Them classic made out of aluminium tubes ones have proved not up to it on mtbs for me, specially when rigid.

Another vote for specialized zee (I have the basic carbon filled nylon models). Side-entry is inherently going to work better in bumpy situations, and easier for holding big bottles when frame space is tight.

I’ve seen a couple of Scott bikes with radial lacing and discs – the Speedster and Speedster CX. I’d always thought this was a bad idea too so interesting that they’ve gone this way.

The front lacing isn’t quite straight, pairs of spokes appear to cross at the hub flange. I think it is 1/2 cross – the hub flange holes are not staggered but level on each side, so there is a small amount of lead/trail. Strange.

Has anyone other then the guy in that Conti vid actually used the tyre-lever method? All the tyre/rim combinations I have tried (mainly Schwalbes, but a Maxxis and a Spesh as well) on Stans have been so tight on the rim that I really doubt I would get a tyre lever under the bead with the bead also seated on the opposite side. I guess it is a reason to buy Conti tyres if you can actually do that with them!

Electric motor obviously.

Umm, according to my model chain tension does generate squat or jack even on something like a G-spot (in any gear other than 1:1). Or to put it more generally, when the chainline is parallel to the (real or virtual) swingarm, chain tension has very little effect on the suspension, the more it deviates the more chain tension will move the suspension.

Also, I think drawing lines through the main links will get you to the height of the instant centre, it won’t necessarily tell you about the height of the pivot point of the virtual swingarm, which is what we are interested in.

Anyhow, if I got time I will try to represent my maths mark II on a pretty graph to show you.

Well I’ve done a bit more maths and in fact if you can lay your hands on a full suss with the pivot point (real or virtual) at the BB axle (Cove G-spot, anything else?), you will not notice any difference. The effect then varies with how high the pivot point is, so it would be big on Oranges etc.

You don’t have to do the maths…

Oh but I do, I do. Also, it is possible the effect is different (ie the difference you notice between bigger or smaller front chainrings) when running easy or hard gears at the back. I will have to resort to a computer for this I think.

Phew, I read this as “deaths on singlespeed” – I blame the varifocals.

No, the reason for the change in anti-squat is due to the change in the chain line force vector and its interaction with the line between axle and instant centre and how that moment balances the moments generated by the force vectors from the contact patch (driving force) and rider mass centre (inertial force).

You can simulate it in various packages or have a look at this blog;

http://linkagedesign.blogspot.co.uk
Yes I know that, it is what I am trying to do the maths of, but I can’t get to the same conclusion. Except when you say “instant centre” you are probably talking about what I would call “momentary virtual pivot point” (which is different).

[“Instant Center” (sic) is part of Tony Ellsworth’s theory about why his four-bar designs worked, and is basically wrong (though it didn’t stop him patenting it). Instant Centre is relevant to car suspension designs because in those, the wheel plane is at right angles to the suspension bars and you need to keep track of how the wheel angle to the vertical changes through the suspension travel because of the tyre contact patch etc.]

Something that hasn’t been mentioned is the effect of chain line (the important bit of chain line, in the vertical/longitudinal plane, rather than the lateral/longitudinal place) on full suspension bikes. With most designs the anti-squat and pedal kickback is vastly higher in the granny ring than the big ring – if it has a nice balance of bob resistance without losing too much traction through stiffening in the middle ring then it’ll bob too much in the big ring and stiffen too much in the granny.

Do you have the maths for that chief? I have had a quick go at it and the size of the front chainring seems to cancel out (in rough approximation territory). The reason the anti-squat is high in the granny is because the gear is lower. If you ditch the granny but put on a dinner-plate size first cog for your middle ring to achieve the same gear ratio, then the effect appears to be broadly the same for the same amount of pedal push.

I found in DH that if one was at the slow end of the field, one beat more of the masters than the vets on account of there being quite a few not so serious masters competitors, but fewer slow competitors in vets. I imagine this effect would be even more marked in grand vets (small field, but most of them quite quick) but I haven’t competed in that. I will be in super vet the season after next, but according to British Cycling that isn’t a DH category, so I will have to race XC (!).

I just don’t get it, what exactly are the benefits of 1x over 2x?

It’s not weight, it’s not price, it’s definately not chainline and it can’t be a chain retention thing?
For me it very much is a chain retention thing, in fact if chain retention wasn’t markedly better I would be sticking with 2x. The gear range with 1x is not quite enough for me, I am prepared to put up with needing an extra gear at each end because of better chain retention.

And here’s my 49er. That’s a cross tyre on the front, but it works with a mountain tyre as well.

Rides exactly like it looks…

Are there any technical regulations for the pacing vehicle? One could design a complex fairing that created tailwind around the bike, such that the vehicle towed the bike along. In which case, the record would be mainly about vehicle design. I imagine a rule along the lines of “daylight between the rear of the vehicle and the front of the bike” might well exist. But careful aerodynamic design might still result in a useful forward flow around the bike.

