Box Components - anyone know anything about them quality-wise?

[mzjo]

I have a project coming up in the autumn (picking up the frame beginning of august) which will involve putting a 650b front wheel into a set of forks with brake posts set for a 26" front wheel. The brakes will need 40mm (measured!) between pad and post  (c-c) and I want to use drop bars and equivalent levers. Rear brake will be a Tektro R559 dp caliper. So I am thinking canti or mini-V. I don't think there are any cantis that go that high, they seem to stop at 35mm which won't be enough.

While browsing for a suitable brake this evening I came across these https://www.probikeshop.fr/etrier-de-frein-box-components-three-v-brake-85-mm/ They claim 35mm of adjustment and judging that the brake pad in the photos is halfway up an 85mm arm and not at the top of the slot I would guess that they would be ok for height (and that a 35mm tyre should just fit under the cable although a mudguard might require creative thinking). But they are relatively expensive for my budget (although of course I only need one at the front) and I can find out very little about the maker, other than that he doesn't seem to make brakes any longer and Box 3 is obsolete in his eyes. They look smart but only chrome finish available not the fancy red or blue. So does anyone know anything about these people?

While on the subject I would take advice/opinions on other mini-Vs that would have sufficient pad height. There are XLC ones that are budget. Unfortunately the mini-Vs have the same name as their full size cousins, which are given for 39mm pad height. I would hope that the minis have the same adjustment as the full size (and that buying from a stockist who only advertises the mini will guarantee that that is what will arrive). All advice accepted. 

[andrew_s]

While browsing for a suitable brake this evening I came across these https://www.probikeshop.fr/etrier-de-frein-box-components-three-v-brake-85-mm/

I get a 404 error for that URL.
I guess it should be https://www.probikeshop.fr/etrier-de-frein-box-components-three-v-brake-85-mm/152733.html

Ultimately the only way to be sure is to get some and try it out, but I'd be mildly surprised if it worked satisfactorily.

The difference between 650B and 26" rims is 25 mm (584 - 559). With 35 mm of adjustment, that means the 26" wheel has to use the blocks when set within 10 mm of the bottom of the slot (using the Box calipers) in order to give sufficient adjustment for a 650B wheel. That is quite likely, so on the face of it, you've got some brakes.

The problem is likely to be that raising the blocks up the slots kills your mechanical advantage, so the braking power is lost.
On my 26" wheel bike, the brakes are set so that the blocks are ~ 25 mm above the frame studs. Add 25 mm for the difference between 26" & 650B, and you've got 50 mm, so the brakes will have only half the power (25/50).
If your 40 mm for 650B is correct, that implies that the blocks are only ~ 15 mm above the stud, so the ratio is 15/40 = 37% as powerful.

You'll get some back by using drop bar levers (road rather than V), but I'd be surprised if the braking was OK for general use.

[LittleWheelsandBig]

There were some cantilever brakes with a lot of height adjustment but those models were fairly rare and are long out of production e.g. https://bikerecyclery.com/onza-h-o-high-output-cantilever-brakes-rare/

There are/ were some V-brakes with lots of pad adjustment and expensive ones still exist.
https://www.bricklanebikes.co.uk/paul-components-motolite-bmx-brake-black

[LittleWheelsandBig]

Somebody OTP uses Box Component brakes.

https://yacf.co.uk/forum/index.php?topic=122407.0

[iandusud]

While browsing for a suitable brake this evening I came across these https://www.probikeshop.fr/etrier-de-frein-box-components-three-v-brake-85-mm/

I get a 404 error for that URL.
I guess it should be https://www.probikeshop.fr/etrier-de-frein-box-components-three-v-brake-85-mm/152733.html

Ultimately the only way to be sure is to get some and try it out, but I'd be mildly surprised if it worked satisfactorily.

The difference between 650B and 26" rims is 25 mm (584 - 559). With 35 mm of adjustment, that means the 26" wheel has to use the blocks when set within 10 mm of the bottom of the slot (using the Box calipers) in order to give sufficient adjustment for a 650B wheel. That is quite likely, so on the face of it, you've got some brakes.

