Cycling UK Forum

peetee wrote: ↑8 Aug 2024, 2:08pm Transfer of l, and effect of forces applied to a bike frame is a very complex subject and, although I have made significant inroads, I’m not fully up to scratch yet. Many years ago I used the limited knowledge I had to great effect with a custom steel MTB frame where I chose every single tube from a Reynolds list. It’s fantastic to ride and way better that a ‘tubeset’ model from that time.
I do believe that it’s possible to have a compliant and responsive bike frame if the builder considers the riders needs, weight, power and riding style and has access to the materials and tooling for the job.
I understand that rigid frames feel (and usually can be) faster and that almost always results in a harsh ride - how can it not?
Well, perhaps by making the frame more resistant to lateral and torsional forces because it’s those forces that come in to play when full-gas efforts such as out-the-saddle sprints or hill climbs are on the cards. This can be achieved with a substantial main ‘triangle’ ie, head, seat, top and down tubes. At the same time lighter gauge seat stays can be used - perhaps curved to perform the same function of a front fork. Along with a stiff frame a short wheelbase is advocated for maximum results but maybe a better option would be slightly longer chainstays so their horizontal section can be maximised between the crankset and rim/tyre. Wide but vertically slim chainstays would be stiff horizontally and compliant vertically which takes us further in the right direction.
I am, of course, referring to these tubes individually and, as inferred earlier, things are not that simple. No tube in a frame works independently and any force applied to one will affect an adjacent tube in one way or another. Likewise no force is independent and whilst transferring power the frame has to track straight and true, support the riders weight and deal with braking and road forces in a controlled manner.
That heavy main tube and slim stays look was a strong feature of early Cannondale road frames.
I’m not a great fan of aluminium bikes but stole myself to buy a 1990’s ‘Dale which was immaculate and can’t have had more than a few yards use as the rims have no brake block marks whatsoever. I have a bit of recommissioning to do on it but I’m keen to get it down the road to see if that performs to my liking or not and compare it to my steel and titanium bikes.

DiTBho wrote: ↑31 Jul 2024, 9:21pm

rareposter wrote: ↑31 Jul 2024, 7:33am Have you got anything specific in mind?

Something like this.
Made in 2003.
Classic design
TIG welded
Oval section down tube.

vs something like this



Made in 1996
Classic design
Brazed
Circular section down tube.

rareposter wrote: ↑31 Jul 2024, 7:33am

DiTBho wrote: ↑30 Jul 2024, 11:41pm I would like to understand how much steel technology has improved from the 80s ...

Hugely - there are far more steel alloys now whereas back in the 80's you had a couple of variants of 531 and that was your lot.

DiTBho wrote: ↑30 Jul 2024, 11:41pm I would like to understand ...how much do the various frames weigh?

PH wrote: ↑16 Jun 2024, 9:42pm Can you really get 35mm tyres in a Yukon? Is that without guards? I've only seen 28's with guards, that's pretty much the same restriction ....

I'm running Jack Brown 700C x 33.3 mm on my VN Yukon on Mavic Open Pro and they fit just fine - in the summer, enjoying the extra plushness whilst the mudguards are off and "on holiday". Rivendell have them made by Panaracer for them to fit their bikes that have road bike brake clearances...

https://theeverydaycyclist.wordpress.co ... -of-plush/

https://www.rivbike.com/products/jack-b ... 10092-blue

Despite the extra plushness and larger air pocket in these lightweight (c.300 g) high- volume 33.3 tyres, the substantial extra stiffness conferred to way it rides by the very over-sized tubes of Van Nicholas frame - with its 1 5/8" down tube / 40mm ) comes through very noticeably compared to my lightweight steel frames (1 1/8"
down tube / 28.6mm ) running 28/25 tyres which are less stiff and transmit less road jarring.... so belying the myth that comfort is "all in the tyres".... That immediately noticeable extra rigidity may be welcome if you are carrying a load, but for unladen day rides I leave the Yukon at home and take a lightweight steel frame where I feel the feedback in the frame and appreciate its suppleness over the road...

Nearholmer wrote: ↑23 Jul 2024, 4:57pm Ergotec sell adjustable ones, with which it would be possible to play a limited number of tunes, but they have a very low safety rating because of the joints.

colin54 wrote: ↑30 Aug 2018, 8:03pm

hamster wrote:

Brucey wrote:if it says



on it then it is a fake, just as a watch with 'rholex' written on it would be.....

cheers

My typo ...a Whitcomb would truly be a cut and shut! Rolega perhaps?

Witcomb, proudly brazed in Deptford.

As hamster says, his is a Witcomb but if he lived near Liverpool it could well have been a Whitcomb in a

parallel universe.This link explains all....

http://merseysidebicycles.blogspot.com/ ... tcomb.html

Brucey wrote: ↑18 Jun 2024, 6:14pm if I was KOTW, I would make rims a wee bit heavier by including a really durable brake track, and stick with rim brakes, on the road, at least. They could be hydraulically actuated of course, and the net result might be the best (however you choose to define it) bicycle brakes ever.

Brucey wrote: ↑4 May 2024, 11:29am has anyone used the panaracer product? Incidentally, isn't this more than a bit overdue? We have had almost uncuttable woven kevlar fabric since the 1980s. I wonder if it possible to fit it into another tyre and use it repeatedy?

Brucey wrote: ↑4 May 2024, 11:29am has anyone used the panaracer product? Incidentally, isn't this more than a bit overdue? We have had almost uncuttable woven kevlar fabric since the 1980s. I wonder if it possible to fit it into another tyre and use it repeatedy?

rareposter wrote: ↑29 Apr 2024, 12:05pm

....XTR M952 is probably one of the few complete groupsets other than some of the vintage Campag Record to command very high prices if any ever comes onto the market although admittedly the number of potential buyers of such kit remains very low...