Thorn Raven Nomad mark 2 Series frame and fork X510 for sale

[paulwebster]

Thorn Raven Nomad mark 2 Series frame and fork X510 matt black. Purchased about 12 years ago for  End to End  but barely used since, approx 2000 miles in total. Has lived in my garage with rare outings.   Ex-box black anodised Rohloff hub (19 sprocket circlip type) serviced annually. Thorn seat post, chainset (38t) and guard.Shimnao UN55 73 mm shell

26 inch (559) wheels Regina Andra rims with Shimano Deore  HB-M590 front hub,   Deore brake levers,  Shimano XTR  V brakes with Shwalbe marathon tyres Thorn comfort bars ,Humpert Change adjustable stem.

Tubus rear rack (and  low riders not attached in photo) spare  sprocket,  Thorn eccentric bottom bracket ed  Shimano Un55 shell .

the bike is in very good condition. A slight cosmetic dent in down tube  is  covered by a rohloff transfer. Asking price  £750 

update more details. bike currently set up for a tall person to try out but the frame is a small size .Steering column stack height set by Thorn originally for a person wanting it that way but I can cut down to suit. For a quic k sale on reflection I am reducing my asking price £600.I really want to clear out my garage. I live in Birmingham and would really want any prospective buyer to come out bike out etc.NOW SOLD LOCALLY

[Andyb1]

I always wondered, what was the logic of having the front brake mounted behind the fork?
More room for front panniers?

[mickeg]

I always wondered, what was the logic of having the front brake mounted behind the fork?
More room for front panniers?

I have no clue why they did it that way.  I find no advantages and several disadvantages to that on my Nomad Mk II.  I bought mine as a frame and fork, built it up myself.  Initially I set up my rear with canti brakes, later changed to V brake. 

When V brakes first came out, manufacturers were talking about the hazards of the canti brake system.  If your cable broke on a front wheel and your straddle cable did not break, the straddle cable on canti brakes could lock up the front wheel and cause injury.  Maybe Thorn decided that it would be impossible to use canti brakes this way and chose to do it that way for that reason?  I have canti brakes on three bikes, two of those have fenders that would prevent a straddle cable from catching on tire tread.

V brakes on a Nomad Mk II need to have very long arms if you run larger tires, I use 57mm tires on mine.

[in4]

I find they tend to accrue a lot of mud;  create a sort of collection point for all the ‘stuff’ you ride through, particularly when it’s wet.

[mickeg]

I find they tend to accrue a lot of mud;  create a sort of collection point for all the ‘stuff’ you ride through, particularly when it’s wet.

When I pack my bike with the S&S couplers into a small case, I can't fit fenders.  On my Iceland trip on a rainy day, I had so much mud accumulate on the cable actuated V brake on the rear that my brakes would not release.  I had to get off the bike and pull the brake arms apart each time I used the brake.

That was rear, and they always are installed that way in the rear, did not happen on the front.  But after that I decided to use some mini little fenders when I go somewhere without the full fenders.  So, that was my last tour with no fenders of any kind.

I don't have a good photo of my bike without panniers that show the mini fenders, but the attached photo has the rear wheel with fender.  I made the bracket out of a piece of aluminum bar about 19mm wide, roughly 3 or 4mm thick, attached with one bolt in the seatstay bridge fender mount hole.

Second photo shows the front mini fender, did the same there, made a bracket out of aluminum that is attached under the fork crown with one screw.

These mini fenders do not extend under or in front of the brake, only behind, but they do a good job of keeping mud mostly off of the brakes.  They came with brackets that would not work on my bike, so I had to fabricate my own.

[Danneaux]

I recall a past post here where Thorn designer Andy Blance spoke to the matter. If I recall correctly, the goal of this placement was to reduce brake judder and squeal by pulling the mounts, brakes, and pads inward under brsking rather than outward as in conventional designs.

I recall seeing some early Thorn-sourced photos that showed cantis mounted on the rearward-facing fork bosses. They were actuated by a Sun Tour bell crank -- a little teeter-totter device. The cable was routed through one side of the bellcrank and secured to one canti brake arm, the bellcrank served as a bedstop for the housing. The other side pulled canti through a short straddle cable. Equal and opposite forces were split evenly between the arms with disconnection as easy as a v-brake. Sometimes, a similar setup is used to actuate rear cantis from below on an open frame.

There are times my good memory is a curse, so here's a truly esoteric bit of trivia that may have inspired Andy's rear-side fork brake boss placement: I can't speak for Andy, but as a longtime roadie and with Robin Thorn starting with bike repairs...

In the early 1970s, road rims were available with flat-sided/"straight"/parallel or angled sidewall designs, where the rim edge was wider than the base. Most sidepull calipers of the day had pretty flexible arms that were pulled forward by the brake pads. 

On the rear, when used with angled rims, this had the effect of pulling the pads from the wider to narrower part of the rim, reducing braking. Canny bespoke framebuilders and mechanics would reverse the rear sidepull caliper, mounting it on the forward side of the seatstay brake bridge. Under braking, the pads would be drawn forward and upward into the wider part of the angle-sided rim, creating a mild self-energizing effect and reducing judder and squeal.

I have a couple bikes dating from 1970s originally equipped with angled rims and sidepulls and, yes, there was a noticeably positive difference to reversing the rear brake. I'm guessing such influenced Andy, at least for a time, but of course confirmation would have to come from him.

Whew! Enough historical trivia and esoterica from me for the moment; I'm tapped out!

All the best, Dan.

[mickeg]

Interesting on mounting the calipers on the other side made it better.

I have several complaints about the front brake system design on the Nomad Mk II, but since this thread is intended to sell someone's bike, I will refrain.

[Danneaux]

I have several complaints about the front brake system design on the Nomad Mk II, but since this thread is intended to sell someone's bike, I will refrain.

I hear you, George, and appreciate the effort to avoid off-topic thread fragementation. I created a new topic here...
https://thorncyclesforum.co.uk/index.php?topic=15450.0

I'd love to hear your thoughts!

Best, Dan.