Grant Petersen’s Rivendell Roadini

[robc02]

I dislike brake cables on the top of the top tube for various reasons (aesthetics, the likelihood that the cable will be repeatedly pushed and rubbed against the frame by the weight of the crotch pressing against it [especially on a horizontal top tubed bike with its inherently high standover], the rattle of the cable on the frame when riding over bumps because the cable doughnuts never stay in place, and my experience of the cable guides and cable being more prone to holding water and promoting rust [albeit that was with fully enclosed cables as opposed to cable stops and bare cable]).

Stainless steel braze-ons should sort out the rust problem. The rattle and abrasion to the paint are still annoying, though. For this reason when I refurbished a frame a couple of years ago I replaced the original top of top-tube guides (for full length outer) with stainless stops at about the eight o' clock position. Of course, this is no good at all if the bike needs to be shouldered - unless, perhaps, the brakes used will allow the cable to be on the right hand side of the tube, e.g. cantis or centrepulls.

[Bmblbzzz]

For that matter you could have stainless tubing if you're worried about rust. My preference for cable guides is probably fully enclosed cables running under the down tube. On top of the top tube would probably be good too, but wherever they go I'd have them fully enclosed in order to prevent the rattling over bumps Samuel mentions and more so, to prevent snagging on other bikes' bars, levers and so on when parked in an urban situation (or on a train or even piled in a heap outside an audax cafe, etc).

[slowster]

Stainless steel braze-ons should sort out the rust problem.

The rust on both frames is more of the tube itself next to the braze on and cable. I suspect that the cable guides and fully enclosed outers result in small gaps and spaces between the braze on, top tube and cable outer in which water tends to sit rather than drain away, something which is aggravated by the top of the top tube providing something of a flat surface. I think the old clamp on cable guides were especially prone to this, and it was pretty common to find rust underneath the clamps.

In contrast I think two cable stops between the four and eight o'clock positions will drain better and more quickly, both with the assistance of gravity and because I think they present less space and fewer gaps for water to sit.

Another advantage of the four and eight o'clock positions with cable stops and bare cable, is that there is no rattle (at least not IME, albeit that I do fit cable doughnuts as well), because the cable has to bounce much higher to reach the side of the top tube above it, compared with if it were on the top of the top tube.

[fastpedaller]

Ah gotcha, the squared bends variety or ergo bars. The Deda piega comes in a variant very similar to that and 26.0 IIRC

That may work, but I forgot to mention that I prefer a compact bar. These are standard drop and reach.

I'm late to the discussion, so forgive me If I'm talking nonsense....... I think a previous poster wants to use ergo bars similar to this shape with a quill stem. Again I may be wrong, but I don't think a quill stem could be 'threaded' around the bars to arrive at the centre section, as some of the bends are too tight to allow it?

[MikeDee]

Ah gotcha, the squared bends variety or ergo bars. The Deda piega comes in a variant very similar to that and 26.0 IIRC

That may work, but I forgot to mention that I prefer a compact bar. These are standard drop and reach.

I'm late to the discussion, so forgive me If I'm talking nonsense....... I think a previous poster wants to use ergo bars similar to this shape with a quill stem. Again I may be wrong, but I don't think a quill stem could be 'threaded' around the bars to arrive at the centre section, as some of the bends are too tight to allow it?

Well, I was able to get my Soma Hwy 1 bars through the clamp of my Salsa quill stem by spreading the clamp open more. I think I reversed the clamp bolt and screwed it into a penny to widen the clamp opening. That technique may not work on other stems.

[tatanab]

I'm late to the discussion, so forgive me If I'm talking nonsense....... I think a previous poster wants to use ergo bars similar to this shape with a quill stem. Again I may be wrong, but I don't think a quill stem could be 'threaded' around the bars to arrive at the centre section, as some of the bends are too tight to allow it?

