Mercian Renovation

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pickerd1
Posts: 36
Joined: 31 Mar 2014, 5:05pm

Mercian Renovation

Postby pickerd1 » 16 Jun 2015, 3:42pm

I've recently got my hands on a 1975 Mercian frame and fork. They weren't exactly sure which model when I asked in the shop - never mind. I am considering renovating it.
It's Reynolds 531 in decent condition - needs a seat stay repair - £75 at Mercian I believe.
It's has all be lugs for racks and mud guards and has lugs for cantilever brakes.
Given the date it will be for 27" wheels.

Should I convert to 700c?
How many gears can I fit on the cassette / freewheel?
Should I stick to a cartridge BB or go for external, e.g. Hollowtech II
Down tube vs STIs?

My gut feeling is to maybe go for the 1975 feel and not update it too much??

Any tips and ideas???

Has anyone updated an old Mercian?

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Mick F
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Location: Tamar Valley, Cornwall

Re: Mercian Renovation

Postby Mick F » 16 Jun 2015, 5:56pm

First port of call is Mercian themselves.
The serial number of the frame will be on the bottom of the BB shell. The numbers are serialised and have a year indicator too, plus there may be another number specifying the frame builder chappy.

Mercian had a full record of all their frames, but lost some of the older info due to a fire. It may be that they can tell you something about the frame, but when I asked about this, I was told that the info is in a big filing cabinet and not on a modern data base. :lol:

Mine was made for me in 1986 so is a bit younger than yours. I took mine back to them for its 21st birthday in 2007 for a refurb and a respray (same colour - Ruby Flamboyant) plus have a couple of modifications done. They also spread the rear out to 130mm to take the modern road cassettes. Serial number for mine is a three digit serial number followed by 86 for the year and there's a separate 3 to say who the builder was.

They were very happy to see my Vincitore back with them and when I phoned to ask how it was getting on - it took a few weeks - they referred to it as "Ruby Flam". :D
Mick F. Cornwall

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531colin
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Joined: 4 Dec 2009, 6:56pm
Location: North Yorkshire

Re: Mercian Renovation

Postby 531colin » 16 Jun 2015, 6:12pm

700c, obviously gives better parts availability, but also better tyre clearance, and the existing front canti. mounts will be too close together to fit modern brakes....new is about 80mm apart, old was anything from 65mm to maybe 75 if you were lucky.
talk to Mercian about spreading the back end to a modern dimension.....135mm is best for a strong wheel for touring if they will go to 135. failing that, 130 (modern Road width) is easier to live with than the old 126/120mm .
Square taper crankset/cartridge BB for me.
If you want the best (rim) brakes, go for full-size Vee brakes and the specific drop bar levers, with downtube/bar end gear levers. If you must have STI, mini vees work with STI, and stop better than modern cantis

LollyKat
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Joined: 28 May 2011, 11:25pm
Location: Scotland

Re: Mercian Renovation

Postby LollyKat » 16 Jun 2015, 10:19pm

OP will also have to get the brake bosses moved to take V-brakes, won't s/he? On my 1987 Mercian which originally had 27" wheels, the bosses are too high and too close together for modern cantis and v-brakes. It took old cantis and a bit of bodging to make it all work with 700c rims.

Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: Mercian Renovation

Postby Brucey » 16 Jun 2015, 10:42pm

pickerd1 wrote: My gut feeling is to maybe go for the 1975 feel and not update it too much??....


that is what I'd do; modern bikes are ten a penny but 40 year old ones are somewhat less commonplace.

If your canti-bosses are narrow and high up (when used on 700c wheels) I'd suggest (if Mafac cantis won't fit) using shimano BR-AT50 cantis (or similar) because these brakes have a little vertical adjustment for the brake blocks, and will work with a wide range of boss spacings too.

