Author Topic: Help with frame related questions (Read 296810 times)

mzjo · « **Reply #325 on:** 08 March, 2014, 09:07:19 pm »

I have just (like this afternoon) been given one of those Peugeot frames with the lugless construction and the hidden brazing mentioned by Dave somewhere up post. It has a weakness for me in that the frame has mudguard eyes but the fork does not. How practical would it be to braze or weld (welding would have to be gas; no tig available) eyes to the fork ends solid enough to take a pair of low-loaders? I am pretty confident of my brazing skills and the low-loaders would be for light loads. Which would be the better choice, weld or braze?
I am not especially enthusiastic about P clips - not sure why, probably aesthetic.
Cheers Jo

PS the frame is free and requires guard eyes to justify its continued existence.

Bicycle Repair Man · « **Reply #326 on:** 10 March, 2014, 11:30:40 pm »

Hi Mzjo,

Definitely braze, if you gas weld you will probably melt the braze securing the dropouts, if that then contaminates the weld you will end up with weak joints all round. Best bet with a job like this is to use Ceeway rear pannier mounts just behind the dropout. Much more brazing area for the sort of loaded pannier loads on this sort of joint. I this position you can fit mudguards as well.

Cheers

Dave Yates

mzjo · « **Reply #327 on:** 12 March, 2014, 07:40:25 pm »

Thanks Dave , that was just what I wanted to hear

EMnut · « **Reply #328 on:** 24 March, 2014, 07:45:54 pm »

Hi Dave

I got a question about geometry in regards of seat set-back.

Due to my old tourer having a bent top tube and downtime, I've taken off all the working parts and put them on another road bike frame. My old frame has 531 decals on it, and is quite hefty, the new one is 501, but is much lighter (possibly because more of it is 501)

The new frame is bigger than the last one, the 1977 Galaxy was 23.5 inch the 1983 Raleigh Record Sprint is 25inch. However when I compare the old frame with new one, the relative positions of the crank to saddle height, and saddle to top tube are pretty much exactly the same. The only difference other than standover height, (the bigger frame allows me an inch of stander, I am 5ft11), is the angle of seat tube, it is steeper.

On the first few rides I've done I've had a sore lower back, so my thoughts were I need to set the saddle back more than my current seatpost allows. However looking at photos of racing cyclists from the 70s and 80s I've noticed that many of them tilt their saddles backwards a fraction, and that most of them are ridding with a Brookes saddle.

So my question is, other than setting back the saddle more, what else should I consider to make the frame more comfortable? Is it a case of being a harder road frame and different position, pushed further forward in relation to the cranks means I need to get used a new riding position? Or would there be milage in a longer stem (the current one is quite short), my other bike is a Bianchi road bike and this had a very low top tube and low bars, and I find it very comfortable?

Squarewheels · « **Reply #329 on:** 12 April, 2014, 10:06:59 pm »

Do you do advice on aluminium frames?

I have a frame (Cervelo S1) that has a crack under the seat clamp (hairline). It makes many creaking noises.

My question is then...Is this about to end in some sort of catastrophic failure which could kill me and anyone in the surrounding area?

And:

Should/Could it continue to be used as it is?

And:

Is it worth getting it reapired and heat treated? What would that cost?

Thanks

jsabine · « **Reply #330 on:** 28 April, 2014, 03:37:58 pm »

It's fairly clear that my experiment with a shorter wheelbase bike hasn't worked, and that although I was able to make these modifications with the help of a large wooden post and about 100kgx25km/h worth of kinetic energy, I'll need professional help to reverse the process.

The forks, clearly, are FUBAR (though I don't know whether they're beyond the attentions of Mr Scaffold Pole); more seriously, there's a crease in the head tube just above the lower bearing race, as the joint transitions into the tube.

I can't tell whether there's also a crease in the down tube and top tube - I don't think so, because although there's a tiny lump in each - again, at the end of the joint/tube transition - I remember noticing these several times well before the crash, and there's something similar at the seat tube end of the top tube.

(Loads more photos, none of them as clear as I'd hope, in this Flickr album.)

