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

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

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

Postby fastpedaller » 9 Jan 2020, 5:30pm

I can't help with BB length because I'm only using a single chainring on mine, but IMHO chainline isn't critical per-se with a derailleur set up because the chain's always 'out of line' :D I await correction, but add the chailine IS important as regards front mech position. The front mech has a 'special' spacer because of the shallow seat tube angle, so worth using the original front mech. The cartridge bottom bracket I used was a Shimano UN55, and it just fitted , indeed it was so close that the ID label on it was grazed when the cartridge was put in, but otherwise no issues.

DevonDamo
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Joined: 24 May 2011, 1:42am

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

Postby DevonDamo » 9 Jan 2020, 5:50pm

fastpedaller wrote:...The cartridge bottom bracket I used was a Shimano UN55, and it just fitted , indeed it was so close that the ID label on it was grazed when the cartridge was put in, but otherwise no issues.


Thanks for the reply. As I wasn't sure whether that bottom bracket would squeeze past the seat tube bulge in my frame, I decided to go down to my local Evans Cycles in Plymouth and see if they could kill two birds with one stone - check it fitted and match up a chain-set to fit my chain-line. In the end, we discovered another great option: a hollowtech 2 bottom bracket, which has a narrow plastic sleeve so fits in easily. As for the chainset, you can adjust the chainline to an extent with a hollowtech b/b, and standard mountain bike triples (with 140mm hollow crank tubes) fit fine.

Brucey
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Joined: 4 Jan 2012, 6:25pm

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

Postby Brucey » 9 Jan 2020, 9:55pm

a HT-II BB will work provided the seat tube doesn't intrude into the BB shell by 5mm or more. I have not tried it but I think this would be 'marginal' on my BiFrames (which are black and therefore slightly different from the blue ones). When you get close to 5mm intrusion you won't be able to fit the plastic sleeve between the cups, but this is no big deal; in an unperforated BB shell it doesn't do much anyway.

I happen to value low Q and for this purpose a road triple would be best (if it fitted) but a ST MTB triple can often be fitted on a shorter BB spindle and this is a pretty good compromise. A HT-II MTB triple is rather wide and can't be adjusted for Q.

The shifters used varied with model so I'm not sure whether the ones you have are worth keeping or not. Obviously the shifters ought to match the mechs if they are indexed, so this ought to guide you; no point in keeping shifters if they match knackered/unreplaceable mechs.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

DevonDamo
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Joined: 24 May 2011, 1:42am

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

Postby DevonDamo » 9 Jan 2020, 11:01pm

Brucey wrote:...I happen to value low Q...


What about fitting a road double? The front shifter isn't indexed, so would I be right in thinking it would just be a matter of setting the end-stops on the mech to make it work with the existing set-up? Also, I've read that using my current 6-speed chain with 9-speed chainrings wouldn't really be a problem - is this being a bit optimistic?

Brucey
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Joined: 4 Jan 2012, 6:25pm

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

Postby Brucey » 10 Jan 2020, 2:22am

a road double will work fine unless you have a chainring that is too big, in which case you may find that the FD can't be raised enough. At the other end of the gear range most road doubles don't give you very low gears; it is more or less the same as you would get by omitting the smallest chainring from the triple and fitting it on a shorter BB spindle.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

DevonDamo
Posts: 417
Joined: 24 May 2011, 1:42am

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

Postby DevonDamo » 18 Jan 2020, 10:58pm

I've finally got mine on the road and really happy with it. I thought I'd record some detail on compatible parts etc. for anyone else working on them.

1. A hollowtech 2 bottom bracket will allow you to fit a cartridge bearing without any drama. You only need space for the 26mm tube to go through, so the bulge from the seat tube won't be a problem. All you need to do is shove the plastic sleeve through on its own as it has wide flanges at either end and these willl probably need to squeezed in a bit to get past the bulge. Once the sleeve is in, the steel tube will slide through inside it no problem.

2. The original OvalTech chainset wouldn't come out - the threads just disintegrated when I used the crank extractor. I instead had to apply a heat gun and smash it with a mallet to get it off. The pedals were also terminally seized into the cranks, and all in all, I felt glad to bin it.

3. I fitted an R3030 Sora road chainset. I've found the 50-39-30 chainrings are a great companion to the gearing on the standard rear sprockets, there are no clearance problems with the standard front derailleur and it changes smoothly.

4. The gear levers are built like battleships, so worked perfectly after a clean and a lube - I'd forgotten how simple, easy and effective friction levers are. The original derailleurs also came up like new after a quick clean and work great after I'd replaced the cables.

5. The bearing cup inside my rear hub had actually split in two along the line the ball bearings follow. I was able to knock the broken cup out easily and a bit of online research suggested it was worth chancing a campagnolo replacement cup. The diameter was short by a fraction of a millimetre, so it needed a bit of tin foil around it to jam it into the hub. I then did a test which Brucey had described on an old thread and this confirmed that the cup, cone and bearings were compatible and were all doing what they are supposed to. The Campagnolo cup is an FH-VL001, and SJS cycles provided one (in their usual speedy fashion) for £6. This means I've been able to keep the original wheels, which I'm happy about as they're in fantastic (perfectly straight) condition despite the bike having clearly been abused for many years.

