Chain case/ chain guard

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fastpedaller
Posts: 2786
Joined: 10 Jul 2014, 1:12pm
Location: Norfolk

Chain case/ chain guard

Postby fastpedaller » 30 Dec 2020, 12:42pm

The other thread about fitting a chain guard got me thinking (not always a good thing)....... On our mucky Norfolk roads a chain case on my Winter bike (Pompino) could be a good idea. I don't like the idea of the floating one, and an online search didn't reveal a lot - closest was a full case from Holland. The other option is a partial one, which I'd be ok with, except that the 'case' part on this type only protects the top of the chain. It would seem logical to me that the dirt comes mainly off the front wheel (despite mudguards) and protecting the lower part would be better? I suppose I could mount one of those upside-down, but having the drivetrain on the left side of the bike would be a bit extreme. :lol:
My other option is to custom - make something out of glassfibre. Any pointers of where I could get a chaincase? (which doesn't have to enclose the rear sprocket) preferably UK supplier.

Cyclewala
Posts: 178
Joined: 7 Nov 2019, 11:07am

Re: Chain case/ chain guard

Postby Cyclewala » 30 Dec 2020, 1:59pm

Full mudguards are usually insufficient. If you fit a mudflap to the front mudguard so that it's about an inch or two short of touching the floor, that eliminates the throwback from the front wheel.

I looked into full chainguards, but found two issues: 1) difficulty mounting to a bike not designed for them, and 2) avoiding chain rub. This would be for a derailleur bike.

When I've been to the Netherlands, their derailleur bikes had the half way house you mentioned i.e. circular protection around the chainset and along the upper run of the chain. The bottom was exposed.

Brucey
Posts: 43056
Joined: 4 Jan 2012, 6:25pm

Re: Chain case/ chain guard

Postby Brucey » 30 Dec 2020, 2:20pm

The second major source of crud is probably stuff being carried round by the rear wheel and being spat out of the mudguard sideways. Chaincases are indeed wonderful things. However there are snags! They are noisy when the chain gets slack, if the chain falls off inside them it is a nightmare, and they obviously get in the way when working on the rear wheel. You can't easily have derailleur gears, either. However they are brilliant at keeping a chain (not to mention your troos) clean too. This is my potted review of some of the options;

Hebie chainglider; a flexible system which will support chainring sizes from ~38 to 50T in 2T options, different length chainstays and a range of different rear sprockets via adaptors. Downsides include cost (it'll be about £60 for a full kit), that the system won't accept every sort of chain, won't accept every sort of chainring, and that the chain is in constant contact with the chainguard, which is both slightly noisy and slightly draggy.

Most other chaincases will only accept a range of chainstay lengths; if your chainstays are the wrong length; tough. Obviously any hard case will only accept certain chainring sizes too. What is perhaps less obvious is that most chainsets (as used on quality bikes) are not compatible either; common problems include that the chainring bolts and spider arms make the crank too wide and/or require a much larger opening in the RH side of the chaincase. Cranks that fit easily include those with a ~95mm dia disc set in the centre (for matching chaincases such as Hesling 'excelle') and those where the chainwheel is fixed to the crank (either by bolts or swaging) on a small diameter, and there is still a gap of at least 10mm between the crank and chainwheel. At the back there can be various arrangements (mostly weird bulges) which allow for specific IGH controls.

Hesling make a number of half-decent chaincases in ABS. I am lucky enough that local to me there are a few dealers who will order such chaincases from suppliers they deal with in the Netherlands, so I can get hold of them if I need them. They themselves sell bikes with chaincases and will (obviously) replace a broken chaincase with the same model if it is still available. However what they won't usually do is to attach a chaincase to a bike that never had one before, because it is almost invariably a king-size pain in the posterior to do this.