Opinions welcome - once I've stripped it, is it even worth sending it off to someone for a proper look? Any ideas as to ballpark repair costs?

I have no sentimental attachment to the frame, though it has been extremely comfortable and a very nice ride; it cost me buttons and I don't even know what tubing it is (though I was told high-end Columbus).

clarion · « **Reply #331 on:** 28 April, 2014, 06:48:26 pm »

Is there a touch of toe overlap on that frame?

Ian H · « **Reply #332 on:** 28 April, 2014, 06:53:22 pm »

Quote from: clarion on 28 April, 2014, 06:48:26 pm

Is there a touch of toe overlap on that frame?

If the front wheel was the other side of the down-tube it might still be ok for the track.

jsabine · « **Reply #333 on:** 28 April, 2014, 08:44:27 pm »

Quote from: Ian H on 28 April, 2014, 06:53:22 pm

Quote from: clarion on 28 April, 2014, 06:48:26 pm
Is there a touch of toe overlap on that frame?

If the front wheel was the other side of the down-tube it might still be ok for the track.

I did contemplate hoping for high-camber roads and only r/h bends. But yes, while you can cope with toeclip overlap, downtube overlap's a bit more of a fundamental problem.

Ian H · « **Reply #334 on:** 28 April, 2014, 08:49:37 pm »

Quote from: jsabine on 28 April, 2014, 08:44:27 pm

Quote from: Ian H on 28 April, 2014, 06:53:22 pm
Quote from: clarion on 28 April, 2014, 06:48:26 pm
Is there a touch of toe overlap on that frame?

If the front wheel was the other side of the down-tube it might still be ok for the track.

I did contemplate hoping for high-camber roads and only r/h bends. But yes, while you can cope with toeclip overlap, downtube overlap's a bit more of a fundamental problem.

Sorry, shouldn't joke. It's nasty when that happens to a frame. Hope you can sort it.

clarion · « **Reply #335 on:** 28 April, 2014, 08:51:12 pm »

I hope you can sort it. Won't be cheap, mind.

jsabine · « **Reply #336 on:** 28 April, 2014, 11:01:12 pm »

Oh, no point in not joking about it. It happened because I'm a muppet who wasn't looking where he was going, and I'm fine. Well, pissed off, but fine apart from that.

The immediate solution is to fish out the Roberts frame I have in the loft and get myself in gear to build that, and then find out whether this one is terminal. At least sorting the Roberts will be effort rather than money as I think I have everything I need.

Bicycle Repair Man · « **Reply #337 on:** 29 April, 2014, 01:19:05 pm »

Now then,

I am afraid that looks pretty terminal. From your description it seems everything forward of the seat tube is donald ducked. Cost of repair would be in the £500+ region, ie new top / down and head tubes and new forks and it would never be the same again. Best to write it off to experience.

Cheers

Dave Yates

jsabine · « **Reply #338 on:** 29 April, 2014, 02:09:01 pm »

Clearly that's not the answer I was looking for ... (though the one I thought I was likely to get).

As I said though, I don't think (or at least I don't want to believe) that the top and down tubes are affected - once I've stripped the parts, is there a straightforward way of telling for sure? I'm pretty sure that the tiny lumps I mention were there before the crash and are no worse now.

If I've been lucky, how practical might a new headtube be?

Cheers

John

(On the upside, the front wheel is, unsurprisingly, still true.)

Bicycle Repair Man · « **Reply #339 on:** 30 April, 2014, 08:45:42 am »

Hi John

Upon closer inspection of your pics I think the tiny lumps you describe are in fact undercuts on the top and down tubes where the builder has been a little over enthusiastic with his cleaning up of the fillets. Initially I read this as classic front end damage where the front triangle has been pushed up and back This undercutting would normally be considered a fault but as the joints have survived the impact then I would say it is not a matter for concern. The forks are definitely beyond redemption, I would not risk repairing these, I suspect a Mickey Mouse Metal steerer for it to bend so much.
Without inspecting the frame in the flesh I cannot be absolutely sure but a new head tube is a possibility. The problems faced by anyone attempting this on a fillet brazed frame are getting the old tube off without damaging the top and down tube, then getting the remnants of the fillets off the tubes so it is not an easy job. Of course with any major repair such as this there is always a risk, it will never be "as good as new". If I were to do this you would be looking at about £200 for the metalwork. Other builders are available

Cheers

Dave Yates

Bicycle Repair Man · « **Reply #340 on:** 30 April, 2014, 08:57:35 am »

Quote from: Squarewheels on 12 April, 2014, 10:06:59 pm

Do you do advice on aluminium frames?

