Stability

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silva

silva

Über Member
Location
Belgium
Too many people have ridden vast tours, including around the world on Santos's for there to be a problem with stability. Bollocks
Santos is the brand of the bike, partly mounted by a mechanic of the brand, partly mounted and sold to me by a dealer of the brand. Who of both screwed up stability, in the bike I received, I really don't care. My goal is to hunt causes of problems and solve them.

The most plausible explanation for the instability is rear tyre not lined up with front tyre.
Fact 1: the center of the spokes flanges sits 5 mm away from the center of the frame dropouts - towards the drive side.
Fact 2: the rear tyre wears away from its middle - towards the non drive side, verified on both rear tyres that have been mounted so far.
If I put some kilo's luggage on top of the rear rack, the instability (which makes it harder to follow a road marking line), is gone.
A plausible explanation is that the inertia of the added fixed-position (unlike the rider of the bike) mass gives the bike more laterial stability, thereby reducing the required steering corrections.

So the first time I have the chance (bike needs work) I'll try to check the rear versus front tyre center. A couple ways I can think of is trying to mount the rear flipped and compare distances to rim brake mount. If no difference then the rear tyre isn't umbrella-spoked which means the rear tyre indeed doesn't run in the front tyres trail (spoke flanges center not in center of dropouts). A wheel spokes trueing stand would help but don't have one.
Another (additional) method may be holding a straight stick/whatever along the tyres or better the rims, and see if the stick sits parallel to the frame tube. That would take into account any out of center cause. Of course, judging 5 mm may be hard on this relatively short distance.

Oh, and I don't have problems with 50 kilo loaded on top of the rear rack. It's just harder hill up that's all. No problems staying on a line on the road. For the same reason: mass inertia - it's harder to change the path of a bigger mass than of a smaller mass, meaning, yes o dear fellow forum users, more stability when riding. :smile:
 
You’ve got all sorts of totally unnecessary stuff stuck to the bike. The centre of gravity is all over the place. I’m surprised it’s even vaguely rideable. That bike is designed for being ridden by a rider, with maybe a rucksack, and possibly a small bar bag / frame bag.
 
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silva

silva

Über Member
Location
Belgium
You’ve got all sorts of totally unnecessary stuff stuck to the bike. The centre of gravity is all over the place. I’m surprised it’s even vaguely rideable. That bike is designed for being ridden by a rider, with maybe a rucksack, and possibly a small bar bag / frame bag.

1) I decide what is necessary, not you.
2) https://www.santosbikes.nl/nl/fietsen
Travelmaster Serie

De pakezels.
Reisfietsen voor het zware werk.
Google translate it.

Things to do at first opportunity:
- check if the rear tyre is centered between the dropouts. The center of the flanges of the spokes is 5 mm off towards the drive side, meaning that the spokes should be umbrella shaped in a degree in order to bring the tyre in the center of the dropouts.
- check the frame itself, holding something straight along the tyres/rims or whatever method that could be used.
 
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1) I decide what is necessary, not you.
Ooooh get you.

I’ll decide what I google translate, not you.
Things to do at first opportunity:
- check if the rear tyre is centered between the dropouts. The center of the flanges of the spokes is 5 mm off towards the drive side, meaning that the spokes should be umbrella shaped in a degree in order to bring the tyre in the center of the dropouts.
- check the frame itself, holding something straight along the tyres/rims or whatever method that could be used.
:okay:
 

Vantage

Carbon fibre... LMAO!!!
Ooooh get you.


I’ll decide what I google translate, not you.

You're arguing for the sake of arguing. :headshake:

@silva There are 2 things you need to check.
1: Is the frame straight?
Check this by tying a piece of string to a rear dropout, around the head tube and back to the other rear dropout. Measure the distance of the string on either side of the seat tube. If both sides are the same, the frame is fine.

2: Are the wheels correctly dished (running central to the axle locknut?
Have this done by a competent bike mechanic or yourself if you know what you're doing.

If these two things are the way they're supposed to be then the only other possible problem is your load and how it is carried. No ifs, no buts. It's that simple.
 
