Thorn Cycles Forum
Technical => Transmission => Topic started by: chipbury on June 21, 2023, 09:53:57 AM
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Good Morning All,
I have a Nomad Mk3 with the new style eccentric BB fixings (two capscrews clamping the frame onto the BB).
I can't find a torque setting for these two bolts?
Any thoughts?
Cheers,
Chris
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Congrats on the new bike, lets hear more!
I don't know if there's an official figure, they don't have to be very tight, they're just pinching it shut. For the original four bolt mini EBB, as found on the earlier Mercury, the recommendation was 5Nm, I'd suggest that was plenty. I've never put a torque wrench on mine, or had it come loose, for me, hand strength without leaning on it is the right tightness for many steel components.
Is it in the current handbook? I don't have a copy, though it's probably downloadable. If not and you're concerned, ask Thorn.
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I can't find a torque setting for these two bolts?
5 Nm sounds fine. I can tighten the bolts enough to hold perfectly, for many thousands of km, with my belt drive using just my little multitool.
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Thanks for the above,
I nipped them by hand so are probably about right. I had to change the bottom bracket due to the bearings failing (@2000 miles), Thorn sent a free replacement as they hadn't fitted their preferred standard during the build as they weren't available due to Covid 19 supply issues. Good service on there part I think.
See attached for a fairly recent picture of my bike. No long distance touring but about 100 miles a week on short jaunts out (max 80miles).
I was sick of replacing transmission parts on derailleur fitted bikes - mostly due to the towpath near me turning all chain oil into grinding paste!
Cheers,
Chris
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Lovely bike, Chris and so glad things are sorted for you.
I see you're using a Thudbuster LT suspension seatpost. I'm a big fan and have LTs or STs on four of my bikes, appropriate to use. I have found fitting the optional neoprene sleeve cover from new has really kept the bushings clean over time and through weather and it was something Cane Creek/Thudbuster asked me if I'd fitted when I had an early bushing failure (persistent clicking) on one covered nicely by warranty (they sent new bushings and the tool to quickly and easily remove/install).
Best, Dan.
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Looks great, appropriately dirty without being filthy!
Marathon Plus tyres and a Thudbuster....
What size wheels and tyres are they?
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I was sick of replacing transmission parts on derailleur fitted bikes - mostly due to the towpath near me turning all chain oil into grinding paste!
It may be worthwhile considering a Hebie Chainglider to further reduce this problem.
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It may be worthwhile considering a Hebie Chainglider to further reduce this problem.
The Nomad Mk3 frame is belt-drive-ready, so no need for a cludge like the Hebie Chainglider.
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What's a cludge?
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It may be worthwhile considering a Hebie Chainglider to further reduce this problem.
The Nomad Mk3 frame is belt-drive-ready, so no need for a cludge like the Hebie Chainglider.
It might be belt drive ready, but photo shows the bike in question with a chain. Upgrading to a belt is not cheap and has not been done yet. The Chainglider is relatively inexpensive and reduces grime reaching chain, reducing wear and maintenance and like prolonging life of the running gear. It also reduces ankle tattoos in oil, or getting oil on your clothes.
I was a Chainglider doubter till I bought one. My commute in all weathers used to take me shortcuts through the forest which were always messy. Every weekend I’d need to clean and re-oil the chain. I am currently on a chain approaching 8,000km that is fairly clean (but never been cleaned) which I have oiled about 3 times- once because factory lube had worn off, and the other times because I had the wheel off for other reasons and used the opportunity to lightly oil seeing as the Chainglider had been removed for the work I was doing.
My approx 16,000km experience with Chainglider have saved countless hours of chain maintenance for sure compared with the first 5,000 km without one.
+1 on John‘s suggestion. I also recommend a Chainglider
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What's a cludge?
Chain Lube Un‘ Dirty Grime Eluder? ;D
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What's a cludge?
A word defined as “a haphazard or makeshift solution to a problem”.
Upgrading to a belt is not cheap and has not been done yet.
At least on the continent, you can upgrade to a belt for not much more than 200€ – historically the high price came down to the need for a special frame, but the OP for whom my advice was ultimately intended already has a Nomad Mk3. A Chainglider is 30€. I’d say that the 170€ difference is a great price to pay for never again having to oil a chain or adjust a Chainglider, and if you can afford a Rohloff-based bike, that is not a lot of money relatively speaking. Though it stocks them, SJS Cycles does not recommend Chaingliders, and my own experience with the product led me to the same opinion.
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and my own experience with the product led me to the same opinion
What happened to put you off?
I love mine and echo the above positive comments.
Anyone any idea why SJS don't recommend them?
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What happened to put you off?
The Chainglider is not sealed, and therefore it will not keep out sand and soil in places where the wind blows that along – some of the world’s most popular bicycle-travel routes are like that. Complete disassembly was then required in order to adequately clean the chain. Plus, even under ideal conditions the Chainglider required more frequent adjusting than I wanted to do.