I have ergo bars fitted to 3TTT and Nitto 26mm quill stems with no undue problems. I did not have to spread the clamp to do it either.

Edit - it is possible to get 26mm quill stems with removable face plates e.g 3TTT Mutant

[robc02]

......... My preference for cable guides is probably fully enclosed cables running under the down tube. On top of the top tube would probably be good too, but wherever they go I'd have them fully enclosed in order to prevent the rattling over bumps .........

I thought I would prefer fully enclosed cables as well, mainly to prevent water ingress and consequent seizing at the stops. That bit worked well, but I still had rattles where the outer casing rested against the top tube between the guides!

[robc02]

Stainless steel braze-ons should sort out the rust problem.

The rust on both frames is more of the tube itself next to the braze on and cable. I suspect that the cable guides and fully enclosed outers result in small gaps and spaces between the braze on, top tube and cable outer in which water tends to sit rather than drain away, something which is aggravated by the top of the top tube providing something of a flat surface. I think the old clamp on cable guides were especially prone to this, and it was pretty common to find rust underneath the clamps.

In contrast I think two cable stops between the four and eight o'clock positions will drain better and more quickly, both with the assistance of gravity and because I think they present less space and fewer gaps for water to sit.

Another advantage of the four and eight o'clock positions with cable stops and bare cable, is that there is no rattle (at least not IME, albeit that I do fit cable doughnuts as well), because the cable has to bounce much higher to reach the side of the top tube above it, compared with if it were on the top of the top tube.

Yes, I agree with all of that, though I don't use doughnuts.
Also, I find the rusting of the stops/guides themselves is mainly due to the ease with which the paint can be chipped off the corners and edges. This is where stainless ones score.

[Brucey]

side-mounted braze-ons are OK and avoid rust traps on the top of the top tube. But you can still get corrosion around these braze-ons ( if the flux residues are not removed, it is guaranteed) and on a bike with caliper brakes,

a) the handedness of the caliper is set, you can't change it without having a rubbish route for the rear part of the cable running to the caliper (not such a problem these days because DP calipers are all clones of one another) and
b) the route from the (left side) cables into a standard British lever setup is rubbish; there is a needlessly tight (and often multiple) bend in the rear brake cable. Exactly how bad this is depends on how high/forward your bars are. But IME with aero levers a left side braze on always gives an inferior cable run, usually with rubbing on the side of the head tube. If you use the rear brake lever on the right the cable run is better.

If you use non-aero levers then at the front a right side cable run is still better (for a left rear setup) but this is incompatible with all modern caliper brakes, all disc brakes, drum brakes, etc etc. A right side cable run is OK for shouldering the bike but it is only going to work with some old side pulls, cantis and centre pulls.

A left side cable run is still basically no good for shouldering the bike; the braze-ons can dig into your shoulder and the cable can still be forced to rub.

Stainless braze-ons don't themselves go rusty but they can cause accelerated corrosion in the (now guaranteed to be an anode) frame tube itself around the braze on, which (should it occur) is a far more worrying problem.

Arguably a little rust on a conventional top tube braze on (not very harmful in its own right) is just a warning that there is worse on the way if you don't do something.

Conventional top tube cable routing ain't perfect by any means, but it might be the least bad option.

cheers

[Bmblbzzz]

......... My preference for cable guides is probably fully enclosed cables running under the down tube. On top of the top tube would probably be good too, but wherever they go I'd have them fully enclosed in order to prevent the rattling over bumps .........

I thought I would prefer fully enclosed cables as well, mainly to prevent water ingress and consequent seizing at the stops. That bit worked well, but I still had rattles where the outer casing rested against the top tube between the guides!

My enclosed cables don't rattle - but they're under the downtube. Other things on the bike do rattle, mostly the back mudguard.

[robc02]

side-mounted braze-ons are OK and avoid rust traps on the top of the top tube. But you can still get corrosion around these braze-ons ( if the flux residues are not removed, it is guaranteed) and on a bike with caliper brakes,

a) the handedness of the caliper is set, you can't change it without having a rubbish route for the rear part of the cable running to the caliper (not such a problem these days because DP calipers are all clones of one another) and
b) the route from the (left side) cables into a standard British lever setup is rubbish; there is a needlessly tight (and often multiple) bend in the rear brake cable. Exactly how bad this is depends on how high/forward your bars are. But IME with aero levers a left side braze on always gives an inferior cable run, usually with rubbing on the side of the head tube........

..........Stainless braze-ons don't themselves go rusty but they can cause accelerated corrosion in the (now guaranteed to be an anode) frame tube itself around the braze on, which (should it occur) is a far more worrying problem.

Arguably a little rust on a conventional top tube braze on (not very harmful in its own right) is just a warning that there is worse on the way if you don't do something. ...........


cheers

Yes, the cable routing and resulting rubbing is a nuisance but I have learned to put up with it. I always make sure there is enough sweep in front of the top tube to allow the bars to swing from side to side without straining the cables. This also results in more rubbing, including from gear cables when using Ergos. I usually put self adhesive patches (made from helicopter tape or similar) to protect the paint - with varying degrees of success.

I considered the anode effect of stainless braze-ons but considered it the lesser of two evils, given the severe corrosion issues I have had with traditional top tube guides. In one case the guide corroded to the point where the middle section disappeared completely, so now is a curved two sided clip rather than a loop. That said, I might be unusual in that my sweat seems to be very corrosive - when seat posts were polished aluminium they used to get pitted very quickly and the the top of the seat lug needed regular retouching to keep rust under control. I never managed to control the rust on stops and guides.

The frame I fitted with stainless guides about three years ago is still corrosion free around all my mods....... but there are signs of rust where the original top tube cable routing was. So much for the quality of the powder coating/shotblasting work! In future I will either paint frames myself or do much more preparation before handing over to the powder coater.

[531colin]

These will block up your bottle cage bosses, with a bit of threadseal.....https://www.westfieldfasteners.co.uk/A2_ScrewBolt_GrubFlat_M5.html
Reynolds 725 is 0.6mm thick in the middle of the tubes, 0.9mm at the ends apart from the top of the seat tube which is (I think) 1.2mm externally bulged. If you have crushed the bottom of your seat tube with a clamp that's a hard lesson learned, but its time to move on; I don't think you will find a quality tube set in thicker wall. Reynolds are quite shy of publishing numbers, this was the best I found with a bit of a Google.. http://www.torchandfile.com/assets/images/Reynolds/Reynolds%20Tubing%20Parts%20List%202014.pdf ....although I have a printed 2016 version, so its out there somewhere! It shows that even 531 (for brazing?) is thinner than 725. Working in bike shops I probably saw more stuff broken by overtightening than worn out, and that was before carbon fibre became popular. You can always put a bit of tape round the seat tube under the front mech. clamp to give a bit of grip, and double-sided carpet tape works well to hold spacers.
Seatposts that move are a pain, I have one bike that does it, because the post "fits" the seat tube like a dick in a bucket, so as the amount of weight on the back of the saddle varies the post can rock back and forwards and slip down. However (as in a previous discussion) I think 725 is the same internal diameter all the way down to the bottom butt; so I would be tempted to ovalise the seatpost a bit just up from the bottom and see if you can stop it rocking; it won't work for me as my seat tube is bigger diameter but sleeved at the top for a standard 72.2mm post. Grrrr. Alternatively you may find a more expensive seatpost is a bit closer to the nominal diameter.
I don't understand your aversion to Vee brakes; almost all rim brake pads move in an arc, cantilever pads move in precisely the same arc as Vee pads. To me, dual pivot sidepulls are the worst, because one pad moves up the rim and one moves down. If you are always fiddling with your GF's brakes, I suspect either they are cheap and nasty brakes, or they are being used outside their design spec. If you could set them so that when the pad is half-worn, the pad is vertically above the pivot, then the pad would be at its highest when half worn, with the least possible movement up and down. Vee brakes with wide-set pivots working on narrow rims will always be wanting to slide off the bottom of the rim. I bought a number of XT parallel push Vee brakes when they were still available, they are not without their own issues but at least the pad stays on the rim. Or if you can use long replaceable pad holders, you may get acceptable results by simply changing the pads when they wear, the long ones are usually thin anyway, but being longer they last acceptably well.
I have never seen a seat tube fail at the top; if a seat tube is going to fail, they "usually" fail just above the bottom bracket, due to pedalling stress, not rider bounce.
I have only ever once dented a frame, that was a lugless Gillot with pencil seatstays and lightweight tubing, from the fifties I guess....it fell against a concrete lamp-post and dented the top tube. I don't deliberately abuse my bikes, (unless roughstuff is abuse) but they certainly aren't wrapped in cotton wool.

