Cycling UK Forum

4 out of 5 bikes seized by South Yorkshire Police and shown in this article - https://www.bbc.co.uk/news/articles/cj6zp8313wxo are from one such brand, Allegro, and the force commented,

"We have built up our knowledge around these vehicles and the fact we have seized a total of around 55 shows that we won't hesitate to act against riders who are breaking the law and putting other people in danger."

531colin's DIY frame alignment check is here - viewtopic.php?p=501647#p501647 (and it would not surprise me if that were also the method Spa would use to check frame alignment). I would only go to the bother of doing that check after first trying to ride the bike no handed, since I presume significant misalignment is unlikely if the bike rides OK no handed.

I am not sure about how to check the fork alignment, but again the OP does not suggest that the wheel flop is biased to one side.

(I realise it is theoretically possible for the frame or fork to be damaged such that it would affect the handling equally whether steering left or right, but I suspect that would be an uncommon occurence.)

The first company I would contact about a repair of a Karrimor pannier is Lancashire Sports Repairs - https://lancashiresportsrepairs.co.uk/, because its staff are more likely already to be familiar with the pannier and its design, including how it was made and how best to repair it.

Per Karrimor's wikipedia entry:

Some warranty and repair workers remained active with Karrimor products at the associated company Lancashire Sports Repairs, which until around 2012 acted as Karrimor's warranty, repair, and after-sales service provider and as of 2013 provides paid repair services of Karrimor equipment.

If you have not already done so, I would try riding the bike no handed.

WARNING - To state the obvious, if the bike is somehow faulty, riding no handed could be very dangerous. Nevertheless, given what you describe, it is what I would try in order to try to identify the problem. The way I would attempt it is by lifting my hands only a few millimetres from the bars/hoods, so that I could quickly regain control if anything untoward happened.

If there is some fault or damage, I think it would be unlikely to affect the handling symmetrically. In other words, when riding no handed the bike would tend to steer more to one side (or you would have to lean the bike underneath you to the left or the right in order to keep it going forward in a straight line).

If the bike handled symmetrically when riding no handed, and the tendency towards wheel flop was the same on both sides, that would suggest to me that it was unlikely that there was a fault.

A change of some kind involving the tyres might still be a more likely cause than a fault with the frame/fork or headset. Even if the tyre is the same model as before, a significantly higher tyre pressure than before might account for the change.

Additionally, I think Vittoria have used some of its names like 'Randonneur' for more than one model of tyre, with the result that replacing a 32mm Randonneur with another 32mm Randonneur might be a significant change rather than a like for like replacement, e.g. a different thread per inch count and/or a different tread (and maybe also a different recommended/maximum tyre pressure).

What tyre (model AND width) was on the wheel when you punctured and rode home with it flat?

Is it the same tyre still? If it is, I would be inspecting it closely, including the inside. I don't know that a damged tyre would cause what you are experiencing, but I would want to rule out a damaged tyre.

If it is a different tyre, what is the new model and width? I think a change to a significantly narrower tyre might cause what you are experiencing.

Regarding the original question, I think the simplistic answer is no: the bars/stem are just a lever, and it's what is on the other end of the lever that determines handling, not changing the position where the lever is held (relative to the pivot, i.e. mechanical advantage). Less simplistically, handling can be affected by variation in the distribution of bodyweight resulting from a major change in where the lever is held, but that will be more noticeable for extremes, e.g. switching from drops to flats and to a much more upright position, or vice versa.

As regards no handed turns, when riding no handed the brain/body is constantly making small adjustments to left/right bodyweight distribution (more so at lower speed) to counter small movements of the front wheel away from the centre line. In other words, the frontwheel constantly oscillates slightly between pointing left and right of the centre line. I suspect therefore that a no handed left turn is probably initiated by deliberately/sub-consciously delaying making the usual small adjustment when the front wheel is at the phase of its osccillation where it is pointing slightly right. That delay results in the wheel continuing to turn slightly further rightwards, creating the conditions for counter steering and the next shift in body weight is greater than usual and turns the wheel sufficiently far left to make the turn.

AndyB1 wrote: ↑27 Dec 2024, 6:05pm Precession?

From Whikepedia……
Precession is a change in the orientation of the rotational axis of a rotating body. In an appropriate reference frame it can be defined as a change in the first Euler angle, whereas the third Euler angle defines the rotation itself.

More to do with celestial bodies and spinning tops….What has this to do with BB threads?

I felt sure that the thread direction chosen at the RH (chainwheel) end of the BB was a LH one so that if the BB seized solid then the rider’s pedalling action was not suddenly stopped (causing a crash). Instead the rotation of the BB axle would undo the BB shell from the RH side of the frame and the rider would have a chance to progressively stop pedalling.

No. See the Wikipedia entry for *mechanical* precession - https://en.wikipedia.org/wiki/Precessio ... hanical%29.

MartinS wrote: ↑27 Dec 2024, 4:14pm Karrimor pannier with 1 main holder plus an external zip pocket and 3 mesh external pockets in the high vis top. All the main canvas and fasteners are sound but the high vis top is tearing probably because of UV damage

Sounds like these - https://www.ebay.co.uk/itm/226499298654, which I think were made with yellow lids as well as the black version shown in the photograph below.

