Tourer - 26" or 700c wheel?

[Brucey]

it also says

26˝: 2.1˝ with or without fenders; 700c: 42mm with fenders, 45mm without fenders Individual tire and rim combos affect tire clearance

https://surlybikes.com/bikes/long_haul_trucker/frame_highlights

cheers

[meic]

I have just had the calipers out to my 26" LHT (largest frame size)
There is about 2.9" from the top of the rim to forks and frame but both are only 2.5" wide.
So plenty of room for mudguards with any tyre, on the 26" version.

[Brucey]

that is what I thought; bags of room for mudguards and tyres on the 26" wheeled version, but appreciably narrower tyres must be fitted on the 700C version if you want to use mudguards as well.

cheers

[meic]

I find that my choice between 26" and 700C is almost always made for me by what is available, either absolutely, commonly or affordably.
Lightweight rims and tyres for Audax are cheap and abundant for 700C, not so for 26".
As shown with these Surly frames, 700C frames with loads of clearance are less abundant than 26" frames. If you are even given a choice.
The new popularity of disk brakes does open up our options but I suspect it still will very rarely be the case that you can get "like for like" in 26" and 700C.
I agree with RMurphy, check out rim and tyre availability (and if you can get a frame to accept them) before working out the gearing arithmetic.
Gears are possible to sort out.
It is generally accepted to use 26" for more durability and 700C for more lightweight speed. Even if you dont like the theory behind that it determines what is on the shelf to buy.
My tandem is 26" wheel mainly because the manufacturer has a strong prejudice towards them, he also has a strong prejudice towards long steerer tubes which I share, so that is the reason why I have a 26" wheel tandem. If there had been a 700C alongside it, equal in all other respects, I would have taken that instead.

[Brucey]

FWIW I think that cheap MTBs (with 559 rims and rim brakes in 36h) will be with us for a good while longer yet. This being the case, if you are running 36h rims in 559, and trash a 'special' rear rim whilst on tour you can build the original front rim into the rear wheel and rebuild the front with a cheapo rim. Even a pretty basic single-wall 559 rim in 36h is strong enough for a decent sized touring load provided it is fitted into an undished wheel.

Similarly if you want a single tyre type/size that you are going to find almost anywhere it is arguably a 559 MTB tyre. If you don't want the knobbly tread, simples; just cut the knobbles off, e.g. using a sharp knife.

In all fairness the world of cycling (and wheels/brakes especially) is now so diverse that there is no longer a 'lowest common denominator' wheel. Twenty years ago if you were running 36h 700C or 559 with rim brakes you would expect to find a replacement wheel easily in most parts of Europe, but these days that is less certain. With very many wheelsets that you might used for touring, you might end up in a pickle having to build rims into wheels to be able to carry on, because you can't easily find the correct wheel.

cheers

[reohn2]

Looking at bikes (and drooling)

Don't we all

I noted that some come with the option of 26" (650C) or 700c (27") wheels

This has been covered else where in the thread,but 26inch = 559 and 700C = 28inch

Whilst noting that the smallest frames seem to come with 26" wheels and the largest frames with 700c which doesn't seem unreasonable there is quite a wide overlap in the middle range

The smaller frame sizes come in 26inch wheel sizes more often than not to avoid toe overlap,toe overlap refers to when the cranks are at the horizontal(9 o'clock/3 o'clock) and the the steering is turned the foot(toes) don't overlap the wheel and cause an accident bringing the rider down.This problem doesn't seem to both some people but a bike without toe overlap is a ster bike IMHO

The different wheel sizes in the middle to bigger frame sizes are for rider preference,some prefer 559 others 700C.

Stand over height isn't necessarily appreciably lower for the two different wheel sizes for the same frame size.

I read that the real measure of speed/performance is the "gear inches" and that you put different ratios on the 26" and 700c transmissions to roughly maintain the same "gear inches".

Gear inches is usually the measurement of progress and means that for every turn of the cranks the rear wheel will turn X inches ie; on a 50inch gear one revolution of the cranks the bike moves forward 50inches.
Any given gear inch is a constant on any wheel size but to achieve that gear inch with need differing sprockets and chainring sizes.
The important thing with gearing is not to be geared too highly,especially when touring,better to have 2 or even 3 ratios lower than you think you'll ever need,for that unexpected time when you're feeling rough it's piddling down with rain and you've just gone around a bend and are met with a wall of a climb

One thing that hasn't been mentioned is optimum cadence(OC),speed at which your legs are happiest at turning the cranks.OC can vary quite a bit between riders but most acoplished cyclists prefer an OC somewhere between 85 and 95rpm,this saves the knees,doesn't 'burn' the quads as much,and doesn't strain the cardiovascular system.