One type traditional type of chaincase comprises a steel loop which surrounds the chain; this frame is covered in fabric, which is zipped (or laced, or clipped) up. You can still buy these, but you have to cut your own openings in the fabric. The fabric is vulnerable to being damaged, can rot, and (largely because it is vinyl-covered in modern incarnations) the fabric tends to shrink too. But this kind of construction could easily be adapted/ replicated if needs be, and fitted with a covering of your choice. (mad idea; could carradice make a chaincase using cotton duck fabric...?) The rear section of the frame is meant to be removed when the wheel has to come out;

Image

the rear section of the frame is secured by a bracket, and once the bracket is freed, the rear section usually just slides out from its engagement with the top and bottom rails.

If you can get hold of a chaincase from an old Raleigh, it can be run less the disc cover and less the rear lower section and will still provide very good protection for the chain. This chaincase fits chainwheels up to 46T IIRC. It will only fit easily if the chainstay is pretty well lined up with the hub axle, ie. not cranked.
Image
Raleigh chaincase; there are two lengths, for 26" wheel bikes and 28" wheeled bikes respectively. [The 26" wheel type is most likely to fit a modern frame with ~30mm wide 622 tyres.] NB there are also two sliding pieces which fit behind the sprocket; these are missing in the photo

Image
traditional Hesling 'original' chaincase

The Hesling 'traditional' (original) model will fit at least 44T chainrings, but requires that the RH crank fits through a small hole in the RHS of the chaincase, or that the opening is made large enough to accommodate the spider. It is intended to mount via a clamp round the RH chainstay near the BB, and a (very annoying) bracket onto the rear axle. Obviously these arrangements can be modified without too much difficulty.

Hesling 'Excelle' is meant for chainsets of about 38T which include a large centre disc. The Shimano Nexus range includes such a chainset, but like most others of this sort (with a swaged centre connection), the chainwheel is likely to be slightly eccentric, which is annoying. IME a swaged centre connection is not reliable in fixed gear use; the chainwheel tends to work itself loose. This chaincase typically mounts via a bracket which is sandwiched between the RH BB cup and the frame (the disc shaped part in the photo below).
Image

There is a bracket at the back which is designed to be fitted to the chainstay, ideally using a braze-on fitting. The square cutout in the chaincase near the rear axle is sized so that (with a little modification in some cases, depending on the angle of the arm) it will accommodate the cassette joint arm as found on Nexus 4, 7, and 8 speed models. I have a Hesling Excelle which is destined to be fitted to an old Dawes Galaxy when it is reborn as a town bike; I think it will fit just fine.

Hesling do other models which are specific to certain IGH models; if you have that model IGH and insist on having the shifting gubbins hidden from view, you might like to consider one of those.

There are good photos (including relevant dimensions) of most Hesling models on the dutchbikebits website. However I don't think there are very many places which sell these chaincases in the UK.

Bikes like the 'Paper Bike' have a built-in chaincase with plywood sides. This may give folk ideas too.

One of my mad ideas is that you could make a frame for a chaincase using wire, expanded metal, or similar, and then cover it using anything that took your fancy. This could include gaffer tape, of course.

Of chaincases that you can buy I think the Hesling 'original' may be the easiest to adapt and make work on a bike that never had one to start with, but my suggestion would be that you should be prepared to replace the chainset etc with parts that are compatible with the chaincase, rather than expect to be able to modify the chaincase to fit the transmission parts you have.

cheers
Last edited by Brucey on 31 Dec 2020, 5:40pm, edited 12 times in total.
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ElCani
Posts: 401
Joined: 5 Mar 2015, 11:24am

Re: Chain case/ chain guard

Postby ElCani » 30 Dec 2020, 4:47pm

I know you said you didn’t want a floating chaincase, but given the complications of any other sort it might be wise to reconsider. I use a Hebie Chainglider on a Genesis Day one Alfine and it’s been excellent, the final piece in the “truly low maintenance” puzzle. The concept itself is somewhat unappealing and the noise of the rubbing is clearly audible on the workstand, but in actual riding I don’t notice it.

