Author Topic: Help with frame related questions  (Read 145555 times)

PH

Re: Help with frame related questions
« Reply #50 on: July 18, 2011, 09:54:43 pm »
Tewdric's Bob Jackson is a different case - it's got horizontal track ends with the wheel towards the front of the adjustment range so as the wheel goes back, the pads can come down in the slots. You can get round this by using long forward facing (and slightly angled) dropouts such as Campagnolo 1010 instead of track ends.

Totally agree about not using the full range of brake adjustment on a bike with vertical dropouts though.
Ah, thanks.  I'm glad there's an explanation in that case as it is otherwise a gorgeous looking bike.

Re: Help with frame related questions
« Reply #51 on: July 19, 2011, 11:22:44 pm »
I have a question about preparing and protecting the inside of a steel frame.

I've finally got my seatpost out and there's some surface rust on the inside of the seat tube. I'd like to remove this and protect the tubing so it doesn't happen again. I figure a squirt of waxoyl down each tube would be a good way of protecting them (is this a reasonable assumption?), but how do I clean the rust off the seat tube first?
Do you put anything inside your steel frames to protect them from rust?

Cheers
Duncan

Duncan

Last question first. I recommend Waxoyl to all my customers. It is extremely good for protecting bare steel as it creeps if damaged and self heals.  I do not apply it as standard as some people want to do their own thing and it is a bit messy.
If the rust in your seat tube is just a dust of surface rust I would just spray the Waxoyl straight over it. If it is a little heavier then the best way to shift most of it is with a strip of abrasive cloth inseted into a slot in the end of a length of dowel, stick the other end in a power drill and wizz it up and down inside the tube. Then spray your waxoyl into the tube.
A long time ago when Noah was a lad, I had a Mark one Ford Cortina that was a perambulating rust ball. I sprayed the underside with Waxoyl and it stopped the rust dead in its tracks. It taught me a lot that car, I learned to weld rust  ;D

Cheers

Dave Yates (No relation to John Yates, late of the Met !!!!!)
It's not just hitting it with a hammer but knowing where to hit it and how hard

Re: Help with frame related questions
« Reply #52 on: July 20, 2011, 11:43:00 am »

...Dave Yates (No relation to John Yates, late of the Met !!!!!)

Well, that's a load off my mind!

clarion

  • Tyke
Re: Help with frame related questions
« Reply #53 on: July 20, 2011, 11:44:36 am »
Can we have further updates on relations to Paula and Trish Yates? ;D
Getting there...

Re: Help with frame related questions
« Reply #54 on: July 20, 2011, 11:52:21 am »
Can we have further updates on relations to Paula and Trish Yates? ;D

Sean Yates?

clarion

  • Tyke
Re: Help with frame related questions
« Reply #55 on: July 20, 2011, 12:01:47 pm »
WB & Jack? ;D
Getting there...

Re: Help with frame related questions
« Reply #56 on: July 20, 2011, 12:08:16 pm »
WB & Jack? ;D

Anagrammatic relations.

Re: Help with frame related questions
« Reply #57 on: July 20, 2011, 01:51:56 pm »
Hi Dave.  One I've been pondering while thinking/dreaming of the next bike. 
What determines the maximum tyre size when using deep drop brakes?  Some bikes using them seem to only manage 25mm by distorting the mudguard, others seem fine with 28mm and I've heard of people using 30s.  Is it just the height of the brake bridge?  If so why are they not all designed to take the maximum possible?  Or is there some disadvantage?  What tyre size would you say was possible if I was asking for these brakes and mudguards?
Thanks

Also, it's not just the frame that determines this but the profile of the brake and the mudguard.  Some brakes have arm profiles that make a narrowing arch, some make a flat arch.  The former will require you to drop the mudguard placement even though there's room in the frame.  The distance from the bolt centre to the top of the arch also varies and affects how high you can fit the 'guard.  SKS narrow guards have a rectangular trough shaped profile which maybe won't fit up into the brake arch in the way a round profile 'guard would.

Re: Help with frame related questions
« Reply #58 on: July 20, 2011, 02:42:40 pm »
Dave, who do you recommend for a frame strip down and re-spray on a moulton? 

clarion

  • Tyke
Re: Help with frame related questions
« Reply #59 on: July 20, 2011, 04:28:43 pm »
WB & Jack? ;D

Anagrammatic relations.

Hmm.  Yeah, I think they're a bit homophonic.
Getting there...

