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PostPosted: Tue Aug 13, 2013 11:01 am 
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Joined: Fri Sep 04, 2009 9:37 am
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Location: Bristolcestershire
This is a new project which I've just taken on, inspired by a riding buddy who's just bought a Moulton. Going out on a ride with him coincided with this coming up for sale on the CTC forum. The seller and I had both been inspired by Sheldon's page on the Twenty - http://sheldonbrown.com/raleigh-twenty.html. The seller had got some way down the road with it, but then needed to clear some space. Here it is as I bought it -

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Some of the important work had already been done to modernise it - i.e. get around Raleigh's proprietary threading from back then.

* The steerer has (I think) had a 24tpi die run down it, so I can make a frankenheadset with the top half of a standard 1" one. The original bars are clamped with a collar which clamps over the threads, with slots cut in the back to allow the tube to pinch. I'll be replacing the stem with a modern 1" one, so I will probably cut the tube down and add a top nut.
* A square taper BB has been fitted - with plastic cups at 24tpi run into the 26tpi shell. I'm not 100% sure about this but it seems rock solid at the moment. Time will tell.
* The seller had a new rear wheel handbuilt for it, with a 7 speed Hyperglide hub. I'm not sure whether I'll use this or not, because it's still a bit wide for the rear triangle. If I can find a suitable 5 speed screw-on freewheel, I might use the other rear wheel which came with it, which is for a screw-on block. That's a bit wide too but I think it would be easier to narrow the OLD on that one - plus it's bolt-through, and I'm not keen on a QR on the rear wheel. The 7 speed one is actually 6 really, because the smallest cog is far too close to the seat stay to actually use it.
* As you can see, it came with alloy wheels and Marathon Slick tyres - big upgrade from the steel wheels that were standard.

Here it is as it stands at the moment - I'm waiting for some more parts to arrive, hopefully today.

Image

Work done so far:

* Ditched the supplied rear mech and fitted a long cage Acera one with a claw for the mount (both courtesy of the parts bin). This is another reason for wanting a bolt-through rear wheel, as I don't plan on taking the wheel out for transport.
* Removed the old mudguards - if it turns out to fit me OK, I will have to add some modern ones.
* Replaced the Stronglight singlespeed c/set with my Biopace double. Plan is (yes, really), just to use it without a mech, and manually shift the chain for big hills! We'll see how that goes...
* Ordered and fitted a looooong stem, I think I've managed to find the only one which is actually heavier than the original! But it has loads of insertion, and is adjustable so I can sort out the position.

The plan:

* New alloy post, with my Selle An-Atomica saddle
* New pads in the loooooooong drop brakes, and see how/if these work. Long term, if it's a keeper, I'll braze on some canti mounts.
* Cable up and test ride!

If it fits after all that:

* Mudguards
* 400mm drops (if I think these will work given the frame size and the fact that I am tall)
* Perhaps a front mech
* Probably change the fork to one of these: Click - more suitable trail, and proper mudguard mounts.

Watch this space... here's Sheldon's version, for some inspiration :)

Image


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PostPosted: Tue Aug 13, 2013 11:24 am 
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Location: The Cock Inn, Tillett, Herts
Been tempted to try this myself but concerned I'm too tall and heavy. Watching with great interest.


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PostPosted: Tue Aug 13, 2013 11:49 am 
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Location: Bristolcestershire
Well, I'm 6'2" and about 95kg, so I am certainly no lightweight :D


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PostPosted: Tue Aug 13, 2013 11:59 am 
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Location: Bristolcestershire
I've done a bit of fiddling with the bar set up, and put some pedals on, so even without a saddle/drive/brakes, I can roll it around and see how it feels. I want at least two hand positions, so my options are drops, or flats with bar ends (I don't get on with butterfly bars). Also, the overall dimensions matter, because I want it to be as small as possible when folded, which is why I was thinking of 40cm drops. At the same time, I've got quite big hands, so I need to actually be able to get my hands on the bars in the first place.

Here is the front end with some thumbshifters, old school canti levers and grips applied.

Image

Image

However, that's going to be over 50cm wide when I've added bar ends, so I think the flat bars are a no go. I've had a roll around on it and I think, with the stem at maximum height, it's high enough to go for drops. It's going to have to be 40cm shallow drops, but with some canti/V levers in the centre (I'll use the ones above for a while, ideally swap them out for Avid Speed Dial levers eventually) and I think - though this may not quite work out - I'll mount the shifters on the ends of the drops, but inside, so the shifters don't stick out beyond the bars themselves. I want it to be as simple as possible so there will be no indexing to worry about.

The fork does feel a bit odd, because it sticks a long way out to the front, so I am more convinced now that I probably need to swap the fork at some point. Sheldon found that the small wheels gave a harsh ride and a suspension fork was needed. I'll have to wait to make a decision on that until I've actually ridden the thing though :)


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PostPosted: Tue Aug 13, 2013 5:08 pm 
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Joined: Mon Dec 28, 2009 7:06 pm
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i'd hold off replacing the forks until you've ridden it. as for brazing on cantis, it's what got done to mine by a friend that i got it off...and with BMX20" (406mm) your tyre choice is vastly improved. 50mm big apples says no need for suspension.

can't advise at all on the peculiar gear set up you've gone for :roll: :P

good luck 8)

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PostPosted: Tue Aug 13, 2013 7:20 pm 
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Joined: Thu Jun 18, 2009 1:07 pm
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Location: Sheppey, Kent
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Mine - viewtopic.php?f=23&t=214800&p=1621978&hilit=oops#p1621978 - Which was considerably easier than others as it was a newer R20

