Rudge 'Bi-Frame' -a 'Proper' Folding Bike....?

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DevonDamo
Posts: 275
Joined: 24 May 2011, 1:42am

Re: Rudge 'Bi-Frame' -a 'Proper' Folding Bike....?

Postby DevonDamo » 4 Feb 2020, 3:44pm

cpg wrote:... it looks like you have the smallest size frame that was available...


Yep, although I hadn't realised there were 3 sizes - I'd only heard of two. My one was being flogged for next to nothing on eBay by someone who didn't know what it was and had literally listed it just as 'bike.' In other words - too good an opportunity to miss, even if too small. I have bid on a couple of the larger sized ones, but was outbid - there's obviously a bit too much demand for them and I'm probably not helping by rabbiting about the things on here. Coming from a Dahon folder, the Rudge feels positively palatial, but I will keep trying to source a bigger one and will swap all the new bits over from this small one if I do.

fastpedaller wrote:DD - I have a cunning method of secure quick release fitting for a short mudguard which I fitted to my Rudge to stop grit being flung into my eyes. It could be modified or used with additional (as said above) tennax for the stays of a long guard. I'll send photos later today.


You legend. I was going to ask cpg about Tennax fittings - I hadn't previously heard of them and Googling produces too much choice.

I tried to sort out the gears today - chain thoroughly cleaned, swapped the old Suntour derailleur with a Shimano Alivio job I had in my spares box and set the limit screws correctly. Yet its still jumping on the smallest cog, which is frustrating because there are absolutely no signs of wear on it or the chain. I guess I'll put a new chain on first, and if that doesn't sort it, I'll buy a new Sunrace freewheel. In the meantime, I've just set the high-stop on the derailleur to lock out the smallest cog.

fastpedaller
Posts: 2283
Joined: 10 Jul 2014, 1:12pm
Location: Norfolk

Re: Rudge 'Bi-Frame' -a 'Proper' Folding Bike....?

Postby fastpedaller » 4 Feb 2020, 5:51pm

DD - here's some (not very good due to bad lighting) photos. I don't know what happened to the missing 5th photo showing the view from the other side of the steerer, but leaving the camera outside all night in the rain last year hasn't enhanced its abilities!
Anyway, they should be fairly self-explanatory. I tried to use 'features' of the mudguard as it was supplied...… the hexagonal nut recess on the underside was useful, as were the two raised ribs on the top ( I filed the aluminium to just sit inside these). When I offered the completed aluminium parts to the bike the vertical strip which was intended to be in front of the steerer had to be inside, due to my poor measurement! But it works nicely. Put simply it's some bracketry with a m6 bolt cut to length with a hole cross-drilled. A keyring fits through the hole to secure it all. Nice and quick and it won't fall off. Re the tennax fasteners, they are available from boat or vintage car parts suppliers. Unless you pay and arm and 2 legs for m5 thread copy ones, the nearest genuine tennax ones are IIRC 2BA - which is close to m5 and with care, a following wind and some threadlock can be used. Incidentally the plating on these genuine ones is (or certainly was) first class, as the ones on my car have lasted 30 years in the open and have no corrosion.
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Brucey
Posts: 36822
Joined: 4 Jan 2012, 6:25pm

Re: Rudge 'Bi-Frame' -a 'Proper' Folding Bike....?

Postby Brucey » 5 Feb 2020, 2:46pm

just to clarify, the combination of worn (even slightly worn) sprocket and new chain is the one that is most likely to skip under load. The skipping almost invariably occurs because the chain is unable to feed smoothly onto the sprocket when the chain is under tension. It therefore rides over the teeth and then slips (skips) by one link before it settles into the sprocket again (briefly). The most obvious thing about the sprocket is that it is usually slightly hooked in appearance; however there are other more subtle kinds of wear that accompany the hooking and this causes a new chain to move under load such that the chain won't engage smoothly as it is fed onto the sprocket from the derailleur.

If you load the transmission up (e.g. by standing on one pedal) and then let the bike forwards by easing off the brakes, an observer will usually be able to see the chain not engaging with the sprocket properly.

FWIW I have only ever seen two frame sizes in BiFrames.

cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

DevonDamo
Posts: 275
Joined: 24 May 2011, 1:42am

Re: Rudge 'Bi-Frame' -a 'Proper' Folding Bike....?

Postby DevonDamo » 6 Feb 2020, 3:14pm

fastpedaller wrote:DD - here's some (not very good due to bad lighting) photos...


Thanks very much for those - that got the old cogs whirring and I've now come up with a plan. If I don't use your metal bracket idea on the front mudguard, I'll definitely do something similar on the back - as a replacement for the Rudge rear mudguard adaptor bracket which was originally supplied with each bike. I think I'm going to attach the front mudguard at the top with a long bolt and wing-nut as that will allow me to quickly torque it up enough to prevent it rattling around. I may even go for a more traditional mudguard with the two wire rods and use two thumb-screws(!) to quickly screw them to the bottom of the fork legs. I know this isn't in keeping with your ultra-quick design, but it's probably the right solution for me as I'll only be using the bike infrequently and hopefully won't be using any mudguards on the majority of the few trips I do.

