Mercian bike fit experience

[nextSibling]

I think I may have quite a list of questions for Grant, though I understand that email communication is not (or at least wasn't) Mercian's forte...

I won't bore you with a boring story, but my personal experience is that the only chance of getting what you asked for from Mercian is to go there in person. Email is a black hole.

[Oxford_Guy]

I think I may have quite a list of questions for Grant, though I understand that email communication is not (or at least wasn't) Mercian's forte...

I won't bore you with a boring story, but my personal experience is that the only chance of getting what you asked for from Mercian is to go there in person. Email is a black hole.

This is pretty much what I was expecting. Seems to be a trait of a number of bike builders...

[quixoticgeek]

re frame size; I think (purely on aesthetic grounds) that many people are riding frames with horizontal top tubes that are too small, and that anytime you are planning to have as much or more exposed seat pin vs the length of the head tube, the frame starts to look a bit small.

Practically speaking you need to be able to straddle the frame without being castrated (and you may only need about 2" of exposed seat pin for this) and you need to be able to put the handlebars at the right height.  If you are racing and need the bars very low then this might be a good reason for having a smaller frame size but you might as easily need to go the other way. My guess is that with a 52cm frame you might struggle to get the handlebars level with the saddle unless you use a stem that is longer than normal, and that the lowest adjustment is a lot lower than you might ever use. If that is right then a frame that is 1-2cm longer in the seat tube might be a good idea; it would arguably fit better with the retro aesthetic too.

The thing there is that some times the seat tube needs to be a bit longer in order to be able to attach saddle bags. The Ortlieb saddle bag I use on my bike needs 150mm of exposed seat post to attach to. This limits how close to horizontal I can get my top tube. I'm quite short, and my standover height isn't particularly high.

This thread is really interesting as I'm going through a similar decision process for my new bike.

J

[Oxford_Guy]

re frame size; I think (purely on aesthetic grounds) that many people are riding frames with horizontal top tubes that are too small, and that anytime you are planning to have as much or more exposed seat pin vs the length of the head tube, the frame starts to look a bit small.

Practically speaking you need to be able to straddle the frame without being castrated (and you may only need about 2" of exposed seat pin for this) and you need to be able to put the handlebars at the right height.  If you are racing and need the bars very low then this might be a good reason for having a smaller frame size but you might as easily need to go the other way. My guess is that with a 52cm frame you might struggle to get the handlebars level with the saddle unless you use a stem that is longer than normal, and that the lowest adjustment is a lot lower than you might ever use. If that is right then a frame that is 1-2cm longer in the seat tube might be a good idea; it would arguably fit better with the retro aesthetic too.

The thing there is that some times the seat tube needs to be a bit longer in order to be able to attach saddle bags. The Ortlieb saddle bag I use on my bike needs 150mm of exposed seat post to attach to. This limits how close to horizontal I can get my top tube. I'm quite short, and my standover height isn't particularly high.

This thread is really interesting as I'm going through a similar decision process for my new bike.

I'd like to be able to use a saddle bag, but just a small one like a Carradice Super C Audax or similar

[Cudzoziemiec]

Vroomen has some observations on handlebar height over the years in these short blog posts. Read them in order:

• One
• Two
• Three
• Four

Ideally you’d know the basic arrangement you want before going to a frame builder, but I suppose they’re used to customers changing their mind a few times.

I'm not sure about Vroomen's arm position observations. He says that a common reason people ride with straight arms is to support their weight because their back alone is not strong enough, which seems likely. Given this, it's only ever going to be a fit and fast minority who will be able to ride with bent arms (unless they have very high bars and an upright position).

[hubner]

Vroomen has some observations on handlebar height over the years in these short blog posts. Read them in order:

• One
• Two
• Three
• Four

Ideally you’d know the basic arrangement you want before going to a frame builder, but I suppose they’re used to customers changing their mind a few times.

I'm not sure about Vroomen's arm position observations. He says that a common reason people ride with straight arms is to support their weight because their back alone is not strong enough, which seems likely. Given this, it's only ever going to be a fit and fast minority who will be able to ride with bent arms (unless they have very high bars and an upright position).

