Fixing a front dynamo to the bow of a low rider

[Bob999]

I have had my dynamo mounted on the front brake, I could only do it with a bodge by putting on a longer pivot bolt as I needed spacers to stop it rubbing against the headset.

Now I am thinking of putting it on the bow of my low rider - I think that keeps it at the right height but I haven't been able to find a suitable mount, so I wonder if anyone either knows of one or has a homemade arrangement? I'm not sure of the wisdom of drilling a hole in it (it's a Tubus low rider 14mm diameter).

[Brucey]

I doubt whether such a mounting will be satisfactory; the front loop on low rider style carriers is not that stiff. Also you don't say what kind of dynamo it is, but if it is the bottle sort that swivels (rather than tilts) you will probably have some difficulty in getting it to stay put on the loop alone; you may find you need some extra meccano reaching up from the carrier frame itself. You may have issues If it is the roller sort too.

The other thing is that even if you do get it to work OK, I suspect the noise will be unbearable; the entire carrier will be acting like a sounding board for the dynamo.

cheers

[andrew_s]

The current version of the Tubus Tara has a mounting hole at the top of the bow for a light, so a dynamo light would be possible

[Carlton green]

I have had my dynamo mounted on the front brake, I could only do it with a bodge by putting on a longer pivot bolt as I needed spacers to stop it rubbing against the headset.

Now I am thinking of putting it on the bow of my low rider - I think that keeps it at the right height but I haven't been able to find a suitable mount, so I wonder if anyone either knows of one or has a homemade arrangement? I'm not sure of the wisdom of drilling a hole in it (it's a Tubus low rider 14mm diameter).

I’m a great supporter of bottle Dynamos but they are an imperfect method of electricity generation (hubs are better overall but IMHO bottles are a pragmatic choice that can work very well). To my mind what you are really looking for are better methods of mounting your Dynamo which, as you have one fitted, might or might not utilise your low rider rack but must take account of it. If that’s the case then perhaps you could change the thread title (to say: ‘bottle Dynamo front wheel mounting problems’) and see what answers are offered.

I think driving a bottle Dynamo off of the rear wheel is better than driving it off of the front, but many folk successfully use the front wheel instead and have no problems.

Edit. There are several alternative ways to mount a front Dynamo, google images shows me several, search: ‘dynamo front fork mount’.

[Brucey]

is the OP talking about the dynamo itself or the dynamo light? I assumed it was the former before but it would make more sense if it was the latter.

FWIW mounting a light on the front loop can be OK but there are two issues;

- vibration can be worse and this may kill some front lights (eg non-LED ones) and
- a single 'p' clip won't necessarily prevent the lamp from moving; you would be better off with at least two, positioned appropriately.

I wouldn't recommend drilling holes in the front loop BTW.

cheers

[Jdsk]

And add a photo, please.
Jonathan

[cycle tramp]

I have had my dynamo mounted on the front brake, I could only do it with a bodge by putting on a longer pivot bolt as I needed spacers to stop it rubbing against the headset.

Now I am thinking of putting it on the bow of my low rider - I think that keeps it at the right height but I haven't been able to find a suitable mount, so I wonder if anyone either knows of one or has a homemade arrangement? I'm not sure of the wisdom of drilling a hole in it (it's a Tubus low rider 14mm diameter).

Hello there,
If you're talking about your headlamp driven dynamo then personally speaking I'd check out Saint John Street Cycles for a different headlamp mount - luckily Saint John Street Cycles do lots of different styles...
...I've got a tubus low rider too, and I've often thought about mounting a light to the bow.... however two things stop me, the first is the route the wiring takes - unless I run the wires inside the front rack (which means more holes) there's no where I can mount the wires with running the risk of being snagged when I mount or dismount my panniers...
..and even if I solve that one, placing the lamp at the arc of the bow, puts it in a very vulnerable position. I'm a clumsy person and I've lost count of the times my front forks have swung around causing the bow of the front rack to hit a wall, fence or even the ground... I think that without some sort of additional protection then mounting a headlamp there could see it being damaged very easily....well, it would do if I owned it, anyway...

[Bmblbzzz]

I might be inclined to wrap an old bit of inner tube round the rack, then either a P-clip or a specific reflector bracket on top of that, and bolt the the headlight to that. But I'd try it out at home and see how it responded to bumping and swinging first.

[Bob999]

Thank you for the replies and my apologies - I did indeed mean the lamp not my dynohub.

I have one of those lamps that meets the German regulations and, just from the pictures in the manual really, https://herrmans.eu/wp-content/upload-assets/PICC01673.pdf, I have been assuming it needs to go at front fork height for the best beam. But the manual does not actually state that so perhaps it is worth trying it on the handlebars, for which St John Street Cycles does have fixings.

