Thorn Cycles Forum
Community => Non-Thorn Related => Topic started by: fossala on December 29, 2014, 08:08:10 AM
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I bought on of these around a month ago for my Raven Tour but when I fitted it there was a lot of friction. It was quite difficult to turn the cranks by hand. Would this be considered normal or did I fit it wrong?
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Folks says the friction is negligible. One possibility is the chainring. You need a thinner steel chainring (e.g. Surly) rather than a thicker aluminum one (e.g. Thorn).
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Agreed, Jim. I removed my 'glider this fall, as part of a general tidy-up, and took my Raven for a short ride without the 'glider. I didn't notice any difference. When the bike is on the stand and the 'glider is mounted, if I spin the cranks, the 'glider slows down the wheel more quickly than if it's not there. On the road, as mentioned, with pressure on the cranks, I can't tell the difference.
Fossala, I run an 8-speed chain with my 38T Surly ring & 'glider -- I think that one could use a 7- 8- or 9-speed chain.
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I've got a Thorn double sided chainring and a KMC X1 chain. I think I'm just going to sell it on instead as I quite like the double sidded thorn one.
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I bought a thin Surely front ring when I fitted the chain glider.
Minimal to no friction or sound.
Why not do that?
What is so special about the double sided Thorn front ring? I know you can flip it but with the glider on there will be considerably less wear on both sprockets and chain.
Am I wrong?
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My chainset is a 104bcd Thorn and the Surly chainrings only go up to 36t it. I would need to invest in a new chainset that I don't want to do at the moment.
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Hi Matt! Hi Fossala!
Matt, the Surly chainring can also be flipped, just something to keep in mind a long, long way down down the road.
Fossala, I have the same "dilemma" as you; I am also running an EBB drivetrain (Deore crankarms, Phil Wood BB and reversible Surly 36t stainless chainring) and -- yep! -- the Surly chainrings in 104BCD top-out at 36t and the Hebie Chaingliders bottom-out at 38t.
Hebie, make that 36t Chainglider! (says Dan, beating the drum once again :D )
All the best,
Dan. (...who for Christmas only wanted his two front teeth [in a Chainglider]!)
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I'd buy a 36T 'glider too, if Hebie made one. And if three's a crowd, how many is a niche market?
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I'd buy a 36T 'glider too, if Hebie made one. And if three's a crowd, how many is a niche market?
You only need a double handful of people who're really keen for a product to create word of mouth. Even one, if articulate and trusted, will do. Until recently, nobody here had an enclosed chain. Then I wrote a couple of articles about chaincases I tested and now the one I recommend, the Chainglider, is pretty common. Frankly, in my opinion (and I was once a marketer whose skill was rewarded by a salary several times what anyone at Hebie, including the chief executive, earns, so there isn't anything humble about my opinion), Hebie is behaving like two thick short planks together: if they weren't, they would have made a 36T Hebie the first time an opinion-former like Dan asked, the first time I (an opinion-former) agreed it was a good idea, the first time the idea was floated on this forum (a trendsetter for touring and utility bikes quite out of proportion to its membership -- for instance, Dan reported my piece on the n'lock was read by a factorial multiple of the membership). That's three separate counts, each sufficient onto itself, for calling Hebie smug for letting a flunky brush off Dan when he tried to tell them of an unexploited market for their product. It's almost as if they don't like money.
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Thanks, Andre. Might also be worth a group of us writing to a couple of online Hebie retailers, such as bike24 or starbike, to ask them to let Hebie know that There Really Is a Market, and you build it, they will come...
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Might also be worth a group of us writing to a couple of online Hebie retailers, such as bike24 or starbike, to ask them to let Hebie know that There Really Is a Market, and you build it, they will come...
...with each mentioning that Rohloff really do now approve a 36x17 combo, the sticky wicket in my correspondence.
Best,
Dan.
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When I enquired with Hebie they said it would need a new mould, the brake even for the mould was around 5,000 units, hence their reluctance.
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I've been thinking about 3-d printing as an approach for this sort of thing. Unit cost would be higher but practically zero up-front cost. Probably the part down at the sprocket is the same, so it is just the front half that needs to be built.
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Many thanks, Dave; very helpful. Now I better understand their reluctance.
Tooling is expensive, whether it be for lugs and dropouts (!) or for moldings.
I like Jim's idea, but wonder if a similar plastic would be readily extrudable by a 3-D printer. Also, the thing putting me off 3-D printing so far is the long-term durability. Some things I've seen so far seem fracture-prone because they are essentially sintered, with each hot pass being laid down atop a cooled previous pass, rather than an as-one hot molding. Great for prototyping, maybe not so much for actual product? Maybe things have gotten better since the samples I saw and played with last Spring.
All the best,
Dan. (...who really really wants a 3-D printer also!)
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I have switched to a Surly 38T chainring, and the Chainglider I recently installed works marvelously.
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When I enquired with Hebie they said it would need a new mould, the brake even for the mould was around 5,000 units, hence their reluctance.
So they have considered it! Good.
A 5000 unit barrier at first seems pretty high. But I think that eventually we will see that 36T Chainglider front end. It needs just one large manufacturer to ask about it...
It is a pity Hebie didn't give Dan the straightforward, perfectly understandable commercial answer they gave Dave.
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So they have considered it! Good.
A 5000 unit barrier at first seems pretty high. But I think that eventually we will see that 36T Chainglider front end. It needs just one large manufacturer to ask about it...
It is a pity Hebie didn't give Dan the straightforward, perfectly understandable commercial answer they gave Dave.
To be fair I was asking a slightly different question, if they could make the front section wider to take our rings as most of the Surly rings we have found are fairly out of round and create a large tight/loose difference on the chain tension.
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That's interesting Dave, A chain glider that works with the thorn rings would be an improvement. I've also not quite got mine to work on the RST frame -it 'almost' fits but needs modifying (bodging). Probably not a problem for the nomad and new ravens though.
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To be fair I was asking a slightly different question, if they could make the front section wider to take our rings as most of the Surly rings we have found are fairly out of round and create a large tight/loose difference on the chain tension.
Thanks for the clarification, Dave. I don't think the precise small variation in thickness or diameter of the mould matters: the breakeven would be around 5000 units in almost all cases.
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I've been thinking about 3-d printing as an approach for this sort of thing
Keep me posted, Jim, if you nudge towards a 36T version. My 38T Surly ring (+ 'glider) works just fine so far, but I want to test it over some more serious hills this coming summer, anticipating a possible trek in the Rockies next year, where I think a 36T ring would be just a wee bit easier. A 36T 'glider would make a nice addition, as I understand that it can rain in them hills.