NEW-Thorn Catalyst Rohloff MTB

[Andrew]

Here's a forum sneak peak of the Raven Catalyst info before the web and print brochure are completed.
The frames are all in stock and ready to build up!

Thorn Catalyst 2005
from £1499 GBP with Pace RC31 fork

The Catalyst is very similar to the Enduro; it uses the same Reynolds 853 tubeset, it has identical geometry (except the chainstays are ½” longer) and it comes in exactly the same range of 5 sizes (they sound slightly smaller, so that they have a different frame number, to avoid confusion with the stock system).

Why a different model if it is so similar to one we already produce?

The Enduro is designed for serious mountainbiking in UK conditions, it is designed to carry only the smallest of loads, the Enduro is very precisely focused…the Catalyst is much more multi-functional. It can be built up into a bike which will excel in one of the following categories;
[1] An easy going, low maintenance, less expensive, Rohloff equipped mountainbike.
[2] A state of the art, trailer-pulling, round the world touring bike.
[3] A front suspension light touring bike with proper rear carrier and mudguards…in other words a supremely sensible hybrid with more sensibly sized wheels!

What are the differences that allow the Catalyst to be multi-functional, whilst the Enduro is so sharply focused?

The, previously mentioned, ½” longer chainstays and the provision of rear drop out carrier bosses (made possible by the absence of rear disc mount, which competes for space with dropout carrier eyes) means that a standard rear carrier can be used…this carrier can accommodate medium-sized rear panniers with heel clearance for most people without putting too much weight too far back for optimum stability. (The extra ½” also allows the “maximum tyre width, with sensible clearances” to be increased to 2.3”)

The Catalyst has fittings for a proper rear mudguard, at the dropout, under the seat stay bridge and at the back of the seat tube…this allows for massive mud clearance between the chainstays and BB when the Catalyst is in its MTB mode.
The cable routing guides provided are for the standard, 500/14 CC OEM version of the Rohloff hub which is considerably less expensive than the 500/14 CC DB OEM hub, which must be used with the disc brake on the Enduro…however it is still possible to request the external gear mech version of the hub (500/14 CC EX OEM) as an upgrade.

The Catalyst has V brake bosses…it does not have disc fittings. Whilst expensive, top quality disc brakes are very desirable in heavy UK (winter?) mud, they can be a pain to maintain for everyday use. The discs brakes’ rim-saving qualities can easily be duplicated by the fitting of ceramic rims. Their awesome braking performance in dry off road conditions or general road conditions can easily be exceeded by the fitting of top quality V brakes, especially when top quality levers are fitted, which can be adjusted for increased leverage. In fact, in these conditions, the V brake is the brake of choice, having a much better “feel” with more modulation, than a disc!
On a tour a V brake needs few tools to maintain and it uses easily available service items (cables and brake blocks)
It is often said that having disc brakes makes life easier because having a buckled wheel will not matter…this is not strictly true and please consider that during transportation of the cycle a disc rotor itself is very vulnerable, and once damaged a small warp in the rotor can not be removed…this produces a noticeable drop in the quality of the feel of the brake. And a large deformation can not be straightened sufficiently to allow the rotor to pass through the calliper at all…this will mean that the brake will be applied during every rotation of the wheel, forward progress will be at best very frustrating…if possible at all.
It is easier to true a buckled wheel than it is to replace a rotor! V brakes can be easily adjusted to allow a slight buckle of the wheel to pass through them, almost without being noticed and a really seriously buckled wheel would need to be trued before it could be used with a disc brake in any case…it is impossible to ride a bike at speed with a seriously buckled wheel.
Car and Motorcycle disc brakes often suffer from seized pistons when exposed to winter road conditions…there is no reason to believe that cycle disc brakes will suffer fewer incidents.
With today’s motor vehicles you have no choice other than discs and considering vehicle weights and today’s traffic, you would not want any other system…But you do have a much better option available to you, for most applications, on a bicycle!

What size Catalyst should I have?