I have a frame (Cervelo S1) that has a crack under the seat clamp (hairline). It makes many creaking noises.

My question is then...Is this about to end in some sort of catastrophic failure which could kill me and anyone in the surrounding area?

And:

Should/Could it continue to be used as it is?

And:

Is it worth getting it reapired and heat treated? What would that cost?

Thanks

Hi Squarewheels

Abject apologies for missing your post, I have been very busy recently and just missed it.
I dont do aluminium frames but from your description of the crack it may be weldable by someone who knows what they are doing. For an area like this I dont think heat treatment is an issue and it depends on which alloy it is as to whether it was heat treated in the first place.

Sorry, thats the best I can do.

Cheers

Dave Yates

Bicycle Repair Man · « **Reply #341 on:** 30 April, 2014, 09:13:33 am »

Quote from: EMnut on 24 March, 2014, 07:45:54 pm

Hi Dave

I got a question about geometry in regards of seat set-back.

Due to my old tourer having a bent top tube and downtime, I've taken off all the working parts and put them on another road bike frame. My old frame has 531 decals on it, and is quite hefty, the new one is 501, but is much lighter (possibly because more of it is 501)

The new frame is bigger than the last one, the 1977 Galaxy was 23.5 inch the 1983 Raleigh Record Sprint is 25inch. However when I compare the old frame with new one, the relative positions of the crank to saddle height, and saddle to top tube are pretty much exactly the same. The only difference other than standover height, (the bigger frame allows me an inch of stander, I am 5ft11), is the angle of seat tube, it is steeper.

On the first few rides I've done I've had a sore lower back, so my thoughts were I need to set the saddle back more than my current seatpost allows. However looking at photos of racing cyclists from the 70s and 80s I've noticed that many of them tilt their saddles backwards a fraction, and that most of them are ridding with a Brookes saddle.

So my question is, other than setting back the saddle more, what else should I consider to make the frame more comfortable? Is it a case of being a harder road frame and different position, pushed further forward in relation to the cranks means I need to get used a new riding position? Or would there be milage in a longer stem (the current one is quite short), my other bike is a Bianchi road bike and this had a very low top tube and low bars, and I find it very comfortable?

Hi Mr Nut

As with Squarewheels many apologies for missing your post, I plead a) pressure of work and b) senility !!
It is virtually impossible for me to give advice on position problems without seeing you in the flesh sitting on the bike in question. There are just too many variables however I will do what I can.
Sore anywhere usually indicates that particular area being under abnormal stress. I normally associate lower back ache with seat too high. Try sitting on the bike with your heels on the pedals, pedal backwrds, if your bottom rolls from side to side then your seat is possibly too high. Measure the distance from BB centre to saddle top then try dropping it until you can pedal with your heels with no lateral movement of your bottom on the saddle.
As I said, difficult to be precise but try that and see what happens, if you are not happy then put the saddle back where it was and try raising your bars a touch.

Cheers

Dave Yates

jsabine · « **Reply #342 on:** 30 April, 2014, 10:44:38 pm »

Quote from: Bicycle Repair Man on 30 April, 2014, 08:45:42 am

Upon closer inspection of your pics I think the tiny lumps you describe are in fact undercuts on the top and down tubes where the builder has been a little over enthusiastic with his cleaning up of the fillets. Initially I read this as classic front end damage where the front triangle has been pushed up and back This undercutting would normally be considered a fault but as the joints have survived the impact then I would say it is not a matter for concern. The forks are definitely beyond redemption, I would not risk repairing these, I suspect a Mickey Mouse Metal steerer for it to bend so much.