I do have a mount but it does not work straight off the bat and I haven't seen one that I think would - because I have caliper brakes. So when I put the mount on the pivot bolt it is tight against the lower headset; when I add spacers to fix that, the bolt is too short for a good fit. Unfortunately this is exacerbated by having Berthoud mudguards, with the fork crown fitting that prevents a longer recessed nut being used. So I ended up digging out an old non-recess brake and swapping the bolt over. A bodge. But I thought surely many people before me must have encountered this and I am not doing it right!

Thanks for the comments about the Tubus, mine does not have the hole and the point about wiring is very useful.

[Brucey]

'Dynohub' is a trade name for sturmey archer's hub generators. Strictly speaking dynamos produce DC electricity which means that most electrical generators on bicycles (be they bottle style, roller type or in the hub) are not even dynamos.

But anyway fitting front lights onto bikes with shallow fork crowns and caliper brakes is not always easy. Some engineering is often required.

You don't say what type of brake (or headset?) you are using but you can get longer centre bolts which fit a range of dual pivot brakes, provided they use an M6 thread on the main part of the bolt and an M7 thread where the bolt and locknut secure the caliper itself.

Of the available brackets this one

https://www.sjscycles.co.uk/lighting-spares/schmidt-stainless-steel-headlamp-bracket-for-mounting-schmidt-e6/

isn't much money and has a pretty good shape for clearing the headset. Some filing of the slot and reshaping might be required to get the best fit, but a smaller spacer is usually required with this bracket than others. An added complication is your lamp, which is wide where it mounts to the bracket. I'd suggest that a centre cut through the bracket I've indicated should allow the bracket to be spread so that it will fit the mounting on the light.


If the GB daruma style fixing remains problematic then you can either make a new one with a larger hole through it or (provided you are not short of clearance) you can use a simple L shaped bracket (or better yet one at the front and one at the back of the fork crown) onto the brake centrebolt instead. If you are having to use spacers on the brake anyway, you may as well have them do something useful.

Regarding height of light, there are two main issues;

1) casting of shadows by holes in the road; if the light is too high there are no shadows to see and you can go into a bad hole in the road. A lot of riders prefer a low mounted light for this reason.
2) light distribution. If the lamp is set too low, you may find the near field too bright (relatively speaking) and this makes for relatively poor illumination at greater distances (the bright spot immediately in front of you means it is less easy to see what is further away and less well illuminated).

You will have to see what you like; between personal preference and variations in the lamp itself, as well as its exact aim, there is plenty of scope for variation. I find most modern lights work OK for me at fork crown height, but others prefer them elsewhere.

hth

cheers

[Bmblbzzz]

I think you're right that the light is designed for optimum beam at fork crown height. But you could try it on the bars, the difference might not be too much and in any case should (I think) only be noticeable right in front of the wheel.

AIUI your problem is that the brake mounting bolt is not long enough. As you can't extend the bolt itself, what about the nut at the back? Something like "Problem Solvers Sheldon Nuts" – expensive for what they are, but probably you can find a cheaper non-cycle specific equivalent.
https://www.tritoncycles.co.uk/componen ... 466/s35661

[cycle tramp]

...can I ask how long your front mudguard is? Is it long enough to fit under the bow, and if so can is your front lamp small enough to fit under the bow...?
The reason for asking was that if the answer was yes, then with the right mount you could fit the front lamp to the front of the mudguard underneath the bow, and support the lamp by fitting another set of mudguard stays from under the front lamp mount to the front forks to support the additional weight, and then run the wiring from the dyno-hub up the stays to the front lamp...
....sadly this method does involve you drilling some mounting holes into your rather lovely front mudguard....
...you may wish to think very very carefully about that..

[freiston]

You could mount the light using a bracket that replaces a spacer above the headset - imho, this would still put the light at about the right height.

Here's a bracket for a threadless headset ("Designed to fit on a 1 1/8" steerer by replacing a 10mm spacer"):
https://www.sjscycles.co.uk/lighting-sp ... ht-holder/

and here's a bracket for a threaded headset with a 1" steerer:
https://www.sjscycles.co.uk/lighting-sp ... in-chrome/

[Bob999]

Thank you for the helpful answers. I bought the mount suggested by Brucey, filed it down, undid the nut holding the caliper spring, put in the mount and then did up the nut. I added a spacer for a little more clearance to the headset, then used one of the longer spindle screws as suggested by Bmbibzzz (cheaper version). That has done the job. To facilitate the long spindle screw I swapped the Berthoud fork crown fitting for an ordinary bracket. The new mount fitted well to the mount supplied with the light - the fixing on the light itself is wider - so I have two mounts in place, one horizontal so the light stays at the height I want.