Cycling UK Forum

Ian, she's a peach, great job sir. I enjoyed reading about her resurrection, top marks for attention to detail. I've been daydreaming about a 753 frameset for a while, hopefully one day I'll get my hands on one. Enjoy your new bike matey. Best wishes, Luke

531colin wrote:I'm retiring in June, I hope it lives up to my expectations! At the moment I have too many hobbies, so I'm hoping to finish plumbing the shower room and stuff like that.

Hope you're not retiring from the CTC Forum Colin! Here's wishing you a great retirement. Sigh, I wish I was retiring in June...

Hi Drake, have you considered a 'donor bike' to provide the gears (and wheels etc.) for your frame?
A colleague and I did this last summer. We liberated a dumped 1990s Saracen MTB from the bike shed at work (unlocked and unloved, had been there for at least a year). We brought a 2006 Ridgeback Bora on Gumtree for £50 and swapped most of the parts over, greasing and lubing as we went. We treated it to a new chain and cassette IIRC.

Best wishes,

Luke

Hi, I'm another with a UN54 with a cracked plastic LH cup, works absolutely fine. Forgive me if I sound poncey but I do find the grey plastic looks a bit naff.

Here's another idea for a high quality BB:

http://www.shedbornbikes.com/skf-bottom ... t-24-p.asp

Apparently it has a 10yr / 65,000miles warranty. But it's 85 squid...

niloc wrote:Please could you let me know the distance between the front axle and bottom bracket centre (Front centres distance) of your 58cm 700c LHT

Hi, I make it ~625mm.

Regards,

Luke

Hi, I have a 58cm LHT with 700c wheels. There's no toe overlap since I cut the mudguard stays down. Initially I didn't bother and my toe would catch occasionally. I have 175mm Stronglight triple cranks (?Impact - can't remember off the top of my head); P45 (or P50) SKS mudguards; and 32mm wide Panaracer Ribmo tyres. I've had 37mm wide Paselas on there in the past. I have shimano mtb spds (?m520s) and size 10 shimano touring shoes. HTH. Regards, Luke.

Doh, I've just re-read your first post - 'CUSTOM light tourer'.

Whoops, that'll teach me to read more carefully in future. Measure twice, cut once!

Would you consider a second hand frameset? E.g. some second hand 18-20" frames available here:

http://hilarystone.com/frameset.html

Plus also Gumtree, or the For Sale section of this forum.

Echoing Valbrona and Trigger, an old rigid mountain bike frame can fit the bill. My girlfriend is 5ft 3" and I built one up for her with slick tyres. As others said, lots of tyre / parts availability, wheels are proportional to frame size and frames usually feature eyelets for guards / racks. Also not so desirable to the magpies if you decide to use it for commuting / shopping.

However, mountain bike framesets might be a little overbuilt for light, petite riders. Fine for load carrying but I find a stiff, heavy tubeset a little 'dead' on unloaded rides.

You could also consider a complete bike from Islabikes? I've no experience of them myself but they have been favourable reviewed within CTC's 'Cycle' mag, plus on this forum.

http://www.islabikes.co.uk/

Best of luck!

Regards,

Luke

Brucey wrote:the perceived differences in 'performance' are far greater than the 'actual' differences in performance. People get hung up on this stuff as if it makes a real difference; in reality it (variations in wheel diameter for given tyre section) doesn't make a very big difference, and you'd generally never know because they are seldom (if ever) fitted to a bike that is otherwise the 'same' anyway.

Hi Brucey, fair point. Though objective data is available that supple, fat tyres at lower pressures reduce rolling resistance, on smooth and rough surfaces. See Bicycle Quarterly back issues:

The first "real-road" test of tires debunks many myths. Super-high pressures aren't faster: Vol. 5, #1.
Statistical analyis of our tires tests, more tires tested: Vol. 5, #3.
Optimizing your tire pressure for your weight: Vol. 5, #4; also available online.
Do larger wheels roll faster over bumps? We measure power output with three wheel diameters: Vol. 9, #4.
More tires tested: Vol. 6, #1; Vol. 6, #4.
Suspension losses measured, and more tires tested on rough and smooth surfaces: Vol. 8, #1.
Casing construction (threads per inch/tpi) and performance: Sidebar in Vol. 9, #1.