The problem is likely to be that raising the blocks up the slots kills your mechanical advantage, so the braking power is lost.
On my 26" wheel bike, the brakes are set so that the blocks are ~ 25 mm above the frame studs. Add 25 mm for the difference between 26" & 650B, and you've got 50 mm, so the brakes will have only half the power (25/50).
If your 40 mm for 650B is correct, that implies that the blocks are only ~ 15 mm above the stud, so the ratio is 15/40 = 37% as powerful.

You'll get some back by using drop bar levers (road rather than V), but I'd be surprised if the braking was OK for general use.

Whilst you are correct that the difference in circumference of a 650B rim over a 26" is 25mm the brake blocks will only need to be raised by the increase in radius, which is 12.5mm.

[iandusud]

While browsing for a suitable brake this evening I came across these https://www.probikeshop.fr/etrier-de-frein-box-components-three-v-brake-85-mm/ They claim 35mm of adjustment and judging that the brake pad in the photos is halfway up an 85mm arm and not at the top of the slot I would guess that they would be ok for height (and that a 35mm tyre should just fit under the cable although a mudguard might require creative thinking).

You don't say what brake levers you are using and this will determine what length of V-brake you can use. I use a full length V-brake on the front of one of our tandems with Shimano Tiagra brake levers, which are SSLR, and it works very well. On our other tandem I have a full length V-brake on the front with some older brake levers and this one works very well using a Travel Agent. I am however about to fit a pair of Tektro RL520 levers (cheaper option than buying another Travel Agent for the rear brake). All this is to say that there are options that will give you better clearance for fitting a mudguard.

The Box brake I think you are referring to is available here in 85mm and 108mm and they do appear to have a lot of vertical adjustment. https://www.sourcebmx.com/products/box-three-race-v-brakes?variant=31227721810031

These ones appear to have even more adjustment but at a price https://crucialbmxshop.com/ice-jaw-v2-v-brake However still cheap compared to Paul Motolites https://www.bricklanebikes.co.uk/paul-components-motolite-bmx-brake-silver

As has been stated elsewhere moving the pads up will affect the mechanical advantage but I reckon that the 108mm Box brake would be worth a punt.

[mzjo]

While browsing for a suitable brake this evening I came across these https://www.probikeshop.fr/etrier-de-frein-box-components-three-v-brake-85-mm/

I get a 404 error for that URL.
I guess it should be https://www.probikeshop.fr/etrier-de-frein-box-components-three-v-brake-85-mm/152733.html

Ultimately the only way to be sure is to get some and try it out, but I'd be mildly surprised if it worked satisfactorily.

The difference between 650B and 26" rims is 25 mm (584 - 559). With 35 mm of adjustment, that means the 26" wheel has to use the blocks when set within 10 mm of the bottom of the slot (using the Box calipers) in order to give sufficient adjustment for a 650B wheel. That is quite likely, so on the face of it, you've got some brakes.

The problem is likely to be that raising the blocks up the slots kills your mechanical advantage, so the braking power is lost.
On my 26" wheel bike, the brakes are set so that the blocks are ~ 25 mm above the frame studs. Add 25 mm for the difference between 26" & 650B, and you've got 50 mm, so the brakes will have only half the power (25/50).
If your 40 mm for 650B is correct, that implies that the blocks are only ~ 15 mm above the stud, so the ratio is 15/40 = 37% as powerful.

You'll get some back by using drop bar levers (road rather than V), but I'd be surprised if the braking was OK for general use.

Whilst you are correct that the difference in circumference of a 650B rim over a 26" is 25mm the brake blocks will only need to be raised by the increase in radius, which is 12.5mm.

I was thinking this (about the radius, not the diameter). This would hold true of course for any brake on a  fork using 26" posts and a 650b rim since the maths would not change - but people do do this conversion without failing to stop at the first hazard so it must actually work, at least some of the time. I am not a particularly heavy user of brakes, I doubt I'd notice the difference!

