Thorn 130mm BCD 5 Arm Reversible 3/32 Inch Single Chainring - Black

Customer Reviews (20)
4.7 / 5| Write your review
£49.99 Please note this product has selling restrictions to your country. was
Manufacturer : 
SJS Cycles part number : 
Manufacturer part number : 
for use with 3/32nd or 1/8th chains.
Product Reviews (20)
Questions & Answers (13) Q & A
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Product Reviews (20)
Overall Product Rating 4.7 / 5
Just what was needed
06 Aug 2022
5 / 5
I recommend this product
A really good quality item.
Really long lasting, great quality.
16 Mar 2021
5 / 5
I recommend this product
ProsLong service life, reversible.
Long time user on my commuter bike, must be at least 3 years and I've not even had to reverse it yet. Because it's not worn out quickly and effectively increased the pitch between the teeth, the chain and sprocket have also not worn in sympathy so although the price might seem a little steep compared to similar in value terms I've never had better.
Solidly built
By Anonymous
20 Apr 2020
5 / 5
I recommend this product
Seems well made so hopefully will provide plenty of life.
Brompton Trailer Spaniel Dartmoor
By Anonymous
02 Mar 2020
4 / 5
I recommend this product
ConsCosts of shipping sting
ProsThey have what you need.
The great thing about SJS is that they have what you need, no matter how esoteric. Need to go low on a Brompton? = SJS will come up with something that will save your knees! Only downside is cost of shipping - because of the cost I only tend to visit SJS for the esoteric stuff I cant get elsewhere
Perfect Ring!
By slowalloon
27 Nov 2019
5 / 5
I recommend this product
ProsWell made, looks great, reasonably inexpensive.
Searched high and low for a replacement ring for my singlespeed and found this beauty. Well made, the black contrasts nicely with the machined surface. More importantly it runs beautifully and quietly with a KMC 1/8" heavy duty chain and a cheap Shimano freewheel. Supposedly reversible but a long way off from needing to. Definitely recommend.
The quality one would expect
By Michael T
31 Jul 2019
5 / 5
I recommend this product
Well machined, perfect fit. Prompt delivery
Thorn Chainring
By Steve
25 Aug 2018
5 / 5
I recommend this product
ProsQuality reversible
Great quality, I purchased two chainrings, one for my brompton and on for my on-one pompino. So hard to find similar at a competitive price in Australia
Quality Chain Ring
By Richard B
21 Mar 2017
5 / 5
I recommend this product
ProsPrecise machining:/reversible
This item exudes quality and performs faultlessly. I particularly like the option of turning it over when one side if the teeth are worn.
By New2Fixed
17 Oct 2016
5 / 5
I recommend this product
ProsThick, round, reasonable price, reversible
All these good reviews are right. This is a great chainring for fixed/singlespeed bikes.

It is nice and thick, making for a really feel. I was able to use double-chainring bolts on a road crankset and this chainring, which was convenient.

It seems to be well made and nicely round (!) - no tight spots (though I paired it with a high quality chainset which helps).

Great quality, lots of choice and good value.
Great Replacement
By Mark Royle
08 Oct 2016
5 / 5
I recommend this product
ConsHard to find
Bought this for my Genesis day one alfine. Impressed with the quality of this hard to find product.
Nicely Made. Thick.
By Anonymous
08 Jul 2013
3 / 5
What looks wierd is the thickness of the chainring body against the thin 3/32 teeth. Because it is reversible, it has chamfers on both sides of the chainring bolt holes which results in a thick thing. If you can live with that, it is a nicely made chainring.
Excellent Single Chainring
By AlanD
13 Jan 2013
5 / 5
I recommend this product
ProsQuality, Reversibility,Clean looks.
Have bought 4 3/32 rings and all have worn well with the bonus of reversibility. Good quality kit. How about a quantity discount?
Keep Spinning
By PhilS
13 Nov 2012
4 / 5
I recommend this product
Have bought 4 of these c/rings for 4 Fixies including a turbo training bike. Proven to be reliable and smooth. Price could be a little more competitve if buying more than one. Buy the thorn c/r bolts as standard alloy bolts tend to split with higher gearing.
Wonderful Chainring
By Pete
08 Nov 2012
5 / 5
I recommend this product
I bought this as part of replacing my current cranks and is fantastic. It looks good and most importantly is quite than what it replaced.