That bike is designed for being ridden by a rider, with maybe a rucksack, and possibly a small bar bag / frame bag.
If you are talking about the Santos Travelmaster your wrong. It is designed to be used on tours. It is normal for it to come with racks. I have yet to find one on Ebay that doesn't have racks. I am happy carrying heavy loads front and rear. I have tried a few tourers including good old Thorns. Nothing beats a Santos....for me.
 
If you are talking about the Santos Travelmaster your wrong. It is designed to be used on tours. It is normal for it to come with racks. I have yet to find one on Ebay that doesn't have racks. I am happy carrying heavy loads front and rear. I have tried a few tourers including good old Thorns. Nothing beats a Santos....for me.
Yes, but what weight do YOU call "heavy loads"?
It's understood a good tourer hauls weight, but just how much, including rider?
 
Yes, but what weight do YOU call "heavy loads"?
It's understood a good tourer hauls weight, but just how much, including rider?
I am 12 stone.....and a bit! Large panniers (carradice rear on front, shoppers on back). Regularly filled with firewood, weight...... No idea but emptied into Tesco tray.
502245
 
But still not up to 50kg/120lb, I'd bet? Hundredweight sack of coal in old money. That's a lot.
 
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silva

silva

Über Member
Location
Belgium
If you are talking about the Santos Travelmaster your wrong. It is designed to be used on tours. It is normal for it to come with racks. I have yet to find one on Ebay that doesn't have racks. I am happy carrying heavy loads front and rear. I have tried a few tourers including good old Thorns. Nothing beats a Santos....for me.
Irrelevant:
On the other hand, I had such a so called "bombproof vacation wheel" with the outer rim wall showing a crack running the entire circumference, splitting all the spoke holes.
And a so called sturdy bike stand, losening over and over again, requiring more frequent retightenings, until several times in an hour, with dismounting and inspection unveiling white powder and damaged alu thread, identified as galvanic corrosion of the aluminium by the stainless steel (marked A2-70) bolts they chosed.
And a frontlight mount (alu stand), same story, unveiled when I tried to move it more to the front, with the lights cable blocking tool access to the allen head bolt, requiring me to file the stands hole out in order to not damage the cable.
And a rear fender, broken on the place of the U shaped brake pad mounting bracket, likely due to the brackets dimensions not allowing it to get it over the fender so forced there by deforming it.
And after just some weeks daily usage, something inside the bottom bracket losening, causing the chainring to wobble and scratch the frame, corrected by dealer by using Loctite and contradicting the advertisement claim that Loctite is standard applied.
And rear rack mount, the 2 arms connecting the frame to the seat tube, allen key bolt heads faced towards eachother at the inside, unreachable with the tool, unveiled when the rack losened there and inspection showed one bolt missing and the other loose.
The pedals - anti grip allen key bolthead screws with tool head at the wearing (shoes) side, ruining the boltheads and with it the ability to adjust them.
The rim tape - too narrow, they took the horizontal width of the rim, not taking into account the extra of the sloping of the rim causing the inner tube to contact metal corners - discovered at the new bikes first flat tyre, no outer wall puncture - worn spots on inner wall one with the hole causing the flat.
The rear hydraulic brake line, trajectory along top tube, resulting in a sharp corner under the handlebars towards the brake lever, causing it to break at its most frontwards top tube mounting bolt.

More general, one may question the choice steel for the luggage racks - it is rustprotected by black lacquer and if there is anything that a luggage rack suffers everyday it's grinding from bags and whatever, resulting in lacquer gone and rust.
When I showed the dealer the rust places he said that people tape the steel tubing off as a solution, rather awkward for things with such a price tag.
Also note the contradiction: on one hand they chose stainless bolts wherever but its on aluminium so galvanic corrosion prone and on the other hand they chose non stainless steel instead of aluminium so ordinary corrosion prone.
Grease? Not on any bolt including one I had to unscrew to repair the broken rear fender - seized - had to use a tong around the head, guess what: repeated story: white powder meaning the thread in the frame got damaged, had to tap it out.
It's like they think stainless - nothing can go wrong no grease needed.
Also no grease on any drivetrain component or its mount. I have had the axle and crankset replaced by a third party dealer, he noted there was not any grease applied on the older.