I eventually just took the Chainglider off as too much bother, and tossed it into a bin on the roadside, and I can’t say that the remaining 6,000 km of that tour were worse because of that. Of course, now with the Nomad Mk3 and a belt drive, that is all a distant memory anyway.
As for why SJS Cycles doesn’t recommend them, I don’t know exactly. All I know is that when I was originally planning to buy one and told SJS that in an e-mail, the employee replied that he and his colleagues had found the Chainglider “a poor product” during their own riding, and they did not recommend that I buy one.
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The Chainglider is not sealed, and therefore it will not keep out sand and soil in places where the wind blows that along – some of the world’s most popular bicycle-travel routes are like that. Complete disassembly was then required in order to adequately clean the chain. Plus, even under ideal conditions the Chainglider required more frequent adjusting than I wanted to do.
It doesn't keep out water either, but it still works quite well in the prevailing weather conditions in southern Brittany where I live and it does keep most of the wet muck off the chain.
Fine, dry dust isn't a problem where I ride, but I imagine this would be a good reason not to use a Chainglider in some places. The sand on the tracks in the dunes that I occasionally use is probably too coarse, because the Chainglider works quite well on that.
I've had one on a utility bike for 12 years now, and have progressively fitted Chaingliders to all the family bikes that are compatible (it won't work on the Brompton folders or the large visitor bike with vertical dropouts and a chain tensioner).
The main advantage for me is increasing the intervals between chain maintenance by a factor of about 3, maybe even more. It probably also increases chain, sprocket and chainring life, but this is difficult to prove because the transmission had already been used on most of the bikes to which I have fitted Chaingliders.
Another advantage is keeping chain oil off clothing or skin.
I eventually just took the Chainglider off as too much bother, and tossed it into a bin on the roadside, and I can’t say that the remaining 6,000 km of that tour were worse because of that.
I was very sceptical when I first tried one, but reckoned it was worth a try at the price. And had it not worked for me, easy to remove and discard, even when on tour.
Though having used Chaingliders for more than a decade, if I ever ride in fine dust, nowadays I would probably remove it and keep it to refit later after leaving the dusty area and cleaning the chain.
Nomad Mk3 and a belt drive
None of the 8 family bikes with Chaingliders are compatible, so that would mean new frames or expensive frame modifications, plus all the specific parts for belt drives.
So belts aren't an economic option for me. It might be different for someone buying a new bike, or who already has a belt-compatible frame.
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I was sick of replacing transmission parts on derailleur fitted bikes - mostly due to the towpath near me turning all chain oil into grinding paste!
It may be worthwhile considering a Hebie Chainglider to further reduce this problem.
... and another thread bites the dust ::)
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Morning all,
Chain gliders do seem to be a 'marmite' accessory!
I have looked at them but decided not to fit one to my bike, I'll be interested to see how many miles a chain lasts on this bike. So far it's done almost 2000 miles and the chain wear gauge 0.75 will not fit in yet (I have a 1.00/0.75 gauge not the 0.75/0.50 type). My last derailleur bike went through 7 chains at approx 2000miles each (at 1.00 wear).
Cheers,
Chris
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Morning all,
Chain gliders do seem to be a 'marmite' accessory!
I have looked at them but decided not to fit one to my bike, I'll be interested to see how many miles a chain lasts on this bike. So far it's done almost 2000 miles and the chain wear gauge 0.75 will not fit in yet (I have a 1.00/0.75 gauge not the 0.75/0.50 type). My last derailleur bike went through 7 chains at approx 2000miles each (at 1.00 wear).
Cheers,
Chris
There are numerous posts on the subject and varied approaches to drivetrain maintenance, none of them are wrong. I subscribe to the method in some of the Thorn literature, that is to treat the three components as a single entity and replace together, rather than the derailleur thinking of sacrificing chains to protect a cassette.
Understanding what is wearing what, and why it is/isn't important, will save you much effort and expense, more than any added attachments, though the two are not mutually exclusive. I get more life out of a chain than some on here using chaingliders and I do no more than wipe and oil when it looks like it might benefit. I might reconsider that if my usage was anything like that of steve216c, I'm riding in far more benign UK conditions and my Mercury is on about 20,000km with the current set of components.
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Chain life anyway depends to a very large extent on the rider. For me 4506km inside a Chainglider in a controlled experiment (using only the factory lube) was 3x what I got BC (Before Chainglider), whereas to the next fellow, getting 8000m on a bare chain, I look like an example of his just reward overtaking a masher. My multiple of about 3 aligns with Martin's experience above, though the base BC mileages may be very different. It's a masher's lot to be amazed by the extraordinary mileages some people get on a chain or even a set of tyres.
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Chain life anyway depends to a very large extent on the rider.
There are numerous variables, but I suspect in a comparison between any two riders chain life the largest will be the point at which they consider it to be done.