Tourer for gentle off-roading?

[Nearholmer]

For a given head angle, increasing trail will, I think increase wheel-flop and, so far as I understand things, will increase stability at speed, but increase the tendency to “dive in”, which I would regard as a form of instability, when cornering at low speed, so I think that, as with most things, it’s a case of selecting a compromise that suits the way the bike will be ridden.

Of course, selecting the head angle in the first place also affects handling, and my limited understanding suggests that it can be a more significant decision than selecting the trail.

[SwiftyDoesIt]

With mostly no concern and occasionally just a little care I find that I can go all over the place on 700 x 35C’s (at small sizes a bit of extra width makes a noticeable and significant difference, well thats my experience) and 700 x 38C’s would likely be plenty wide enough for pretty much anything - well anything that’s rideable, and for what’s not rideable you have two feet. My 700 x 35C’s run in an ordinary road bike (a low end old Raleigh) and a lot of hybrid or trail bikes use 700 x 38C and have done so for ages … maybe see the second hand market and customise something to your tastes?

If I wanted new then Spa Cycles would be towards the top of my list. However I tend to buy second hand and then tweak what I’ve got to suit my needs.

This post I agree with wholeheartedly.
700x35 Conti Speed King CX which I use on my 'gravel' bike are grippy enough for most situations you'll encounter, I use my all rounder bike with 32/28mm slicks and this does light mud and rutted paths without too much bother for me if I slow down a bit.

Of course I realise we are all different in skill level and attitude to what is comfortable and indeed, what is "gentle off-roading" but I recall this young lad, Pidcock something or other, did alright in a world champs CX riding 32mm tyres on a cantilever shod bike in horrible snow/ice/sand/hardened mud conditions going at it like a bat out of hell.

At the OPs weight, (20kg less than me) one can reduce the pressures a fair bit compared to on road with the Marathon's, something with light knobbles, even the 'small knob' of the Panaracer etc should suffice for gentle off road use, there's no need to go above 40mm IMHO for anything except proper MTB riding.

Buying something s/hand as you say allows one to fettle to the hearts content knowing you've still spent far less than a new machine you're likely going to change bits on anyway.

Could be a situation of buying another older Galaxy, fit some nice high end cantis and top end pads, shod it with slightly wider 'gravel' wheels and tyres, a carbon seatpost and handlebars and jobs a good 'un

[531colin]

"When I use a word" said Humpty Dumpty "it means just what I choose it to mean - neither more nor less."

Yesterday, Brucey posted about "low trail" bikes

................
1) it retains a light steering feel even when the bike is loaded up or heavy wheels are fitted.
2) it seemed to make the steering unusually sensitive to geometry changes or deficiencies of any kind.

The downside to 1) was that should you fit very light wheels in the same bike, the steering was probably too light. Most racing machines had more trail than this, and were (for the most part) more stable because of it.

One of the side-effects of 2) was that it didn't take much to upset the 'riding no-hands' experience. Should there be even a slight discrepancy in the dish of the front wheel or it's exact position in the dropouts, it would be quite normal to only be able to ride 'no hands' whilst obviously leaning the bike. For a very long time I didn't own wheels which didn't work differently each way round and nor was I capable of fitting them accurately enough anyway. Had I had a longer trail I probably wouldn't have even noticed.

In addition, if you ride low trail then I think there may be less information about lateral tyre grip coming at you through the handlebars. If you ride high trail the bike is more stable but it may also be more tank-like too and when off-roading at low speeds the camber thrusts may be worse.

My question is, was that low trail achieved (or accompanied by) a steep head angle? For clarity I regard 73 degrees and above as steep.

[531colin]

With the same Humpty Dumpty caveat, I find it very difficult to get anything definitive out of the Rene Herse video clip.

The different camera angles make any meaningful comparison difficult. Surely you would do multiple runs with identical camera placement and post the most comparable ones?
It looks to me that on his own bike because he is much too close to the fallen tree he starts the turn much too late, and his weight is forward.

He says he is too weak to turn the bars without assistance from wheel flop on the high trail bike. Personally, I have never even felt any steering input from wheel flop on un-tarred surfaces, but I don't know if I have ridden a bike with similar geometry to the one in the video, and one reason for that is he doesn't give us geometry information for that bike.

