Author Topic: Which Raven Model? (& Max Load Chart)  (Read 37022 times)

jawj

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Re: Which Raven Model?
« Reply #30 on: July 23, 2007, 09:03:41 PM »
Hang a minute Al, don't get it into your head that the Catalyst's fragile! It looks to be a great bike and I'm still debating the choice myself. I just fancy a Nomad as it has both V and Disc brake mounts, routing for the external gear box (which I already have anyway), S&S couplings that might prove useful (and certainly look rather nice!) and the ability to carry shedloads if I need it to.

DEFINTELY get in touch with SJSC and maybe even Andy Blance (the Thorn designer, who's very helpful) to discuss specifics rather than just listen to the denizens of the forums (although Stutho has been doing this for a while... [;)]).

Also, if the weight limit on the Catalyst really is 20kg (and I tried and failed to find where it says that's the limit on-road, though 12kg off-road is stated) decide if you will be carrying 20kg. 20kg is a heck of a lot, even carrying an excess. Using a front rack as well, as can be fitted to suspension forks, would mean you could carry quite a bit more than 20kg.

As Stutho wisely points out, do as much of your own research as you feel you need to. It's easy to rely on the forums, and they're great for real-world user feedback, but go to the original source for advice on the right bike for you.

Oh, and hold out for matte green! I'm definitely going to wait as it's beautiful [:D]

Your trip sounds like an adventure and a half! Mine was, for the most part, considerably more tame. My girlfriend at the time and I took an overnight train from London to Inverness (it was great to wake up in the highlands!) and headed North up the coast and then North West towards Cape Wrath. I decided to give John O' Groats a wide berth as I'd been there when I was younger and remember being underwhelmed by the fog...
Anyway, it sounds like we made the same mistake as you which was to head back down the Western side of Northern Scotland - directly into the prevailing wind! The slog in the driving rain from Durness to Scourie was extremely miserable... Our trip was quite tame in that we were on road and using campsites (hot showers!) but the isolation up there was wonderful. Just the occasional Dutch caravan spoiled the peace.
The greatest skill the trip taught me was that you can imitate a sheep at one end of a field and it will spread a chorus of "Baaaaaa!"s throughout the whole flock! Heh heh heh.

Hamish

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Re: Which Raven Model?
« Reply #31 on: July 23, 2007, 09:20:36 PM »
I have just bought a Catalyst as a do anything bike.  I noticed the 20 kg limit after I had ordered it but I don't thnk it is a problem for me.  

I intend to use my bike to commute (at present around 60 miles/week), touring- mainly family tours where I tow a trailer full of camping stuff, for day rides and, one day, I will use it for proper off road touring.

I went touring in Ladakh and Zanskar in India years ago (before I had even heard of anyone cycling there - we picked the route from a trekking book and the Times Atlas). I was on a steel, rigid Fisher MTB.  That bike did just fine but the Catalyst is a much better bike overall so I figure it would be OK for a similar tour.  We probably carried about 25 Kg when we had food on board.

I could have bought a Nomad but I can use the Catalyst as a MTB and on road I guess it is a bit more nippy with the shorter stays. It has a steeper top tube (think Kona Explosif) so less of those spacers people go on about- I wasn't too worried about spacers but I have to say that I think my bike looks fantastic.

I think Thorn are about to stop doing the Catalyst and replace it with the Stirling which will be similar but with disk mounts- apparently  people are asking for them.  I didn't want disk mounts as the disks on my kona MTB drive me mad on the road.

In terms of off road handling- whilst my Catalyst is still in road mode, a friend uses his for proper mountain biking.  He has done a load of the Welsh trails alongside the rest of us on Konas, Marins, Fishers, etc.  The Raven keeps up on everything and doesn't miss a beat in the mud when the rest of us are struggling with clicking and clanging rear mechs.

As the Rohloff habit is developing, I confess that I have been thinking that I could sell my Kona buy a Raven Tour minus the back wheel.  I would dedicate the Catalyst to mountain biking and use the Tour for everything else- that way it would only mean changing one tyre to swap between bikes and I would save 600+.  

In summary- if you want one bike to tour, ride proper off road and commute, etc, etc then the Catalyst is great.
 

jawj

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Re: Which Raven Model?
« Reply #32 on: July 23, 2007, 09:36:16 PM »
Oooh Hamish, you make a very convincing argument!