So a pondering moment. Assuming that the derailleur has a maximum and a minimum range that it will handle, does it mean that a 26" wheel setup has the potential to be geared lower (at the extreme) than a 700c setup? Conversely does a 700c setup have a potentially higher maximum gear? This is assuming that the front ratios have the same maximum and minimum gearing (because frame not wheels)

See above,but to clarify a say 48t chain ring and a 14t cassette sprocket(48x14) gives a higher gear on a 700C wheel than a 559 wheel assuming the same tyre size.

I do note that the actual wheel circumference is also dependent on the tyre profile

On tyre section(tyre height measured from the rim radially) yes,as Brucey has posted you'd need a huge tyre section to get the same overall diameter as a 700C wheel with a very small section tyre.

Alternatively, would you go for 26" and fat tyres or 700c and skinny tyres? Ultimate top speed versus comfort and versatility? Same circumference and gearing, different ride.

Generally yes but I prefer 700C and a fat supple tyre.
A tyre with a stiff carcass and a lot of tread on it will be uncomfortable compared to a more supple tyre with a slick tread,although the supple tyre will need more air in it than the stiff tyre to support the load but will roll much better and still be more comfortable.
Put more air in the stiff tyre to aid speed and it becomes very uncomfortable,doesn't adhere to the road surface well especially in the wet and still isn't as fast as the supple tyre.

On the forum we get a lot of people complaining they can't get low enough gearing but never do we get anyone complaining they can't get high enough gears.
It's worth considering the fastest speed you want to pedal at,a say 30mph gear(calculated at your OC)is useless if you're not able to use it where at the other end of the scale an 18inch gear may seem very low but not climbing a 15% hill with a full load on board

[andrew_s]

You may also like to consider the availability of different types of tyre against the type of riding you anticipate doing on the bike.

What choice is there of fast-ish road tyres, at what prices?

Will there be clearance for a tyre you may want to fit for rough or muddy off-road, or snow & ice?
(if you want knobbly, 29" tyres are mostly over 2 inches)

Gearing:
With 26", and a 32 mm tyre (a good general touring width), the wheel diameter is 24.5", and the lowest gear available with modestly-priced standard parts is 24x34 = 17.3" using a 110/74 5-arm triple chainset, or 22x34=15.8" if you use a rarer 4-arm 104/64 bcd chainset.

With 700C, and similar tyres, the wheel diameter is 27", so the lowest gears are 24/34=19", or 17.5" respectively.

To get a gear as low as the 26" bottom gear, you would need a 38T large sprocket.
Alternatively, you could equate a 36T cassette on 26" with 40T on 27".

That would push your replacement cassette cost up from maybe £20 to around £50, and would probably force you to 11-speed


I'd regard 19" as being low enough. My bottom gear is 16.8" (20x32), and it's really too low for good bike control.

[LittleGreyCat]

The original question was around 650B (584etro), not the (old) 26in MTB (559 etro) size...

actually he said 650C. Not a size used on many touring bikes these days.

But talk of small frames with 26" wheels and larger ones with 700C wheels sounds like the Surly long haul trucker to me, in which case it is 559 vs 622. You get a choice of wheel sizes in middling and large frame sizes only with this frameset.

My take is if you are riding mostly loaded, and/or on rough surfaces, choose 26" since this gives you stronger wheels and more wide tyre choices that fit easily. Otherwise 700C is a better choice for unladen road work.

IIRC the 26" LHT frames accept wider tyres than the 700C ones; the fork length seems to suggest that this is the case; the rim radius is different by 31.5mm but the forks are only 14mm different in length.

cheers

Aaaarrrrrggghhhh!

O.K. so if I am offered a choice (Surly Trucker or Spa Wayfarer) of wheel sizes, this is also a choice of different frame build?
Not the same frame with different wheels.
O.K. on reflection that seems reasonable for rim brakes where the mounts on the forks need to be where the rim is (at least I think that is reasonable). Possibly disc brakes could remove that issue.
One more thing to factor in.

I think my main use will be daily circular rides, with the occasional longer ride. In that case I think the 700C will probably be the better option.
First, of course, I have to chose the bike (including test ride) and speak soothingly to my credit card and install extra cooling.

Edit: and as others have very helpfully pointed out I also need to decide on the maximum width of tyre that I need/want to run.