Brucey wrote:just to clarify, the combination of worn (even slightly worn) sprocket and new chain is the one that is most likely to skip under load...


Message received and understood Brucey. I've just ordered a new 7-speed 13-34 SunRace freewheel and a new chain. Remarkably cheap.

cpg
Posts: 44
Joined: 30 May 2015, 1:08pm

Re: Rudge 'Bi-Frame' -a 'Proper' Folding Bike....?

Postby cpg » 6 Feb 2020, 5:14pm

There were 3 frame sizes in the Schwinn branded Bi-Frames, although that is not to say that the Rudge was available in the same sizes. Have a look at the top right of the photo in this link: http://bikecatalogs.org/SCHWINN/1991/Catalog/FULL/1991_18.JPG
Here is a clearer image taken from the 1992 cataloge: http://bikecatalogs.org/SCHWINN/1992/Catalog/FULL/1992_cc_specsb.jpg

fastpedaller
Posts: 2283
Joined: 10 Jul 2014, 1:12pm
Location: Norfolk

Re: Rudge 'Bi-Frame' -a 'Proper' Folding Bike....?

Postby fastpedaller » 6 Feb 2020, 5:28pm

DevonDamo wrote:
fastpedaller wrote:DD - here's some (not very good due to bad lighting) photos...


Thanks very much for those - that got the old cogs whirring and I've now come up with a plan. If I don't use your metal bracket idea on the front mudguard, I'll definitely do something similar on the back - as a replacement for the Rudge rear mudguard adaptor bracket which was originally supplied with each bike. I think I'm going to attach the front mudguard at the top with a long bolt and wing-nut as that will allow me to quickly torque it up enough to prevent it rattling around. I may even go for a more traditional mudguard with the two wire rods and use two thumb-screws(!) to quickly screw them to the bottom of the fork legs. I know this isn't in keeping with your ultra-quick design, but it's probably the right solution for me as I'll only be using the bike infrequently and hopefully won't be using any mudguards on the majority of the few trips I do.

Brucey wrote:just to clarify, the combination of worn (even slightly worn) sprocket and new chain is the one that is most likely to skip under load...


Message received and understood Brucey. I've just ordered a new 7-speed 13-34 SunRace freewheel and a new chain. Remarkably cheap.


For the rear mudguard I used the standard clip on one that came with the front one (as a pair from Ebay). The rear is all-plastic (best described as half length) and has plastic clips securing it to the seatstays above the brake bridge, and another clip securing it to the seat tube. It's what's generally called an A###saver I believe. Works ok and removes in less than a second. The shape is such that it can't tangle with the wheel, but stops the brake cable doing so. On a safety note it's worth having a small mudguard (or a reflector bracket) fitted to the hole on the fork and the rear brake bridge in case of a cable failure! If a 'main' cable fails with cantilever brakes this means the straddle wire could be pulled by the springs onto the tyre, catch on the knobbles and hurl the rider into the future.

DevonDamo
Posts: 275
Joined: 24 May 2011, 1:42am

Re: Rudge 'Bi-Frame' -a 'Proper' Folding Bike....?

Postby DevonDamo » 6 Feb 2020, 11:20pm

fastpedaller wrote:If a 'main' cable fails with cantilever brakes this means the straddle wire could be pulled by the springs onto the tyre, catch on the knobbles and hurl the rider into the future.


That settled it - I ordered a set of traditional-style mudguards earlier. (After decades of having mud sprayed up my back because my plastic clip-on mudguards have shifted, I've finally given in to proper old man mudguards with stays.) I also had a flash of inspiration about making my own quick-fix mountings for them. I had been looking in the R.S. Components catalogue etc. for some kind of 'thumb screw' i.e. a bolt with wings (they exist and are called 'wing-screws') when it finally dawned on me that I could make a better system with the commonplace odds and ends that I already have. I've got some 2cm long stainless M5 countersunk allen bolts, which I've screwed 'outwards' through the mudguard mounting holes at the bottom of the forks and at the top of the seat stays. I've locked them off with M5 nuts on the outside. Then, whenever I want to attach the mudguards, I will just slot the mudguard stays over the sticky-out threaded end of these bolts and secure them with wingnuts. It will be quick, easy and secure - and eliminates the risk of cross-threading the holes in the frame from repeatedly screwing bolts into them. A longer M5 bolt, M5 nut and wingnut through the hole in the fork crown, and something similar at the rear, and it's job done.

fastpedaller
Posts: 2283
Joined: 10 Jul 2014, 1:12pm
Location: Norfolk

Re: Rudge 'Bi-Frame' -a 'Proper' Folding Bike....?

Postby fastpedaller » 7 Feb 2020, 9:27am

DevonDamo wrote:
fastpedaller wrote:If a 'main' cable fails with cantilever brakes this means the straddle wire could be pulled by the springs onto the tyre, catch on the knobbles and hurl the rider into the future.


