Cycling UK Forum

Is a 26 inch wheel with a 32 hole dynamo hub (which I have) almost as strong as a 36 hole one and suitable for loaded touring on gravel roads? Nothing too heavy or rough!
What rims are decent quality but not high priced?
If I supply the dynamo who builds decent wheels and how much can I expect to pay? Is there anyone on here f'instance?

always the question how much do u weigh?

Assuming that it isnt a disk brake version.

Front wheels have a much easier life than rear ones, less weight on them, not being driven and even spoke tensions.
The only time I have heard of front spoke failures is when something gets caught in them.
All my front wheels are 36 but I wouldnt worry about 32 up front.

mercalia wrote:always the question how much do u weigh?

172lbs - about 12st but more after xmas I don't plan to put more than 12lbs on the front carrier. Its likely that I won't have a front carrier in fact.

559 rims build into stronger wheels than 622 ones, by and large.

But if the likely failure mode is rim cracking near the spoke holes, then it doesn't make anything like as much difference between 559 and 622; what becomes significant is the spoke tension. So more spokes, a stiffer rim, less dish, DB spokes, less weight carried etc all allow a slightly lower spoke tension (for any given wheel) and this can help a wheel survive without rim cracking.

If you are going on gravel roads and/or carrying a load, I'd suggest that you don't choose a lightweight single eyelet rim; go for a double-eyelet rim of medium weight, or a heavier single eyelet rim perhaps.

Anyone building a wheel for you should want to know weight, luggage weight on front end, intended tyres, if a match is required to an extant rear wheel (in terms of rim section, appearance or simply spare spoke length), type of brake.

Note that most hub generators do build to a very slightly dished wheel, but the dish isn't enough to mandate different spoke lengths.

Personally I'd choose a 36 spoke front wheel for your intended service, but if you are not going nuts with it, 32 should be OK.

cheers

Brucey wrote:559 rims build into stronger wheels than 622 ones, by and large.

But if the likely failure mode is rim cracking near the spoke holes, then it doesn't make anything like as much difference between 559 and 622; what becomes significant is the spoke tension. So more spokes, a stiffer rim, less dish, DB spokes, less weight carried etc all allow a slightly lower spoke tension (for any given wheel) and this can help a wheel survive without rim cracking.

If you are going on gravel roads and/or carrying a load, I'd suggest that you don't choose a lightweight single eyelet rim; go for a double-eyelet rim of medium weight, or a heavier single eyelet rim perhaps.

Anyone building a wheel for you should want to know weight, luggage weight on front end, intended tyres, if a match is required to an extant rear wheel (in terms of rim section, appearance or simply spare spoke length), type of brake.

Note that most hub generators do build to a very slightly dished wheel, but the dish isn't enough to mandate different spoke lengths.

Personally I'd choose a 36 spoke front wheel for your intended service, but if you are not going nuts with it, 32 should be OK.

cheers

Thanks Brucey. Given my weights above & its a heavy touring bike could you recommend a make & model of rim please. I'll be using 2 inch rugged tyres, exact model tbc. Very grateful for any information.

I'm no expert, but I happily raced 32 spoked wheels on my mountain bikes for years including a short downhil racing period with only one bent due to a rock that jumped out and attacked the bike.
Having said that, I do like knowing there's 36 spokes holding my current front wheel together.

AFAIK, the engineer Jobst Brandt, who wrote "The Bicycle Wheel", came to the conclusion, that while 36H 3X was the optimal design compromise for standard 622 mm wheels, 32H 3X was the optimal compromise for 26" wheels.

climo wrote:
Thanks Brucey. Given my weights above & its a heavy touring bike could you recommend a make & model of rim please. I'll be using 2 inch rugged tyres, exact model tbc. Very grateful for any information.

Assuming you have rim brakes and weight isn't too much of an issue I'd suggest that a Rigida/Ryde sputnik is worth a long hard look. You can spend a lot more than that for relatively little (if any) benefit.

cheers

32 spokes are enough for a strong front wheel particularly in 26" with the large flanges of a dynamo hub. Time was when bikes had their 72 spokes as 40 in the back wheel and 32 in the front rather than 36 in each. Same number of spokes really means you've either too many at the front or not enough at the back.

There are quite a fe tandems with 32 spoke 26" front wheels. They don't seem to have too many problems.

in all fairness riding bumpy trails with a load strapped on the front of a (presumably rigid) bike is a lot different use than others for which 32 spoke wheels appear perfectly adequate.

The idea that hub generators build into stronger wheels doesn't always hold water; often the flanges are closer together than in standard hubs, and/or the wheel is dished. Usually getting enough spoke length (to give enough stretch to avoid loosening) whilst having the spokes come to the rim at an acceptable angle becomes something of a compromise with 559 rims especially.

The OP hasn't confirmed what the hub is, what the 'matching' rear wheel is like, or indeed what kind of brake is going to be used.

If you build a 36 spoke wheel with DB spokes then (compared with a PG 32 spoke wheel) it is both lighter and stronger. It would be my first choice for this kind of use, for sure, (even if I was pretty sure that a 32 spoke wheel would be fine). It can allow the use of a lighter rim without requiring an excessive spoke tension that might otherwise crack it. If a heavier rim is used it might carry additional benefits such as using the same rim (or spoke length) as the rear wheel.

cheers

A wheel build would cost about £30 to £35 for just the labour or maybe less if your chosen shop isn't in central London.

You could also build it yourself. The experience should be useful for any later repairs needed.

Brucey wrote:in all fairness riding bumpy trails with a load strapped on the front of a (presumably rigid) bike is a lot different use than others for which 32 spoke wheels appear perfectly adequate.

The idea that hub generators build into stronger wheels doesn't always hold water; often the flanges are closer together than in standard hubs, and/or the wheel is dished. Usually getting enough spoke length (to give enough stretch to avoid loosening) whilst having the spokes come to the rim at an acceptable angle becomes something of a compromise with 559 rims especially.

The OP hasn't confirmed what the hub is, what the 'matching' rear wheel is like, or indeed what kind of brake is going to be used.

If you build a 36 spoke wheel with DB spokes then (compared with a PG 32 spoke wheel) it is both lighter and stronger. It would be my first choice for this kind of use, for sure, (even if I was pretty sure that a 32 spoke wheel would be fine). It can allow the use of a lighter rim without requiring an excessive spoke tension that might otherwise crack it. If a heavier rim is used it might carry additional benefits such as using the same rim (or spoke length) as the rear wheel.

cheers

It a supernova infinity 8, 32 hole, there's no 36 hole made, V brakes. Rear wheel is a 36 hole Mavic (719??) on a Thorn Ripio with suspension forks but may be used on other bike with rigid forks (hence the possible load factor) It's not going to be used on anything rougher than a gravel road.
I prefer suspension forks due to a painful shoulder injury.
I prefer a dynamo for the usual reasons and will buy a usb charging front light. I like to camp and can't see a way of charging light batteries or phones, etc from a tent.

I must confess to buying the dynamo and one more for my wife as it was on offer at half price and wasn't going to be there long! If at the end of this thread it looks like a bad idea I'll return it unused. Nothing lost.
Basically it's a punt.

bryce wrote:A wheel build would cost about £30 to £35 for just the labour or maybe less if your chosen shop isn't in central London.

You could also build it yourself. The experience should be useful for any later repairs needed.

Luckily I live in Hampshire.
I'd like to build the wheels but being a mechanical klutz I'm worried that I'll make a stupid mistake. I sorta don't want to find that out at speed down a hill.