fastpedaller
Posts: 2786
Joined: 10 Jul 2014, 1:12pm
Location: Norfolk

Re: Chain case/ chain guard

Postby fastpedaller » 30 Dec 2020, 6:29pm

Thanks to all for the info. I had considered adding a mudflap to the front mudguard and if it's flexible and secured in position with a sacrificial adhesive (eg bonded with PU adhesive) it shouldn't present any danger if it hits an object on the ground. I may use some cardboard to mock up something with a view to copying in GRP - the difficulties I anticipate are 1) securing it to frame and 2) making it easily removable (at least in part(s)) to enable wheel removal in case of P#######. No2 is less of an issue if the sprocket isn't encased, and this may be the design of choice.

StephenW
Posts: 158
Joined: 22 Sep 2010, 11:33am

Re: Chain case/ chain guard

Postby StephenW » 4 Jan 2021, 11:48am

I have the Hesling Original. I fitted it to a bike which previously just had a "hockey stick" chainguard. I have also fitted the Hesling Miranda to a bike which previously had a "hockey stick" chainguard and the Nexus chainset, which has a big bulge in the middle.

I agree with Brucey that the Hesling Original would be a good choice. My bike already had the type of chainset which fits through the small hole. These types of chainset are not expensive.

Do you ride fixed? The chain case could make it harder to set the chain tension really accurately, although I suppose one of those tugs would solve that problem.

Although there may a little faffing involved in getting it set up, I think it is definitely worth persevering with, because a chain case is such a handy thing! I think most bikes without derailleurs ought to have them.

bgnukem
Posts: 612
Joined: 20 Dec 2010, 5:21pm

Re: Chain case/ chain guard

Postby bgnukem » 4 Jan 2021, 4:34pm

Definitely try a long front mudflap and perhaps also an additional rear flap located behind the seat tube (and wider than the mudguard) if your rear mudguard does not extend below the chainstay bridge, to keep the crud away from the chain. The front flap should be pretty close to the ground and maybe 50% wider than the front mudguard. Makes a big difference in winter as almost all mudguards I've bought have been far too short, particularly the fronts. I also find if the 'guards are wider than the tyres and not too far above them (subject to safety considerations) it also helps reduce the amount of crud thrown out sideways from the tyres.

A guy in my local club made his own chainguard which is only a partial guard mounted inboard of the chainset (only) and covers the front and lower half of the chainring circumference, with no encasement outboard of the 'ring. He says it keeps most of the muck off the chain.

GrahamJ
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Joined: 18 Nov 2020, 8:15am

Re: Chain case/ chain guard

Postby GrahamJ » 4 Jan 2021, 6:50pm

I have an MTB with 3x9 drivetrain, so a chain guard is tricky. I did make something from vinyl floor tiles and wood (maybe like the guy in bgnukem's club??):
DSCI0004.JPG

I'd say the front part worked well, the top part was dubious. The front part was constructed like this:
DSCI0015.JPG


I have now attached SKS mudguards, with a DIY flap on the front. Although they're intended for MTBs, it seems my MTB was not intended for these. I had to do a lot of DIY to get them fitted - only one of the 5 attachments works as intended by SKS. The DIY flap works, but it does catch on my doorstep...

fastpedaller wrote:It would seem logical to me that the dirt comes mainly off the front wheel (despite mudguards) and protecting the lower part would be better?


I think it's more the front than the bottom of the chain that needs protecting, though the front should reach lower than the bottom of the chain. Here's my picture of how I reckon dirt reaches the chain:
Untitled.jpg

I am excluding 'external' sources, like dust blown in by wind, and stuff thrown up by other vehicles or heavy rain. The vast bulk is from the front wheel, nearly all from the bottom, but there might be a fine spray blown back from the top. The second most important is thrown down and sideways from the rear wheel near the bottom bracket. A flap here like bgnukem suggested could work, I'd just note that if you stop muck going sideways towards the drivetrain that should work too. Finally there is muck which gets stuck anywhere above the drivetrain and washes off later.

