube/top tube junction) it needs additional composite reinforcement, especially on a mountain bike, so ends up very little different in weight than a hydroformed ally frame. On a road bike it can be significantly lighter. It is incredibly difficult to construct a reliable rear triangle using a carbon composite because the forces it has to withstand are directionally too varied.
Given that hydoforming techniques for aluminium tubes can now vary wall thickness and tube shape so deliver both required stiffness and flex, it now competes very well with carbon designs and has the added benefit of being automated reducing but not totally eliminating the variability incurred with more hands on construction methods. The material and labour costs are less than a construction method using carbon composite.
Having spent many years ( and ££££s) using and breaking carbon composite components for windsurfing I know the care that needs to be taken both in terms of purchase choices and use!! Extreme lightweight and stiffness (boards and booms) and flex/fast reflex (masts) deliver tangible performance results for windsurfing but for MTB my money is on ally!!

 

[Binhill1]

I had a carbon paddle repair done that part is a lot thicker than the rest of the paddle. Guy who repaired it said it would be the strongest part of the paddle now. Top Scottish paddler Gordon Brown said I wouldn't trust my life with a repair. He's probably got twenty other paddles he can use though . So money will play a part as well with a lot of folk.

 

[JimmyBoy]

The type of repairs I was thinking about was replacing frame and head bearings, something which I do frequently.
I just replaced the main pivot bearing on my aluminium Canyon Spectral and had to use a number of heavy blows with a hammer on the blind bearing removal tool.
Would a carbon frame withstand this?
Or are the bearings fitted in a different way?

 

[Montana St Alum]

The type of repairs I was thinking about was replacing frame and head bearings, something which I do frequently.
I just replaced the main pivot bearing on my aluminium Canyon Spectral and had to use a number of heavy blows with a hammer on the blind bearing removal tool.
Would a carbon frame withstand this?
Or are the bearings fitted in a different way?

I hammer out my PF bottom bracket and then use a press to reinsert. The last time I had bearings replaced was at the LBS. People change bearings on carbon bikes all the time.

 

[Binhill1]

The type of repairs I was thinking about was replacing frame and head bearings, something which I do frequently.
I just replaced the main pivot bearing on my aluminium Canyon Spectral and had to use a number of heavy blows with a hammer on the blind bearing removal tool.
Would a carbon frame withstand this?
Or are the bearings fitted in

I hammer out my PF bottom bracket and then use a press to reinsert. This isn't rocket surgery! Or brain science. The last time I had bearings replaced was at the LBS. People change bearings on carbon bikes all the time.

Not everyday maintenance for a lot of people a headset . A lot of folk wouldn't have a press and lots of other really basic tools . No offence intended . A piece of wood is all I ever needed for a headset . Plenty of people couldn't or wouldn't be comfortable doing what is basic maintenance to a lot of people .

 

[Montana St Alum]

Not everyday maintenance for a lot of people a headset . A lot of folk wouldn't have a press and lots of other really basic tools . No offence intended . A piece of wood is all I ever needed for a headset . Plenty of people couldn't or wouldn't be comfortable doing what is basic maintenance to a lot of people .

No offense taken. The point is that this sort of maintenance is about the same on a carbon frame as on an alloy frame. Some carbon frames have threaded BB's as well (in the case of non-motorized mountain bikes). But bearing replacement is bearing replacement on either type of frame. You can build your own press out of readily available and cheap materials.

 

[Plummet]

The type of repairs I was thinking about was replacing frame and head bearings, something which I do frequently.
I just replaced the main pivot bearing on my aluminium Canyon Spectral and had to use a number of heavy blows with a hammer on the blind bearing removal tool.
Would a carbon frame withstand this?
Or are the bearings fitted in a different way?

My experience is that those bearing fits are easier to remove/install. There's less corrosion issues and they punch in and out nicely.

Do do have to watch that you dont slip and punch a punch directly into a carbon face. You can chip the face easily. I have done that before too.... but also fixed it up as readily.

You can use super glue and baking soda for small immediate repairs.

 

[Stihldog]

I think the next level of service, for me, is a small hydraulic press and a bearing puller kit, along with a few dyes for specific jobs (Bosch motor).

A hydraulic press needs to be small enough (for the job) and not take up too much garage space. Sometimes a single LBS service can justify or pay for these additional tools. As long as I have the ability, the will, and the time , I’ll add to my collection.

I wondered if the park tool wheel alignment/tensioning tool would ever get used by me, but it does. It’s already payed for itself and can be a bit therapeutic, with the right tunes playing (Disney, Dr Suess, Teletubby etc ).


It helps too if you’re retired and the Wife is very very understanding.

 

[steve_sordy]

I hammer out my PF bottom bracket and then use a press to reinsert. The last time I had bearings replaced was at the LBS. People change bearings on carbon bikes all the time.

I did an apprenticeship in mechanical engineering and one of the things I learned was that when it comes to hitting stuff with hammers, bigger is better! If you use a small hammer you have to hit the object really hard to get the same effect as using a big hammer striking gently. The bigger hammer used more slowly allows more control and you are less likely to mis-strike and hit something you shouldn't.

But be reasonable; don't try knocking out a bearing on a carbon frame with a 14lbs sledge hammer!

 

[Plummet]

But be reasonable; don't try knocking out a bearing on a carbon frame with a 14lbs sledge hammer!

Wheres the fun in being reasonable?

 

[Stihldog]

…so… I need a bigger hammer?

 

[Stihldog]

Kinda tough to decide but trust me…they all work.

 

[JimmyBoy]

I think the next level of service, for me, is a small hydraulic press and a bearing puller kit, along with a few dyes for specific jobs (Bosch motor).
It helps too if you’re retired and the Wife is very very understanding.

The trouble with a hydraulic press is that you need a range of driver tools and unless you have a lathe it gets even more expensive. I did think of making one from a car hydraulic jack.
I always felt that doing my own Maintenace was part of the fun and you keep on top of developing faults before they become a disaster or spoil a biking holiday.
My wife is also my riding buddy and I maintain her two bikes as well as my own two so she's on my side when I order new tools.
I can see this thread turning into "Show us your hammers".

 

[Stihldog]

I think @steve_sordy is right though. With the right technique and tool choice, most bearings can be removed. We’re not working on Swiss Watches here. A hydraulic press would be nice but it eats up shop space and most of us would only use it once in a while.

Regular maintenance is key, especially for suspensions.

Oh!…and I’m gonna go to a different site to talk about my hammer.

 

[Binhill1]

If you are too mechanical and maintenance oriented the paranoia can take over. You feel you need to carry this and that and need a 63 litre rucksack. I manage with me 30 ltr rucksack some basic tools , but stove and sandwiches and bus pass in case of emergency. Oh Vhf radio ,plb locator and bivi bag.