That is nice. If you are listening BETD – how about a Boost length axle?

You can get forks in a few axle-to-crown heights. If you pick a 420 mm a-c fork with a shallow crown, you can fit a reasonable sized 29er tyre in there (just) and a 27.5+ easy. 420 is old-style suspension corrected for 26″ and 80mm ish travel. On my Scapin (designed for 100mm travel I think) ^^ it still left the front end a wee bit high with a 29″ x 2.2 tyre in, but was a little low with a 26″. With the 27.5 x 2.8 the bb height is spot on (27.5+ is a little smaller rolling diameter than 29). Rigid 26″ forks are more commonly 440 mm now, which corrects for 100mm suspension. That might work well with a frame designed for 26″ wheels and 120mm travel forks.

That’s a 1 1/8 Exotic carbon fork there

ETA yet again, they do a range of heights, should be something there that works for many frames

I am running 27.5+/ 26 on the singlespeed, used to be 29/26.

I’d agree with all of that bright, ample history to support your final conclusion. I would add that consideration is also needed between mountain bikers with different interests. I like jumps and berms, I also like natural trails and some need to be left that way.

copa – I share your concerns.

I suspect the increase in the numbers of people riding, and what they like to ride, is a key driver here. My initial reaction to theraq’a “huge groups” was “what?” – but you are right, formal (almost club-like) groups are springing up all over and they do tend to form quite visible groups at weekends. I guess some people will be offended by the mere presence of large numbers of cyclists, not sure what can be done about that. If there is only two or three of you, you can say hello, exchange pleasantries about dogs/horses/the weather and generally chat people up. That’s not so practical in a large group.

Though the acidity of the pineapple juice would curdle it.

It would be more a coconut substitute in a pina colada.

Fortunately never had an explosion with tubeless-ready tyres and rims. In the old days of tubeless conversions and dodgy tyre/rim combinations it was a different matter altogether, put me off tubeless for a decade.

So not in the washing machine then….for the clothes

Guessing not. Latex is lots of long chains of protein molecules suspended in water. If you agitate it the chains get tangled together exactly like wool fibres in felt, making the liquid into a solid. Same happens if the liquid evaporates. But the solid rubber is then in the fibres of your clothes so never comes out.

Try rubbing the liquid in your fingers. This is why it works as sealant – as the air forces it through the hole in turbulence it forms solid rubber. So I would worry your washing machine would have the same effect before it could be washed out.
Shaking a bottle of sealant, or indeed neat craft latex, does not cause it to polymerize. Nor indeed does leaving it in a tyre and riding over bumpy trails. So there must be quite a high amount of shear needed before this happens. Alternatively, some evaporation is needed to get the concentraiton up before it happens. The finger-rubbing would result in a fast-evaporating thin film.

This is all a bit of a random. Cycling UK (formerly CTC) appeared to be getting involved in access rights when it partnered with a group calling itself OpenMTB[/url] to lobby on behalf of mtb-ing on the Welsh Government’s access consultation (now closed). They also launched a subsequent survey about access.

I have twice asked OpenMTB for information about who they are (apart from a bunch of logos) and if they have a constitution, but have not got a reply. So it is impossible to work out what their agenda is and who exactly they are representative of. Or even if they really exist at all.

Cycling UK does seem to have variable approach to matters off-road. Maybe the answer is for more off-road riders to join and try to get it to exercise a more consistent voice. (I am a member but I don’t get involved beyond that.)

ooo where’s this jump/gap thing? Been in the woods behind the pub a few times.

Diff to explain, and things change there (and I don’t go there that frequently). If you go in via the top of the lane next to the Maenllwyd and then climb up through the woods off to the left of the main track you will get to the general area I am thinking about.

I thought there was an informal agreement around The Warren and not building trails there? As per the article on STW.

Not that I can find a map showing which areas are OK and which aren’t.
If there was, it was very informal because the first time I heard of it was that news article. There is a fenced-off area of woodland along the West side of the bottom end of Caerau Lane looked after by the Caerphilly Woodlands Trust[/url]. It says

In April 2003, CWT became the sole and permanent owners of approximately 23 acres of woodland within ‘the Warren’. This consists of an area known locally as ‘the old clay pits’ and the surrounding woodland.

Cycling is not allowed there, it says so on signs (and there has been no trail building there). “The Warren” is a name on a map, I have no idea how far it extends. I am not inclined to pay for a Land Registry search to find out the extent of their 23 acres and if it coincides with the fenced area. But the fact that someone referred to a “voluntary agreement” suggests that the area where trails were dug up and Ron Davies was involved was not part of their 23 acres.

