Thorn sizing

[janeh]

Hello,

My Sherpa has chipped paint and is going back for re spraying. I am thinking of swapping for a frame for straight bars. Thorn have recommended a 500L (I am 5'4" with standover 77.5cm). This has a top tube that is longer than that on my husband's bike (he is 5'10"). Does this mean Thorn are recommending a bike too big for me or is my husband's bike too small?!

Is their sizing advice generally good? It is difficult trying to size a bike when you can't see it but Thorn seem confident they can do it. The problem is though, once the components are swapped, the new bike is now 2nd hand.

The current frame has drops and is probably a bit too short (probably more due to me pushing for a short frame than due to Thorn's advice). I don't want to make a mistake again but I probably really should trust Thorn's advice. Obviously my husband's Marin Novato and a Sherpa have different geometry.

Any thoughts?

Jane

[Danneaux]

Hi Jane,

For what it's worth and hoping it will help...

When I ordered my Sherpa, I didn't start from scratch on the sizing. At that time (Summer 2011), Thorn had a different sizing system, and I simply transferred my measurements from a bike (several, actually) that fit me perfectly. The Sherpa I received (a 560S with drop handlebars) fit just like my other bikes. The only "adjustment" from Thorn's usual was the inclusion of a large-layback seatpost to get my relationship with the bottom bracket to match my other bikes.

The Nomad sent in replacement was modeled after my Sherpa's measurements. It not as ideal a fit frame-wise with drop 'bars due to different geometry (590M with longer top tube than the 560S Sherpa's), but with some juggling of the stem's reach (shorter) and brake lever placement on the handlebars (higher and closer), the effective fit is the same as the Sherpa and matches my other bikes so it feels the same when on it. The Nomad also required the large-layback seatpost to put me where I needed to be over the BB with my preferred Brooks B.17 saddle, which has short rails; the seatpost setback makes up for that.

I do know the Sherpa Mk3 line was redesigned after my Mk2 was produced, and the new frame geometry would have resulted in a less-ideal basic fit for me. I do think it could have been adapted with adjustments in stem length (reach).

All of this is by way of saying I found Thorn's sizing to be excellent in duplicating the fit of a bike I already owned and liked and fit me properly. I don't know how it would have been if I had started from scratch.

Thorn have recommended a 500L (I am 5'4" with standover 77.5cm). This has a top tube that is longer than that on my husband's bike (he is 5'10"). Does this mean Thorn are recommending a bike too big for me or is my husband's bike too small?!...Obviously my husband's Marin Novato and a Sherpa have different geometry.

Without seeing the bikes or knowing if one or both have dropped or straight handlebars, I would guess the difference is due to geometry and intended use and preferred position.

Jane...do you have the opportunity to try some friends' bikes or perhaps take a test ride of a local bike so you can get an idea how a different frame/bike might feel or fit? Actually getting on a bike can make a tremendous difference, and even a cm one way or another on handlebar reach or height can transform a bike from good to bad or vice versa.

I hope something in this helps.

Best,

Dan.

[wildrover]

Hi Jane!

My S/O is the same as yours, but I'm a 1/2" to an 1" taller.  Last year when I bought my Raven Tour, Thorn recommended I get a 487L, since I wanted to use the comfort bars.  I've compared the specs on the old and new RTs, which Thorn says has the same geometry as the Sherpa, and the Virtual TTs are the same between the old (487L) and new (500L) RTs.  I don't feel stretched out on the bike at all.  Actually I've just bought a longer stem, and I often use the Ergon 5's to stretch out more.

The biggest issue for me though, was getting used to the comfort bars when I'd always ridden drops.  The measurements didn't transfer well from my old bike style to the new, and it was VERY important for me to get the uncut fork to work the fit out. 

So I would trust Thorn's recommendation, and enjoy the view!  Actually, I hope to hear what you think about the handling of the new frames. 

Regards,
Holly

[janeh]

Hello,

Think things have been clarified a bit more by taking a pic of me on husband's bike and sending it to Andy B. He confirmed what my thoughts were: That the bike was a bit too strecthed out but better position wise than my old bike (which was too small). So he still feels that the 500L will give me the position I need.

Thanks for the helpful comments,

Jane

[phopwood]

Jane,

I just built up a Sherpa using a 500S frame and it fits me perfectly, and I am the same size as you, I went for a small as I have always had problems finding a bike to fit me.  I went for a small based on Andy's advice at the bike show at the NEC, I sat on a 500L and it felt too long for me.

But I feel you are always better taking a test ride before making the investment. Is it possible for you to visit thorn and have a go on a 500S or L.

Peter

[janeh]

Hmm, is a bit difficult to visit SJSC. Need a 500L or S owner near Edinburgh!

[janeh]

Hello Peter,

Do you have the same height and standover as me?

Jane

[JWestland]

For what it's worth...I cycle a 525L XTC with a standover of 77 CM and a a virtual top tube CTC of 55.5 CM.

I am 5 5 and have longish arms/legs but a short upper body. The bike is setup with drop bars. In order for this to work I needed to put on a short stem (8 cm reach) and need to put the saddle all the way forward.

On my straight/moustache bar bikes a virtual top tube of 54 cm is perfect for me without having to put the saddle forwards.

It looks like that 500S Sherpa has exactly that top tube length (540) so yes with straight bars it should be fine I would say The 500L is 575 I think that might be too big...

[StuntPilot]

Hope this helps Jane ... I have a Thorn Raven Tour 2009 model 512L (I have Thorn Comfort bars on it). My inside leg (shoes off, book between the leg, and measuring from the floor up) is 79cm. My height is 173cm. The Raven Tour top tube mid-point is about 75cm above the ground.

Yes, we are a long way from Thorn HQ! I am South of Edinburgh - you are very welcome to contact me and come and try the bike if you need to.

Richard

[phopwood]

Jane,

Sorry for the delay I am 162cm tall and my standover is 76cm.  I have comfort bars set so the top of the bars are level with my saddle, but this is a personal choice.  But I feel very comfey on my 500s.  I am sure that I could have made a 500l fit but my biggest problem for every bike I have ever brought is reach, so the s was recommended by andy.  Hope this helps a little.

Peter

[janeh]

Thanks for the replys. I think the Thorn Raven just South of Edinburgh (and probably quite near me as we are in Penicuik) would be too big but thanks for the offer of a test ride.

Andy B was so sure I would be ok on the 500L that I went for this frame. Hmm, it's a long bike and I am actually not really sure it's ok. The 100mm 17 degree stem he suggested is too long I think and so far I am just using the 90mm one I already had. He suggests I raise the bars to get the right reach too. I'll just have to do more test riding, but if it doesn't feel ok I might be in a bit of a pickle!

Cheers,

Jane

[StuntPilot]

Jane

Glad you have got your bike. I am sure it will be fine. If it is any consolation, when I got mine I thought it was the wrong size.

I made small individual adjustments in this order:

1: Saddle height - extended to max height where I could only just reach the ground with the tips of my toes while seated (test ride and reduce by small amounts between tests so my hips are not moving up and down while peddling).

2: Handlebar height on the stem - so I could practically take pressure off my hands and not feel like I was falling forward.

3: Adjusted saddle forward and back so I did not slide forward or back while cycling.

Its amazing how even a small change of a few mm can make a difference.It  took me a while but I am now totally satisfied with the fitting and comfort.

Keep us posted on your testing and final solution! At least with a Thorn you have 100 days to be happy with the bike!

[rualexander]

Even though it is just a frame you have bought and Thorn don't specifically offer the 100 days deal on Sherpa frames (I think), I'm sure they will offer to swap the frame for you if you ask them.

[Erudin]

From the Sherpa brochure:

[Danneaux]

Hi All!

Perhaps the following will be helpful...

The Thorn FAQ, "What if I don't like my bike?" ( http://www.thorncycles.co.uk/FAQ/100day.pdf ) refers to "...all complete bike sales".

The Thorn FAQ, "What if there is a problem with my new bike?" is here: http://www.thorncycles.co.uk/FAQ/problem.pdf

Root link for the Thorn Cycles FAQ is here:
http://www.thorncycles.co.uk/faq.html

From the Owner's Manual ( http://www.thorncycles.co.uk/thornpdf/ThornBikeOwnerManual2Web.pdf ): "Thorn branded frames, framesets and frame kits are not included in the 14 or 100 day 'money back if not delighted guarantee'". [page 40]. According to this, the Thorn-branded bicycles are covered by a 14-day trial; the Raven (Rohloff) bicycles have a 100-day trial; both trials are subject to residency requirements and may not apply in some geographic areas, as noted in the brochures.

According to the Owner's Manual (ref. above), the warranty against failure or defects varies by model and/or intended use (i.e. competitive use and racing). All warranties apply only to new frames or new complete bikes (not used) and are valid only for the original owner.

That said, Thorn are very cooperative and committed to making things right for new owners and are easy to talk to if contacted directly.

Best,

Dan.