There are 5 sizes available, these sizes range from small to large, with some different top tube length options. Because the suspension fork takes up so much room, and being for UK conditions we wanted to be able to fit a crud catcher, we can not make any extra small sizes. We have chosen not to make any extra large sizes either because, for the intended uses, we would have needed to commission a new tube set.

Size Small…this is the smallest size we can make using a straight top tube and a diamond frame design, with crud catcher clearance, to allow it to be as small as possible, it has been designed to perform at its best with 80mm travel forks. This size could suit some men but it has a short top tube and it is designed to be perfect for most, averagely proportioned, women from 5’ 5”to 5’8”.
 Size Small Extra Long…this size gives much more reach for slightly shorter than average people with shorter than average legs…it too is designed for an 80mm travel fork.
Size Medium…This frame is almost as small as we can make with 100mm travel forks and crud catcher clearance…it should suit averagely proportioned people from 5’9” to 6’
Size Medium Large Extra Long. This size gives a more aggressive position for averagely proportioned people from 5’10” to 6’2” or a more conventional position for tall people with shorter than average legs (long backs). It is designed for 100mm travel forks.
Size Large…this is the largest size we make, it is designed for 100mm travel forks and is suitable for taller people with average proportions 6’ to 6’3”.

What will happen if I use a fork with different travel to that which is intended?

Using an 80mm travel fork on a frame designed for a 100mm travel fork will steepen the head and the seat angles by 1 degree; the change to the seat angle can usually be compensated for by sliding the saddle back on its rails…but the change to the head angle will affect the way the bike handles; the delicate balance between sharp handling on singletrack and stability on fast fire roads will be changed…the bike will be even sharper on singletrack, but may exhibit instability when taking big hits at high speed, especially in strong cross winds. The top tube will also be lowered by approximately 20mm. The converse will also apply when fitting 100mm travel forks to a bike designed for 80mm.

I like the idea of V brakes…what is the ultimate set up?

Currently, Shimano XTR V brakes and levers and either Mavic X717 ceramic rims for mountainbiking or Mavic EX721 rims for heavier duty work, are the ultimate set up.

I want to tow a heavy trailer very long distances over severe terrain, I want the strongest, most trouble free wheels possible, what rim should I use? Which tyres should I choose?

The Sun Rhyno rim will outlast all other rims…its heavy weight is entirely due to the thickness of the aluminium used…especially at the braking surface! We have literally sent tandems around the world on this rim and the wheels have stayed so true they did not have to be touched! If you don’t want the weight, if you have sufficiently deep pockets, if you are prepared to use a spoke key occasionally and you do plan to end your journey at some point (!) the Mavic EX721 Ceramic rims are a better option.
Schwalbee Marathon XR 1.9” tyres do not roll as quickly as most other tyres but they are really tough and last longer than any other tyre we have tried…you need to have a good reason not to use these!

I want to use the bike every day, in all weathers, to commute on tow paths, jump kerbs etc, I would like light weight and minimum maintenance, I want a good spec, but I don’t want to blow the budget, what would you suggest?
Shimano Deore V brakes…these are powerful and work sweetly, consider XTR if you live in a hilly area and/or travel at high speed in traffic!
Mavic X 717 ceramic rims…these will last well and, being lightweight, give you a turn of speed,
Schmitt dynohub…you will always be able to see where you are going when it gets dark,
Pace RC31 fork…very light weight, no maintenance at all, good comfort on non challenging surfaces and we can easily fit ‘guards to them,
Panaracer Pasela 1.75 tyres…fine on tow paths, great on country lanes, quick in the town,
P55 mudguards…strong, durable and very effective,
Thorn Std carrier with perfectly aligned Vista LED bracket…carry the shopping home, or the PC to work and be confident of being seen in the dark!

I want to use one bike to commute to work, to go on  holiday and to take mountainbiking at the weekend, what would you suggest?