Re: Help with frame related questions
« Reply #60 on: July 20, 2011, 10:46:11 pm »
If the rust in your seat tube is just a dust of surface rust I would just spray the Waxoyl straight over it. If it is a little heavier then the best way to shift most of it is with a strip of abrasive cloth inseted into a slot in the end of a length of dowel, stick the other end in a power drill and wizz it up and down inside the tube. Then spray your waxoyl into the tube.
A long time ago when Noah was a lad, I had a Mark one Ford Cortina that was a perambulating rust ball. I sprayed the underside with Waxoyl and it stopped the rust dead in its tracks. It taught me a lot that car, I learned to weld rust  ;D

The dowel idea is a great idea - I'll give that a go - thanks for your reply.

My garage is full of 1976 Lancia Beta that I need to restore - I suspect I'll spend a lot of time attempting to weld rust. ;)
Cheers
Duncan

Re: Help with frame related questions
« Reply #61 on: July 20, 2011, 11:39:16 pm »
Sorry chaps, all the speculation on my relatives passed me by as I've been painting all day. The kitchen and staircase that is, not frames  :'( Jobs been waiting for about 3 years !!!
All the other Yateses mentioned are nowt to do with me. I am from the minor but exclusive Geordie branch of the clan  ;D

Dave Yates (Howay the lads !!!)
It's not just hitting it with a hammer but knowing where to hit it and how hard

Re: Help with frame related questions
« Reply #62 on: July 20, 2011, 11:46:06 pm »
Dave, who do you recommend for a frame strip down and re-spray on a moulton?

Pass !  I have not had that much experience of Moultons and, to be honest, I try to steer clear as there is so much more work involved. If I charge a commercial price it tends to put people off.  If I dont then I am not making any money which is not the object of the exercise when running a business.
All I can suggest is to contact all the usual suspects and see who is prepared to do it.

Cheers

Dave Yates
It's not just hitting it with a hammer but knowing where to hit it and how hard

Re: Help with frame related questions
« Reply #63 on: July 21, 2011, 12:22:45 pm »
Sorry chaps, all the speculation on my relatives passed me by as I've been painting all day. The kitchen and staircase that is, not frames  :'( Jobs been waiting for about 3 years !!!
All the other Yateses mentioned are nowt to do with me. I am from the minor but exclusive Geordie branch of the clan  ;D

Dave Yates (Howay the lads !!!)

I hope you did a better job than Jack...

Re: Help with frame related questions
« Reply #64 on: July 22, 2011, 07:28:48 pm »
Hi Dave.  One I've been pondering while thinking/dreaming of the next bike. 
What determines the maximum tyre size when using deep drop brakes?  Some bikes using them seem to only manage 25mm by distorting the mudguard, others seem fine with 28mm and I've heard of people using 30s.  Is it just the height of the brake bridge?  If so why are they not all designed to take the maximum possible?  Or is there some disadvantage?  What tyre size would you say was possible if I was asking for these brakes and mudguards?
Thanks

Now then Mr PH

It depends on how the frame was built. Specifically the height of the brake bridge and the length of the forks. I usually set these dimensions so the brake blocks are at the bottom of the slot on the intended brake giving the maximum clearance. Usually that will take a 28mm tyre with guards. All 28mm tyres are not created equal so you may get a skinny 32 in  but may have difficulty with a beefy 28. This is assuming a 57mm drop brake. There are deeper brakes on the market but all the ones I have seen tend to be a bit Mickey Mouse in the retardation department. Biggsy's comment on chainstays is quite correct but why would you want to put big tyres on a bike with a short back end which is more in keeping with a race type bike.
The two things I get asked most about are the two things with least relevance to "performance" ie weight and wheelbase. I design a frame to do a job and the weight comes out at whatever the weight comes out at !!! With decent tube and components there will only be a difference of about 2lb between a super light steel frame ( about 3lb) and a heavy steel frame (about 5lb).
Wheelbase is a function of about 11 different dimensions all of which are more important than their sum. Again I design the frame to fit and suit the purpose of the customer and it comes out at whatever it comes out at. I have never used either as a design parameter.
Some of the worst handling bikes I have ever ridden were ultra short wheelbase TT bikes most of which were nothing short of lethal.