I don't think he mentions backs, just that locking your arms straight requires less effort than bent arms.

The lower your back goes, the more weight is on your arms, so it could be that straight arms are actually more "comfortable" than bent arms when trying to ride with a low position.

[jessand]

I am the same height as OP and have lower back issues also. I approached my bike purchase from a slightly different angle, that is deciding the position I needed to be on the bike then finding one that met the criteria whilst being aesthetically pleasing (to me at least!))

Having previously had a bike fit I was able to take the required measurements from my old bike. So I knew that I needed:

A seat angle of less than 74deg or I'd need a seatpost with more than 25mm setback
A virtual top tube of 54cm to give correct reach with a 100mm stem
A tallish headtube to get bar height without resorting to flipping stem or spacer stack
I preferred steel, wanted clearance for 25s with full mudguards, deep drop brakes and a triple chainset

This is the bike chose, which I know is exactly what OP doesn't want, but I think is handsome. I have swapped my 9-speed drivetrain over to it and it's a joy to ride.
http://2015.konaworld.com/kapu.cfm

My point is that if you start out with a particular style of bike and try to make it fit, you are going to come up against challenges in trying to bring the style and fit together (as seen in previous threads).  Although going custom should be the answer, it isn't guaranteed.  Sometimes compromises are needed but I don't think it should be in the fit.  My main objective was to be able to continue enjoying my cycling in the future - which means ensuring there is also room for adjustments to be made in the future.

I wish OP well and hope he ends up with his ideal bike.   

[mattc]

You don't need very strong arms to ride without your elbows locked! Look how puny some of the pros are up-top. But locked elbows take away almost ALL of the shock absorption in your arms.

Anyway, you don't need big muscles to support a gentle load for long periods - its about practice. The human body adapts, and the first adaptation is very quick; so riding a very different bike can seem very odd/tiring at first, but get on it a week later and suddenly you've magically become an elite gymnast that can sustain a couple of hours in this "extreme" position without fatigue 

[tatanab]

You don't need very strong arms to ride without your elbows locked! Look how puny some of the pros are up-top. But locked elbows take away almost ALL of the shock absorption in your arms.

Exactly.  It seems to me that riding with locked arms is a modern fashion that goes along with shallow bars, the insistence on riding the drops all the time and a big drop from saddle to bars.  I started club riding and racing back in the 1960's and we were all capable of bending our arms to get lower (chew the handlebar stem) or for suspension.  I still do it and I am a puny 10 stone pensioner, that's 64kg in newspeak. 

[Oxford_Guy]

- 74 degree seat angle is too steep for a lot of combinations of saddle and seat pin; there is no way I could use that with most leather saddles for example, because they don't slide as far back as far a lot of other saddles.

- you could (bearing in mind the sporty intent of this frame) easily go 10mm shorter in the chainstays and even 20mm might be possible

BTW I was just checking on the Mercian web page about the Strada Speciale frameset again and was interested to note that for frame sizes 50cm to 55cm they specify as standard "73 degree head angle – 75 degree seat angle" (but for 56cm to 66cm 74 degree head angle – 74 degree seat angle), so for the 52cm  frame they specified for me, they have already "relaxed" this a little to a 72 head angle and 74 degree seat angle. BTW when I was measured for the bike, think it had a Brooks Team Pro saddle on the jig.

Also looks like for small frames a 40mm fork rake is usual, but they've specified 45mm for me.

I also noticed that the standard chainstay length is 410mm -so they've only gone an extra 10mm for my measurements, to 420mm - presumably to allow for the mudguard clearance I asked for.

I think the main thing I would question is the frame size - 52cm seems a bit too small, with a lot of seatpost showing and an extension needed for the headtube about the top tube - so I may ask if they can reconfigure for 53cm or even 54cm

[Brucey]

one thing I noted many years ago is that (for some reason I still don't understand, probably to do with the way lugged frames are brazed up in sequence) careful measurements of a number of frames indicated that it was common for the actual seat angle to be 0.5 degrees steeper than the specification required.