Subjectively too they feel great!

The 650b serves as a vehicle to allow one to use high quality fat supple tyres, like Hetres, within conventional frames, or (more rarely) on dedicated 650b framesets. Subjectively I find 650b and a fat tyre gives a nice balance between stability and agility, and bags of comfort. In theory it should give a stronger wheel too?

Brucey wrote:Practical considerarions like 'will the bike fit?' and 'is there a bike available which does the job I want?' (regardless of wheel size fitted) and 'can I get spare parts easily where I'm going?' must surely dominate over the niceties of small variations in wheel size; for tyres of a given section, the total variation we are discussing (from 559 to 622 seat diameter) is ~30mm in radius, or about 10%. Stuff all really....

Agreed 650b rims and tyres are impractical and expensive. I keep my commuter Long Haul Trucker as 700c for this reason.

Brucey wrote:I was somewhat amused to discover that a tandem I once owned was meant to be 'special' because of its mysterious '650B' wheels. The aura of mystery lasted precisely until I bought new tyres at which point I discovered that the only ones I could get at the time were the same as those fitted to a Butcher's bike.

'pound of scrag end luv?' was the cry as we mounted up for a while.....

Grand bois Hetres are filet mignon

Brucey wrote:oooh.... we are dangerously close to territory normally reserved for the likes of Rene Descartes and Bertrand Russell here...

logical outcome; 'I think, therefore my tyres are nice'



cheers

Did you know Karl Marx was a cyclist? "Cyclists of the world unite. You have nothing to lube but your chains..."

(Cue Tumbleweed rolling)

Best wishes,

Luke

Hi, AFAIK this is the only UK retailer of the 26 inch Compass Cycles / Grand Bois tyre.

http://www.shedbornbikes.com/compass-cy ... h-12-p.asp

ersakus wrote:why?
...there is a premium tyre called Grand Bois hetre in this format. That is almost why I still ride my 650B bike. I do ride a 700C tourer as well but fat hi-performance 650Bx42 Hetre tyres are something to be experience to believe. Super fast and light + grippy yet you feel no vibrations...

+++1. I had a 1970s 650b Peugeot with these tires. My LBS respaced it to accept a modern OLN 650b wheelset with Hetre tyres. The tyres are an absolute pleasure. Unfortunately the frame is too small so I'm going to try this wheelset on my audax-style bike, with long drop Tektro 556 brakes - for me 650b has the benefit of allowing larger tyres and 'guards on road frames limited by clearances.

reohn2 wrote:But that assessment seems to do with tyres,not rim size.Would the same tyre in 700cx42 perform any differently?

Good point. I'm afraid I don't know! I don't know of any 700c tyres of comparable quality to Grand Bois tyres in this size. I had 700c x 37mm tyres (Panaracer Paselas) on my tourer / commuter. I found them slow and heavy, but this could be due to other factors and not the 700c wheel size.

Regards,

Luke

Anyone know of the list of approved 753 builders past or present ?

Hi Ian, I wrote something like 'the list of 753 builder's is limited'.
I should have written 'my knowledge of 753 builder's is limited.'

I understand Raleigh, Brian Rourke and Ellis Briggs made 753 frames. There's so much knowledge on this forum so I think someone will know of others.

Cheers,

Luke

Thanks Ian, great tips. I sprayed frame saver inside my Surly Long Haul Trucker frame on purchase, but haven't done anything since. It has vent holes so I really should give it the treatment. Cheers, Luke

Hi, I once read on another forum that one can use beeswax to plug these holes. Haven't tried it myself, anyone out there tried it?

As an aside, I once also read that one can drill a small 'drain hole' at the base of the bottom bracket shell of a steel frame, to prevent water collecting and corroding. What do you think chaps?