It seems to me that the seat stay, seat tube, and down tube provide three good attachments for a partial chain guard, but I have not seen commercial one attach like that.

tommydog
Posts: 285
Joined: 11 Feb 2017, 6:48pm

Re: Chain case/ chain guard

Postby tommydog » 5 Jan 2021, 12:22am

Does anyone know if there are any manufacturers that make a Rohloff bike with a full chain case? I know Katz used to, but they closed down. I am also aware of the Idworx Easy Rohler - but are there any others?

Also I can't understand why full cases aren't used on belt drives? This would go some way to preventing grit etc destroying the belt. I think a belt drive in a case, would have the advantage of ultra low maintenance.

colin54
Posts: 1564
Joined: 24 Sep 2013, 4:34pm

Re: Chain case/ chain guard

Postby colin54 » 5 Jan 2021, 8:08am

Another link to the Thorn forum about chaincases.
Entitled ; A Fully Enclosed Chaincase That Works', bear in mind the thread was started in 2009, so diferrent Hebie Chainglider options become available as the thread progresses.
http://thorncyclesforum.co.uk/index.php?topic=2233.0
tommydog wrote:Does anyone know if there are any manufacturers that make a Rohloff bike with a full chain case? I know Katz used to, but they closed down. I am also aware of the Idworx Easy Rohler - but are there any others?

.

Utopia Velo's 'Kranich model', fitted with their Country chaincase with Rohloff, Thorn Forum member Andre Jute's excellent detailed article here with photo's :-

http://www.audio-talk.co.uk/fiultra/BIC ... Drool.html

bgnukem
Posts: 612
Joined: 20 Dec 2010, 5:21pm

Re: Chain case/ chain guard

Postby bgnukem » 5 Jan 2021, 2:18pm

GrahamJ wrote:......
Here's my picture of how I reckon dirt reaches the chain:
Untitled.jpg
I am excluding 'external' sources, like dust blown in by wind, and stuff thrown up by other vehicles or heavy rain. The vast bulk is from the front wheel, nearly all from the bottom, but there might be a fine spray blown back from the top. The second most important is thrown down and sideways from the rear wheel near the bottom bracket. A flap here like bgnukem suggested could work, I'd just note that if you stop muck going sideways towards the drivetrain that should work too. Finally there is muck which gets stuck anywhere above the drivetrain and washes off later.
....


I think your diagram shows the direction of most of the dirt well. Consider a tangent to the front tyre where it leaves the ground that passes/intersects the lower end of the mudguard/mudflap and extend the line to the bottom bracket - this possibly approximately indicates the highest possible direction of dirt travelling from the front tyre contact patch towards the chainset/bottom bracket and is often higher than the bottom of the large chainring, which shows that most mudguards - with or without mudflaps - are too short to stop muck reaching the chain.

A mudflap which is close (say 50-60mm) to the ground will stop a lot of the muck reaching the chain. Since this might also catch on kerbs, etc, it's worth ensuring it can flex slightly to pass over obstacles, but not be so flexible that it blows backwards in the wind and so allows more dirt to pass.

Also there's a slight increase in aerodynamic drag when the flap is made wider than the tyre, which obviously catches some of the air which is not in the turbulent wake immediately behind the tyre itself. If the flap is asymmetric, or the mudguard itself is not centred on the tyre, it's possible to get a recurring sideways movement of the end of the mudguard due to aerodynamic effects which obviously flexes the mudguard material and might eventually crack it.

I notice also that front mudguards are often short at the front end also, such that riding in the wet results in a plume of spray/muck/salt etc. from the top of the front tyre being blown backwards onto the head tube/lower headset bearing, so I think a top mudflap would also be useful on the front mudguard.

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mjr
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Re: Chain case/ chain guard

Postby mjr » 5 Jan 2021, 2:56pm

After changing my crankset, I couldn't get my Axa chain guard to fit, so I'm currently using a "hockey stick" type one from Oxford Products. I think the model code is CG330.