As always had wonder service from SJS.
Just Bought 2Nd
By Ryan
24 Jan 2012
4 / 5
I recommend this product
Reviewed this when I bought one last year. It has been on the fixed road bike all year and I have now decided to get a different size for more gear options. First one hardly looks used, no question in buying the same item again.
Thorn 130Mm 5Arm Reversible Chain Ring
By Carter
25 Sep 2011
5 / 5
I recommend this product
Prossee above
This is a beutifully made chainring. Proper engineering for everyday abuse. Looks good too. Considering this and all the varying sizes is very well priced. SJS as always give top quality service. Happy Days.
Good Piece Of Kit
By Ryan
16 Feb 2011
3 / 5
I recommend this product
ProsSolid, Well made
Fitted this but not ridden it yet. Fitted on fine but is thicker than normal double chainring. Looks great and feels very solid. Good service from SJS when I had a subsequent question about the diameter of other sizes.
Exactly What Was Needed
By TomF
23 Dec 2010
5 / 5
I recommend this product
I'm turning my old fixed into a SS cross bike. For a laugh. Previous chainset was a fixed tooth Stronglight with 44 teeth. I had a spare triple chainset that looked like it would do the job, and allow me to change ratios. This ring, though unridden, fitted fine - build quality is great. It's sturdy and tough, and ought to last well, especially though the double sided nature.
Excellent Singlespeed / Fixie Chainring
By Lee Woolston
18 Nov 2010
5 / 5
I recommend this product
Consnot supplied with chainring bolts
ProsGood Price, Hardwearing
This is a very well-made chainring, suitable for any fixie / singlespeed rider looking to replace or upgrade their exisiting set up. fixing it to the bike is a piece of cake (remember to retain the chainring bolts from your current set-up), and the build quality is excellent. Being two-sided it is very sturdy and perhaps a shade wider / heavier than other single chainrings on the market. The ability to reverse the face should give the ring twice the life of other 'rings.
Top gear
By Anonymous
31 May 2008
5 / 5
You can stop using rings designed for shifting on your singlespeed or fixed bike; these are stiff, round, reasonably priced, available in all the right sizes and they have proper teeth which won't let go of your chain the first time you hit some rough stuff. If I ever wear it out, I'll tell you about the cool double sided feature, which lets you use them for twice as long by wearing out the other face of the tooth by turning the ring over
Questions & Answers (13)
What metal is chainring?
10 Feb 2022
Need a burly stainless steel chainring for my 11speed ebike, with take the torque abuse?
For any information or advice on any of Thorn bikes, frames and forks or parts, please contact our dedicated Thorn bikes sales team either on 01278 441505 or [email protected] and they'll be able to provide you with all of the information you need.
Can I use this with Brompton B75?
16 Jun 2021
Can I use this with Brompton B75, it already has 44t would this fit? How low I can go? 38T? Do I need any extra part? Thanks
You can go as low 39t,no other parts needed, just shorten the chain 2 links.

Thanks! 17/06/21 RH
Would i be able to use it with my kmc k710 chain 1/8
14 Feb 2021
Thank you for your enquiry, yes will be fine

Regards WD 15/02/21
Hi is this compatible with 10 speed SRAM road?
17 Jul 2019
Says 3/32 and 1/8...
Is this still compatible with current Brompton transmissions?
16 Jul 2019

I have a 6 speed Brompton black edition from last year. I'd like to drop the gearing from 44t. Will your Thorn chainrings fit? Is there a limit on how low I can go?


The lowest you can go is 39t. Our Thorn rings work great! Brompton also offer a 44t - SJS Cycles part number : 43747

Thanks - 19/07/19
Can I use this on a 1X10 conversion?
24 May 2019
Yes, but its possible the chain will drop, would would recommend using a narrow/wide ring and/or a chain guide.

Thanks - 24/05/19
I have one of these and am looking to replace the cranks, due to stripped thread. Do you make any?
08 Jan 2019
Looking for 172.5 or 175 length.

Thank you for your enquiry, the only 130mm BCD crankset that we now stock compatible with this chainring is our item number 24749. If you type this number in to the search box then it should take you straight to the product, its available in 175mm.

Regards 09/01/19
Replace an FSA Vero chainring?
31 Aug 2018
Can I use this to replace the chainring on my FSA Vero single speed chainset? Will it affect the chainline? It might be my imagination but my old Vero chainring seems dished.
If the bolt pattern matches, yes. Without seeing the currently items we could not suggest whether this would affect the chainline.

Which bolts does this chainring need - the length
29 Aug 2018
Hi, 6.5 mm for a single setup 8.5mm for double. Thanks
How many teeth?
25 Jun 2018
This came up when I filtered for 42t, the description says it's 39t and the photo is of a 44t chainring.

Which is it?
Using the drop down menu you can select the size you would like, this item is available in 38t all the way to 52t.

Is this chainring suitable for a Rohloff geared bike?
10 Jan 2018
Hi there,

This is the perfect choice! It can be reversed and we fit these to many many bikes!

Suitable For Brompton Spider Crank.
14 Jun 2017
Hi, are these chainwheels suitable replacements for the Brompton spider crank ? Thanks

As this ring uses the 130BCD fitting it should be suitable for use on a Brompton spider crank.

Mounting Hole Thickness?
24 Apr 2015
Can you tell me how thick the ring is at the mounting holes please? I'm wondering if it will stand proud against my cranks spider.

The ring thickness at the mounting holes is 5mm for these chainrings.