[reohn2]

.......First, of course, I have to chose the bike (including test ride) and speak soothingly to my credit card and install extra cooling.

Don't install extra drooling or your credit card won't like you for it

[horizon]

LittleGreyCat: would you be so kind as to say how tall you are? Or simply to confirm whether you come in the "Must have 26" wheels due to height" catgegory. For some of us it isn't an issue as Spa for example don't do 26" wheels for their Tourers in the larger sizes - the issue as pointed out above is overlap (etc) as opposed to the desirability of one wheel size over another.

[slowster]

I also need to decide on the maximum width of tyre that I need/want to run.

We've established on the separate thread about the Wayfarer that it has clearance for 47mm tyres with mudguards. So I would suggest that you ask Spa to set up a demonstrator with 47mm tyres, and point you in the direction of some tracks comparable to what you normally ride. If a test ride tells you that 47mm tyres would be wide enough/wider than you need, then you know the Wayfarer will do. If you decide that the 47mm tyres simply do not provide enough comfort etc. compared with the tyres which you are used to on your MTB, then maybe look instead at the 26" Surly Truckers (although I suspect that the quoted max tyre size for the Surly of 26 x 2.1, i.e. 50mm-55m width, would be less comfortable on some tracks than bigger diameter but slightly narrower 47mm tyres in 700C size*).

* My own experience is that the nature of the tracks can make quite a difference. On gravel tracks I need tyres wide enough to provide traction on the loose gravel, and there is not so much difference in comfort between different wheel sizes. On grassy trails or similar where the surface is irregular/has small bumps, I find 26" tyres much less comfortable than 700C/29" tyres which tend to roll better over the undulations in the surface.

If the Wayfarer or another similar 700C/622 ETRTO wheeled bike suits you, then one option you would have with such a bike would be to swap to narrower/slick tyres if you were doing a long ride on good roads where you decided would not need or want the full 47mm width tyre with a tread pattern, e.g. a 32mm or even a 28mm slick tyre.

[gregoryoftours]

out of interest what was the mode of freehub body failure?
cheers

It was a bit of a weird one and I never found out for sure, but my best guess is that the inner part of the freehub body got fractured.

I can't exactly remember all of the specific symptoms of the problem and the sequence of events, but a couple of days into the trip the wheel wobbled from side to side when in the frame causing the rim to push against the brake pads when cornering or pedalling hard.

I am 90% sure from memory that the hub was one of those old black LX FH-M565. I bought the wheel second hand. I serviced it before I left but the hollow bolt wasn't 10mm allen as I was expecting from an old Shimano (and as the tech docs indicate), or 12mm, and I think it might not even have been 11mm. In any case I couldn't get any tool to get purchase on it to remove it or make sure it was fully dogged up. The freehub felt fine though and there was no looseness or play. I was fairly assiduous in servicing the rest of the hub as I didn't want any problems on tour. A hint of bearing play to be removed by the qr, everything locked off etc.

Upon experiencing the problem on tour and removing the wheel to check, the axle wasn't snapped, the cassette didn't have any unusual wobbles or play and the freehub still turned freely. I think I remember that the hub bearings had developed play but the locknuts were definitely still tight on both sides, or it might have been that there was still no discernible play in the bearings but the wheel moved side to side when in the bike. Took it to a bike shop where a guy took the axle out, checked everything was ok and put it back together again, was ok for a couple of days but then the problem re appeared.

Neither of the 2 following bike shops had a tool that could remove the freehub so I ended up having to ditch the wheel. at no point did the cassette or freehub feel like it had untoward movement when out of the frame and trying to move it by hand, so I wonder if the inner was cracked but held in place by the hollow bolt, and the movement only became obvious when the wheel was in the frame and greater leverage applied.


A while later I took a shim out of another shimano freehub to reduce the play and shortly after putting it together the inner part cracked in half (parallel to the plane of the rim). That made me wonder if it was on its way out anyway, or if I'd somehow caused the failure by overtightening the freehub cone/race when re-assembling. It also made me wonder if I'd also done something to the freehub that died when on tour, although I couldn't think what.

[gregoryoftours]

I also need to decide on the maximum width of tyre that I need/want to run.

We've established on the separate thread about the Wayfarer that it has clearance for 47mm tyres with mudguards. So I would suggest that you ask Spa to set up a demonstrator with 47mm tyres, and point you in the direction of some tracks comparable to what you normally ride. If a test ride tells you that 47mm tyres would be wide enough/wider than you need, then you know the Wayfarer will do. If you decide that the 47mm tyres simply do not provide enough comfort etc. compared with the tyres which you are used to on your MTB, then maybe look instead at the 26" Surly Truckers (although I suspect that the quoted max tyre size for the Surly of 26 x 2.1, i.e. 50mm-55m width, would be less comfortable on some tracks than bigger diameter but slightly narrower 47mm tyres in 700C size*).