6. I've got the small frame and it's tiny for me. I've got 34" inside leg, and I've had to fit a ridiculously long stem at the front and am waiting for a ridiculously long seatpost. It now looks like a bit of a clown bike, but I'm used to looking silly on folding bikes and it rides beautifully so I'm not bothered. If you're tall, definitely try and get the larger frame.

7. The old stem was seized inside the fork tube, and I ended up using a 4 foot long steel bar as a torque arm to turn the forks against the handlebars in order to release it. I needed to use so much force that the stem itself shattered by the wedge. I bent the forks out of true in the process, but I bent them back and surprisingly the bike seems to be running straight. (I've now painted the inside of the fork steerer tube with coppaslip.)

8. The bike still had the original Suntour Alpha cassette/freewheel, which looks a bit ancient but was actually in great condition. I cleaned it in paraffin and soaked it in 4-stroke oil and it now sounds like a new, good quality freewheel and the sprocket teeth all look perfect.

9. The frame fold was very stiff at first, but I first squirted WD40/GT85 down the joints and through the grease nipple hole which loosened it up enough to allow me to repeatedly fold it and so loosen it further. After this, I used a grease gun and displaced the very old grease with new stuff and it's now fine.

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

Postby Brucey » 19 Jan 2020, 1:31pm

good work!

Any photos?

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

DevonDamo
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Joined: 24 May 2011, 1:42am

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

Postby DevonDamo » 19 Jan 2020, 3:08pm

Brucey wrote:good work!

Any photos?

cheers


I was worried you were going to ask that! This bike is definitely not easy on the eye: I haven't attempted to tart it up cosmetically and, as well as the aforemetioned 'clown' stem and seatpost, I butchered the paint on the forks trying to get the old stem out. So it looks decidedly rough, which is perfect for my needs, i.e. having it in the back of the car for work trips so I can pedal from my hotel to the nearest decent pub where it will be left chained up outside.

However, as soon as I get the final three pieces of the jigsaw (long seatpost, new saddle and nice tyres) I will post a pic.

DevonDamo
Posts: 417
Joined: 24 May 2011, 1:42am

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

Postby DevonDamo » 1 Feb 2020, 7:31pm

First test ride on Thursday night, meeting some friends in a pub 7 miles away. Riding home with a screaming rear wheel hub due to the axle having broken in two (just as I reached the pub) was character-building. I had previously noticed that the old axle was bent, but I'd straightened it in a vice(!) When inspecting the damage and blowing out the swarf, I noticed the chainstay was bent inwards, so it looks like the bike has had a very hard knock at some point. (This is presumably also explains the smashed bearing cup which I'd already replaced.) I bent it back out and bunged in a new axle and it did a 20 mile round trip without missing a beat today. The crankset seems to be spot-on: it got me up the two 'hills of death' on my regular route no problem, but I was on my smallest chainring and biggest sprocket. On my hybrid, the smallest of my three chainrings never gets used no matter how steep the section, so I'd nearly considered sticking a double on the Rudge - I'm now glad I went for the triple. The only problem is that the chain is jumping on the smallest sprocket, but I guess that will either be a case of replace the chain or tinker with the derailleur adjustment.

It looks weird with the long stem/seatpost, for which I've taken a lot of military-grade urine-extraction off one of my regular riding buddies, but job done - the bike fits me. I've fitted quick-clip pedals, luggage and rear mudguard, and it's a doddle to break down and easily fit in the boot of my car. I might paint the worst of the paint damage to prevent rust, but I'll keep it looking rough to keep it under the radar of bike thieves when it's outside the pub.
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Brucey
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Re: Rudge 'Bi-Frame' -a 'Proper' Folding Bike....?

Postby Brucey » 2 Feb 2020, 3:25pm

Oh, you are having an exciting time! I'd suggest that the dropouts are checked for alignment; if they are bent then there is a preload on the axle and this will hasten breakage. If you are determined to retain the original hubs (or indeed use any hub that has a screw-on freewheel) the rear hub can be supplemented with an 'outrigger bearing' under the freewheel and this (plus well aligned droputs) ought to result in a very strong arrangement.

I'm surprised that you are happy with the saddle where it is; probably it is way further back than you might have it on other bikes because the seat angle is so slack on the BiFrame design. Usually the correct position is only obtained with the standard saddle clip facing the wrong way or (sometimes not always) by using an inline seat post. I'd suggest a little work with a plumb-line and tape measure ought to get the saddle in the same place as your other bikes; possibly (probably) you could use a longer stem too.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

DevonDamo
Posts: 417
Joined: 24 May 2011, 1:42am

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

Postby DevonDamo » 2 Feb 2020, 7:29pm

Brucey wrote:I'd suggest that the dropouts are checked for alignment


So far I've just checked them with the Mark 1 eyeball. I take it I need to put an appropriately-sized square object in between them to make sure the dropouts are completely parallel?

