Fast and long

A bit of an aside, but yesterday I was working on the other side of the project - my legs! Went for lactate and respiratory gas testing. I only have some of the data back so far, but its good news (for me); I can go faster and longer than last year! :-)
FTP is down, but I don't give a monkey's - I'm much more interested in what I can do for 8-24h, and how I might need to fuel that (which then has a bearing on what I need to attach to the bike).

How about this as a response to my request to the manufacturer?!
Perhaps this is the issue with buying direct from China. You wouldn't get this if you went to your local shop, but I've not done that. I can fix this; but its just not right, and if anyone else is thinking of going this route, be ready!

So, my solution is probably to mount the stem and spacer to an old bit of steerer tube and drill all the way through the spacer and just into the stem by 2mm, then put in a new bit of dowel. If I just try to measure and drill for the existing dowels, I am not 100% confident I can be accurate.

Today is also the day to cut the steerer tube, I guess. Gulp. I'll remeasure, but I'm sure that 50mm drop from saddle to bars is OK; if anything, I need to go down 10 or 20mm.

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Gosh. Could you put a dab of white out on the spacer nubs and just touch em to to stem to mark?

Dear me, I am procrastinating badly due to a few things, which I'll try to explain...
First-up, marking the stem to drill the two small holes is a pain. I tried @Yemble's trick, but its not easy to do it cleanly. I tried again with marker pen and masking tape. Its a little better. But even on a mini pillar drill, I am not 100% confident I can drill these so there is no slop.

Next up is the real issue; having mounted the bars I need to figure how to add aerobars. Any suggestions welcome?!

I have lined up three different bars - Toseek on the left, the SPCycle that came with the frame in the centre, and a separate bar and stem on the right. Each of these has aero-profile bars on top. None really plays nicely with aerobars. I am nervous about drilling bars, having tried this once before and it not ending well. So, to mount aerobars, I either have to make something that clamps onto the bars or the stem. Or something else??

I do have these 3T Team clip-ons which have a really slim clamp, like 13mm. They nearly go onto the 3T Aeronova bars either side of the stem. I'd still need to shave a bit off the stem/clamp to make it work, but its nearly there. Or I could just go with a round bar. But that's no fun!!

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Gotta say I had a chuckle reading their email. Nice blend of honesty, oooops, and matter of fact. Big fan.

After a big gulp of confidence, I drilled the stem yesterday. It worked OK, and the bars are now in place; next: Cutting the steerer.

I couldn't resist sticking some wheels on today. Tyres are Conti Gatorskins in 32mm flavour, on Mavic Open Pro rims. There is only 4mm above the tyre both front and rear, but a lot more clearance around the sides. So, a 32mm on a wide rim would be a good option.

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That's good news!

This week's delay is procrastination over the handlebars.

As I said up-front, the bike will run aerobars. Not having them isn't an option. The internal cable routing in the bars (I guess with most bars these days, whether they are integrated bars/stem or separate bars but with an aero profile) means the cables and hoses are also inside the bar, which means changing bars is just not realistic.

So, I need to commit to a bar, and make this work. And now the SPCycle bars that came with the frame are drilled and test-fitted, it makes sense to use them. The big problem is how to fit an aerobar?

I've been kicking around a load of ideas - making up some custom aluminium clamps, adding some threaded inserts, drilling the bars versus epoxying or laminating onto the bars... the permutations are driving me nuts!

After chewing on this for a week, the solution I think I'm going with is to fill the hollow section of the inside of the bar (underneath the channel for the cables) with epoxy/chopped carbon, which will add some weight but also increase strength. Then I'll drill through and insert 3 or 4 stainless M5 threaded fixings, and epoxy these in place.

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Things like this exist but are pretty expensive

https://www.giant-bicycles.com/us/contact-aero-clip-on-clamps-for-contact-slr-aero-handlebars

Not sure if you're set on full size aerobars (do we know if they're allowed yet?), but Controltech makes some stem mounted ones, with square stem shapes.

https://www.controltechbikes.com/products/item/417.html
https://www.controltechbikes.com/products/item/383.html

Cheers, @Georghe That's kinda what I was thinking about, but there is a big risk that the bars I have are not quite the same shape as the Giant bars, and I've wasted £200! But I could make something pretty similar, I think.
I wonder if Giant have reinforced their bars for these to work?

Thanks, @barry - interesting! Again, I think I would need to custom-make the clamp, as ControlTech say this only works with their own stem. But it does show the concept works!

I think that full-size aerobars are permitted this year, and I'm taking the risk on that. I have used mini bars before and they're very uncomfortable for me.

The point of the aerobars isn't so much the aero as much as the comfort. I think this is sometimes not understood by the organisers. A full aerobar with decent side and rear support allows me to take all the weight off my wrists and palms and spread it over my elbows/forearms with comfort.

At PBP last time, without aerobars, I lost all feeling in my little and ring fingers, both hands, and the numbness was getting worse. It was only a matter of time before I couldn't use my hands - bit worrying!!

I'd say if you are thinking of drilling bars or fabricating a custom mount for extensions, then why not buy some bars that are designed for mounting armrests and remove the worry of losing your teeth at some point?