[Orbit531C]

I wonder if this helps - it gives very detailed geometry details of "René Herse 650B Randonneuse Jan Heine 585"


https://bikeinsights.com/bike-geometrie ... -heine-585

[Orbit531C]

... I'm assuming that that frame is one of the very limited edition "80th Anniversary Rene Herse Framesets" that
J.Heine commissioned based on his own bike.. for wealthy cyclists with an insatiable urge to try that particularly French approach to randonneurs. Potential buyers first had to write saying how they were going to use the bicycle, before they were selected to get on the list of potential owners....and only after paying top dollar

80th Anniversary Rene Herse Frameset

https://www.renehersecycles.com/shop/bi ... n-payment/

[djnotts]

Skimming the above geometry issues makes me wonder how I've managed to ride so very many, very varied, bikes over last 25 years without ever bothering my brain with such knowledge!

[531colin]

Sub 30mm trail is definitely low.
73 degrees parallel frame with 70mm offset is.......interesting!
I couldn't keep that in a straight line on smooth tarmac if I as much as glanced behind me, let alone ride it down a steep slimy track.

[Orbit531C]

...deeper in the brochure Jan Heine writes:

" TECHNICAL SPECS
Geometry / Handling / Fit:
These frames are designed with a low-trail front-end geometry for a bent-elbows riding position with a light touch on the handlebars. If you tend to grip the handlebars firmly, these bikes will feel 'nervous,' as they react even to small handlebar inputs.

.....

[Brucey]

IIRC the head angle of my first witcomb was around 72 degrees. I have owned quite a few bikes with head angles in the 72-73 degree range; However I have also owned/ridden tandems, delivery bikes and MTBs with much slacker head angles as well.

[Orbit531C]

Skimming the above geometry issues makes me wonder how I've managed to ride so very many, very varied, bikes over last 25 years without ever bothering my brain with such knowledge!

What fascinates me is that Jan Heine has ridden that bicycle on some amazing long distance events & very fast:
"To some, the Herse may look like a classic from a bygone time, but its performance is totally modern. I choose it when I want to go far and fast, so I’ve ridden it in 2 Paris-Brest-Paris, 2 Raids Pyreneen, the Oregon Outback..."

"....the Velo-News editor when he heard about my FKT (Fastest Known Time) on the Oregon Outback, the 363-mile (585 km) bikepacking route that stretches all the way across Oregon, from the California border to the Columbia River. So much of my bike goes against bike industry trends…

....Except for the fact that the bike was 1:14 hours faster than the previous best. As much as I’d like to claim superior legs, all the other racers who have ridden the Oregon Outback in less than 30 hours are stronger and faster than I am. If it’s not the rider, then the bike at least has to contribute…"

https://www.renehersecycles.com/oregon- ... r-madness/

[cycle tramp]

Skimming the above geometry issues makes me wonder how I've managed to ride so very many, very varied, bikes over last 25 years without ever bothering my brain with such knowledge!

What fascinates me is that Jan Heine has ridden that bicycle on some amazing long distance events & very fast:
"To some, the Herse may look like a classic from a bygone time, but its performance is totally modern. I choose it when I want to go far and fast, so I’ve ridden it in 2 Paris-Brest-Paris, 2 Raids Pyreneen, the Oregon Outback..."

"....the Velo-News editor when he heard about my FKT (Fastest Known Time) on the Oregon Outback, the 363-mile (585 km) bikepacking route that stretches all the way across Oregon, from the California border to the Columbia River. So much of my bike goes against bike industry trends…

....Except for the fact that the bike was 1:14 hours faster than the previous best. As much as I’d like to claim superior legs, all the other racers who have ridden the Oregon Outback in less than 30 hours are stronger and faster than I am. If it’s not the rider, then the bike at least has to contribute…"

https://www.renehersecycles.com/oregon- ... r-madness/

...that's a top link - nice to see the return of 26" wheels

[Nearholmer]

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.

[rareposter]

Skimming the above geometry issues makes me wonder how I've managed to ride so very many, very varied, bikes over last 25 years without ever bothering my brain with such knowledge!

Because, much like with cars, people get ever so worked up about things that - in the real world - make little practical difference.

Poring over geometry charts can give a basic idea of bike fit to those that know what they're looking for but you can dramatically change the handling of a bike by raising or lowering the tyre pressure by 30psi so - in the real world - most people can get on most bikes most of the time and (broadly speaking) "adapt" to them.

Head angle, trail and rake all work together to influence the steering and handling - seeing one figure on its own doesn't really tell you a lot. As a general rule, the designers have already done the hard work and when designing (eg) a road bike, it'll have desired road bike handling attributes...

[Nearholmer]

Also, if you’re an engineer, it’s simply very interesting.