I was (as usual) in danger of running out of saddle adjustment  so when I ordered a frame years ago (from an un-named but reputable source) I asked for it to be built with a certain seat angle. I said that if the seat angle was likely to turn out 0.5 degrees steeper than specified (as my measurements showed was likely to happen) they were very welcome to aim for 0.5 degrees slacker to start with, because 0.5 degrees slacker would be OK, but 0.5 degrees steeper would be a disaster. 

Imagine my dischuffment when the poxy thing (inevitably) turned up with a seat angle 0.5 degrees steeper than I had specified; to rub salt into the wounds this had rendered the frame virtually the same as the 'standard build' would have been, so as far as I could tell I'd just paid a healthy premium to have a custom frame geometry only to be given what was basically similar (in one of the key dimensions that I'd specified) to an OTP frameset.... Grrrrr….

As a general rule one of the things that determines the maximum seat angle is how hard you push on the pedals; basically this unweights your hands and allows a modicum of comfort. The further back the saddle is, the less hard you need to push to give this unweighting effect and therefore give your hands, arms and shoulders a comfortable time of it. When you are tired you can often feel this instantly; when you stop pedalling there is a significant increase in the load on the handlebars.

 Steeper seat angles are thus tolerated by more powerful riders and for any given rider the most appropriate seat angle may vary depending on the intensity and duration of the envisaged usage. So a seat angle of 75 (or even 76) degrees may be appropriate for a short TT or on a typical track bike but the same rider might be better off with a 72 degree seat angle (and a slightly more rearward-set saddle) for longer races, audaxes,  six-day track events etc. 

I'd therefore urge caution in specifying a seat angle that is likely to be appropriate for shorter length races on (say) a bike that you hope to be comfortable all day long. If you have not experimented with moving your saddle around, (a surprising number of experienced riders have not) now is probably the time to do so, before the die is cast.

Note also that the flare in the saddle (not to mention the rivets on a leather one) can stop you from sliding back in the saddle but during high intensity efforts the natural urge is to slide forwards towards the saddle nose (almost regardless of its original position) so that a slacker seat angle is almost invariably less of an impediment than one that is too steep.

cheers

[Oxford_Guy]

one thing I noted many years ago is that (for some reason I still don't understand, probably to do with the way lugged frames are brazed up in sequence) careful measurements of a number of frames indicated that it was common for the actual seat angle to be 0.5 degrees steeper than the specification required.

I was (as usual) in danger of running out of saddle adjustment  so when I ordered a frame years ago (from an un-named but reputable source) I asked for it to be built with a certain seat angle. I said that if the seat angle was likely to turn out 0.5 degrees steeper than specified (as my measurements showed was likely to happen) they were very welcome to aim for 0.5 degrees slacker to start with, because 0.5 degrees slacker would be OK, but 0.5 degrees steeper would be a disaster. 

Imagine my dischuffment when the poxy thing (inevitably) turned up with a seat angle 0.5 degrees steeper than I had specified; to rub salt into the wounds this had rendered the frame virtually the same as the 'standard build' would have been, so as far as I could tell I'd just paid a healthy premium to have a custom frame geometry only to be given what was basically similar (in one of the key dimensions that I'd specified) to an OTP frameset.... Grrrrr….

As a general rule one of the things that determines the maximum seat angle is how hard you push on the pedals; basically this unweights your hands and allows a modicum of comfort. The further back the saddle is, the less hard you need to push to give this unweighting effect and therefore give your hands, arms and shoulders a comfortable time of it. When you are tired you can often feel this instantly; when you stop pedalling there is a significant increase in the load on the handlebars.

 Steeper seat angles are thus tolerated by more powerful riders and for any given rider the most appropriate seat angle may vary depending on the intensity and duration of the envisaged usage. So a seat angle of 75 (or even 76) degrees may be appropriate for a short TT or on a typical track bike but the same rider might be better off with a 72 degree seat angle (and a slightly more rearward-set saddle) for longer races, audaxes,  six-day track events etc. 