[Brucey]

years ago one of my chums rode a CX frameset on the road. He had absolutely no intention of straying off tarmac for long; he rode time trials, road races, and even toured on it. It (of course) made stuff-all difference that he had the mafacs sticking out sideways as he did, it just made everything easier most of the time, eg fitting mudguards, unhooking the brakes to let the wheels in and out (even with fatter tyres on) and of course he wasn't stuck with a ridiculous mudguard clearance either.

The biggest difference it did make was that (even then) he got endless comments from roadies about 'his funny brakes'...I am sure that this would be worse these days....

The Mafacs were pretty good brakes BITD; easily as powerful as most brakes used for road racing and today still (with the right levers) powerful enough for unladen riding. These days you can get far better cantis which allow you to fine-tune the brake geometry and therefore MA vs running clearance. No other brake allows you to do that. With any one set of levers the system MA can be varied by a factor of about two (and folk getting it wrong are a major source of 'my cantis don't work very well' type comments) and if you choose the levers to suit your preference the range of possible canti MA values varies by a factor of at least three (again you can get this wrong as well as right...).

However I object on principle to setting up bikes that are mainly going to be used with skinny rims and fairly narrow tyres for V-brakes. There are several aspects to this; some trivial and some less so.

1) I just think they look ugly. Sorry, but there it is.
2) They are easily damaged if the steering swings round to the right. In this respect they are little different from DPs I suppose, the difference being that the V pipe and yoke are flimsy and easily damaged, and DPs are a bit more substantial; they can damage the frame.
3) the cable routing is poor/troublesome. It is difficult to arrange the cables so that the front brake cable doesn't foul the gear cables when the steering is moved far, and this pulls the brake off centre. This is worse on something that is set up more like a road bike, because the cables are liable to all be set closer to the bike centreline and the run to a low set handlebar is short.
4) once you have chosen your levers, there is no adjustment for MA. You can buy different length arms but that is about it.
5) V brakes restrict your choice of brake levers (so do cantis in fairness but the restriction is different)
6)V brakes can (with about one exception which is a now-long-obsolete STX model I think) only be fitted to wide spaced bosses.
7) any brake that is fitted to wide spaced bosses (with the exception of the now obsolete/occasionally troublesome parallel push shimano V brakes) will make the brake contact point travel down the rim as the brake wears. With narrower rims this is even worse, obviously.
8 ) V brakes use brake blocks with skinny inserts (which has good and bad aspects). Some V's fitted to bike with narrow rims can use 'road' inserts but these are the exception, and height adjustment is very likely when the inserts are half-worn.

Canti bosses were only ever set wide to allow 2" tyres on MTBs to pass between them with the tyre inflated. Even though there are very many bikes which will never use tyres this wide, and MTBs have mostly moved on to discs, we are now stuck with this 'standard'....
With cantis set to narrow bosses the contact point of the brakes does not descend at anything like the same rate as the brakes wear. However inflated tyres over about 35mm won't easily slide out between such bosses.

