Identifying a Thorn Chainset

[rifraf]

Gidday everyone,
a newbie from Aussie here.  I was looking for a single geared crankset and spotted one on ebay.
The auction number was 190776314549.  Having heard of Thorns quality yelled from the rooftops down here in the Antipodes I hit the buy now without realising that Thorn actually has a number of different sets/models available.
I'm hoping that someone may be much cleverer than the simple soul that I am and be able to recognise which model set I've purchased.
Wish I'd bothered to check first of course but I was already down a Shiraz or three when I spotted them.
I had a squiz at the Thorn models available at SJS Cycles but alas I'm still in the dark.
Thanks to anyone who has time to answer.

[rualexander]

It looks like a standard Thorn chainset, which would be this one, but the ad doesn't state the crank length so could be anywhere between 140mm and 175mm, most likely 170mm though. I notice that the Thorn cranks in the link I just gave only go from 140mm to 160mm, which seems odd, they used to have the full range, maybe out of stock.
The chainring is this one in a 38 tooth size.

[il padrone]

A  bit of rough measurement off the photo (using the 55mm radius of the crank bolts) suggests the crank is most likely a 175mm length.

[rifraf]

Hi rualexander and il padrone,
thanks for your input.
He seems as good as his word anyway as promised, it was posted within the hour and I received a tracking number.
I just need to sit back and relax.  It'll be arriving in the post no doubt in a couple of weeks and I'll be able to see for
definite myself.
I must get a smaller wine glass me thinks.
Cheers

[rifraf]

It looks like a standard Thorn chainset, which would be this one, but the ad doesn't state the crank length so could be anywhere between 140mm and 175mm, most likely 170mm though.

Cranks arrived today but I"m still unsure exactly which ones I've received.
They are 170mm long. Stamped with XS2R in a rectangular box close to the bottom bracket spindle square tapered hole.
Closer to the pedal spindle hole there is stamped SX 170 T- 8

[in4]

Dan'll be along shortly, he'll sort you out!

[Danneaux]

Thanks for the vote of confidence, Ian!  Rif', I think the cranks you received are these:
http://www.sjscycles.co.uk/thorn-110-74-pcd-triple-solo-alloy-crankset-silver-prod1673/

...but I'm betting the final voice of authority on this will be Dave Whittle, since he can confirm the markings on the back.

You surely got some nice photos there, Rif'. Product photos are hard to do, but a nice non-glare background (fleece or textured knit) and a bounce-flash umbrella help a lot. Fine job!

Hope this helps.

Best,

Dan.

[rifraf]

Thanks for the vote of confidence, Ian!  Rif', I think the cranks you received are these:
http://www.sjscycles.co.uk/thorn-110-74-pcd-triple-solo-alloy-crankset-silver-prod1673/

...but I'm betting the final voice of authority on this will be Dave Whittle, since he can confirm the markings on the back.

You surely got some nice photos there, Rif'. Product photos are hard to do, but a nice non-glare background (fleece or textured knit) and a bounce-flash umbrella help a lot. Fine job!

Hope this helps.

Best,

Dan.

Hi Dan,
thanks for your update.
Appreciate the kind words on the photo.  Pure fluke on my part that they worked out ok but my now ancient Sony F717 did its magic, as did the ironing board the cranks are sitting on.   Just the camera handheld and nothing else.
Is Dave another forum member?
My next question will be about what length bottom bracket to achieve a 54mm chain-line and whats currently considered the best spec
Shimano square tapered version for the job.  
I'm sort of open minded about the chainring position and not yet sure if I'll use a chainguard ring or not.

[JimK]

Those look mightily similar to the cranks on my bike, which was built up by the SJS folks.

On mine, the chainring is bolted on the outside of the arms, rather than on the inside as in your photo. But yeah it is probably a matter of getting the chain line right, which is way out of my realm of competence!

FWIW the item number on my invoice is: 1673l170

[JimK]

Here's where 1673 takes me... looks about right...

http://www.sjscycles.co.uk/thorn-110-74-pcd-triple-solo-alloy-crankset-silver-prod1673/

[Danneaux]

Hi Matt!

Dave Whittle was in SJSC Sales, now in SJSC Workshops, and drops in with the Official Word on such things from time to time. He is here:
http://www.thorncycles.co.uk/forums/index.php?action=profile;u=43

However, this question has come up in the archives before, and these posts pay prove helpful"
http://www.thorncycles.co.uk/forums/index.php?topic=3118.msg14315
http://www.thorncycles.co.uk/forums/index.php?topic=3298.0

All the best,

Dan. (...who is adding an ironing board to his bag of product-photography tools, thanks to Rif's success)