That settled it - I ordered a set of traditional-style mudguards earlier. (After decades of having mud sprayed up my back because my plastic clip-on mudguards have shifted, I've finally given in to proper old man mudguards with stays.) I also had a flash of inspiration about making my own quick-fix mountings for them. I had been looking in the R.S. Components catalogue etc. for some kind of 'thumb screw' i.e. a bolt with wings (they exist and are called 'wing-screws') when it finally dawned on me that I could make a better system with the commonplace odds and ends that I already have. I've got some 2cm long stainless M5 countersunk allen bolts, which I've screwed 'outwards' through the mudguard mounting holes at the bottom of the forks and at the top of the seat stays. I've locked them off with M5 nuts on the outside. Then, whenever I want to attach the mudguards, I will just slot the mudguard stays over the sticky-out threaded end of these bolts and secure them with wingnuts. It will be quick, easy and secure - and eliminates the risk of cross-threading the holes in the frame from repeatedly screwing bolts into them. A longer M5 bolt, M5 nut and wingnut through the hole in the fork crown, and something similar at the rear, and it's job done.

Like that - some good ideas there DD. May be worth carrying a couple of spare wingnuts in case of dropping one in your travels when folding the bike and finding you have to either bin the mudguard or carry it in your hand :oops:
ETA. I 'tried' to test what would happen by disconnecting the main canti wire and allowing the straddle wire to take its own course (bike was in bike stand I hasten to add) - and yes the result was dramatic enough in the bike stand. A dead stop with either wheel. With slick tyres there may have been little or no danger. I tried it with the clip on plastic guards and decided that although part of the guards could be brought into contact with the tyre (in the event of main cable break) the result wouldn't be dangerous - just like an old spoon brake from 1800's :lol:

Brucey
Posts: 36822
Joined: 4 Jan 2012, 6:25pm

Re: Rudge 'Bi-Frame' -a 'Proper' Folding Bike....?

Postby Brucey » 7 Feb 2020, 4:33pm

I've secured mudguards using wing nuts onto captive studs and it works well. However there is the small issue that the wing nuts can very quickly back out via vibration, should they not be/remain tight enough. I would therefore suggest that some means of secondary retention for the wing nut might not be a bad idea; a (suitably weatherproof) 'O' ring stretched over the wing nut and the fitting would do the trick. This could also be used to prevent the wing nuts from being lost when the bike is in transit, too.

BTW you can buy wing nuts in stainless steel these days, in M5 and M6 sizes; much better than the rusty old stuff which was all I could get BITD.

cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

fastpedaller
Posts: 2283
Joined: 10 Jul 2014, 1:12pm
Location: Norfolk

Re: Rudge 'Bi-Frame' -a 'Proper' Folding Bike....?

Postby fastpedaller » 7 Feb 2020, 5:39pm

Good advice (as always from Brucey) Screwfix do packs of wingnut is SS m5. Another option re threads (Brucey may wince :lol: ) is (once your screw and locknut are on) to 'squash' the threads on the screw a little, say with a pair of sturdy pliers to mis-shapen them a bit so the wing nuts become tight. This may not be solution long-term though, depending on how the 'mis-matching threads' wear each other and become loose again.

nigelnightmare
Posts: 625
Joined: 19 Sep 2016, 10:33pm

Re: Rudge 'Bi-Frame' -a 'Proper' Folding Bike....?

Postby nigelnightmare » 17 Feb 2020, 2:54pm

fastpedaller wrote:Good advice (as always from Brucey) Screwfix do packs of wingnut is SS m5. Another option re threads (Brucey may wince :lol: ) is (once your screw and locknut are on) to 'squash' the threads on the screw a little, say with a pair of sturdy pliers to mis-shapen them a bit so the wing nuts become tight. This may not be solution long-term though, depending on how the 'mis-matching threads' wear each other and become loose again.


Brucey's not the only one wincing!
You're not related to A Mr I bodge-it or his partner Mr N Scarper are you? :lol:

fastpedaller
Posts: 2283
Joined: 10 Jul 2014, 1:12pm
Location: Norfolk

Re: Rudge 'Bi-Frame' -a 'Proper' Folding Bike....?

Postby fastpedaller » 17 Feb 2020, 4:20pm

nigelnightmare wrote:
fastpedaller wrote:Good advice (as always from Brucey) Screwfix do packs of wingnut is SS m5. Another option re threads (Brucey may wince :lol: ) is (once your screw and locknut are on) to 'squash' the threads on the screw a little, say with a pair of sturdy pliers to mis-shapen them a bit so the wing nuts become tight. This may not be solution long-term though, depending on how the 'mis-matching threads' wear each other and become loose again.


Brucey's not the only one wincing!
You're not related to A Mr I bodge-it or his partner Mr N Scarper are you? :lol:

Could be better than losing the wingnuts on a dark and wet night though :lol: