Search found 44397 matches

by Brucey
10 Sep 2013, 4:41pm
Forum: Bikes & Bits – Technical section
Topic: Pitted cones
Replies: 29
Views: 7315

Re: Pitted cones

the drive side cone is severely worn. I would be surprised if the hub rotated smoothly with that wear on the cone.

The drive side cup is screwed into the freehub body on a left handed thread; removing it exposes the freewheel bearings. But the cup looks OK to me.

It is difficult to see how two week's use could cause that much wear on the cone. Very odd.

BTW bent freehub axles are pretty rare; if the axle is bent badly you will normally see it by rotating the axle in the assembled hub, provided the bearing is in good shape.

Measuring ball bearings with verniers will weed out any that are real outliers in average size, but can't reliably discriminate between different grades of bearing, say.

cheers
by Brucey
10 Sep 2013, 4:33pm
Forum: Bikes & Bits – Technical section
Topic: Avid BB5
Replies: 13
Views: 3124

Re: Avid BB5

avid do at least two types of pad compound; organic or sintered being typical. I have seen BB5s supplied with either, and the organic pads wear about x5 faster than the sintered ones.

The BB7 pads are about x2 the area so (might...) wear half as fast with the same pad compound.

Users with BB5s fitted with sintered pads generally don't complain about pad wear rate TBH; they are not bad brakes, but they are not quite as good as BB7s in most respects.

Both brakes share the same fixed pad adjuster, which can give trouble by seizing up in winter weather (= scrap caliper) and there have been a few reports of the adjuster knob starting to melt on very long descents. The former is 'quite likely' on a commuting bike; the latter is extremely unlikely unless you go to the alps with a big load on.

cheers
by Brucey
10 Sep 2013, 10:21am
Forum: Bikes & Bits – Technical section
Topic: What To Do With A 1948 Frame - PT Stallard
Replies: 26
Views: 3835

Re: What To Do With A 1960s Frame - PT Stallard

deliquium wrote: I guess the original bike came with hubgears?


The frame looks to have braze ons for 5s (or 10s) derailleur to me, not a hub gear. What tunnel is there on the left side of BB shell? You may find there is a small braze-on on the down tube, intended to stop clip-on derailleur levers from sliding down. The dink the outside of the RH chainstay is a dead giveaway too; this simply isn't necessary with a typical IGH setup, and is more typical of a 10s frameset.

Weight of frame, seatbolt, forks and headset 6lb 4oz.


which is pretty much what you would expect for a 531 DB frameset, (or the Accles and Pollock equivalent).

cheers
by Brucey
10 Sep 2013, 10:10am
Forum: Bikes & Bits – Technical section
Topic: Boy In The Bubble; Obree's Beastie Fairing
Replies: 69
Views: 8881

Re: Boy In The Bubble; Obree's Beastie Fairing

the fairing is the newest part of the machine; I doubt it is yet fully optimised.

Aerodynamically speaking, tape may be the best solution; the reason is that with tape, the surface can be smoother than any other joint that can reasonably be made.

In addition, there is nearly always a pressure difference between the inside and the outside of the fairing, so air will tend to leak (in one direction or the other) through any gap which may screw the aerodynamics up. Tape will provide a seal that would otherwise be very difficult to achieve.

It would be better if it were colour-matched though; I might have made the fairing the same colour as, say , parcel tape for this reason... :roll: :wink:

cheers
by Brucey
10 Sep 2013, 9:59am
Forum: Bikes & Bits – Technical section
Topic: Shimano 105 Front Mech With 8 Speed Chain?
Replies: 13
Views: 3902

Re: Shimano 105 Front Mech With 8 Speed Chain?

the first thing I would do is try a different type of chain. I have found that -for reasons I don't fully understand- the front shifting can be sensitive to chain type as well as chain condition. I think that a very flexible chain that has chamfered inner side plates, doesn't have such chamfered outer side plates, and is a relatively snug fit on the chainring laterally, is often reluctant to be pushed off the middle chainring.

I spent months being driven berserk by a similar issue. In the end I simply fitted a different chain and the problem vanished. When I measured the old chain I could find almost no difference in the chain dimensions that I could measure, yet one was snug on the chainring and the other wasn't. The chamfering on the side plates was different as well; that may have been the thing that did it.

Anyway, the worst that can happen is that you end up with a spare chain, which you will surely use sooner or later anyway, so a different chain has to be worth a go.

cheers
by Brucey
10 Sep 2013, 9:48am
Forum: Bikes & Bits – Technical section
Topic: Cranky 105
Replies: 35
Views: 5278

Re: Cranky 105

did you resolve the issue with the ultegra pulleys then?

Have you changed your preferred chain lubricant in the last few years, or riding/maintenance habits? More wet rides?

Re pulley/pulley bushing wear; 10s pulleys and pulley bushings are narrower than 9s ones (slightly) so would be expected to wear faster on that basis. There is no guarantee that the bushing materials were the same, even if they were both 105 rear mechs, either; this is the kind of thing that shimano often play tunes with. [I have seen quite a few 10s 105 mechs with new pulleys in, but have not examined any old pulleys for signs of intrinsic weakness].

One additional factor is that the chain and sprocket design becomes ever more tolerant to running quietly whilst slightly misaligned, yet shifting slickly when called upon. This is a good trick but it is, I think, also one that can more easily leave the transmission set so it is quietly grinding itself to atoms.

Worth checking that the system is A-OK in every other respect (cables not sticky, ferrules fitting properly and not deforming etc) else you may find the same thing happens again.

cheers
by Brucey
10 Sep 2013, 9:27am
Forum: Bikes & Bits – Technical section
Topic: Oil instead of grease?
Replies: 82
Views: 12933

Re: Oil instead of grease?

as noted in an earlier post, it appears that if you buy the 'max-chain' motorcycle chain lube version, it works out around half the cost per fl.oz.

cheers
by Brucey
10 Sep 2013, 9:22am
Forum: Does anyone know … ?
Topic: Is a folder a practical proposition for touring?
Replies: 11
Views: 3019

Re: Is a folder a practical proposition for touring?

part of the question boils down to 'what kind of bike can I take on a train without hassle?' (which varies with the train company; a trailer may just add to your woes here....) and part of it boils down to 'given that (bike), can I tour on it?'.

The answer to the second part is 'yes' because you can tour on almost anything. 35 miles isn't far. I'd try to keep the luggage weight down to about 10kg if I could though.

cheers
by Brucey
10 Sep 2013, 7:46am
Forum: Bikes & Bits – Technical section
Topic: 7speed to 8speed
Replies: 36
Views: 7224

Re: 7speed to 8speed

QUIST wrote: I use 8 speed cassettes (As I was told 7 spd were becoming diff to source) ....

....I would say if it had been poss to keep getting 11-28 7 speed cassettes I would have


I think reports of their demise are greatly exaggerated. 7s cassettes were still being fitted to a range of bikes (not just cheap ones) five years ago and for all I know still are being fitted to new bikes.

SJS have a choice of 11-28 7s cassettes including shimano, sunrace and ( I think) IRD. Should these ever cease to be made, it isn't difficult to take (say) an 11-32 8s cassette and remove the 32 from it. Again there is a choice in this fitment.

cheers
by Brucey
10 Sep 2013, 7:33am
Forum: Bikes & Bits – Technical section
Topic: What To Do With A 1948 Frame - PT Stallard
Replies: 26
Views: 3835

Re: What To Do With A 1960s Frame - PT Stallard

deliquium wrote: ...Did 5 speed screw on freewheel rear hubs come in 120mm?


yes, that was the standard for many years.

Sounds like 55-64mm brake drop required for 700C then...

cheers
by Brucey
10 Sep 2013, 7:31am
Forum: Bikes & Bits – Technical section
Topic: Double brakes. How daft?
Replies: 50
Views: 6817

Re: Double brakes. How daft?

re. pulleys/balance bars for one lever/two brake operation; there are three issues;

1) the return springs need to be matched else the brakes don't come on at the same time (or worse still one drags).

2) the force distribution is fixed between the two brakes which may or may not be what you want if they have different MA.

3) if one brake or cable fails, then (unlike many twin cable levers) you have neither brake in operation.

cheers
by Brucey
10 Sep 2013, 6:48am
Forum: Bikes & Bits – Technical section
Topic: Performance Type Saddles
Replies: 6
Views: 1534

Re: Performance Type Saddles

if you use a seat pack then you need not worry about crud coming through saddle cutouts.

Do also bear in mind that if/when this would ever be a concern, you would already have a stripe of crud up your rear end anyway.

cheers
by Brucey
10 Sep 2013, 6:36am
Forum: Bikes & Bits – Technical section
Topic: What To Do With A 1948 Frame - PT Stallard
Replies: 26
Views: 3835

Re: What To Do With A 1960s Frame - PT Stallard

you will get the range by using a current SA-5 (W) hub but the internal design of the hub is not as good (IMHO) as the previous versions of the gear. However with a 30" bottom gear an older SA-5 hub (any non-(W) hub) will only give a 67" top gear. Speaking as a long-time user of older 5s gears (with more in the works...) I have usually used them with gear 3 set for 'normal' use because this is most efficient and leaves the 2-3 shift (which can be made under some load on all variants) most used. It doesn't leave you with a very low bottom gear though.

If you are tempted to do likewise it is as well to remember that in reality an FW hub will do the job just as well; you just omit the 5th (highest) gear with this hub vs a 5s. The 1940's FW hub (even with a steel shell) is IIRC actually slightly lighter than the more recent X-RF5 models.... :roll:

BTW I would use the derailleur braze-ons for the hub gear control routing. I have modifed the chainstay stop on some frames by running a 5/32" drill through it, then sleeving it with a short length of 4mm nylon pneumatic hose, which is retained because it is a push-fit. Should you ever need to use the stop for a derailleur gear again you may need a slightly different ferrule but otherwise you have lost nothing with this mod.

If with this cable routing frame flex causes the gear to shift by itself then there is a fault with the cable adjustment or the shifter.

Re shifters; the nicest looking and seemingly best made single-cable 5s shifter is the current version in aluminium alloy (available as DT or thumbshifter for 22.2mm bars). However my measurements indicate that it pulls about 2mm less cable than the previous 5s shifter versions. I think this means that it will shift a (W) hub as intended, but won't necessarily give reliable shifts with a non-(W) hub unless modified.

cheers
by Brucey
9 Sep 2013, 11:31pm
Forum: Bikes & Bits – Technical section
Topic: Pokey spokey
Replies: 17
Views: 5096

Re: Pokey spokey

individual spokes need to be passed between the crossings of other spokes if you wish to remove them completely. With a little effort you can get them out without too much of a struggle but some bending is likely. I don't think it is necessary to take them out completely if you are careful whilst shortening them.

Nipples have a tapered entry under the square, so only about 2/3 (it varies with the manufacture) of the nipple length is usefully threaded.

cheers
by Brucey
9 Sep 2013, 11:12pm
Forum: Does anyone know … ?
Topic: Cadence - how do you measure?
Replies: 107
Views: 8362

Re: Cadence - how do you measure?

LittleGreyCat wrote: ... wonder if it should allow the entry of gear inches (or similar) of a chosen gear so you can get it to calculate your cadence for you. ...


I may have misunderstood this (I'm not super- interested in bike computers ) but isn't that what shimano flightdeck and campag ergobrain computers were intended to do? Or did I dream that? :shock: :wink:

cheers