For me, price comes into it too: the Catalyst uses a higher class of tubing (Reynolds 853) but I'm not sure it would translate to real world benefits for me. A Raven Nomad would include some very nice rigid forks in the package as well as the S&S couplings.

Though you have got me thinking of the Catalyst again, especially as I wouldn't have to wait for one...

Couple more things Hamish: put a picture of your Catalyst in the Member's Gallery - there's not enough MTBs in there! And... NEVER EVER EVER sell your Kona. I had a dream of an Explosif once and sold it. I regret it to this day. :-(

Off to look at the Catalyst brochure again now!

stutho

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Re: Which Raven Model?
« Reply #33 on: July 24, 2007, 04:24:09 PM »
quote:
don't get it into your head that the Catalyst's fragile!

Well said Jawj, however I would be more concerned with the geometry than the tubes if you are thinking of exceeding the 20kg limit

Have a look at this thread it is here that I have got the 20Kg (on road) limit (from Andy Blance)


« Last Edit: July 24, 2007, 04:28:03 PM by stutho »

Al Downie

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Re: Which Raven Model?
« Reply #34 on: July 24, 2007, 05:27:23 PM »
Blimey. The decision's not getting any easier! On one hand I'm prompted to think of pictures of people in Delhi, transporting entire families, balanced precariously all over the frame of clapped-out, rusty old boneshakers (so maybe I should just tart up the old StumpJumper one more time). On the other hand, I can't help being seduced by the thought of a shiny Rohloff hub, good brakes and... SPRINGY FORKS! Oh yes. Maybe even a springy saddle too. LUXury.

It sounds like the most versatile and robust option would be the Nomad. With front suspension fitted, I'm guessing it'll be fine for some proper off-road use (I'm talking about playing in a forest rather than crazy downhill racing). However, taking into account what Andy said in the other thread about the load around the headset when using the front brake while fully laden, how robust would suspension forks be when put under that kind of forwards pressure? (As opposed to the up/down abuse they're designed to deal with.) Or are suss-forks just a non-starter for touring?
 

jawj

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Re: Which Raven Model?
« Reply #35 on: July 25, 2007, 07:00:10 PM »
Al, you'll never look back when you get a Rohloff! I've only used mine for mountain biking (where it's been flawlessly perfect in the grottiest of mud) but can't wait to get a Thorn frame to try it out for EVERYTHING. Incidentally out the Rohloff was orignally designed, I believe, FOR crazy downhill racing. [:D]
Your stumpy will no doubt conitnue to offer great service, but seriously think about a Raven, even without suspension. Suspension is mildly overrated for mountain biking (IMO!) and I've definitely had the most fun rides on 'rigid' bikes, steel of course. I've had several full-suspension bikes (I even had a couple of goes at downhill racing on my old Orange Patriot...) and they were great but hammering the rigid Explosif I used to have was out of this world. I can't wait to get a Nomad and see how it copes with touring, moutain biking and, especially, loaded off-roading.




Back to that 20kg limit:
Thanks for the link Stu, I remember that topic now. Well researched you!

And talking about 'only' being able to carry 20kg I was looking at racks today and noticed that Blackburn's toughest rack is rated for "up to 40lbs" which is just over 18kgs. That was a bit of worry for me as I'm sure I've WELL overloaded one in the past but anyway, it does mean that I'm sure we over estimate how much we need to carry sometimes, which isn't always a bad thing. (Also, don't buy an aluminium rack - if it doesn't snap it will get worn through by constant rubbing from panniers - IMO again...)

The important point is that you realistically consider how much you're likely to want to carry and don't compromise on handling/off-road capability if you aren't going to carry too much. e.g. if you aren't going to carry a month's food and water plus the kids and dog and want to go fast on road, buy a RST, or off road, a Catalyst.

Phew, long winded, but hope it helps if you're interested... [|)]

bike_the_planet

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Re: Which Raven Model?
« Reply #36 on: July 26, 2007, 03:00:11 AM »
quote:
Originally posted by stutho

quote:
don't get it into your head that the Catalyst's fragile!

Well said Jawj, however I would be more concerned with the geometry than the tubes if you are thinking of exceeding the 20kg limit

Have a look at this thread it is here that I have got the 20Kg (on road) limit (from Andy Blance)



But for what weight of rider?