Cheers

Dave Yates

Interesting one, this. I have a Bob Jackson not dissimilar to Tewdric's although I think his is custom whereas mine is off the shelf. Same geometry though. I really like the frame, it's turned out to be really comfortable for me and I'm delighted with it except for one thing: that rear brake bridge is too low. I have deep drops but the blocks are usually near the top depending how far back the wheel is. There just isn't enough comfortable clearance for a mudguard of the SKS type, and there is a fair bit of stone-scraping noise at times. The limiting factor is the underside of the brake calipers. OK so it was never really intended to have mudguards on it, I suppose. The fork - still a bit tighter than I'd like but tolerable.

I like the bike so much I'd consider having the bridge moved if I get it resprayed at some future date. How feasible is this, Bicycle Repair Man? Is it inevitable that doing so would weaken the frame, for one thing?

Re: Help with frame related questions
« Reply #65 on: July 22, 2011, 08:16:28 pm »
Quote
I like the bike so much I'd consider having the bridge moved if I get it resprayed at some future date. How feasible is this, Bicycle Repair Man? Is it inevitable that doing so would weaken the frame, for one thing?

No problem at all, I have done lots ( read hundreds) of this repair with no ill effects. Cut bridge out cold and file back the stubs to the stay surface then braze a new bridge in at the desired height.
I often do jobs like this to make a nice frame nicer !!! The problem with a lot of off the peg frames is that they try to be all things to all men (and women) and inevitably some owners find them not quite "right" This is the beauty of a steel frame, it can be modified like this without any great hassle by a competent builder.

Cheers

Dave Yates
It's not just hitting it with a hammer but knowing where to hit it and how hard

Re: Help with frame related questions
« Reply #66 on: August 12, 2011, 03:18:30 pm »
Hi Dave,

Is there a reliable way to identify whether a frame is 531 or not? The sticker looks genuine and 531 was an original option according to the Peugeot sales brochure. The sticker just states '531 Butted Frame Tubes'.

A few measurements if it's any help- seat tube wall thickness 0.8mm, outside diameter 28mm, seat tube internal diameter 26.4mm.

Cheers.

Re: Help with frame related questions
« Reply #67 on: August 16, 2011, 09:03:24 am »
Hi Dave,

Is there a reliable way to identify whether a frame is 531 or not? The sticker looks genuine and 531 was an original option according to the Peugeot sales brochure. The sticker just states '531 Butted Frame Tubes'.

A few measurements if it's any help- seat tube wall thickness 0.8mm, outside diameter 28mm, seat tube internal diameter 26.4mm.

Cheers.

Many appologies for the delay in replying. We had a lightning strike on the power line outside our house and among other things it fried the router with the ensuing power spike. A nice man called Barry from BTs Bombay call centre said he would send us a new router, it never turned up !!! Another attempt produced a router on friday and its taken this long to sort out the strange things that happened to the computer.

Now then Doosh

The "531 frame tubes" indicates that the main triangle ie seat, top and down tubes are 531 but the stays are of indeterminate origin. The 28mm seat tube indicates French metric standard tube. The French, being very parochial have their own standards for everything. Frame tubes were 28mm dia seat and down tube and 26mm top tube. Despite the transfer the seat tube sounds plain gauge as a normal single butted seat tube would have a wall thickness of .5mm.
If you can get a picture up I can probably give you some more details

Cheers

Dave Yates
It's not just hitting it with a hammer but knowing where to hit it and how hard

Re: Help with frame related questions
« Reply #68 on: August 16, 2011, 12:43:26 pm »
Thanks Dave. Which parts, specifically, would you need pics of?

Re: Help with frame related questions
« Reply #69 on: August 18, 2011, 02:55:07 pm »
Thanks Dave. Which parts, specifically, would you need pics of?

Seat cluster and head tube joints. Incidentally is it French or English BB?

It's not just hitting it with a hammer but knowing where to hit it and how hard

Re: Help with frame related questions
« Reply #70 on: August 18, 2011, 03:05:35 pm »
Ha ha! bone of contention that one Dave!

I've yet to find a sufficient 14mm tool to remove the crank bolts (none of mine fit into the dust cap recess  ::-)) and not being old enough to have any experience of the old cup and cone BBs I can't tell just by looking.

I'm starting to think it's a 501 frame that some sneaky git has stuck a 531 sticker on, all the other identical models I've found all seem to be 501.

Re: Help with frame related questions
« Reply #71 on: August 19, 2011, 12:38:01 pm »
Dave, I've been following a few threads around frame geometry and specifically ST angles. Searching the web brings up all sorts of posts from people trying to get their saddles far enough back. It also seems to me, watching the TdF in recent years, that there is more of a trend for saddles to be lower and further back. Looking at some of the detailed bike specs there are some serious lay back seatposts in use.