There were some cantilever brakes with a lot of height adjustment but those models were fairly rare and are long out of production e.g. https://bikerecyclery.com/onza-h-o-high-output-cantilever-brakes-rare/

There are/ were some V-brakes with lots of pad adjustment but only expensive ones still exist.
https://www.bricklanebikes.co.uk/paul-components-motolite-bmx-brake-black

There's no shortage of V-brakes that will do the job. They are mainly of the cheap and cheerful type. I have a couple of sets in the garage, the Saccon brakes fitted to the folder and some chinese bent tin ones that I took off a bike to replace with something more adequate. I started out by fitting the wheel in the forks and seeing if the pad lined up using these tin brakes (it did!). But I wouldn't want to use them to try to stop anything (other than while going up a very steep hill!). And I don't want to use V-brake levers - and I do want to use drop bars, the shifters will be bar-ends (although I do have non-indexed thumbies so I could use flats!).

If Andrew's maths and theory is correct then I will end up looking for a different fork so perhaps the answer is to spend 15€ on some XLC mini Vs and not throw too much money at the job before knowing the result. It's an aluminium fork (Planet X, supposedly sus-compensated for a mtb, except that the axle-crown length is about 395mm which is fine for a road frame but completely out for a sus mtb. I tried it on a mtb but the change in seat tube angle was intolerable, ended up about 76° and ever since I have been looking for a use for the damn thing!). Obviously cutting the posts off and welding new ones is not an operation that many frame builders would want to take on - too much risk of weakening something!

[mzjo]

While browsing for a suitable brake this evening I came across these https://www.probikeshop.fr/etrier-de-frein-box-components-three-v-brake-85-mm/ They claim 35mm of adjustment and judging that the brake pad in the photos is halfway up an 85mm arm and not at the top of the slot I would guess that they would be ok for height (and that a 35mm tyre should just fit under the cable although a mudguard might require creative thinking).

You don't say what brake levers you are using and this will determine what length of V-brake you can use. I use a full length V-brake on the front of one of our tandems with Shimano Tiagra brake levers, which are SSLR, and it works very well. On our other tandem I have a full length V-brake on the front with some older brake levers and this one works very well using a Travel Agent. I am however about to fit a pair of Tektro RL520 levers (cheaper option than buying another Travel Agent for the rear brake). All this is to say that there are options that will give you better clearance for fitting a mudguard.

The Box brake I think you are referring to is available here in 85mm and 108mm and they do appear to have a lot of vertical adjustment. https://www.sourcebmx.com/products/box-three-race-v-brakes?variant=31227721810031

These ones appear to have even more adjustment but at a price https://crucialbmxshop.com/ice-jaw-v2-v-brake However still cheap compared to Paul Motolites https://www.bricklanebikes.co.uk/paul-components-motolite-bmx-brake-silver

As has been stated elsewhere moving the pads up will affect the mechanical advantage but I reckon that the 108mm Box brake would be worth a punt.

Thanks for that, I think you might well have solved the problem. I might well go with the Box brakes if I can get the long arm version in France or imported. I already have suitable brake levers. (I don't much like Travel Agents though, just a personal bias not based on any experience or logic).

[iandusud]

Thanks for that, I think you might well have solved the problem. I might well go with the Box brakes if I can get the long arm version in France or imported. I already have suitable brake levers. (I don't much like Travel Agents though, just a personal bias not based on any experience or logic).

I hadn't realised that you are in France. Tu le trouveras moins cher ici https://www.usprobikes.com/fr/freinage-v-brake/5702-etrier-box-three-pro.html

[DuncanM]

I recently installed Box mini-V brakes on the front of my 'cross bike (to replace the infuriating Avid cantis), but I've not ridden them much.  They seem well made, were easy to set up (* see below for install issue), and seem fairly powerful. Mine are the 85mm ones - I got them from here: https://www.sourcebmx.com/collections/bmx-braking/products/box-three-race-v-brakes?nosto_source=cmp&nosto=62c3f0b903d81b15fe4c860e&currency=gbp

I had a bit of an issue installing them, in that one was binding on the brake posts, but that might have been due to me part installing them in a rush in the rain and using the supplied bolts which were loads longer than those on the bike originally. I only noticed when I went to fettle them days later, and had to use a small amount of sanding on the last few mm of the brake post (and the brake arm) to make it fit on and still move freely.

If you want me to take any measurements/pictures, let me know