636mm toptube and 100mm stem make 29”.
that is huge in anyones terms. you will struggle to find csomeone who rides such a size bike.

I’ve just built a bike with a 620mm top tube and 140mm stem 🙂

But anyway, that wasn’t my point. What I meant was that for your reach of about 71cm, most people would get there with something like a 60cm top tube and 11cm stem.

100mm stems aren’t large by any means. A 636mm top tube, however (assuming we’re talking drop bar bikes), is way off the scale of nearly all off-the-shelf geometry charts. 😉

Aye, but you’re helping them a lot more than they’re helping you so it would still make sense to be able to drop them.

100mm stems aren’t large by any means. A 636mm top tube, however (assuming we’re talking drop bar bikes), is way off the scale of nearly all off-the-shelf geometry charts.

xl Genesis tour de fer.

Yeah, I realise it’s obviously on at least one geometry chart 😉 Surly and Soma both go that long, too, IIRC. But it’s pretty uncommon and it’s right up one end of the available range. Whereas a 10cm stem is very common and you can easily get one 40% longer.

Most people would expect to find such a long frame fitted with a rather longer stem than 80mm. That’s not too say it’s not right for you, it just kind of explains why 100mm stems on medium-to-large touring bikes isn’t remotely surprising 😉

i have got a whole load of stems, ranging from 50mm right up to 130mm and in loads of rises.
gonna start on the 65mm and see if i can stretch my back up to 100mm.

cheers Bez. 😀

Hey, I’m not suggesting you should change position just because some other bike has a different stem on it 🙂

I am using a 90mm stem but at 5’10” I am towards the lower end of recommended sizing for my size L frame and I am a bit more leg than torso… The fit of the bike is good for me like this, so I can live with a bike that doesn’t quite conform to the rules.

Use Stack and Reach to make meaningful comparisons. My (massive, unrideable by most anyone else) Soma ES has a 618mm Effective Top Tube and I’m pretty sure you’d not even be able to throw a leg over that.

Most of the research has been done for you – and you’re not that tall:

http://www.cyclingabout.com/list-of-xxl-xxxl-bikes-for-tall-cyclists-62-63-64cm/

has a 618mm Effective Top Tube

so the genesis tour de fer has a longer toptube than your bike then?
and mated with a 100mm stem the bike is very long then?
so does a bike with such a long toptube need a long stem?

has a 618mm Effective Top Tube

so the genesis tour de fer has a longer toptube than your bike then?[/quote]

The Genesis geo simply states ‘Horizontal Toptube Length’ but the graphic is a bit weird so who knows where is actually measured from (since that horizontal distance will change a little depending where you measure due to difference in seat and headtube angle).

Look at the angles and the reach measurement too, for example your TDF XL is only 20mm longer than the L in reach, but 32mm longer in ‘Horizontal Toptube Length’, thats because the seat angle is slacker, there’s more to geometry than just a published number for ‘top tube’

also, this will make you chuckle, the geo chart for the TDF lists 100mm stem for ALL sizes, so actually the small ones have long stems for their size, and the large ones have short stems!

Stem length isn’t *just* about fit either, its about handling, not ‘steering’ as such but weight distribution, if you whack a short stem on a long bike to sort fit, you move a significant portion of weight back, you might not notice (or will get used to) any ‘twitchiness’ but you might notice loss of front end grip and changes in handling overall, admittedly not as important on a tourer compared to a road bike but just highlighting the point, its a complicated game bike fit 😉

My AWOL was similar in that the TT measurements are ‘long’ for a drop bar bike, but I had to fit a longer stem (100mm vs 80mm) to standard to get it to fit properly, and I couldn’t size up as the seat tube would have been too long, and even with the longer stem it’s still very short and upright compared to my road bikes.

Anyway, stop worrying about it and just put on whatever stem makes you comfy!

Anyway, stop worrying about it and just put on whatever stem makes you comfy!

oh i have mate. just wondered about stem lengths on bikes overall.
dont get me started on them mondraker things……. 😆

so the genesis tour de fer has a longer toptube than your bike then?

Like I said, use Stack and Reach and then you can compare bikes – but the Tour de Fer does seem to be a long bike, but that seems fashionable for gravel bikes.

But stack and reach—certainly the latter—are more meaningful for MTB than they are for road. (Touring being somewhere in between depending on preference.) They tell you a lot about the relationship between the bottom bracket and the top of the head tube but they completely ignore the position of the saddle. And since on a road bike you’re seated nearly all the time, that’s not helpful.

For instance, I need a long saddle-to-bar reach and I also need the saddle a good way behind the BB. That doesn’t actually result in a high reach value on the geometry charts, because it demands a slack seat angle, which reduces reach for the same body position when seated.

Reach actually tells me pretty much nothing at all. IME, more often than not a large reach is the combination of a not-very-long top tube and a steep seat angle, both of which are precisely what I don’t want.

Reach actually tells me pretty much nothing at all. IME, more often than not a large reach is the combination of a not-very-long top tube and a steep seat angle, both of which are precisely what I don’t want.

Most of the cycling industry (eg Cervelo), specifically tri and road, disagree with you.
If you have a particularly out of proportion femur length I could see why you need your seat an unusually long way behind the BB. I have very long legs and have never failed to get my knee over the pedal spindle through saddle adjustment alone on any bike (that fits me and that I’m not trying to force a fit) without a layback seatpost. Seat tube angle is part of it, but stack and reach are prime.

The Genesis Tour de Fer is a bit of an oddity. It was a flat bar bike last year but this year they have fitted drops without changing the frames so they are really long, especially the larger sizes.

The Genesis Tour de Fer is a bit of an oddity. It was a flat bar bike last year but this year they have fitted drops without changing the frames so they are really long, especially the larger sizes.

thus confirming that I was right all along………. 😆

it is too long with a 100mm stem. I tried it earlier. now fitted with a 70mm 17degree rise. we will see. 😀

If you have a particularly out of proportion femur length I could see why you need your seat an unusually long way behind the BB.

I’m not sure. But I do seem to have quite a rearward position: 72-72.5deg seat angles, 20-30mm layback posts, and the saddle pushed right to the back (or close, depending on the angle/layback combination).

I’m guessing I’m not alone. I’m no expert on riding position but some others (including folk who work in bike shops and presumably fit plenty of people to bikes) on the CTC forum have remarked that no-one ever has a problem getting their saddle far enough forward, but it’s not uncommon to be unable to get it far enough back (it seems that a more rearward position tends to be preferred by distance riders, a more forward one by speedier riders).

For anyone in the same position, reach isn’t helpful, as it won’t tell you whether you can get enough saddle-to-bar reach. (And even to get pedal-to-bar reach, to gauge out-of-the-saddle comfort, you still need to do some maths to get the third side of the reach-and-stack triangle.)

Granted, if you can always get your seat in the right position regardless of seat angle—whether due to riding style or body shape—then it’s no big deal.

I guess that’s the majority and reach makes sense for most people; it just feels weird to me to be unable to envisage where the saddle will (or perhaps more pertinently, won’t) end up, and I’m probably stuck in my ways of 25 years of looking at geometry sheets where top tube is the most critical dimension for me.

thus confirming that I was right all along……….it is too long with a 100mm stem.

I’d say it confirms that everyone else was right all along: you’ve ended up with a top tube that’s longer than it should be 🙂

(It doesn’t matter. As long as you have a riding position you’re comfortable with and handling you like, then it’s all good. But fundamentally it’s not normal design to do what Genesis have done and just swap flat bars for drops: the normal approach when doing that is to shorten the top tube.)

The problem is when people fixate on A measurement, TT, reach, stack, angles whatever they tell you noting in isolation, you have to look at ALL the figures and understand how they interact on any given frame – i know you do Bez but it’s a general point 😉

I also lament the steep seat angles on a lot of road frames, especially on the smaller sizes which they seem to do to artificially ‘shorten” the TT measurement, grrrrr

I am away to france for a nice long tour, so hopefully it will prove comfy. cheers Bez, and all. 😀

I’m not sure why it’s taken me until now to realise that I should simply have been trying to sell you my adjustable stem 😉

joking aside, I was thinking about trying one.

what is it?

It’s for old 25.4mm bars, probably only any use as a paperweight these days 😉

Go, on tell us, what was wrong with the Ogre?

🙂

Go, on tell us, what was wrong with the Ogre?

nothing at all.
thing is that i cant really ride offroad now with any great success, so i have entered a few audax rides. and a road bike is a no go.
so i thought i would treat myself to a nice new tourer that is suitable for audax, and touring.
it is built a fair bit lighter than the ogre. so with a change of tyres, it should be half nimble.