Great thread, reads like a 'whodunnit' detective novel

The thought just occurred to me; if Chevin cycles don't have any records, and is it made from Reynolds 753, isn't the list of approved 753 builders limited, which might help narrow the search a little?

Good luck with the search, and enjoy the new bike.

Cheers,

Luke

Hi Brucey,

The same Bicycle Quarterly article also explored other factors for comfort.
They compared forks with the control bike and the control Bongtrager Hardcase tires:
-A stiff Trek Hybrid fork; steel unicrown, large-diameter, thickwall blades of 22.0mm diameter (130mm from axle). Weight: 1010g.
-An Alex Singer fork with Reynolds 531 S.R. "Super Resilient" blades, 13.4mm diameter. 835g
-A 1998 RockShox "Ruby" fork for road bikes. 1230g.

On rough roads the RockShok and Singer forks both significantly reduced the power output required to maintain a given speed by ~10%.
These flexible forks decreased suspension losses on smoother roads too, but non-significantly.

Subjectively the tester felt the Singer and Rockshox forks more comfortable on rough and smooth surfaces.
The Rockshox fork gave a slightly smoother ride than the Singer fork on the rough surface, but did not match the comfort of the wide tires at 50psi.

The authors hypothesized that the suspension forks were less effective than optimized tyres due to greater unsprung mass: Keeping the unsprung mass low facilitates shock absorbtion.
The tire only has to absorb the movement of the contact patch of tyre and tube (~20g).
The fork has to absorb the movement of the entire front wheel, tire, tube and part of the fork (~800g at least).

They consider that the large travel of suspension forks can be advantageous on large bumps as found off road, but suspension forks with high pressure tyres don't offer any performance advantages over flexible steel forks on the road. They are also heavier.

The authors compared shellacked cotton handlebar tape (ie no shock absorption) with bars wrapped with 6mm foam pipe insulation. It didn't significantly reduce suspension losses. The authors attributed this to padded handlebars having to absorb the movement of the entire front end of the bike, a very large unsprung mass.

I doubt I'm doing the original article justice - it's well worth hunting down for a read, as is the magazine in general.

Best wishes,

Luke

Hi Brucey,

I dug out the article, in Bicycle Quarterly Vol 8 no 1, Autumn 2009.

To identify the potential extent of suspension losses they rode a control bike over smooth tarmac. The control bike had Bontrager "Racelight Hardcase" 28mm tyres (95psi) and a stiff steel fork (steel unicrown, large diameter thickwall blades).
They then rode the same bike over rumble strips with standardised indentions of 11-16mm, judged to be equivalent to "very large cobblestones found in some European cities".
They used a powertap rear hub which recorded speed and power.
They made "at least two repeats for each test run", however I couldn't find how long each test run lasted.
On smooth surfaces the rider spent ~183W to ride at ~15.7mph.
To maintain the same speed on the rumble strips required ~473W, 2.5x the power.

When they compared tyres of different widths and pressures the testers used shallower rumble strip (8-10mm depth). They felt this was more similar to real world conditions "...bad chipseal...medium-sized cobblestones".
They compared power outputs for a constant speed of 19.4mph, the approx average speed for all runs.
They maintained the stiff fork to isolate the effects of the tyres.

They found that:
-lower pressures made no significant difference in performance on smooth surfaces, but significantly improved performance on rough surfaces.
-Wide tyres at low pressures (Panaracer Pasela 700c 37mm) or supple tyres (Grand Bois Cerf Blue 700c 26mm) required 10% less power over smooth surfaces for the same speed vs stiff tyres (Bontranger Racelite Hardcase 700c 28mm).
-Over rough surfaces, there were no significant differences between the Bontranger or Grand bois tyres.
-Over rough surfaces a wide tyre at low pressure required significantly less effort than a thinner, high pressure tyre; 37mm Paselas at 50 psi required 35% less power than the Bontrangers.

The article concludes stating that the human body is 'damped' and absorbs energy. On smooth roads suspension losses can account for ~10% of a cyclist's power output, and on rough roads > 50%.

Best wishes,

Luke