27" wheels to 700cc - advice please

jonnywilkinson

Dear All,

I picked up an old late '70s Raleigh and gave it to my younger bruv in order to get him started at this cycling thing. Anyway, he has done it justice already with a couple of decent rides (for a guy who hasn't sat on a bike in earnest for about 10 years and has a few extra pounds to shift).

The frame is good nick and he loves it. But those heavy old 27" wheels and crappy weinmann brakes have got to go. I have some decent spare mavic 700cc race wheels and some 105 aero levers I can give him and he will buy some new brake calipers,

So apart from having to drill out the brake bridge and fork a bit (to take modern allen key caliper fittings) is there anything else we need to do? Do I assume that going from 27" to the smaller 700cc he will need to buy long reach calipers? I have seen some Tektro calipers on parker-international with 47 to 59mm of reach - will that cover it?

Any advice welcome before I advise my bruv to make the purchase.

All the best

belgiangoth

I bought some Alhonga deep drop brakes from SPA cycles when I did a similar conversion. Check with sheldon, but I think that rim diameter for a 700c is 622 and a 27" is 630, so you need an extra 4mm drop on your brakes. (?)

theoldbiker

I did something similar a long time ago, but still use the bike when its going to be left outside shops/locked to railings etc. i) 700c wheels should go in without trouble - providing there is a 130mm spread between the rear chainstays; ii) if there is sufficient reach (and there should be) just put Aztec blocks into the Weinman brakes and the bike will stop on a sixpence (or even a 5p). A lot cheaper and easier than trying to customise the existing fittings - and later on your brother may wish to upgrade to an altogether more modern bike.

jonnywilkinson

BG,

those Alhonga look good value so might recommend them to my bruv - it says they are nut fitting only so I assume that means you don't even have the hassle of getting the drill into action - is that what you found?

jonnywilkinson

oldbiker cheers,

hadn't thought about the oln on the rear stays - he has got an old 5 speed block so am assuming the oln is more like 126 or something. mmm? might be able to spring it. will see about checking out the aztec option in the current weinmanns but the thing is I think the springs in the weinmanns have seen better days.

you are right though - within six months he will probably splash out on a more modern bike - but then doing this one up now means it can be passed on.

thanks for the advice guys

steowen

Shimano do a brake caliper set with long drops AND a nut fitting, so no drilling required. At £49.99 they're not the cheapest but they are powerful and light - I've used them on my old fixie for over a year and they've been brilliant.

http://www.sjscycles.co.uk/product-Shimano-Shimano-RX100-BR-A550-Dual-pivot-brake-calipers-47-57mm-Deep-drop-NUT-fitting--Front-and-Rear-1819.htm

jonnywilkinson

steve

thanks for that too. will put it in my bruv's hands in terms of what he's prepared to pay for the calipers. the alhonga ones are a lot cheaper at £21 so reckon he will plump for them - but will be good to suggest a couple of options to him, so thanks again

belgiangoth

jonnywilkinson wrote:

those Alhonga look good value so might recommend them to my bruv - it says they are nut fitting only so I assume that means you don't even have the hassle of getting the drill into action - is that what you found?

I didn't need a drill, though I'm not sure exactly what the problem could be - my bike was big enough for campy mirage brakes to fit (except that the forks were too wide I think)