Search found 2685 matches

by Samuel D
10 May 2019, 2:54pm
Forum: Bikes & Bits – Technical section
Topic: Crank Length - formula?
Replies: 22
Views: 746

Re: Crank Length - formula?

170 mm is common but not universal. However, nearly universal are cranks between about 165 mm and 180 mm, which is a smaller range than that of human height or leg length. With a few exceptions, people seem to get along fine with that just as they get along fine with one size of step height on stair...
by Samuel D
10 May 2019, 12:01pm
Forum: Bikes & Bits – Technical section
Topic: New frame. Steep seat angle. Unrideable.
Replies: 79
Views: 3670

Re: New frame. Steep seat angle. Unrideable.

You’re doing everything right. Hopefully they’ll do the right thing too, after a moment of reflection. Give them time and scope to do that. As noted, debating the reasonableness of the angle with them may not be productive. It’s your opinion against theirs and even if the entire industry is on your ...
by Samuel D
10 May 2019, 11:22am
Forum: Bikes & Bits – Technical section
Topic: Lubricants for ratchet mechanisms
Replies: 38
Views: 1489

Re: Lubricants for ratchet mechanisms

Thanks. I don’t think slight leaking would be a problem here except that it would require periodic re-application. I don’t have many choices available at home but I have synthetic 80W-90 and 75W-90 gear oils, TF2 bicycle chain lubricant, a viscous Finish Line lubricant for wet weather, and various g...
by Samuel D
10 May 2019, 10:40am
Forum: Bikes & Bits – Technical section
Topic: New frame. Steep seat angle. Unrideable.
Replies: 79
Views: 3670

Re: New frame. Steep seat angle. Unrideable.

Others may disagree but I consider such a steep seat tube angle simply an error of design. Who’s asking for this and what’s the advantage? If it ever made sense it doesn’t in the days of threadless headsets with stems of any length and angle easily available while seatposts and saddles have no such ...
by Samuel D
10 May 2019, 10:32am
Forum: Bikes & Bits – Technical section
Topic: Lubricants for ratchet mechanisms
Replies: 38
Views: 1489

Lubricants for ratchet mechanisms

I acquired an old Facom socket ratchet for next to nothing and opened the round head to find crud and dried grease inside. Rebuild kits are available for a few euros but I don’t think I need one. There isn’t much visible wear anywhere. I cleaned the pawl and head teeth with a toothbrush using WD-40 ...
by Samuel D
10 May 2019, 7:32am
Forum: Bikes & Bits – Technical section
Topic: New frame. Steep seat angle. Unrideable.
Replies: 79
Views: 3670

Re: New frame. Steep seat angle. Unrideable.

How does a steeper seatpost prevent toe-overlap? Because for a given top tube length, the distance between the bottom bracket and front wheel axle increases as the seat angle is increased (assuming the head angle and fork offset don't change). Smoke and mirrors. The cyclist must move the saddle bac...
by Samuel D
9 May 2019, 11:40pm
Forum: Bikes & Bits – Technical section
Topic: New frame. Steep seat angle. Unrideable.
Replies: 79
Views: 3670

Re: New frame. Steep seat angle. Unrideable.

I think you’re justified to feel as you do. Whatever was the case in the past, a 76 degree seat tube angle is well outside current expectations for a general purpose bicycle and certainly an audax machine, and springing that on the customer by surprise is inexcusable. Your case brings to mind Lord D...
by Samuel D
6 May 2019, 9:43pm
Forum: Bikes & Bits – Technical section
Topic: SP dynamo hubs - narrow flange spacing
Replies: 32
Views: 1179

Re: SP dynamo hubs - narrow flange spacing

I built a wheel for someone using a previous generation Mavic Open Pro and a SP dynamo, Sapim DB spokes. It folded hitting a pothole at speed while they rode back from the pub. Spoke count and approximate rider weight? I’m 65 kg and used 36 spokes. […] might not have folded had they not been lubric...
by Samuel D
6 May 2019, 5:16pm
Forum: Bikes & Bits – Technical section
Topic: Bottom bracket tool 6800 Ultegra
Replies: 31
Views: 984

Re: Bottom bracket tool 6800 Ultegra

One of the reasons could be that most of those tools are simply cast and then put in the thumbler, so their tolerances leave a lot to be desired: the Park Tool BBT19 is like that, and has a noticeable play in the cups. The similar BBT-19.2 is supposed to have improved tolerances for a better fit. I...
by Samuel D
6 May 2019, 2:54pm
Forum: Does anyone know … ?
Topic: RIP Jobst Brandt
Replies: 39
Views: 3649

Re: RIP Jobst Brandt

Brandt was old and falling apart himself by that point. The “detached from reality” comment may have been true. I’ve read he was often overtaken by darkness on solo rides on roads with fast traffic toward the end of his cycling career. The impression I have is that he unreasonably attempted to conti...
by Samuel D
5 May 2019, 10:04pm
Forum: Bikes & Bits – Technical section
Topic: another wheelset bites the dust....
Replies: 9
Views: 531

Re: another wheelset bites the dust....

But for your typical weekend warriors the Mavic / Shimano factory wheel sets are great. Why are they great if they cost hundreds to replace when you damage a rim or wear out the brake track, things that happen often if you ride much? They’re needlessly expensive compared to Brucey’s option (h) and ...
by Samuel D
5 May 2019, 9:52pm
Forum: Does anyone know … ?
Topic: RIP Jobst Brandt
Replies: 39
Views: 3649

Re: RIP Jobst Brandt

Today is the fourth anniversary of Jobst Brandt’s death. So far, no-one has written a biography as far as I know. I think his story would be worth telling, but to do it justice it would have to be told by someone who shared Brandt’s fascination with the mechanical world. I don’t suppose many of thos...
by Samuel D
3 May 2019, 12:45pm
Forum: Does anyone know … ?
Topic: Black Waterproof jackets - a bad idea?
Replies: 164
Views: 5583

Re: Black Waterproof jackets - a bad idea?

They’re all adequately visible at a glance, even in a murky webcam-quality image. Now scroll to the right. Does the illuminated hi-viz motorcyclist stand out against the illuminated hi-viz van – because a white box the height and wingspan of a man is nowadays too subtle – as well as his less-offensi...
by Samuel D
3 May 2019, 12:31pm
Forum: Bikes & Bits – Technical section
Topic: SP dynamo hubs - narrow flange spacing
Replies: 32
Views: 1179

Re: SP dynamo hubs - narrow flange spacing

On the other hand, front wheels experience higher lateral forces, I think in normal riding (landing after hopping kerbs with the handlebar not quite straight, honking while swerving, etc.) and certainly in crashes. You don’t often see a rear wheel wrecked from side forces. You see front wheels destr...
by Samuel D
3 May 2019, 12:16pm
Forum: Does anyone know … ?
Topic: Black Waterproof jackets - a bad idea?
Replies: 164
Views: 5583

Re: Black Waterproof jackets - a bad idea?

No, no!!! They are just as easily seen in black as in bright colours. I'm surprised the SAS didn't wear HiViz when storming the IKranian embassy. According to some of the opinion here it would make no difference. You jest, but I don’t when I recommend they wear hi-viz the next time they’re operatin...