So all in all, these are some design and execution flaws for a bike frame that is advertised as travelbike in worse weather/road/environment conditions.
Last, aboves list is just limited to problems origining from the standard configuration of brand/model.
The ones origining from the conversion to fixed gear would make that list quite longer...unlike other bike frames, one can solve problems and modify the outfitting due to the many frame mount places.

I'm not saying here that the brand/model is crap - I'm saying that it should have been better (choices and job) for the price tag. I have had numerous hours work to make it usable in the way it is advertised.

My usage is abit similar to yours - a variety of whatever, it's not because you don't have a car that you need less stuff, etc.
I find a commonshaped bike frame with "internal" load provisions as most practical. Imagine having to tow a trailer all the time. 10-15 kilo and its own problems, "just in case" due to unknown on forehand if something and if yes, what, to transport. Or a gulliver front part of the bike, even heavier. You won't tilt the bike up let alone putting it upside down to cope with flats / whatever problems. And hard to maneuver in small or busy places.
So I arrived of a configuration of a small backpack (plan to have a wider same height) hanging under the handlebars, big double bags hanging aside the rear wheel, and wide/long (66x50x16cm) basket on top of a rear rack that is extended to the back with two triangular alu frames.
In that large basket, I keep with me a smaller and bigger backpack, an aluminium frame barebone version of a backpack, a handbag and some plastic sheets as raincover for rack and eventual bigger luggage.

Relevant
It all works, I've no problems riding and maneuvering with it, only that my rear tyre wears off the center away from the driveside, and that the barebone bike (no luggage at all) rides alike I constantly have to correct something, making it almost certain that something was screwed up during its production.

So you also use this brand bike in a similar fashion, is it the same model? If so, do you experience it's harder to ride straight with an unloaded bike?
What drivetrain configuration you have?

For some reason (possibly to reduce a chainline error of 10 mm (yes haha) to 5 mm), the middle of the spokes flanges of my rear wheel sits 5 mm off the middle of the frame dropouts, towards the driveside. If the wheel/spokes would be symmetrically (so not umbrella) shaped, the rear tyre would run 5 mm off the trail of the front tyre towards the driveside.
So together, seen from riderposition looking down, the rear tyre wears to the right, and runs to the left of the front wheels trail.

Does that fit or contradict eachother?

If a rear tyre runs to the left, I'd say the bike tends to changes course to the right because in effect a line connecting both wheels ground contacts biases towards the right of the frame line/direction.
Meaning the rider has to correct this by turning the handlebars and/or moving his body weight center to the left. Then the frame bends over to the left, and the rear tyre thus indeed wearing outside its center towards the left (non driveside).

Let's just suppose so, that the bikes producer/dealer would have deliberately (what else?) NOT trued the wheel so that the tyre sits in the middle of the axle ends / frame dropouts. What could have been the motivation?
See, there is another consequence of a tyre sitting 5 mm away from the frame center: the rim is also, and the hydraulic brake pads would thus also sit on different distances from their rim wall sides.
I just "measured" - had a short piece alu rail 13 mm thick. At the driveside, it fits between the side of the tyre and the frame tube, at the non driveside (left), it clearly doesn't, at least 3 mm too narrow, indicating that the rear tyre sits outside the middle towards the non driveside (left).
Why deliberately: because the rear rim has been replaced due to the crack (see the irrelevant section of my post) so despite that I informed the dealer the need for umbrella dishing due to the offcenter of the spokes flanges middle, the wheel with the new rim should have ALSO (just like the first/original and the spare second) been dished symmetrically.
The spare wheel that also got a rim replacement under warranty I didn't use so far so that I don't know without mounting it.
But what on earth could made them absolutely wanting to NOT dish the wheel to compensate for the different frame dropouts and spoke flanges center positions?
 
I ride my bike with no problems whatsoever. The previous owner road to Pakistan and south Africa on it with no problems.
 
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