I don't think repairing the bend is a good idea, for two reasons:

1. at that point, where the handlebar clamp is tightened, it is not possible to add additional layers of carbon to strengthen the part, due to the required diameter.
2. the total cost of the repair, added to the shipping costs, would certainly be too high compared to the value of the component.

That said, I must also say, in all honesty, that I have carried out several repairs of this kind for people in my area, but in their case the damage was always fairly minor and, as they did not have to pay shipping costs, the cost of the repair was cheaper for them than buying a new part.

None of the frames I have modified so far were like this one, so I can't give you a definite answer, but I don't think the fork will work. The best thing would be to try it with a 27.5 wheel to see how much space there is between the tire and the fork crown. I would recommend doing the same for the rear wheel.

If you don't have a 27.5 wheel available to do these tests, there is a very empirical method you can use: measure the space between the dropouts and the 26 tire, both front and rear. If the space is greater than 2 cm, it is likely that 27.5 wheels can be fitted without any problems; if not, then obviously not.

However, this method is not 100% reliable, as it is important to remember that a lot also depends on the type of tire you choose to fit.

Yes, it is possible. The first thing to do is to build a cylindrical sleeve on a lathe with a diameter slightly smaller than the outer ring of the bearing. For example, in the case of a bearing with a nominal outer diameter of 42 mm, the diameter of our sleeve must be 41.900 mm.

The sleeve, suitably treated with release agents (to prevent carbon from sticking to it permanently), is then coated with carbon fiber. Next, after degreasing and treating the worn bottom bracket shell to promote bonding, we insert our carbon fiber-coated sleeve.

Everything is then mounted on the template to ensure the correct alignment of the sleeve with respect to the frame; once this is done, we move on to the composite hardening phase, placing the frame in the oven at the appropriate temperature.

At the end of the curing phase (composite catalysis), the sleeve is removed, the reconstructed surfaces are checked to ensure they are perfect, and the part is painted if necessary.

These are, obviously in summary form, the steps necessary to reconstruct the carbon fiber housing of the bottom bracket bearings.

Steel is one of the most workable materials in nature; it can be welded, bent, and straightened, so technically repair is possible, except in extreme cases.

That said, however, the cost-effectiveness of this type of repair must be assessed, bearing in mind that the market value of a steel frame is not high. If the damage is severe, and this seems to be the case, given that the frame in question is bent in several places, repairing it will probably not be cost-effective.

At this point, however, the owner's personal assessment comes into play, as high sentimental value may justify even a costly repair.

Of course it's possible! In fact, this is one of the easiest frames to work on, as it doesn't require any radical modifications. All you need to do is move the crossbar that connects the upper or lower chainstays (depending on the model), leaving enough space for the wheel to pass through.

On the latest 26-inch Scalpel model, for example, you need to move the crossbar of the upper chainstays by about 1 cm, whereas on the previous model you need to work on the lower one.

Just this month, I made three modifications of this kind, also working on the upper shock absorber bushings: I created new ones with an offset hole in order to recover, at least in part, the increase in ground clearance of the bottom bracket that the installation of 650 B wheels inevitably entails (+1.5 cm). As for the Lefty fork, no modification is necessary, but it is a good idea to check it beforehand by deflating it completely to make sure that, at the end of its travel, the wheel does not touch the lower plate of the fork.

Converting a 26-inch bike to a 27.5-inch bike can sometimes be quite expensive, especially in a case like this, where the old fork has to be replaced with a new one and significant structural changes have to be made to the frame to accommodate the new wheel size.

If it were a front bike, it would be easier to modify, but this bike is a full bike and to mount the new wheels it would be necessary to work on the rear dropouts, remaking them from scratch to make them longer. It goes without saying that the amount of work required would involve considerable expense, which in this specific case I would not be willing to undertake.

Currently, the bikes that can be most easily converted from 26 to 27.5 are the Cannondale models, both the Flash hardtail and the Scalpel full suspension.

My advice for this Nuzzi steel bike is not to make any changes.

Theoretically and technically, the intervention is possible.

In this specific case, unfortunately, it is not worth the effort, because the modification does not seem to be minor.

It would be necessary to rebuild the saddle from scratch, with the same geometry, and, since there is no specific mold available, a new one would have to be created. Since it would only be used for one saddle and not for mass production, it is not economically viable.

I regularly lengthen fork tubes, but not by more than 3 cm, so that the stem collar, once mounted on the bike, hooks at least partially onto the original tube.

With a 5-6 cm extension, this would not happen, and all the bending and twisting forces would be transferred entirely to the rebuilt part. This is not advisable, as this is a critical area of the bike where you cannot run the risk of causing a break, however remote the possibility may be.

My opinion, therefore, is not to go for such a significant lengthening, because it is not worth the effort, either in economic terms or in terms of safety.

Since the damage is not so obvious, it is probably not very serious.

Even in the worst-case scenario, i.e., that the damage is not limited to the paintwork but also affects the carbon fibers, it is likely to be easily repaired at a modest cost compared to the cost of the frame.

An ultrasound inspection is feasible, but it is quite expensive (more than the repair itself). In reality, a good diagnosis can be made with good photos of the damaged area, taken from different angles.

The carbon rim of a wheel can be repaired, but it presents more problems than the frame.
This is not due to the carbon fiber itself, of course, but rather to the type of stress that the rim undergoes, which is totally different from the torsion that the frame is subjected to.

Going into detail, let's take the classic case of a carbon rim with a crack, whether caused by a pothole, a fall, or any other event.
From a technical point of view, repair is possible, provided that the rim itself is not deformed.
The tension of the spokes subjects the rim to continuous traction and, if the crack is too extensive, this traction leads to deformation of the rim.
In order to carry out the repair, at this point, the rim would have to be removed, but the cost of the repair would probably be too high compared to the value of the wheel.

Another type of damage that carbon rims frequently suffer is wear on the braking surface, caused by prolonged use of the brakes in adverse conditions (rain, mud).

Unfortunately, in this case too, the diagnosis is negative: repair is impossible.

Another interesting case, given the value of the wheel in question, is the possibility of repairing the spokes of Lightweight wheels, which are made of carbon like the rim and permanently glued to it.

It was always considered impossible to repair them, so once broken, a €3,000 wheel had to be thrown away. This belief was based on the idea that it was not possible to re-tension the spokes once they had been repaired.

This idea was wrong; re-tensioning is possible, you just had to find a way to do it.

However, the repair process is quite long and complex: first, the damaged spokes must be remade in a mold, then glued to the hub, tensioned, and finally glued to the rim. In order to perform the second part of the process, i.e., gluing the spokes to the hub, it is necessary to destroy the carbon hub cap that normally covers them and build a new one.

It can be concluded that repairing carbon rims and spokes is possible, but not in all cases, and that the extent of the damage, the value of the wheel, and the cost of repair must be assessed. If the cost exceeds 10% of the price of the wheel, it may not be worth it.

In this case, as with frames, the more expensive the wheel, the more cost-effective the repair.