Finding another used pair in good condition is the most straightforward solution. Getting your current pannier(s) repaired to a satisfactory standard would probably be relatively expensive, but still cheaper than finding a modern **close** equivalent. It's not difficult to find panniers that have outer mesh pockets, or full fabric outer pockets, or of the same approximate size, but I think you will struggle to find one that fits all those criteria, especially in a similar configuration as the Karrimor panniers.

If you get a Tern, I think you would be buying it because that is what you really want, which is an entirely valid reason to get one. I am sceptical however that a Tern woud be a better choice for you and your son than one of those Thorn tandems.

A new Tern would be much more expensive. Moreover, although as I understand it the Terns are well made and fitted with good quality components, ebike motors are hard on drivechains and other components, and I think you would have higher running costs than a non-ebike. I suspect that you would be dependent on your dealer/local bike shop to maintain and fix any problems with a Tern, whereas the low tech Thorn tandems are reliable and simple to look after and fix yourself.

Allypally wrote: ↑17 Dec 2024, 11:10am there will be mornings I need it to be as easy as

I suspect you are judging non-ebikes by your Pashley ("I own a pashley, it's heavy but I have never had a light bike so I don't notice"). You would probably find riding a Thorn tandem with a Rohloff hub gear to be a very different experience.

Commuting on a bike is invigorating. You get to work/school alert and refreshed by the exertion, and the ride home is a great way to unwind and leave the problems of work/school behind you, in a way that does not happen without the physical exertion. In short, it's good for your mental wellbeing as well as your physical wellbeing. You won't get as much of that benefit on an ebike, and your son will get none.

Riding a tandem and sharing the effort of getting along with your son would be a great bonding experience for you and your son.

If you want a Tern, then get one. But before you make you mind up, I suggest you contact Thorn and arrange a test ride for you and your son on one of those tandems. I think a test ride would give the confidence that it would work for you both and be a good choice.

Lastly, if much of your route is off-road, I would be very wary of a trike or sidecar unless they were designed for off-road use.

Further to grufty's post, SJS are in Bridgwater, so presumably quite convenient to you. Thorn is their own bike brand, and the bikes and tandems are high end products: good designs and high quality frames and components. They list various used and ex-display tandems here - https://www.sjscycles.co.uk/new-used-tandems-triplets/. This one in particular looks like it might suit your requirements - https://www.sjscycles.co.uk/bikes/thorn ... ndem-used/, or this one which is bit less without the dynamo hub, but with a rear rack - https://www.sjscycles.co.uk/bikes/thorn ... reen-used/.

For your information the Rohloff hub gear is the Rolls Royce of hub gears: 14 speeds (gears low enough for your hill), a reputation for expedition touring (very reliable and long lasting), requires only an annual oil change for maintenance, and a good choice if the route is off-road/mucky, especially compared with derailleur gears requiring quite frequent cleaning to keep them running to a similar standard. The tandem also has a Son dynamo hub and front light (and adding one, or even better two, rear lights connected to the dynamo would be straightforward).

Those two tandems are over your £1,500 budget, but are likely to be a far better choice than many cheaper options. Rohloff hubs alone cost >£1,100 new, and can be expected to last over 100,000 miles. The tandems should similarly be good for many years of use, and you should be able to sell it for a good price when your son has outgrown it. In comparison most new bikes will lose a huge chunk of value as soon as you leave the shop with one, and for some bikes the fall in second hand value is especially poor.

I would add that as well as being good for your school run, the Thorn tandems would also give you and your son a great tool for riding for pleasure, whether that be exploring your local countryside or fitting a couple of panniers and exploring further afield elsewhere in the UK or abroad.

1. Is there anything that it currently does, which it should do differently?

2. Is there anything that it currently does not do, which it should do?

Maybe there should be a separate board on this forum for such bikes?

CycleChat has a dedicated board for folding bikes. A lot of the threads are about Bromptons, but there are also posters who own various other folders like Tern and Dahon.

https://www.cyclechat.net/forums/folding-bikes.51/

Abus have made several different but very similar looking brackets and mounts for their D locks, and you need to take care to identify the clamp correctly in order to get the matching bracket. Yours looks to me like this one - https://www.bike-components.de/en/ABUS/ ... KF-p22198/, which is the clamp for the EaZy KF KLICKfix Bracket - https://www.bike-components.de/en/ABUS/ ... et-p22096/, but you should check for yourself.

Amazon sell them - https://www.amazon.co.uk/ABUS-Eazy-lock ... B003F88PY2, and I expect there are other UK retailers, although their price will probably be higher than the German retailers like Bike Components.

That said, I think Abus usually provide the bracket with the lock in the retail packaging if the lock is supplied with the clamp fitted to the shackle.

Video of how the bracket offers different options for positioning the lock on the bike - https://c3.abus.com/uk/Media/Multimedia ... er-EaZy-KF.

Welcome to the forum. I've moved your thread to 'Does anyone know', where I think it will be seen by more posters, and left a shadow link in 'Wanted'.