Brucey wrote:I'm surprised that you are happy with the saddle where it is


Don't forget it's one of those weirdo saddles, so probably looks further back than it actually is. That said, I've never been at all methodical about bike-fit. So long as my legs reach the pedals and my knees aren't whacking the bars, I'm usually happy. Now you've pointed it out, I'll experiment with moving the seat forward. I do have a longer stem (an angle-adjustable Promax) so I'll have a play with that too. But for the type of use I've got in mind for it, near enough is good enough.

One other thing, re. the chain skipping on the smallest cog. I've yet to do a thorough from-scratch set-up of the derailleur, but presumably the bending of the drop-outs will have had an effect, plus the hanger is probably bent. I guess my only option will be to try and true it all up by eye or borrow a hanger alignment tool? I haven't changed the chain, but it seems good in terms of stretch and tight links. The cog teeth appear to be immaculate, but if I need to swap the Suntour alpha freewheel, am I right in thinking any 6 or 7 speed Shimano one will go on there?

Brucey
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Joined: 4 Jan 2012, 6:25pm

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

Postby Brucey » 3 Feb 2020, 2:25pm

Image

shows how a proper alignment check is done. But you can usually substitute old axles (provided they are straight) for the special tools.

The important thing is to make sure that the axle isn't in any way strained when it is installed; if it is, either the axle or the frame itself may break prematurely.

Re gear slipping; possibly the smallest sprocket is slightly hooked. Eventually it may sort itself out (as the chain and the sprocket wear) but if you have to change to another freewheel any 6s or 7s freewheel ought to fit, provided you are

a) happy to respace the hub slightly if necessary and
b) you are happy to use friction shifting or
c) you have confirmed that the sprocket spacing is correct for your index shifting.

On point c) IIRC SunTour 7s index spacing of sprockets wasn't either perfectly uniform or identical to Shimano 7s index spacing, but is usually 'close enough'.

' Cheap but good' currently includes SunRace freewheels. You can get
6s 14-16-18-20-24-28 or
7s 13-15-17-29-21-24-28

and (I think) because the sprockets are slightly thinner (about 1.85mm vs 2.0mm in thickness) you can use 9s chain as well as 6/7/8s chain with them.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

DevonDamo
Posts: 417
Joined: 24 May 2011, 1:42am

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

Postby DevonDamo » 3 Feb 2020, 9:01pm

Brucey wrote:But you can usually substitute old axles (provided they are straight) for the special tools.


Cheers Bruce - I jury-rigged an alignment checker out of the two broken axle halves and after a small amount of adjustment, I'm now confident the drop-outs are spot-on. I also used the same trick on my mountain bike, on which the various damaged components show that the previous owner has done something spectacular, and got that straight too.

Brucey wrote:Cheap but good' currently includes SunRace freewheels.


I hadn't been aware of the SunRace range, but a quick Google tells me they also do a 7-speed with a 34T 'megarange' sprocket on it, which I''ve always found useful on my hybrid. Surprisingly cheap too and It sounds like it should be an easy swap-over as I've still got the original non-indexed shifters, front and back. The jury's still out on whether I do need to replace the freewheel though. All the other sprockets work like clockwork and visually the smallest sprocket looks immaculate - but it's still jumping. Before I replace it, I'm going to see if there's any straightening-out needed on the derailleur mech and then go through a thorough chain-off set-up procedure.

I've moved the seat forward, but couldn't put the longer stem on yet as I'm waiting for a shorter bolt/wedge to arrive (as I've hack-sawed the ridiculously-tall stem down to the required size.) I did another longish ride on it tonight and it feels like the new seat position has improved the handling, but it's also obviously made it a bit more cramped. Now that I'm no longer paranoid about the rear hub destroying itself again, I was able to relax and appreciate the ride - it's cracking for a folder. Unlike my 5 speed Dahon, this thing can do anything my main hybrid can. I won't bother bunging any more luggage on it as it's just a glorified pub bike, but an easily-removable decent front mudguard would be useful. The only option I can think of would be to find some type of bolt/wing-nut hybrid to attach a standard mudguard.

cpg
Posts: 56
Joined: 30 May 2015, 1:08pm

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

Postby cpg » 3 Feb 2020, 10:03pm

With regard to the saddle and handle bar position, it looks like you have the smallest size frame that was available (I beleive there were 3 sizes) so that is probably why it feels cramped.
For fitting the mudguard you could try using tenax fittings or press studs. I was considering this for my bike but sold it before doing anything with the mud guards.

fastpedaller
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Location: Norfolk

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

Postby fastpedaller » 4 Feb 2020, 9:45am

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.