Tourer for gentle off-roading?

[Orbit531C]

re. "people get ever so worked up about things that - in the real world - make little practical difference":

Jan Heine cycled 1,218 km in just 60:05 hours for the Paris - Brest- Paris on his very low trail steel Rene Herse with just 27.7mm trail (73° head, fork offset of 70mm).

CJ ex CTC technical editor rides a high trail of 68-70 mm trail on his Holdsworth Mystique "My Holdsworth Mystique gravel bike frame, that I chose as the basis for a clubrun/audax style of bike in order to get actual... mudguard and toe clearance in carbon, has 71° & 50mm [fork offset], so 67mm of trail.
That's more than I'd have thought ideal, a LOT more than the Thorn Audax it replaces... and did feel very different at first"

I can't imagine two bikes feeling more different to ride...

[531colin]

71 degrees and 50-odd millimetres offset is pretty standard touring bike stuff.

Spa's Tourer, the first Spa bike I designed, is 71 deg. 54mm offset, same as my old Bob Jackson.

One of my favourite bike shop memories is of a couple coming to Spa in the old shop, wanting to test ride a Spa Tourer each. I fitted them up and sent them off.
They came back in due course, the young lady was bouncing off the walls. I asked if it went OK., he said it was OK, i think she managed a rather feverish nod. I asked if they wanted to try anything else, he said he would like to try a Galaxy, she squeaked a "no".
I fitted him up with a Galaxy and off he went to test it.
I asked her what was going on, why was she bouncing off the walls? She looked out of the window, where her husband was setting off, and I said that I had been married 40 years, and whatever she said to me, her husband wasn't going to hear it from me.
She said, and I remember it better than I remember yesterday...."My husband bought me a road bike, and until I rode that bike of yours, I didn't realise that there was such a thing as a drop-bar bike which didn't wander all over the road as soon as I tried to look behind me."

EDIT.....CJ tested that Spa tourer for the CUK magazine (might have been CTC back then?) and said something like it was the smoothest tourer he had ever ridden....he bought the test bike.

[531colin]

find it very difficult to get anything definitive out of the Rene Herse video clip.

It is a strange old video, and I linked to it mainly because he talks usefully (IMO) about wheel-flop, rather than for the demonstration of how to ride into a log, which was all a bit weird.

I ride stuff like that quite frequently, and I was convinced in my head that I could have got round the log on my bike (65mm trail on the tyres it has), although I would probably have picked a different line that seemed to be free for the taking, and I know full well that I can (usually!) do near-standstill sharp turns, because there are three places locally where I challenge myself to ride without putting a foot down which absolutely necessitate them.

Whether he really, really couldn’t do it on that short trail bike, you’d only know by trying it.

I have to say I had the same reaction, I reckon I could ride that, as an un-athletic man in my mid-seventies. But i would certainly have my backside off the back of the saddle.
To me, it beggars belief that a young bloke (I'm assuming its Jan Heine riding?) who is a considerable athlete can't do it on almost any bike....Martyn Ashton could do it on his road bike, but then theres not much he can't do! https://www.youtube.com/watch?v=7ZmJtYaUTa0

Also, I don't get why he made the video in the first place? To show that his favourite design is fundamentally flawed? Jan Heine has some "interesting" views on steering geometry, he says https://www.renehersecycles.com/a-journ ... -geometry/ a bike which steers quickly to dodge potholes is also more stable.

[531colin]

The "bike insights" piece linked by Jim, and from which Nearholmer posted a graphic appears to be dated 2024.
Again, I didn't find any actual geometry numbers from either "bike insights" or for Nearholmer's hybrid.
So, are we talking about "modern mountain bike geometry" where 45mm offset forks are plugged into frames with ever-reducing head angles? ....because I have never ridden anything like that, so I can't comment on them.

[Orbit531C]

Dave Moulton, framebuilder who later went to work in the States, has an interesting blog page on the evolution of bicycle fork offset and trail from near zero trail in the 30's and the attendant theory about it then: he writes

"... Bicycles built in the 1930s through the 1950s typically had as much as 3 ½ inches (9cm.) of fork rake resulting in very little trial, often zero. There was a theory at that time that trail made steering heavy and sluggish.

I remember writing an article for Cycling magazine in the 1970s; someone wrote to me saying my theories on trail were wrong, and sent me an early 1950s article from Cycling to prove it.

The old theory was that if you had the front wheel’s point of contact behind the steering axis, when the steering was turned 90 degrees the point of contact was then on the steering axis line. Therefore, the front end of the bike had dropped slightly, and to straighten up again, the steering had to lift the weight of the bike and rider; thus sluggish handling.


While this statement is true, in practice when riding, the front wheel never turns 90 degrees. In fact during normal cornering the front wheel turns very little, making this whole theory about the front of the bike going up and down irrelevant.

I started racing in the early 1950s and I can say from experience the bikes of that era did not handle and corner near as well as today’s designs. These bikes handled reasonably well because frames were built with much longer wheelbases, wheels and tires were heavier, and tires were fatter.

Road conditions at that time, especially in countries like Italy and France were often appalling. The long fork rake and the long wheelbase had a dampening affect on the rough road conditions.

As road conditions improved, bikes were built with shorter wheelbases and at the same time tires became much narrower. It eventually became necessary to increase trail to keep the bike going straight.

There was a somewhat chicken and egg situation with regard to shortening wheelbases and adding trail. In my case I shortened the fork rake to shorten the wheelbase and found the resulting increase in trail was an improvement.

Other older established builders, still clinging to the little or no trail theory, shortened the fork rake but at the same time made the head angle steeper to maintain the trail status quo.

This made for some very squirrelly bikes being built in the 1970s, with 75 and 76 degree head angles and front wheels almost touching the down tube. Shorter chainstays to shorten the rear end of the bike were pretty much universally accepted.

A shorter wheelbase means the bike will turn on a tighter radius. Think of a school bus and a compact car, which one will turn tighter? The front wheel turns less on a short wheelbase bike on any given corner; this translates to having to lean less to get around a bend.

I think the big advantage I had was that I was still actively racing and could try out these changes, and experience the difference first hand. Eventually everyone agreed that trail was not a bad thing and head angles became sensible again.

Frames I built had around 2 ½ inches (6.3cm.) of trail. In the early 1970s I did experiment with more trail but found that the bike felt sluggish and had a tendency to wander when climbing or sprinting out of the saddle.

As with any design aspect, more is not necessarily better; for a road bike with a 73 degree head angle the optimum trail seems to be around 2 to 2 ½ inches (5 to 6.3cm.)"

see-http://davesbikeblog.squarespace.com/bl ... story.html

Photo: Typical European road conditions in the 1940s. Louison Bobet leads Gino Bartali (striped cap) and André Brulé in the 1948 Tour de France. Picture from The Wool Jersey.]

[djnotts]

^
"Road conditions at that time, especially in countries like Italy and France were often appalling. The long fork rake and the long wheelbase had a dampening affect on the rough road conditions."

Coming soon then to a road near you!

[Nearholmer]

Again, I didn't find any actual geometry numbers from either "bike insights" or for Nearholmer's hybrid.
So, are we talking about "modern mountain bike geometry" where 45mm offset forks are plugged into frames with ever-reducing head angles? ....because I have never ridden anything like that, so I can't comment on them.

The hybrid had 71mm trail, and 70 degree head angle, so at the very lower edge of MTB territory, but enough wheel-flop to really catch me out a couple of times.

It’s the sort of thing where, if you’re used to the way a bike handles, all is fine, but when you’re not, and it does something very different from what you are used to at a crucial moment, it is highly disconcerting.

The only actual MTB I’ve ever ridden is my son’s 29er, which I originally bought secondhand for us to share. That isn’t very aggressively stretched out either, but the weight of the suspension forks, and the general shape of it, make the handling quite alien for me, and I won’t go further than a quick trip to the shop a mile away on it. I’ve zero appetite to try a full-on modern MTB, I just wouldn’t know how to ride it properly.

[oaklec]

How about a Sonder Santiago?

https://alpkit.com/collections/sonder-santiago

Edit - Oops, already suggested on page 2. I'll get my coat...

[Carlton green]

71 degrees and 50-odd millimetres offset is pretty standard touring bike stuff.

Spa's Tourer, the first Spa bike I designed, is 71 deg. 54mm offset, same as my old Bob Jackson.

One of my favourite bike shop memories is of a couple coming to Spa in the old shop, wanting to test ride a Spa Tourer each. I fitted them up and sent them off.
They came back in due course, the young lady was bouncing off the walls. I asked if it went OK., he said it was OK, i think she managed a rather feverish nod. I asked if they wanted to try anything else, he said he would like to try a Galaxy, she squeaked a "no".
I fitted him up with a Galaxy and off he went to test it.
I asked her what was going on, why was she bouncing off the walls? She looked out of the window, where her husband was setting off, and I said that I had been married 40 years, and whatever she said to me, her husband wasn't going to hear it from me.
She said, and I remember it better than I remember yesterday...."My husband bought me a road bike, and until I rode that bike of yours, I didn't realise that there was such a thing as a drop-bar bike which didn't wander all over the road as soon as I tried to look behind me."

EDIT.....CJ tested that Spa tourer for the CUK magazine (might have been CTC back then?) and said something like it was the smoothest tourer he had ever ridden....he bought the test bike.

This post reminds me that an early post of mine on this thread suggested seeing what Spa had to offer, that comment still stands and I think it a sound direction to go in. The only better way to my mind (than a new Spa) is an appropriate second hand Spa that’s been well cared for and offered at a good discount. Spa have a sale on at the moment, the prices look pretty good value and even had me thinking for a moment.

Page one.

If I wanted new then Spa Cycles would be towards the top of my list.

I note that tyre clearances on frames can vary, so a bike that’s equipped with 32mm tyres isn’t necessarily limited to that size and might well be happy to accept much wider tyres. That possibility is something for potential purchasers to consider and check.

[Orbit531C]

^
"Road conditions at that time, especially in countries like Italy and France were often appalling. The long fork rake and the long wheelbase had a dampening affect on the rough road conditions."

Coming soon then to a road near you!

Good point!
In these conditions analogous to "gentle off-roading", is it my imagination or has the Tour leader Louison Bobet actually got a (short) mudguard on his (gravel) bike -avant le lettre- - as he crosses the Tour de Fer in the 1948 stage 8 in the snowy Pyrenees from Biarritz to Lourdes of the TDF?

https://cyclehistory.files.wordpress.co ... artali.jpg

[Brucey]

.... I didn't realise that there was such a thing as a drop-bar bike which didn't wander all over the road as soon as I tried to look behind me."....

I perhaps should have mentioned this before, but one of the things that changed overnight for me when I started using more trail was what it was like for others trying to follow my wheel. Apparently, following my low trail wheel was kind of unsettling, whereas once I'd got a bit more trail, this was no longer the case.
I think it is nearly always highly instructive to look at your tyre tracks left on the road when you go through a puddle. Usually neither wheel goes in a perfectly straight line; instead the front wheel tends to move in a slight weave, in time with the pedals. The rear wheel follows suit, but in a somewhat more restrained fashion. I think what happens is that each pedal stroke presents itself as a fresh balance perturbation, which is then corrected by the inherently stabilising nature of the castor.
No discussion of steering geometry can be entirely divorced from the slightly vexed topic of shimmy. All castors will shimmy, it is just a question of how badly,and at what speed/frequency too What typically happens in a shimmy is that the frame or fork acts like a spring, there is usually a mass (which is often the rider).and the resonant frequency is close to another which is either in use already, or is insufficiently damped. Shimmy can also be caused by a load on an insufficiently stiff rear rack.

Motorcyclists may know of this as a 'tankslapper', the effects of which are always most intense at a certain road speed. Somewhat ironically, horrible steel bicycle frames are usually too stiff to shimmy at lower speeds, whereas steel frames that you might quite like the feel of, because they are 'responsive' will often shimmy badly at lower speeds.

Note that someone else (so different weight, height, speed etc.) may not experience the same thing at all. If you have a frame that might shimmy, it is as well to understand at what speed the shimmy is most likely to occur. If you ride near to the critical speed 'no hands' and slap the handlebar sideways, often the shimmy can be provoked.
If you are a bit under the critical speed, but would normally expect to accelerate slightly because (say) you are freewheeling downhill, the extra energy that would normally produce more speed goes into the shimmy instead. The shimmy can get rather violent, but normally just a hand on the handlebars (or a knee on the crossbar) will calm everything down again. Just a few bikes/frames will try to shimmy at 'normal' speeds, often aided and abetted by the cadence or rate of wheel rotation. If you have a bike like this, it is probably best if you just avoid the critical speed in the short run. Longer term, you may be able to 'fix' it, but it isn't guaranteed.

[djnotts]

^ "Motorcyclists may know of this as a 'tankslapper', the effects of which are always most intense at a certain road speed."

I never experienced this (a cautious rider!), but as I recall the general advice was to take both hands off the 'bars. This would obviously slow the bike. Whether it worked I know not.

Slightly related, the only time I experienced a sudden scary deterioration in handling (on a baby KH400 triple) was down to an over-inflated front tyre. I never again trusted a garage air line pressure gauge and always carried my own!

[jimlews]

How about a Sonder Santiago?

https://alpkit.com/collections/sonder-santiago

Edit - Oops, already suggested on page 2. I'll get my coat...

I wouldn't use that in UK offroad conditions. There just isn't enough mud clearance, let alone mudguard clearance.
There is perhaps 5mm under the fork crown. The whole thing would become completely clagged up within 100yds
on a typical UK bridalpath.

[531colin]

.........
This post reminds me that an early post of mine on this thread suggested seeing what Spa had to offer, that comment still stands and I think it a sound direction to go in. The only better way to my mind (than a new Spa) is an appropriate second hand Spa that’s been well cared for and offered at a good discount. Spa have a sale on at the moment, the prices look pretty good value and even had me thinking for a moment.

Page one.

If I wanted new then Spa Cycles would be towards the top of my list.

I note that tyre clearances on frames can vary, so a bike that’s equipped with 32mm tyres isn’t necessarily limited to that size and might well be happy to accept much wider tyres. That possibility is something for potential purchasers to consider and check.

Listing here viewtopic.php?t=157086&hilit=Spa of Spa bikes and max. tyre to give 10mm mudguard clearance.

[531colin]

............
I think it is nearly always highly instructive to look at your tyre tracks left on the road when you go through a puddle. Usually neither wheel goes in a perfectly straight line; instead the front wheel tends to move in a slight weave, in time with the pedals. The rear wheel follows suit, but in a somewhat more restrained fashion. I think what happens is that each pedal stroke presents itself as a fresh balance perturbation, which is then corrected by the inherently stabilising nature of the castor......................................

I am aware of a huge network of wormholes we could drop down if we start on this topic, but why is it necessarily an inherent castor correction rather than the rider putting the wheels under the centre of mass?