There’s some really interesting stuff on here! HexhamStu, have you thought about making hollow dropouts for frame builders? Personally, I’d be keen. GoPro mounts are another one I might have a go at, mine’s been sitting unused for a while but some different mounts could be fun.

Thanks very much Matt, I’ve just sent you an email.

I’m definitely going to try it out. Especially now this has just happened:

It’s a Newmad swingarm, I’ll hopefully know more when it arrives. It’s coming with both links as well, hopefully.
It’s exciting, and slightly daunting. Going to have to do some careful planning and drawing, and then start making the pivot mounts. I’ll check dimensions, but I think the lower link can sit between two plates brazed onto the BB shell, one of which can probably be threaded for ISCG mounts too. I’d quite like the shock mount to be stronger than just two plates brazed to the tube, I might think about whether it can be milled. Maybe two separate sides still, but with bigger footprints on the tube to spread the load.

Cheers Matt, I’ll have to talk myself into coughing up my 25 dollars! I think I’ve heard it mentioned before, it seems to be popular. Do you use it?
Just stumbled across this: http://ticycles.com/TCF/mountain-vpp.html
Interesting proof of concept, in addition to Sklar above (https://instagram.com/p/58Il79tjk0/?taken-by=sklarbikes). I’m surprised they seem to have worked out some sort of license! Anyway, need to find a suitable rear triangle before I can move on – I think I’ll probably stick to that plan, at least for the first (!) design.

Thanks Matt, that’s incredibly quick! I have a lot to learn… It would be nice to have the opportunity to try to get a step ahead of the direction the trends are heading, as you obviously were there. That was my reasoning around using an existing rear triangle, anyway – hopefully I’d still have room to play with the geometry at the front. I built my first 29er this summer, with the ‘long and slack’ thing (especially so since it is rigid) and I really like the way it feels. My 2009 Five feels very short and high in comparison.
I have a lathe, but I only have access to a milling machine during term time at university – I haven’t taken advantage of this yet! So I should definitely try to minimise the number of dedicated parts I might need to make.
Here’s (I think) the link if anyone’s interested: http://singletrackworld.com/forum/topic/so-steel-fs-bikes

Cheers Podge, I’ve replied.
There’s interesting potential in it, I wonder if it’s better to have bearings clamped in the linkages and axles brazed to tubes, or vice versa? I’ve seen a combination of both, but an axle would be much less likely to distort and you would have to interfere less with the tube, which I’m keen on.
Anyone know how difficult it would be to plot axle paths in Matlab? I’m not particularly capable at using it, but it would be fun to quantify what’s going on.

No worries, thanks a lot for your help

I was thinking that the diameter of a BB shell means I couldn’t braze/tig the pivot/bearing shell into a tube, I’d have to cut the tube and mitre onto the shell, meaning I’d have joints in areas that need to carry quite high bending moments. I’m sure you’re right though, I’m probably unnecessarily cautious about these things. The advent of dropper seat posts must be great news for pivot placement, because I’m sure it must be lighter and stronger to have a pivot axle crossing through the widest part of the tube.
The width could be problematic because you risk losing too much thread. I’ve not been particularly fast on any of the frames I’ve built, and I think I’d probably enjoy the excuse to play on the lathe making pivots and shells!

I’ve definitely heard of people using BBs as pivots, and it would be a good way to avoid having to deal with distortion. You then can’t use uninterrupted tubes though, which would be a potential compromise structurally (or weight-wise). You’re right though, single pivot is definitely the logical starting point! Of course, everyone likes to try to run before they can walk…

Cheers for that, I’d never heard of him but he’s built some great stuff. That was just what I had in mind, but equally a single pivot is probably a better place to start. I’d be interested to see it, cheers Podge.

Cambridge has the strongest team by BUCS points, but the cycling is flat and boring. We do general engineering until third year, which is arguably better than specialising immediately. Website.

Cheers though!