I weigh 98kg and take around 20 Kg of gear on my derailleur-geared Nomad. In theory then, someone who weighs 60 Kg should be able to get away with heavier loads. I'm not suggesting it for a moment (why would you want to take 55kg with you anyway - hardly a 'getting away from it all' touring philosophy!!! [:)] ). But why can't it be done provided the bike is heavy duty?

A smaller framed bike for a smaller rider should, if anything, be stronger anyway; same gauge tubes but shorter.

I admit I am not the Thorn frame builder, and Andy Blance of course is. But I do think that there is some exaggeration made with talk of luggage weights when rider weight is not included in the equation!

Sorry if I'm labouring a point here!

Cheers,
 

ians

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Re: Which Raven Model?
« Reply #37 on: July 26, 2007, 08:18:42 AM »
quote:
Originally posted by bike_the_planet


But for what weight of rider?
 I do think that there is some exaggeration made with talk of luggage weights when rider weight is not included in the equation!

Cheers,




this is a good point and something I've often wondered.

Perhaps it's something to do with where the luggage (weight) is concentrated.  The rider's weight is distributed more or less over the whole bike - heavy panniers can hang on a flimsy rack in one particular place on the bike.  Maybe that causes additional stresses.

Just a thought.

ian

bike_the_planet

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Re: Which Raven Model?
« Reply #38 on: July 26, 2007, 09:46:11 AM »
quote:
Originally posted by ians

this is a good point and something I've often wondered.

Perhaps it's something to do with where the luggage (weight) is concentrated.  The rider's weight is distributed more or less over the whole bike - heavy panniers can hang on a flimsy rack in one particular place on the bike.  Maybe that causes additional stresses.

Just a thought.

ian



Certainly - having luggage at the back of a bike behind the rear wheel worsens the handling and, as you suggested, the average Blackburn rack is probably not reliable past 15Kg.

But I don't see how that would strain the frame tubing any more than a larger rider would. I don't see many manufacturers, Thorn included, suggesting that there is a limit to the weight of the rider for a given cycle model or size.

In which case, I assume that, if I was a a 6'3" lard-arse (I maintain I am 6'3" and sylph-like, but that's another story..[:D]) weighing 120kg and I wanted to order, say, a Raven Nomad, then Thorn wouldn't turn me away.

Which presumably means that if I was a 5'1" racing snake of only 60kg, and I too ordered a Raven Nomad, albeit a smaller one, then I would have far more potential luggage capacity that the big fella would.

Anyone offer any alternative thoughts on this? Mr Thorn???

Cheers,
 

stutho

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Re: Which Raven Model?
« Reply #39 on: July 26, 2007, 10:06:17 AM »
Just to muddy the water a bit more...

The weight of the rider is NOT equivalent to the weight in your pannier.  Why not?  Three reasons:

As you are riding over a bump your arms and especially your legs act like a shock absorber. This substantially reduces the impact load on the bike, as well as you!  

Centre of gravity, as others have mentioned.  This is especially important under heavy front braking.  Far greater forces can be generated in the headset and the front forks.  Normally a bike will endo  under heavy front braking however it takes far more force for this to happen when the weight is so far back (and low down).

The finally issue with pannier weight is the attachment points.  Under static conditions the weight is carried by the dropouts a very strong location, however under rapid deceleration (say by hitting a big bump) a large force is transmitted from the panniers into the seat stays, mid tube - this is NOT a strong location.

I agree that some allowance should be made for rider weight.  This is mentioned in the OP.  Unfortunately it is not an easy calculation to make.  I would also claim that road conditions are more important than the weight carried.

Final point (honest!)  Andy Blance has designed some of the finest touring bikes in the world. He also does some serious touring himself He knows his stuff and his advice can be trusted.

« Last Edit: July 26, 2007, 06:48:53 PM by stutho »

bike_the_planet

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Re: Which Raven Model?
« Reply #40 on: July 27, 2007, 01:34:50 AM »
quote:
Originally posted by stutho

Just to muddy the water a bit more...

The weight of the rider is NOT equivalent to the weight in your pannier.  Why not?  Three reasons:

As you are riding over a bump your arms and especially your legs act like a shock absorber. This substantially reduces the impact load on the bike, as well as you!  