Shimano Deore V brakes…these are powerful and work sweetly, consider XTR if you are very serious about your mountainbiking, Mavic X 717 ceramic rims…these will last well and, being lightweight, give you a turn of speed, consider EX721 ceramic rims if you will be doing a lot of trailer pulling.
Fox Vanilla forx…These are the longest lasting, most reliable, plushest riding and, to our knowledge, the lowest maintenance fork currently available.
Panaracer Pasela 1.75 tyres…fine on tow paths, great on country lanes, quick in the town,
P55 rear mudguard…strong, durable and very effective,
Crud catcher front “guard”… this will provide some protection during wet commutes, consider also fitting an Ortleib bar bag, which will provide even more protection from tyre spray.
Thorn Std carrier with perfectly aligned Vista LED bracket…carry the shopping home, your panniers on B+B tours, or the PC to work and be confident of being seen in the dark.
Cat eye HL EL400 front LED light…ultimate in reliability with high visibility, consider an additional high performance rechargeable system if you travel on unlight routes.
The above spec will work well as a commuting or light touring bike…
For cycle camping holidays, simply tow a trailer;
For w/e MTB use, remove the carrier and rear guard, change the tyres to 2.1” Panaracer fire XC and away you go!

What other upgrades should I consider?

With a Rohloff transmission and a high quality chainring, you really do not need expensive components, of course for some people carbon bars, stems and seatposts enhance their enjoyment…they certainly look good, save a little weight and give small increases in comfort, they are desirable but not essential. More expensive chainsets, bottom brackets and chains may also be desirable but far from essential.
If you ride at night a Schmidtt dyno hub is certainly worth having…specifying one when you purchase the bike is, by far, the most cost effective option.
Ceramic rims are a good, if expensive option for most people and upgrading the brakes to XT levers or full XTR will be of benefit to those who really push the limits.
 We can offer a multitude of options…you can specify every detail of your bike if you wish, or simply accept that one of the standard bike specifications will give excellent service and value for money. For more specific uses, the options outlined above are highly recommended.


3 colours:
[1] Matt charcoal powder coat
[2] Red powder coat
[3] Blue powder coat

5 sizes:
[1] 531 S
[2] 532 S/XL
[3] 558 M
[4] 564 ML/XL
[5] 588 L

[Stijn]

I’m intrigued by this new design. It’s definitely nicely positioned between the raven and the Enduro. The rear carrier arrangement looks a bit to extended for loaded touring, due to the short seat tube, but if the design has been road tested in Tibet (by the look of it), then I’ll rest my case.

On my raven frame, which has longer chain stays then this new Catalyst frame , I already have very little heal clearance. But then, I use big bags.  The catalyst will definitely take smaller bags better then an ordinary mountain bike geometry, without upsetting the bikes balance.

I’m a bit puzzled why the bike is being presented with a Pace RC31, nice and light, but do they come with V-brake bosses?

I’m perfectly happy with my Raven. But if Thorn would produce a Catalyst in Titanium, Mhhhh….

[Andrew]

PACE RC31 fork fitted with V brakes...[]

[Stijn]

Clamp on V-bosses. I see!

By the way, great pictures!

So how about the titanium Catalyst? Is Thorn ready to take the next step?

[Sprocket]

Road tested in Tibet? Perhaps not in the photo with the sea in the background. Could it be the Canaries?

[Stijn]

The top one could well be Devon, the lovely lady, test driving her new steed.

I was referring to the bottom picture. The geology looks like the Himalayan. The blue in the sky, you only get really high up. So could also be Pamir, or Indian Himashal Pradesh. I don’y think it was in the Andes.

Andrew, were was the photo taken? I'll send you a post card when I get there. [8D]

Cheers,

Stijn

[Andrew]

quote:Originally posted by Stijn

The top one could well be Devon, the lovely lady, test driving her new steed.

I was referring to the bottom picture. The geology looks like the Himalayan. The blue in the sky, you only get really high up. So could also be Pamir, or Indian Himashal Pradesh. I don’y think it was in the Andes.

Andrew, were was the photo taken? I'll send you a post card when I get there. [8D]

Cheers,

Stijn

Hi Stijn,

The top photo was taken in Dorset.
The touring photo is in the Himalaya's.

Look forward to the postcard! []

Andrew