Author Topic: Mercian bike fit experience  (Read 3130 times)

Re: Mercian bike fit experience
« Reply #100 on: July 14, 2018, 07:13:16 am »
quite a few 1" threadless headsets here

https://www.sjscycles.co.uk/headsets-1-ahead/

and campag besides.

cheers

Re: Mercian bike fit experience
« Reply #101 on: July 14, 2018, 10:31:50 am »
Chris King do a 1” threadless - by far the best headset I’ve ever had.

Re: Mercian bike fit experience
« Reply #102 on: July 14, 2018, 10:54:58 am »
I'll be putting a 1" Campagnolo Record threaded headset on my Mercian Strada BTW
Old enough to know better, but young enough to do it anyway

Re: Mercian bike fit experience
« Reply #103 on: July 14, 2018, 11:07:12 am »
Does it have cartridge bearings these days?  If not, consider a Tange FL250C (Falcon) as this is pretty much fit-and-forget and should never develop "indexing".  Stack height 35.3mm but you can use a thinner spacer and lose another mm.  On a new bike, I'd always specify at least 40mm stack height anyway - those 1990s forks cut right down for Shinano 32mm height headsets are really limiting now.
Never tell me the odds.

Re: Mercian bike fit experience
« Reply #104 on: July 14, 2018, 11:25:22 am »
Does it have cartridge bearings these days?  ….

of course not; if it ain't broke, why 'fix' it?  To get the same strength in a typical cartridge bearing construction, you would need to have one about three times the volume.  If it is set up and lubricated correctly a Camppag threaded headset should last the life of the bike.

cheers

Re: Mercian bike fit experience
« Reply #105 on: July 14, 2018, 01:04:49 pm »
I know you don't believe him but I think Jobst Brandt was right on the money about false brinelling.  Nothing with loose races suffers from this, whether it's cartridges or the loose races of a Stronglight A9.  Headsets really need a plain angular contact bearing interface  to accommodate fork flex.
Never tell me the odds.

Re: Mercian bike fit experience
« Reply #106 on: July 14, 2018, 01:34:01 pm »
Would 53/39/30 chainrings and a 13/26 cassette be a not completely insane idea for a road bike like this? Would give a gear range of 30.4" to 107.5", which sounds about right to me. The cassette goes 13-14-15-16-17-18-19-21-23-26 - so straight through to 19T. Found a set of 170mm Record Triple cranks I might use.

Alternatively a 50/34 compact chainset with a 12-30 cassette would give a similar range - 29.5" to 109.9" or with a 13-29 cassette 30.9" to 101.5", but not sure that the latter would be high enough a road bike/
Old enough to know better, but young enough to do it anyway

Re: Mercian bike fit experience
« Reply #107 on: July 14, 2018, 02:52:56 pm »
I know you don't believe him but I think Jobst Brandt was right on the money about false brinelling.  Nothing with loose races suffers from this, whether it's cartridges or the loose races of a Stronglight A9.  Headsets really need a plain angular contact bearing interface  to accommodate fork flex.

For many years JB had a 1" steerer about a foot long and it flexed so much it would knacker any normal headset because the loads were no longer evenly distributed. What he had (and didn't believe he had; he should have known better) was much closer to real brinelling than he thought. He thought he didn't have real brinelling because he couldn't see a ridge of displaced material around the wear marks, but he hadn't done his sums properly; you can have 10um deep dents and the raised area around the holes might only be about 1um high, which would of course be very difficult to detect.

I have seen endless A9s that are knackered through....you guessed it.... fretting wear and in fact I have not seen one that has been used for any distance that wasn't worn unevenly, because the races move and then sit at a funny angle. Folk have even sent me their 'good' A9 headsets to look at and they have been worn just like the others...  IMHO the A9 is the epitome of a terrible headset; it needs a lot of preload in order not to rattle and once so preloaded it binds slightly, even if the raceways are in perfect condition. If you want a built-in steering damper maybe that is OK but if you don't I think it makes for a horrid bike to ride.   

[BTW there is a simple experiment you can do; at the end of a ride with an A9 headset, stop in a straight line using the rear brake, i.e. without turning the handlebars. Pick the bike up at the front and carefully turn the steering. Very often the first turn will be rather bindy and after that the movement will be slightly more free. This happens because the raceways settle into a new position when the steering is first turned in any new loading situation. Unless the road is as smooth as a billiard table the loading is changing all the time as you ride and the inevitable result is a mixture of binding and fretting....ugh...]

Modern cartridges are often built very weakly (too few balls, too small) but a few use a full complement of loose balls of decent size; these headsets are bulkier and heavier than they need be. The ability of the lower race to articulate can be useful if you have a flexy steerer, but in order not to rattle the preload again needs to be high. Swings and roundabouts....

If you have a good quality traditional loose ball headset (Campag, Tange, etc) fitted to a 'normal' sized bike, IME if it dies it has been murdered rather than natural causes, every time...

cheers

Re: Mercian bike fit experience
« Reply #108 on: July 14, 2018, 03:11:14 pm »
Would 53/39/30 chainrings and a 13/26 cassette be a not completely insane idea for a road bike like this? Would give a gear range of 30.4" to 107.5", which sounds about right to me. The cassette goes 13-14-15-16-17-18-19-21-23-26 - so straight through to 19T. Found a set of 170mm Record Triple cranks I might use.

Alternatively a 50/34 compact chainset with a 12-30 cassette would give a similar range - 29.5" to 109.9" or with a 13-29 cassette 30.9" to 101.5", but not sure that the latter would be high enough a road bike/

the first set of gearing is such that I'd end up running cross-chained most of the time. You know what gears you use most of the time; my suggestion is that you use a setup that, if possible, does not leave you running cross chained under 'normal'  conditions.  So for racing having 13-19 in 1T intervals is quite desirable but for pretty much everything else I'd live with 2T intervals in that range if it got me out of a cross-chaining hole.

cheers