47mm tyres on 700c rims should be more than adequate for some pretty gnarly stuff, as well as 700c being more suitable for road and tracks that aren't too rough which it sounds like you'll be spending most of your miles on.

[Brucey]

out of interest what was the mode of freehub body failure?
cheers

It was a bit of a weird one and I never found out for sure, but my best guess is that the inner part of the freehub body got fractured....

If it was a non-shimano freehub then it isn't unusual for the freehub body to be secured with a bolt (or nut) of an odd size that may be accessed from the left not the right. However pretty much all Shimano freehubs (with a steel 10mm axle) use a 12pt spline fitting to which a 10mm allen key is a convenient approximation.

Your failure could have been a freehub body centre failure but this would have been apparent when the hub was taken apart, so my money is on the hollow bolt itself having worked a bit loose and then not seeming loose enough to be worth tightening when the hub was inspected (*). The way the wheel moved around is absolutely symptomatic of a gradually worsening loose freehub body bolt/interface; the hub bearing themselves (if they are adjusted correctly) tend to mask the loose freehub body, and when the axle is out, any slight movement tends to be dismissed as play in the freehub body bearings, not the freehub body moving around wholesale. Of course it moves a lot more once you are sat on the bike pedalling.

The hollow bolt was at one time commonly made from wrought tube, i.e. it had a rolled top and this formed the 'head' of the bolt. More recent freehub body bolts are mostly not made in the same way, I think because the original type wasn't 100% reliable (the move to ever more speeds and longer freehub bodies puts extra load on the bolt BTW). The wrought tube bolts often didn't have much of a head on from the start and occasionally they would start to collapse at the top and once this starts the bolt stands a fair chance of losing its grip on the freehub body.

It seems that even the slightest movement in service can cause an evil chain of events in which the bolt becomes looser and looser as the head gets smaller and smaller. At some point in this process the head of the bolt gets so deformed that it will no longer allow you to fit a 10mm allen key. However at this stage it is usually still possible to fit the correct spline bit because it has a lead-in and a different tolerance on the dimensions. In point of fact it is always better to use a spline bit to tighten the bolt because where the spline finishes on the bit, there is a full diameter/shoulder and this supports the head of the bolt correctly; the bolt isn't so likely to collapse and nip down on the tool as the bolt is tightened, which sometimes happens when a 10mm allen key is used.

The first time it happened to me I felt a proper Charlie when I tightened a freehub body bolt (using an allen key) and felt the evil squodging sensation that accompanies a stripped thread or something equally unwelcome. I felt even dafter when I couldn't get the remains of the bolt off the allen key without using a hammer on it....

In that case I was lucky, a new bolt fixed it. Since then I have overhauled a lot more freehubs and I have learned that such failures are not that uncommon. (*) - I always check the hollow bolt for tightness when working on the hub; if the bolt goes up more than about 1/8th of a turn then this means the freehub body has almost certainly been moving around. In this case the freehub body needs to come off, the crud (and there will be some) needs to be cleaned out of the interface before the thing is reassembled. It really isn't a bad idea to use a little threadlock on the parts if there is any evidence of wear, but when the bolt is checked for tightness again, it is imperative that the bolt is actually moved so that it gets a chance to tighten if it needs to. Once the interface has seen movement, the chances of this recurring are somewhat increased.

If you break the end of the freehub body off there are several reasons why this can happen

- the hollow bolt is not tight enough in service and the loading of the hub bearings is borne by the freehub body alone
- there was one too many shims removed from the freehub body when it was serviced (you cannot get away with leaving the cup not fully seated on the shim bed; the cup will precess inwards and the freehub body will nip up and/or something will break)
- the freehub body parts were not made correctly, such that the material lacked strength and/or was unusually brittle. Shimano (who once had a stellar reputation for quality) have occasionally made parts that were like this, presumably as part of some desperate cost-driven 'race to the bottom'.

cheers

[squeaker]

Gear inches is usually the measurement of progress and means that for every turn of the cranks the rear wheel will turn X inches ie; on a 50inch gear one revolution of the cranks the bike moves forward 50inches.

'Fraid not: "It is the equivalent diameter of the drive wheel on a high-wheel bicycle."