Author Topic: Newbie - frame sizing  (Read 3677 times)

Nigel

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Newbie - frame sizing
« on: November 08, 2014, 09:28:11 AM »
Hi there

I am considering a Thorn Raven and have an initial question regarding the 'How to get the perfect set-up on your bike' form on the website: http://www.sjscycles.com/thornpdf/SetUpHiRes.pdf

At 58, I have been riding a basic 699.00 Specialized mountain bike for many years, regularly doing the South Downs Way in a day. Occasionally I slap on a pair of 1.5" road tyres and ride to Paris from Dieppe in a day. I am always clapped-out at the end, but I am always left wondering if my set-up is right, would I have been 'less-clapped-out' if my setup had been different

The questionnaire starts with 'Are you happy with your current set-up?', the truthful answer is, '..err well, I think so, but I don't want to shell out the thick end of 2.5K on a new bike only to be left wondering if I have the right fit'

How 'person specific' are the frames? Is there a general stash of frames for a 6' 1" bloke with a 34" BFSO measurement which are then fine tuned with 'bar and saddle settings, or is the frame hand made to your exact mesurments?

Any advice?

Cheers


julk

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Re: Newbie - frame sizing
« Reply #1 on: November 08, 2014, 10:31:39 AM »
Nigel,
I bought my first Thorn at 58 and it was a hand made one, the fit was very good.

I think all the Thorns are now made to a set of sizes which allow exact fitting by small variations of components.
The biggest choice to make is dropped (shorter frame) or straight (longer frame) handlebars.

Thorn are very good at getting the fit right and will always change things to give the best fit as after sales service.

10 years on I still fit on and enjoy riding my Thorn.
I have gradually raised the stem up the steerer tube (don’t cut the excess off) and recently put a shorter stem with an upward angle.
I am moving to a more relaxed riding position as my body ages.

Go on, get one. If you don’t like it it comes with a genuine money back guarantee.
Julian.

Kuba

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Re: Newbie - frame sizing
« Reply #2 on: November 08, 2014, 01:57:16 PM »
How 'person specific' are the frames? Is there a general stash of frames for a 6' 1" bloke with a 34" BFSO measurement which are then fine tuned with 'bar and saddle settings, or is the frame hand made to your exact mesurments?

Hi Nigel, and welcome to the forum.

Thorn frames are not person specific at all, but Thorn take pride in supplying enough sizes off the peg to accommodate all riders, including those who need step-through frames. This is why they offer each size with a short and long top tube, which in principle should be used with either straight (long TT) or drop bars (short TT), but if your upper body is, say, shorter than usual, or you want a very relaxed position, then you can opt for short TT with straight bars and thus shorten the reach. Given the variety of the Raven sizes, and multiple stems/bars/saddles you can use, I bet you'll find a suitable size. And by the way, given 587L seems to be the right size, I've just sent you a PM as I have a Raven of this size that I'll be selling.  ;)

Several years back Thorn used to make some of their frames on site in Bridgwater, like then rather wonderfully-looking EXP, but even then these machines came in specific sizes (though in some cases you could choose from more than 20 of them). The rationale, as far as I remember, was that Reynolds tubes also come in a limited range of sizes so while it was a custom build, effectively you could only build N different frames from any given tube set. I'm no expert but understand that holds true for any frame hand made to your exact measurements, they will size you up and then build one of a limited range of sizes they can make from any given tube set (so the advantage is that you can request a specific geometry or tubes to accommodate your riding needs, but you don't need made-to-measure to get a bike that fits; Thorns do!).

One last thing - if I were you, I'd really try and test ride a bike before buying, if Bridgewater is far away maybe there is a Thorn owner near you that can help?

Rockymountain

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Re: Newbie - frame sizing
« Reply #3 on: November 08, 2014, 02:13:09 PM »
Good luck with your bike hunting. I am 6' tall with a BFSO of 34" (long legs and shortish torso) and take a 587L Nomad. Sounds like the right size for you as well. 

If you can, you should pop into Thorn (make an appointment first) and they'll measure you up and give you a ride on one of their demonstrator bikes. That should help.

By the way, whenever I've been in or contacted Thorn on the phone, I've always had excellent service. The staff are knowledgeable and helpful. You'll enjoy the experience.

Fraser

JimK

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Re: Newbie - frame sizing
« Reply #4 on: November 08, 2014, 02:41:57 PM »
I would say that if you go on long rides with your present bike and you're exhausted at the end of the ride but don't have strange aches in specific places like neck or shoulder or knees etc., then probably your present bike fits decently well.

ians

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Re: Newbie - frame sizing
« Reply #5 on: November 08, 2014, 03:44:14 PM »
Hello Nigel

I'm 6'2" and my Raven Tour was 587L (L frames are designed for straight bars, S frames are designed for drops).  Perfect size.  I've had three frames from Thorn over the years and all have been right and comfortable size-wise.  I think they know their stuff.

ians

martinf

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Re: Newbie - frame sizing
« Reply #6 on: November 08, 2014, 09:12:42 PM »
How 'person specific' are the frames? Is there a general stash of frames for a 6' 1" bloke with a 34" BFSO measurement which are then fine tuned with 'bar and saddle settings, or is the frame hand made to your exact mesurments?

Thorn have several fixed sizes for the height, generally with two different frame lengths to suit drop or straight bars. As you suspected, they are fine tuned with 'bar and saddle settings to fit.

For some people at least, the sizes overlap a bit.

I'm a tad shorter than you and have two Thorn Raven Tour frames.

The first is a 587S frame set up with drop bars,a fairly short stem and a Rohloff hub. This is my long-distance tourer.

The second a 612S frame set up with straight bars, a much longer stem and a Shimano 8-speed hub. I currently use this as a utility bike.

If necessary in the future, I am fairly sure I could get a comfortable position for drop handlebars on the 612S or for straight bars on the 587S by using suitable stems. I have kept the steerers full length, so will be able to move the stems up as I get older.

Raven Tour has been replaced by the Raven, if getting one of those I would have chosen the 600S size.
« Last Edit: November 08, 2014, 09:15:38 PM by martinf »