Without inspecting the frame in the flesh I cannot be absolutely sure but a new head tube is a possibility. The problems faced by anyone attempting this on a fillet brazed frame are getting the old tube off without damaging the top and down tube, then getting the remnants of the fillets off the tubes so it is not an easy job. Of course with any major repair such as this there is always a risk, it will never be "as good as new". If I were to do this you would be looking at about £200 for the metalwork. Other builders are available

Hurrah! I knew that if I asked often enough, I'd get an answer that was closer to one I liked. If I ask again about the price, will it come down to £100?

I presume that your approx cost is simply for a new fillet brazed headtube, and I'd also have paint and a new set of forks on top? It's going to be (more than) a little while before I've raked enough out of the back of the sofa to contemplate a repair, and I think I'll try to track down the original builder as a first port of call (doubt I'll get far with that though), but thanks very much for your advice here, and you may well end up seeing this in the metal.

Thanks too for your info about the undercutting - I'd assumed that this wasn't quite how things were meant to be, but that the practical effect was harmless in this case.

As for the forks, I've not taken them out yet but am fairly sure that the steerer was stamped Columbus when I did look at them a while ago - didn't think it was monkey metal. I did hit the post quite hard though.

All much appreciated

John

terryb · « **Reply #343 on:** 09 May, 2014, 04:37:28 pm »

My grandson was servicing a boiler today and ended up with a very old bike which he rescued from the customers intended trip to the tip
A Viking, so assume its 60`s/70`s/80`s. which one he hasn`t said yet, but
he asks if the bottom bracket "is cassette or free balls"

was I right to inform him it should be British thread and 68mm wide and to try the cassette BB he has just taken off his `good` bike after a slight upgrade
This I think should answer his questions and will also show if the shell is knackered thread wise
now to my question.......eventually
How easy and cheap is it to sort the bottom bracket out if there is a problem ?
I remember having to use O/size cups on a MCLEAN frame in the early 70`s
Good news is, he says everything is there

thanks in advance for any help

Bicycle Repair Man · « **Reply #344 on:** 09 May, 2014, 07:02:12 pm »

Quote from: terryb on 09 May, 2014, 04:37:28 pm

My grandson was servicing a boiler today and ended up with a very old bike which he rescued from the customers intended trip to the tip
A Viking, so assume its 60`s/70`s/80`s. which one he hasn`t said yet, but
he asks if the bottom bracket "is cassette or free balls"
was I right to inform him it should be British thread and 68mm wide and to try the cassette BB he has just taken off his `good` bike after a slight upgrade
This I think should answer his questions and will also show if the shell is knackered thread wise
now to my question.......eventually
How easy and cheap is it to sort the bottom bracket out if there is a problem ?
I remember having to use O/size cups on a MCLEAN frame in the early 70`s
Good news is, he says everything is there
thanks in advance for any help

Hi Terry

It should be a standard British threaded BB. I cant answer the question about howeasy it is to fix without seeing it !!! There are too many possibilities, however as it is a steel frame it is "fixable" no matter what , if any the problems are. If the cassette does not fit then give me a shout and I will see what I can do.

Cheers

Dave Yates

Furious · « **Reply #345 on:** 18 May, 2014, 07:40:49 pm »

Washing my bike yesterday morning, in preparation for the #Space4Cycling #BigRide, I noticed this crack at the top of the RH seatstay.

I should be concerned, yes?

The bike is only about 8 months old. The frame is Reynolds 520.

LittleWheelsandBig · « **Reply #346 on:** 18 May, 2014, 08:40:04 pm »

Not something I'd like to ride for too long. The failure mode would likely be fairly benign though.

mrcharly-YHT · « **Reply #347 on:** 18 May, 2014, 08:45:07 pm »

Those welds look really rough. What make is the bike?
It should be repairable.

Furious · « **Reply #348 on:** 18 May, 2014, 10:03:19 pm »

It's a Jamis.
I'll be taking it back to the shop tomorrow, and see what they have to say about it.

mrcharly-YHT · « **Reply #349 on:** 18 May, 2014, 10:23:17 pm »

I've looked closely at some Jamis bikes and been impressed. Sorry to say this, but that is absolutely appalling. I think you should press for a replacement frame.