I’ve come to the conclusion that there’s a lot less magic to carbon than is advertised by the manufacturers. A mountain bike takes a bit of thumping, but I’ve been riding home-repaired Campags on my road bike for the last six months without any issues.

I’ve got a horrible feeling mine’s drive-side. I’ll check – thanks very much for the offer!

Ace, I’ve emailed you.

Slight hijack, but have any of you OneUp users still got the original cage kicking around? I’m after a medium one for an XT clutch mech, although I think there’s probably a fair bit of crossover between the models. Broke mine and running a slightly dodgy handmade replacement.

Sorry, I’ve only just caught up with the 5-10 bit. You’re right, I’d be aiming for 20-25 on the drive side which should leave the rest at at least 15.

As long as there isn’t masses of thread showing when the wheel is dished and tensioned reasonably well, you don’t need to worry about your spoke lengths. I assume the hub flanges must be fairly different diameters or something?

Oops

What do you mean by ‘tension it correctly’? The rim should be centred on the hub – you can easily check this to reasonable accuracy by putting it in the dropouts backwards and seeing if the rim is in a different place, if you don’t have a tool. The drive side spokes should be quite a lot tighter than the non-drive, and you should have quite a lot of leeway in spoke lengths to dish a wheel correctly.

That was pretty good, I reckon! The first thing that will buckle – ‘taco’ – is the braking surface, not the spokes. Assume pin-joints at the ends of the spokes and then in the proper direction they will tend to spread outwards, putting the surface in tension. The other way and the surface will go into compression and buckle, even though the spokes are in tension.
Hopefully that’s not a load of rubbish, I’m only a first year.
You can approximate as pin-joints fairly well as the ends of the spokes will take small moments relative to the other loads around, I think.

Cheap Superstar 10mm bolt-through, nice and non-creaky and won’t undo like a bolt-on.

Footflaps, I hadn’t actually considered companies around Cambridge. I’m hoping I can get back to the hills in the summer, but it would be an option to stay in Cambridge. Cheers Mike, they’re next on my list! Not bikes, but I think there’s some very interesting stuff goes on over there. I’ll see if they have any space.

Bump?

Thanks for the reply anyway. It’s quite tricky finding places, so I’ll bear it in mind. Cheers.

Oh right, what is it you do? Ideally I’m going to try to find somewhere I can reach from home, but I’ll certainly consider it. Thanks.

So incredibly flat…

I’ve been scouting Fleabay for some Salomon Rocker2s ever since my last holiday. Seem to get pretty good reviews. No-one else seems to be as short as me though…

Dunno, felt about right to be honest. Rolled the majority. I might move to 650B to get the right compromise between acceleration and rolling momentum though… ;)

I’ve got the Kris Holme video ‘into the thunder dragon’ about unicycling in Bhutan. It’s a 20″, I think. Maxxis Max Daddy tyre; seems to work pretty well.

Yeah, it was quite good actually. Deep snow. I’d usually be on my bike, but my Duke of Edinburgh group were going out and I find walking incredibly boring!

The Totems on the front were a very lucky afterthought. I’ve already tacoed one front rim!

It’s a 2002 (I think) Patriot swing-arm with a brazed steel front ‘triangle’. It’s a bit flexy, but it hasn’t broken yet. My friend was riding the back and he swore I was going in different directions to him. My dad built the frame.

I’ve only just seen your post Rich – I’m a bit sore, but taking that tape off was much more painful that the original impact!

She claimed she had her eyes shut. Then again, so did my dad!

They came off pretty unscathed from that tumble, if a little irritated by the guy in front (I don’t think it was deliberate on his part). Sister was chuffed with position as first junior girl!

He’s too shy to join in.

It’s my dad and my sister. Here’s some photos of it built up:
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Fives of Orange past and Orange present(ish):


I’ve always liked the raw finish, although I’m not so sure it was worth the immense effort of getting the paint off…

I’ve got a 9sp chain that I won at the Classic Weekender… ;)
It’s light and gold. I reckon it’ll wear out quite fast though.