So if you are not going to use narrow rims and tyres much wider than ~32- 35mm and want to have canti bosses, it would still be my choice to set them to the old 'narrow' spacing (about 63mm) instead of the 'wide' spacing (~80mm), and use cantis even though this restricts the choice of brake arms somewhat. The whole setup is neater and works as well or better in every respect. Forks made this way can easily be built using 'road bike' crowns etc.

I may do some calculations regarding brake contact descent, so that some numbers can be put to it.

cheers

[Samuel D]

Going up even 2cm in frame size will also have a big effect on frame stiffness.

Not sure I understand the mechanism for this. I know a smaller rider would feel their bicycle to be stiffer than a taller rider with a similarly constructed but bigger bicycle, because the contact points are closer together in the first case and so have less leverage. But the position of the contact points wouldn’t change for the same rider (me) on a larger frame.

I dislike brake cables on the top of the top tube for various reasons (aesthetics, the likelihood that the cable will be repeatedly pushed and rubbed against the frame by the weight of the crotch pressing against it [especially on a horizontal top tubed bike with its inherently high standover], the rattle of the cable on the frame when riding over bumps because the cable doughnuts never stay in place, and my experience of the cable guides and cable being more prone to holding water and promoting rust [albeit that was with fully enclosed cables as opposed to cable stops and bare cable]).

I hadn’t considered all of those things, so thanks for bringing them up. Perhaps there’s no neat solution, then.

There are stairs to my basement where the bicycle lives, stairs to my fifth-floor flat (occasionally), stairs on footbridges over local canals, and huge flights of stairs in railway stations. I encounter a lot of them, hence my interest in making the bicycle easy to carry.

My preference for cable guides is probably fully enclosed cables running under the down tube.

Difficult with a rim brake at the rear.

[Samuel D]

These will block up your bottle cage bosses, with a bit of threadseal.....https://www.westfieldfasteners.co.uk/A2_ScrewBolt_GrubFlat_M5.html

I will try those.

If you have crushed the bottom of your seat tube with a clamp that's a hard lesson learned, but its time to move on; I don't think you will find a quality tube set in thicker wall.

I rarely repeat a mistake anyway, being talented at finding new ones. The other dents are from mistakes too, of course: badly leant against a tree from which it rolled and fell (when just a few days old!), and someone who caused my bicycle to fall against another on a train. I learned from those too.

Alternatively you may find a more expensive seatpost is a bit closer to the nominal diameter.

I already have a Nitto that measures exactly 27.2 mm with a Vernier calliper. Previously, though, I had a Ritchey seatpost, also a good 27.2 mm, that got stuck in the frame because, I think, I greased the seatpost and not the seat tube, so that when I inserted the post in the frame the grease got wiped off by the initial good fit. A winter of salt water completed the scenario.

Here it is now. Click on photos to enlarge.





When I got this seatpost out it pulled half the frame with it. The fore-aft diameter near the bottom is now closer to 27.3 mm than 27.2 mm and you can see rust flakes that have corroded solid to the aluminium. This is after rubbing it hard with WD-40 and kitchen roll.

To me, dual pivot sidepulls are the worst, because one pad moves up the rim and one moves down.

The downward motion of the long-arm pad can barely be measured, so in practice only one pad moves (up). But that one is a nuisance. Here’s a video of the problem and my earlier complaints about this. It’s enough to make me want to try single-pivot brakes.

I may do some calculations regarding brake contact descent, so that some numbers can be put to it.

If you do, maybe start a new thread on the topic so we can discuss pad-position error in a searchable way. It seems an under-recognised problem to me, based on the bicycles I’ve see on the road. The vertical movement of the pad does not tell the whole story, because when a lip forms in the pad from wear in the bad position, the lip readily bends up to poke the tyre, like the skin of a potato curling away from the peeler. You can see this process beginning in my video above.