Converting a ten speed bike

[RecordAceFromNew]

No.

I have a big shelf full of second hand wheels off tourers and road bikes dating back to the 1950's, a great deal of which are 5 speed on 126mm hub, some even take a fixed sprocket on the other side depending on the brand of hub.

When you handle a lot of older bikes and work on them (and I mean a lot) you learn what kit was fitted, you don't make the arbitrary assumption that it "must" be this dimension just because it has "x" component fitted.

Companies and riders used stock up on components, they mixed and matched new and old and companies often only offered the very latest kit as an upgrade to standard lines.

Indeed. Zoiders if you check you will see it was you who stated "As a 34 year old mercian it will have been built with 126mm spacing" AFTER I merely said it was most likely to have been built with 120mm spacing despite having seen the Mercian catalogues in which they were ALL 10 speed i.e. 120mm when new.


Given it did turn out to be 120mm, I am having difficulties understanding what your beef is.

 

[RecordAceFromNew]

I'll re-phrase that - the 9 with friction levers gives a good gearing range for not too much money, if you want stronger wheels for touring at the same time then go for the 135mm rear spacing. A Stronglight triple of 48/38/26 plus that 11-34 will cope with Bealach Na Ba plus camping gear. (Yes I've done it!)

Makes perfect sense and is something I should do but resisting. Why? That means I will have to replace my faithful 1982 Campag Super Record rear mech (25 tooth wrap capacity max) with something else. Further I think no 32T, let alone 34T Campag sprocket can be acquired for love or money!

I might change my mind one day, but at the moment I will eat worms before putting a non-Campag cassette or freehub/wheel on that bike. But that's just me...

 

[Zoiders]

Indeed. Zoiders if you check you will see it was you who stated "As a 34 year old mercian it will have been built with 126mm spacing" AFTER I merely said it was most likely to have been built with 120mm spacing despite having seen the Mercian catalogues in which they were ALL 10 speed i.e. 120mm when new.


Given it did turn out to be 120mm, I am having difficulties understanding what your beef is.

You don't understand this do you?

10 speeds were built on 126mm hubs as well.

Quite an awful lot of them, a Mercian from 78 is most likely to be 126mm, the block is not the decider on that.

 

[RecordAceFromNew]

You don't understand this do you?

10 speeds were built on 126mm hubs as well.

Quite an awful lot of them, a Mercian from 78 is most likely to be 126mm, the block is not the decider on that.

What I understand, is that since the OP said his dropout is 120mm, Zoiders you are effectively saying that he has an oddball since based on your extensive recycling experience you are sure most Mercians made then should be 126mm.

In addition, what I understand is that in response to the 1978 Mercian catalogues’ 10 speed specification you are saying manufacturers were building “quite an awful lot of” 10 speed bikes on 126mm hubs. The problem is that that would be the case only if they happened to have unwittingly stashed away “quite an awful lot of” 5 speed freewheels AND 6 speed hubs. You see no manufacturer of sound mind would otherwise put 5 speed blocks on 126mm hubs because one is then getting the worst of both worlds - not only does one lose one ratio (or two), one’s wheel is weaker due to increased dish. This being a common practice simply beggars belief.

From reading a couple of your other posts I suspect you are vastly more experienced and knowledgeable than I, but I am finding this debate somewhat surreal. I know 6 speed existed even in early 60’s, but anybody who was in the market here for a drop bar bike in the late 70’s and early 80’s couldn’t escape noticing that 5/10 speed were dominant, and indeed Ultra6 in 120mm was probably more common than normal 6 in 126mm even in the early 80’s. Many catalogues from Raleigh, Dawes, Holdsworth etc. from that period exist to support this.

Since you cited your opinion in relation to your work experience, I can’t help but wonder if the condition/components of the bikes you recycle today are necessarily what they were when originally built/marketed/sold 30 odd years ago, whether they are statistically representative of the bike population then, or indeed whether they are dated correctly consistently. Backcasting what Mercian and others sold 34 years ago based on finding 5 speed blocks on 126mm hubs today has to be a little tenuous. Just a thought.

 

[jay clock]

Yawn! A fight between techie bike nerds.

Can I be completely different? Get a new bike. There comes a point at which the cost of upgrading all the kit to something new that works well, far exceeds the cost of a new bike. I am sure I will be shot down and in a minority. It helps that I do not particularly like the "old skool" Mercian looks

 

[PpPete]

Nearly as much fun as P&L !

I'd go with cold-setting and the 9 speed suggestion above (I've done exactly that on several bikes of similar vintage) ...if it were not that rear wheel has recently been rebuilt around the original freewheel hub. So, for now the intelligent (and lowest cost) solution is to go with a bigger 5 speed freewheel (links above) and hope the existing mech wil cope with it.

 

[RecordAceFromNew]

Nearly as much fun as P&L !

RAFN (AKA techie bike nerd...)

 

[Zoiders]

You can quote any catalogue you like but we have an industrial unit full of 126mm bikes.

Just because the 6 became available does not mean every manufacturer was forced to offer 6 speed as standard equipment as yes they did indeed put 5's on 126mm hubs.

 

[niggle]

IRD freewheels available in the UK from here, including 13-32: http://www.wheelroom.co.uk/shop/art...6,7-speeds.html?shop_param=cid=40&aid=49.001& Not cheap though at £38 plus post.

 

[niggle]

Thought: what about just going to a triple for the moment? The OP could keep the rear wheel as it is for the moment but fit triple chain set, new BB, front mech (if the latter is essential), probably need new rear mech (future proof with 9/10 speed). Then he gets a wider range 15 speed, then when the wheel needs rebuilding he can move to 9/10-speed with cold setting to 130 or 135mm.

 

[swee'pea99]

I've converted two old 10 speeds to 14 speeds using one of these and some redishing of the back wheel. I highly recommend it. The 28, combined with a standard 52/42 or 53/39 chainset gives a low enough gear for even us older chaps to go up all but the steepest hills, and the smaller increments between the mid-range gears makes a big difference. It basically means you go from six (pretty widely spaced) gears to ten (comfortably close) ones. Plus you don't have to mess about with cold setting or any of that nonsense - just give it a bit of welly when you're putting the wheel in.