If it were mine and I wanted a nice usable machine, I'd stick around 126mm OLN at the rear (so I could still use period correct wheels if I wanted) and use 6/7s cassette hubs as an everyday wheelset. You can run an 8-from-9 cassette at 126mm if you want. Friction shifting is nice and simple (and works very well with modern chains and sprockets!) and it will let you run different gears very easily. Velo orange sell touring cranksets that look like they could come from the 1970s, and Dia compe sell non-aero brake levers.... so you can have a nice reliable machine built with new parts where it matters, but with a vintage look if that is what you want.

If your frame is built light to start with, and choose the right parts you can build a machine with mudguards that weighs around 26lbs and will be both reliable and delightful to ride.

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

pickerd1
Posts: 36
Joined: 31 Mar 2014, 5:05pm

Re: Mercian Renovation

Postby pickerd1 » 22 Jun 2015, 11:51am

Thanks for your replies. I've pretty much decided that I'd like to modernize this frame as a 2nd touring bike would be nice to have. My thoughts are as follows:
- 700c wheels - I have a pair of Mavic A119s - will there be any problems with these?
- 3x10 spd STI gearing - probably Tiagra 2nd hand
- new cantilver brakes - not sure what to buy given the wheels and levers? - Any ideas?

Are there any potential pitfalls with this approach?

beardy
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Re: Mercian Renovation

Postby beardy » 22 Jun 2015, 12:14pm

Two small ones cross my mind.

The faces of the bottom bracket shell would need facing if you wanted to use an external bottom bracket.

The STI gear levers will need a cable stop for the outer cables (somewhere around where the DT levers are now). The front dérailleur cable will need an adjuster, either at the stop, inline or where the cable enters the STI.

pickerd1
Posts: 36
Joined: 31 Mar 2014, 5:05pm

Re: Mercian Renovation

Postby pickerd1 » 22 Jun 2015, 12:29pm

Facing the BB had slipped my mind. Is this an expensive job?
Will an Hollowtech II fit? I'm thinking threads etc?
Interestingly I went for a cartridge square taper BB on previous projects. I might consider this again although I would have to buy a new / 2nd hand crank.
I had considered in line cable adjuster and down tube stops - I have used these before on other renovation projects.

Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: Mercian Renovation

Postby Brucey » 22 Jun 2015, 12:32pm

I would suggest that if you want a touring bike that is to reliably carry a reasonable load, that you perhaps go out and buy one.

Just because the frame you have has rack mountings etc does not automatically mean that it is built to carry much of a load; very many 'lightweight' touring frames from that time were really designed to carry a relatively light load. So first thing to do is to find out what kind of frame/tubing you have; your frame could be built very light, and not at all suitable for load-lugging.

As a general rule if any three of the following apply

- frame size over 22.5"
- seat pin dia 27.0mm or larger
- frame and fork weight less than 6.5lbs
- luggage 15kgs or more
- rider plus luggage weight over 90kg

then I suspect you would most likely be better off with something else.

If you intend to fit 700C wheels the first thing you must do is establish if you can fit brakes to the bosses OK and have them work on the 700C rims; you may not have enough adjustment, or the bosses may be too close together to allow many modern brakes to fit (as per my previous post).

Here, Colin has (quite sensibly) many times suggested that the first thing you should do with a 'project frame' is to build it up (with any old kit really) and see if it

a) fits you properly and
b) rides, steers, and carries a load in the way you would like.

Lots of people have spent a fortune building up a 'dream bike' from a frame only to find that they don't actually fit it or like riding it, and that they have wasted a stack of time and money in the process.

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

pickerd1
Posts: 36
Joined: 31 Mar 2014, 5:05pm

Re: Mercian Renovation

Postby pickerd1 » 22 Jun 2015, 12:55pm

Thanks Brucey - your points are well made.

The tubing is Reynolds 531, and it is about a 23" frame. I am over 90kg (without luggage) - I wasn't really thinking of carrying luggage as I have a Salsa Vaya for that, but wanted something for riding the rougher cycle paths and tracks that I tend to find myself on, as opposed to riding on the road which I don't enjoy as much.

I was thinking of building it up from bits I have to start with.

I was really asking for future reference and to budget for parts etc.