The Caerphilly Woodlands Trust is not connected with the national outfit calling itself the Woodland Trust[/url].

Ah yes, I see some stuff like that there

Which bit you talking about there coatesy?

You mean apart from when Schedule 7 of CROW act 2000 specifically amended S30 Countryside Act 1968 by amending paragraph (1) and adding paragraph (5) to permit them?

Or had you overlooked that?
Thanks ninners, dunno why that didn’t show up on the version of the CA I looked at, it shodl have been there. And indeed, is there when I look it up differently.

There is no case-law on rights of way for electric bikes, all we have is the rule that bicycles are allowed on bridleways as well as horses (Section 30 of the Countryside Act 1968), but cars and motor bikes aren’t. There is statutory law about riding electric bikes on the road, which has the effect that some electric bikes are not subject to the same rules as motorbikes but some are. That doesn’t necessarily alter rights of way, just because something isn’t a motorbike for the purposes of riding on the highway doesn’t mean it is a bicycle for the purposes of s. 30 of the Countryside Act. The government says in guidance that mobility scooters are allowed on bridleways but I haven’t tracked down the statutory reference to that. For permissive use (ie random trails in Forestry) it is up to the landowner

So this is a non-swearing forum. In the sense that I can’t turn of the swear filter. That’s a shame.

Dunno, I had some Bonty Mustang asymmetric 29er rims and they built up nicely, the asymmetry works at both ends to even up the spoke tension. I guess there must be some trade-off in terms of the rim not being quite so optimally designed, but surely that’s nothing a few grammes of extra aluminium won’t cure?

Similarly offset rear ends, worked a treat on my Demo 8 (though 26″ wheels obv).

Yep its the lying in the book that makes Wiggo look bad. Suprised* Marr didn’t pin him on that.

*not at all surprised.

Does anyone know how much of this substance riders were using in ‘the bad old days’?
I imagine they used more effective substances since they didn’t have to bother with the TUE rigmarole.

Many years ago I met the Godfather of Welsh Devolution at the bottom of Machen/Rudry woods whilst I was out on a ride. I think he lived in Draethen at the time, hence the naming of the “Ron Davies Ring” circular mtb route. He opened the gate for me and said “good morning” etc. This was after the Clapham Common incident. He genuinely was walking his dogs. No badgers in sight.

http://www.chainreactioncycles.com/no-flats-presta-valve-core/rp-prod94758?gs=1&gclid=CKu4kOHMoM8CFYYp0wodxJ4ISg&gclsrc=aw.ds

I thought that as well twicewith. But the pivoting of the roller and pin is around/inside the swaged*-in parts of the inner plates. From some odd bits in the garage I see that on a 1/8 chain these swaged-in bits do not extend all the way to the centre, whereas on a 3/32 chain they get much closer. I haven’t actually measured it, but the width of the bearing parts may be the same. Possibly there is only so long a bit you can create by the swaging method.

Anyhow, 1//8 chains come in way more colours.

*may not be the best word for this.

The difficulty is knowing how much spoke stretch and other deformations are going to take place by the time you get to full spoke tension. I’ve never used washers, but if they came in decent thickness that would be useful.

Nipples come to a stop when you screw them too far into rolled threads IME. At least it does with spokes with 2mm dia. ends. According to Park Tool a standard spoke thread is 2.2mm x 56TPI. So the diameter at the bottom of the threads is going to be way more than .2mm lower then the max diameter – approx 1/56″ which is ~0.45mm. Even allowing for a flatter thread profile, it won’t go.

Thanks polebicycles.

Not to mention the expense of bending rims, though I suppose you could just rotate the rim a few degrees and do another test. Maybe a lesa real-world test of applying a constant force with an uninflated tyre and see what force was needed to deform the rim with and without Huck in between the two bits of tyre? You could use a few different shapes of force-applying-thing.

njee20 – Member

Two common mistakes one sees in younger cyclists are too high a cadence and too much force on the pedals

These two things are mutually exclusive, surely? That’s basically saying that the mistakes you see are pedalling too fast and pedalling too slowly. So… Yes, those are the ways it’s possible to do it wrong…

“Easily” holding 180rpm does sound a little optimistic, POIDH!
Not mutually exclusive at all, try it yourself. You just
1 pedal slowly
2 push lightly on the pedals.
The road to cycling pleasure, simple!

I wonder if the real Chuck Norris is on board? I suspect legal problems in the US if he isn’t.

I would guess the stuff forms a layer with sealant above it so it actually gets pushed against the inside the tyre by air pressure, though I think the guy on the vid said it was open-cell foam.

polebicycles – have you done experiments whacking wheels with rocks at varying force to quantify how much extra protection you get? Presumably there is a point where you whack your rim so hard it bends despite Huck’s best endeavours?