I think I understand the theory behind using smaller frames and long stems around handling, weight, etc...not saying I go with them though. But I'd be curious to know if there is some sort of advantage/disadvantage around seat tube angles and seatpost setbacks? For example:-

I have my saddle top about 79cm from the centre of the BB and I find, at this height, that each degree of ST angle equates to 10mm of fore/aft position. So using a Brooks saddle all the way back, on a 71 deg ST with an inline seatpost, to replicate this position on a 73 degree ST I'd need 20mm of layback on the seatpost...roughly, my trig isn't the best.

I'd be really interested to hear your views on this area?

Nuns, no sense of humour

Re: Help with frame related questions
« Reply #72 on: August 27, 2011, 11:37:24 pm »
Dave, I've been following a few threads around frame geometry and specifically ST angles. Searching the web brings up all sorts of posts from people trying to get their saddles far enough back. It also seems to me, watching the TdF in recent years, that there is more of a trend for saddles to be lower and further back. Looking at some of the detailed bike specs there are some serious lay back seatposts in use.

I think I understand the theory behind using smaller frames and long stems around handling, weight, etc...not saying I go with them though. But I'd be curious to know if there is some sort of advantage/disadvantage around seat tube angles and seatpost setbacks? For example:-

I have my saddle top about 79cm from the centre of the BB and I find, at this height, that each degree of ST angle equates to 10mm of fore/aft position. So using a Brooks saddle all the way back, on a 71 deg ST with an inline seatpost, to replicate this position on a 73 degree ST I'd need 20mm of layback on the seatpost...roughly, my trig isn't the best.

I'd be really interested to hear your views on this area?

Now then Mr MacB

First, appologies for delay, I had a course on last week and was totally knackered at the end of each day. Never seemed to get the computer on, just fell asleep in front of the telly after taking the puppy out for "training"
I am afraid the latest "fashions" in bike design pass me by, I do it the way I have always done it because I know it works for most of the people most of the time.
You have missed out the most important bits of info. How tall are you and what is your inside leg measurement. What are you using the bike for, eg club runs, shopping or world championships? You cannot do this by numbers as there are too many variables. I usually want to see the "body" I am working with. When I am designing a frame I always get the saddle position (height and fore and aft) right first then work forward. I subscribe to the theory that seat angle is a function of thigh length. I try and get the front of the knee over the pedal spindle, a touch further forward for a "racing" position.  I do this because it works for most of my customers and always has. My customers tend to be Mr and Ms average cyclists. They need to be set up in a sensible position to be comfortable partaking in whatever riding they do. I have never liked extreme, fadish, fashions, they dont work for most people. My advice would be unless you are racing at a high level (in which case talk to your coach) or in discomfort stop worrying about it and go and ride your bike ;D.
It's not just hitting it with a hammer but knowing where to hit it and how hard

Re: Help with frame related questions
« Reply #73 on: September 06, 2011, 04:40:06 pm »
Replacing a seat tube?
I have a rather nice frame here, with very nice lug work. It is a Les Ephgrave with #2 lugs.
The problem is there is a dent in the seat tube. It’s low enough not to cause problems with the seat post but at some point I would like to replace the seat tube. What are the risks with fancy lug work when replacing a seat tube or is it a relatively straight forward job for a frame builder  :-\
Thanks in advance, I will try and put the bike on the work stand and take a few pictures later

Re: Help with frame related questions
« Reply #74 on: September 09, 2011, 09:36:59 pm »
Replacing a seat tube?
I have a rather nice frame here, with very nice lug work. It is a Les Ephgrave with #2 lugs.
The problem is there is a dent in the seat tube. It’s low enough not to cause problems with the seat post but at some point I would like to replace the seat tube. What are the risks with fancy lug work when replacing a seat tube or is it a relatively straight forward job for a frame builder  :-\
Thanks in advance, I will try and put the bike on the work stand and take a few pictures later

Hi Domestique

Replacing a seat tube is always a difficult job as there are so many other tubes in the vicinity at both ends. Fancy lugs even more so!!! However a dent does not necessarily mean a new tube. I have done a lot of this repair simply by inserting a mandrel into the seat tube and planishing the dent out. Assuming it is 531 (a reasonable assumption) then this is perfectly safe and a lot less damaging to the frame. It depends of course on the severity of the dent. I have managed to do this on several occaisions without serious damage to the paint.
A picture would certainly help to assess if this is feasible.

Dave Yates
It's not just hitting it with a hammer but knowing where to hit it and how hard