I'm using the chainstay and seat tube brackets supplied, but I made a new one from a pipe clip and a bolt for the down tube with a greater offset. I may yet replace that with one made from holey metal strip (like meccano) that attaches to the downtube cable mounts, but not while it is so cold in the shed!

Anglia Motor Cycles in King's Lynn sells Bibia Spatlap Touring mudflaps, which I use. I think one of the main UK distributors has probably got them in their catalogue.
MJR, mostly pedalling 3-speed roadsters. KL+West Norfolk BUG incl social easy rides http://www.klwnbug.co.uk
All the above is CC-By-SA and no other implied copyright license to Cycle magazine.

fastpedaller
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Joined: 10 Jul 2014, 1:12pm
Location: Norfolk

Re: Chain case/ chain guard

Postby fastpedaller » 5 Jan 2021, 4:34pm

Thanks for all the info folks. I've been scrambling my brain thinking about this, and have come up with a plan....... Mock up using card, and then the plan is to produce a GRP one. Making the 'chainring cover' part will be either by laying up a flat sheet and bonding a semi-circle of GRP (thin layup will bend) in place, or adding a barrier (to the layup piece of board) and creating the flat and curve both at the same time - more tricky but likely to be stronger as the matting will be continuous. Anyone who enjoys working with glassfibre will agree it's an easy material to use, and quite rewarding to product things. I've then worked out that some GRP tube can be made by just waxing some plastic tube and again using matting/resin. The GRP tube can then be bonded into position onto flat GRP sheet inside the chainwheel. This will be a rigid fixing and with tubes drilled, some old inner tube can protect the seatube and downtube, and the structure held in place with re-usable cable ties. One tricky thing is working out how to join the inner and outer parts so they are secure/rigid without the fixings interfering with the chain. the cardboard mock-ups will help enormously. I like to use CAD (Cardboard Aided Design :lol: :lol: ) This may take some time, because I've some other hobby tasks to complete first. I'll update when I've done at least some of it.

tommydog
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Joined: 11 Feb 2017, 6:48pm

Re: Chain case/ chain guard

Postby tommydog » 6 Jan 2021, 5:38pm

tommydog wrote:Does anyone know if there are any manufacturers that make a Rohloff bike with a full chain case? I know Katz used to, but they closed down. I am also aware of the Idworx Easy Rohler - but are there any others?


colin54 wrote:Utopia Velo's 'Kranich model', fitted with their Country chaincase with Rohloff, Thorn Forum member Andre Jute's excellent detailed article here with photo's :-
http://www.audio-talk.co.uk/fiultra/BIC ... Drool.html


Thanks for that info, but I note on the Utopia Velo website, the current Kranich model is not shown with a chain case.

LuckyLuke
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Joined: 10 Jun 2010, 11:54am

Re: Chain case/ chain guard

Postby LuckyLuke » 7 Jan 2021, 11:18am

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IMG_20151203_213025656.jpg
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Hi folks, I tried a Hesling 'Excelle' as described by Brucey up thread. The above was a 531 frame with a Nexus 8 rear hub and Nexus 38T crankset.
Pic is from 2015 so details are a little hazy... IIRC fitting was a bit fiddly but ok. The front bracket is sandwiched between the frame and BB cup and is solid. IIRC one has to align the bracket in a particular way. I affixed the rear bracket to the R. chainstay withe zip ties. Bit of a bodge but worked ok. I think there a couple of small screws that bind the two main parts together also?
I think I ran the chain case for 6 months or so.
Pros: lower maintenance. The chain was out of sight, out of mind. IIRC after 6 months it was gritty but not rusty.
Cons: Noisier chain, even without any rubbing.
Loud banging going over bumps as the chain bounces and slaps the chain case.
I think I could only check gear cable alignment by flipping the bike upside down and removing a small rear section of the chain case. Bit of a PITA.
On balance I decided against keeping it on. YMMV so worth a try!
Best wishes,
Luke
PS chain case, front fork, front rack and crate all from the excellent Dutch Bike Bits. Fitting instructions on their website I think.
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