Thorn Cycles Forum
Technical => Transmission => Topic started by: Templogin on January 28, 2016, 10:26:09 am
-
Hi Folks
I need some advice on the best way to tackle this problem please.
I have an eXp with a Shimano Deore XT chainset. It's a 4 arm 42T model. I bought a Hebie chainglider, but the chainring is too thick. The drag is ridiculous. On this forum I have read that the Surly chainrings are thinner and the very thing, trouble is that they don't do anything as large as a 42T in 4 arm models according to SJS.
Is there another manufacturer that I can look towards for a thin chainring with 4 arms and 42 teeth?
If not is there another solution. The BB is a hollowtech if that makes any difference.
I preferred the days of cotter pins!
Thanks
Andy
Shetland
-
take a look at: http://www.benscycle.com/p-13939-shimano-alivio-m415-42t-78-speed-outer-chainring.aspx
-
Hi Andy!
I am in the same situation as you, and have a 36t Surly chainring. I have corresponded with Surly and it appears they won't be adding stainless chainrings larger than 36t in four-arm, 104mm BCD at this time.
Rohloff's FAQ page cites several chainring sources, but I don't know if they are produced in stainless thin enough for a Chainglider:
4-arm chainrings for Shimano XT/LX cranks
Mountain Goat Lonely Wolf Kettenblatt
4 arm chainrings for the 2001 Shimano XT/LX cranks as well as chainrings for nearly every conceivable crank and mounting hole diameter can be produced by various specialist firms such as Speciallites TA (France).
Suitable chainrings are available in both black or silver finishes with a choice of 36-38-40-42-44-46 and 48 teeth from
http://www.tnc-hamburg.de
Mountain Goat Lonely Wolf
Bolt circle 64/104 mm
Teeth 39/42
http://www.mountain-goat.de
NC DH-Rings
http://www.nc-17.de
Idworx offer some larger stainless 'rings in 35t, 39t, and 43t. They advocate odd-odd chainring/sprocket combinations, citing longer wear. I'm guessing their 43t 'ring will result in a less than ideal mating with a Chainglider.
The Idworx parts store is here:
http://www.idworx-bikes.de/de/informationen/parts.php
Although Idworx is a competitor to Thorn in bikes, I offer their parts link as an option simply because stainless 'rings in larger sizes are so difficult to find elsewhere. I am not sure how thick the actually are, and cannot confirm they will work in a Chainglider without creating undue drag. I presume they are thin, but you should confirm via correspondence before ordering. GoogleTranslate is your friend here, as the site is only available in German and Dutch.
Best,
Dan.
-
Thanks a lot folks. I will have a look at the links and let you know how I get on.
@Dan - can you tell me the thickness of the Surly chainring please. Must be less than 5mm. I am considering getting the Thorn chainwheel skimmed down. CANCEL THAT REQUEST - SEE BELOW
It's funny how 42T should be considered small. In the world of Moulton bikes, some riders are putting chainwheels on of over 60T when they want really tall ratios.
88*8***8*
It looks like the 42T Lonely Wolf on Mountain Goat is perfect. Only 3mm thin.
-
Did u look at stronglight and TA .
-
No Jags, I didn't give them a thought to be honest. I think that my better Moulton has Stronglight cranks on it if I am not mistaken. I am in the big city at the moment so can't check.
To be honest I just wanted some "easy". The Chainglider has sat there for far to long as an ornament. The lonely wolf is on order, and I am looking forward to its 3mm slimness.