OK, here's a few cardboard templates of what it could look like. The first one would be two pieces of 3mm carbon (which is pretty strong) top and bottom to sandwich the bar, with fixings between. I'd fill the gaps with wet layup carbon, which is time consuming. My issue with this is its pretty chunky and it would potentially take a long time to get the wet layup looking nice. On the plus-side, I could mount the bars now and make some progress towards actually having a rideable bike whilst I muck about with the carbon. Building the aerobars wouldn't stop me building the rest of the bike. I don't think...
Plus I don't have to drill holes in the bars

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The alternative is to drill the bars and inset three stainless fixings, then screw the aerobars to these. Its neater, I guess. It'd look like a factory job. But I would want (need?) to fill the inside of the bars near to the fixings with epoxy/chopped carbon to make sure I didn't compromise the strength. So, I would need to do some work before I could mount the bars onto the bike...

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I'd say if you are thinking of drilling bars or fabricating a custom mount for extensions, then why not buy some bars that are designed for mounting armrests and remove the worry of losing your teeth at some point?

I agree - this is the alternative, I can run a standard stem and bar with clip-ons, exactly as I am on the red Trek TTX. In fact, I could just take the front end off that bike, which would mean I have to find another turbo slave, but I do have a tried and tested solution.

There is still some customisation required: I'd have to find a way to deal with the cable routing, which means making some sort of custom headset spacer top cap that mates the headset spacers supplied with this frame to a standard stem. But that's possible.

Also, going this route looses some of the aero benefits, maybe, but it would mean I could alter the fit much more easily by swapping stems.

Could you measure your bars against the sizes of the ControlTech stem before you start drilling? I'm sure it will work infinitely better if it's close, even with shimming.

I fully understand the aerobars being there for comfort, but I'd be very wary of compromising the carbon layup in probably the flexiest part of the bar.

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I'd be very wary of compromising the carbon layup in probably the flexiest part of the bar.

@barry - I agree, its the most worrying bit. I did drill some aluminium Cinelli Crit bars once and it didn't end well. I have no way of calculating the loss of strength/likelihood of fracture. Its an educated guess... Not very attractive!
Then again, I have taken bigger risks before with bits of carbon, and its gone well.

Could you measure your bars against the sizes of the ControlTech stem before you start drilling? I'm sure it will work infinitely better if it's close, even with shimming.

@barry - I agree with the concept (and by the way, thanks for finding those drawings!), but there is a lot of customisation in this; the biggest issue is that the SPCycle stem is slightly tapered back to front, and is 41mm wide (so much larger than this cradle). I would 100% have to remake the cradle, as well as use different elbow pads and different extensions. But... its still probably the strongest concept. I wonder if I could make a cradle somehow...

I've enjoyed reading this thread, going to miss you when you've died after a catastrophic cockpit explosion.

I have another approach for you.
If you haven't slammed your steerer yet add ANOTHER short stem on top of the existing one, mount a stub handlebar whose only job is to attach the areobars you fancy.
This may look too rubbish on a fancy bike

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I've enjoyed reading this thread, going to miss you when you've died after a catastrophic cockpit explosion.

All in the name of science and entertainment!

add ANOTHER short stem on top of the existing one

@zephyr26 - I love it! Thanks to all who've made suggestions along the way, btw, I really appreciate it!
Sadly, I think I don't have enough steerer left to make this work. I think I have 20, maybe 25mm? I'll give it some thought, but I am not sure I can incorporate it into another idea. Hmmm.

All these ideas... I need to lie down and breathe slowly!

OK, so having re-read all the suggestions, and with @PhilDAS words in my head, I have come up with two designs. One is a removable two-piece with a cradle underneath (which I will have to mould) and a piece of 3mm carbon sheet on top. The carbon sheet you can buy is a lot better consolidated than I can achieve using wet layup, so I guess its a lot stronger.

The second design is a permanent fix: a smaller carbon sheet on top, and the whole lot wrapped to the stem using wet layup, sanded and painted. I should get better consolidation in this way, because there are no internal corners.

I have some fixings (they're stainless weld nuts). I have used these in the past for modifying cleat position on shoes; they are plenty strong.

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Hmmm. The order that the photos are dropping into the post isn't as intended. Anyways, I am leaning towards the version shown in the middle picture, with the fixings shown roughly on top of the card.
I have no idea whether this is easy for you to visualise or not, so for clarity: I'll make the cardboard shape out of a sheet of pre-made 3mm or 5mm carbon fibre, I'll drill holes for the fixings and bond these fixings in, then I'll glue the sheet to the top of the bars, then I'll wrap the whole lot, bars, fixings and all in several layers of ~200g/spm carbon fibre cloth and epoxy (ie wet layup). Any holes or gaps I'll fill with an epoxy/chopped carbon mix (for strength). Then I'll sand the whole mess down and repaint matt black. I'll look just like it was meant to be there! (Yeah...)

I know absolutely nothing about working with carbon or what access to material, tooling etc you have, but this seems like a hell of a lot of work to attach some clip on aero bars?

I say go for it, just don't ride over any potholes, speed bumps etc