Image
Gavr's mega transformation! - viewtopic.php?f=23&t=218375&hilit=oops


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PostPosted: Tue Aug 13, 2013 7:48 pm 
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Location: Bristolcestershire
That last one is rather splendid! 451 rims would certainly be easier - the mudguards sit properly and you don't need such a big drop on the brakes. It doesn't fold though, and for me the foldiness is key to its appeal!

hubgearfreak, re the peculiar setup, it will become less peculiar if I decide to hold onto it. Basically I don't want to shell out for new bars and a front mech if it's not going to fit me. Hopefully the seat tube will come tomorrow, then I can get a saddle and chain on it and have a test ride. As for the fork change - I'd be more than happy to stick with the stock fork if it weren't for the fact that I need mudguard mounts, and I can't be doing with getting those and canti mounts brazed on.

Hub gear with a coaster brake is certainly the dream setup, but I'm not prepared to spend as much on this one as Gav clearly has on his :shock:


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PostPosted: Wed Aug 14, 2013 12:11 pm 
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Location: Bristolcestershire
Another day, another change of plan :)

First of all, I have decided to swap my MTB to a 1x9 setup, since it's suffering bad chainsuck and is likely to need a new ring anyway. This means there will be a front mech available for this bike - hurrah!

My seatpost arrived this morning, giving me an excuse to distract myself from the DIY and gainful employment I should be doing and fit the saddle. The seatpost is 400mm, just about as long as you can get in 28.6. Good news is that I think it will fit, but where I really need the post is about 1 cm above the minimum insertion point. So for those of you that are interested, I think that depending on your leg length, 6'2" is the limit for Twenty riders.

Here's the bike with the post fitted.

Image

With the saddle on, I could have a roll around to try the bar position too. Reach is short, so flat bars are off the table and so are the MTB brake levers, I think. I need some aero road levers to be able to get a good position on the hoods. Height, however, doesn't seem to be a problem, so this stem looks like it was a good buy.

The reason I'm doing all of the umming and aahing about bars is that they will dramatically affect the size of the folded bike. I'm planning on popping the seatpost and stem right down into the tubes for transport, though the steerer tube is so tight on this stem that I haven't actually done it in this picture. But hopefully you can see what I'm getting at. I don't really want aero brake levers sticking into things if I'm taking the bike on the train or in the boot of the car, but needs must I think.

Image

I'll need to invest in a saddle bag to put folding essentials in - Allen keys, a bungee to hold the whole thing tight together and so on.

I then had a closer look at the rear wheel. I've decided that this 7 speed wheel isn't going to work. It's absolutely bombproof and more speeds can only be a good thing, but the combination of the narrow rear triangle and the relatively thick seat stays mean that it's not really going to be usable enough. So I think the way forward is to swap to a 5 speed screw on freewheel on the other wheel that I have. This picture (with the 7 speed cassette) shows that a 5 speed block, which is apparently 24mm wide, will be much narrower than the current setup. I'll be putting the 7 speed wheel on ebay and hopefully it will buy me a saddlebag or something...

Image

I've changed the locknuts on the new wheel for some thinner ones so it's now almost the exact size of the rear triangle and only needs a couple of mm of stretch to get it in. In doing the wheel swap I also had my first experience of changing 20" tyres. I think I'd better add tyre levers to the saddle bag list - there's no way you can change one by hand.

Progress will now halt for a couple of weeks while I put a load of stuff on ebay in order to raise money for the required parts :) Shopping list -

Saddle bag
Long rear gear cable set
Long rear brake cable set
40cm drop bars
Mudguards
5 speed freewheel
New fork
Mudguards


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PostPosted: Thu Aug 15, 2013 12:20 pm 
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Joined: Fri Sep 04, 2009 9:37 am
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Location: Bristolcestershire
OK, I know I said there would be a break, but that was never going to happen, was it? I'm having too much fun. Plus I went to pick up another frame last night which came with lots of bits attached - rare mechs, cottered cranks (weren't those fun to remove!) and some vintage flared bars.

Seems silly to buy bars when I have just got hold of a set which will do fine for testing the concept. So here it is - also showing my slightly funky thumbshifter setup. I've also fitted my front mech, fitted the narrowed rear wheel, and made a homebrew front-mech-cable-stop arrangement out of a light bracket. If I'm feeling particularly clever I might see if I can still put the light on it.

Image

It's shaping up nicely I think. I might even bring myself to buy a 5 speed freewheel from Halfords this afternoon.

The steerer tube is really really tight on the stem - so tight that I can't put the stem all the way down like I want to for folding it up. Another reason to swap the fork out, but does anyone have any idea why this might be? Is it possible that the steerer tube narrows?


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PostPosted: Thu Aug 15, 2013 2:01 pm 
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See post above re lack of restraint for messing around with this bike. So what I've done is to go round lots of silly options before arriving at the normal solution anyway. Which I do a lot, actually.

Anyway, the tops are too close to me, so I've decided the thumbshifters can go up there. Just like normal people do it! The hoods feel like a good position, as do the drops for going downhill.

I've connected the front brake. Performance is best described as "anaemic", but will do for now. Once I have shortened the outer to the correct length the front should be a bit better, but I imagine the rear will always be a bit pathetic. There is a lot of flex in the bar/stem arrangement so I don't think suspension will be required to soften it up at the moment. Finally, I have realised that it's silly to worry about putting the bars fully down for transport; if I'm undoing the stem wedge, I might as well just take the bars off the bike and strap them to it with a bungee - since I was going to get a bungee to hold the thing together folded anyway.

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