Centre of gravity, as others have mentioned.  This is especially important under heavy front braking.  Far greater forces can be generated in the headset and the front forks.  Normally a bike will endo  under heavy front braking however it takes far more force for this to happen when the weight is so far back (and low down).

The finally issue with pannier weight is the attachment points.  Under static conditions the weight is carried by the dropouts a very strong location, however under rapid deceleration (say by hitting a big bump) a large force is transmitted from the panniers into the seat stays, mid tube - this is NOT a strong location.

I agree that some allowance should be made for rider weight.  This is mentioned in the OP.  Unfortunately it is not an easy calculation to make.  I would also claim that road conditions are more important than the weight carried.

Final point (honest!)  Andy Blance has designed some of the finest touring bikes in the world. He also does some serious touring himself He knows his stuff and his advice can be trusted.



I don't doubt for a minute that Thorn design some great bikes. If I had doubted that, I wouldn't have bought three over the last ten years! But that's not my point. Sure, good riders use their arms and legs to provide some graceful de-acceleration over bumps and thereby reduce forces that the frame experience.

But at the end of the day, the frame has to carry both the luggage and the rider. The only frame manufacturer who I have seen stipulate a max load weight ('load' here meaning rider + luggage) is Dahon (for obvious reasons).

If a rider weighs 97kg, as I do, and my panniers weigh 20kg, want to bet which contributes to the greater frame stress? I think it would be me, regardless of how I ride!!!

Like any other structure, a bike will have a max load limit. Whether designers of steel bikes really calculate down to this level, I'm actually not sure. Conventional steel bicycle frames have evolved over the last 100 years +, and I suspect that most designers just use a reasonable gauge steel (my old nomad has 1.0/0.7/1.0 gauge main frame tubes with 2mm stays) to ensure the thing doesn't snap and leave it at that.

Whilst frame stability will be influenced by where the load is carried on the frame, the rider's weight, usually being far greater, will be the governing factor in frame overload and possible failure.

Cheers
 

stutho

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Re: Which Raven Model?
« Reply #41 on: July 27, 2007, 09:02:06 AM »
Hi bike_the_planet,

We seam to be arguing on different issues here!  The only point I am trying to make is that I don't believe you can simply equate rider mass to pannier mass.  (i.e. as Dahon seam to be doing.)

I have said that 'some allowance should be made for rider weight' and I stick by that.


 


mmackay

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Re: Which Raven Model?
« Reply #42 on: August 10, 2007, 09:09:27 PM »
Hi,

Could the Mercury be added to the chart?

I'm new to Thorn's range and an inexperienced cyclist.  I'd like a bike primarily as a means of taking healthy exercise to extend my retirement as long as possible .... and I can see attractions of liesurely holiday  touring.  I'm most grateful for the comparison chart to see at a glance where the Raven land lies.

I'm assuming the Mercury's strengths are biased towards "on road" use, but how does it compare with Tour Sport or City Slicker? ..... and how much is it's "unsealed road" capability compromised?
 

stutho

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Re: Which Raven Model?
« Reply #43 on: August 13, 2007, 03:21:04 PM »
Hi Mmackay,

Welcome to the list.

I have restricted the table to Ravens only.  However I will say that that the Mercury looks to be a very fine bike amid at fast-unloaded road travel.  

It has a short wheel base that would make it agile (and good at sprinting and climbing) at the expense of stability.  Stability is the most important factor in the "unsealed road" column so you are looking maybe a 2 or a 3.

mmackay

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Re: Which Raven Model?
« Reply #44 on: August 13, 2007, 04:45:27 PM »
Thanks for this orientation, Stutho ….. I think stability is the more important characteristic for me, even although every assist is required with climbing.  


quote:
I have restricted the table to Ravens only.

I‘m just a new boy on the block, but I felt indignant that you just didn’t understand the Raven model offerings.  You see, having read the marketing stuff I believed Rohloff-equipped  =  Raven, this bird being the trade mark of Rohloff, and kindly permitted by the German company to be used on all Thorn’s offerings using this hub gear …. to differentiate them from the other Thorn models.

However, experience wins every time ….. I now notice there are indeed four exceptions to this rule in the present fifteen hub-geared offerings listed ….. of which Mercury is one.

Perhaps this one belongs to another forum, but it raises the question “When is a Raven a Raven?”    Is there a simple answer to this?

Mel Mackay