I'd therefore urge caution in specifying a seat angle that is likely to be appropriate for shorter length races on (say) a bike that you hope to be comfortable all day long. If you have not experimented with moving your saddle around, (a surprising number of experienced riders have not) now is probably the time to do so, before the die is cast.

Note also that the flare in the saddle (not to mention the rivets on a leather one) can stop you from sliding back in the saddle but during high intensity efforts the natural urge is to slide forwards towards the saddle nose (almost regardless of its original position) so that a slacker seat angle is almost invariably less of an impediment than one that is too steep.

Interesting! Although I can't say I've had any problems with the 74 degree seat angle on my Hewitt Cheviot, but I do use a seatpost with a 20mm seatback (with a Giles Berthoud leather saddle - BTW the rivets on this are at the sides, not on top, so can wriggle around anywhere on the saddle without discomfort, also has less flare than a Brooks) - would a seatback seatpost be a bad idea on a road bike, though?

I may well make a point that a 74 degree angle is the absolute steepest angle I want, though, and slacker rather than any steep would be preferable!

[hubner]

The changes in frame sizing and set up:

top tubes got lower
head tubes got shorter
bar tops got lower
brake levers mounted further up the bars (sometimes higher than bar tops)
drops got shallower
stems point upwards
straight arms
lots of headset spacers

Also bars rotated up.

https://yacf.co.uk/forum/index.php?topic=17.msg2297946#msg2297946

20180623_072029 by rogerzilla, on Flickr

 

[Brucey]

….I do use a seatpost with a 20mm seatback (with a Giles Berthoud leather saddle - BTW the rivets on this are at the sides, not on top, so can wriggle around anywhere on the saddle without discomfort, also has less flare than a Brooks) - would a seatback seatpost be a bad idea on a road bike, though?

I may well make a point that a 74 degree angle is the absolute steepest angle I want, though, and slacker rather than any steep would be preferable!

There is one good (or bad) reason for setting the bike up so that you use most of the rearward adjustment of the saddle in your 'normal' position; it allows more flex in the saddle rails. This can be bad (if you tend to break saddles anyway) but otherwise it is good, because it has a marked effect on comfort.

IMHO it matters little whether you get the seat clamp in any given place via choice of seat pin or choice of seat angle. Full-on racing frames can have fractionally shorter chainstays if the seat angle is a bit steeper, but that is about it, provided you make appropriate adjustments to the top tube length and so forth.

cheers

[jessand]

Oxford_Guy

Have you sorted your bike yet?

[Oxford_Guy]

Oxford_Guy

Have you sorted your bike yet?

Not yet, I sent a long email to Merican, which Grant said he'd read but said it would be best for me to come back to the shop for another appointment, which is fair enough. Haven't booked it said, but will probably do so tomorrow and see them again in a few weeks. I think I have a bit better idea what I'm looking for now.

[Jethro]

I think that blue and white Strada Speciale was originally owned by me.  I did have one built that was exactly the same as that one in 1989 but no longer have the frame number for it.   Great to see it again though after all this time.  It was originally a dark red with silver panels but I had it resprayed in about 1991 and later sold it through the CTC website in about 1993.

Not yet had time to read all postings but for now, I have never ridden with a triple chainset and find that a compact 34/48 or 34/50 works fine for me even though I dont get up the hills anywhere near as quick as I once did!

[Oxford_Guy]

I think that blue and white Strada Speciale was originally owned by me.  I did have one built that was exactly the same as that one in 1989 but no longer have the frame number for it.   Great to see it again though after all this time.  It was originally a dark red with silver panels but I had it resprayed in about 1991 and later sold it through the CTC website in about 1993.

Intriguing!

Not yet had time to read all postings but for now, I have never ridden with a triple chainset and find that a compact 34/48 or 34/50 works fine for me even though I dont get up the hills anywhere near as quick as I once did!

I'm still considering my options, might go for a triple, might go for a compact, if I can find a suitable Ultra Torque chainset. What cassette do you use with a compact? Was thinking either 12-27 or 12-30, 13-29 gives a closer spread in the higher gears, but think I want a higher gear than 13/50

[Jethro]

I normally use a 13/26 cassette with my compact chainset of 34/50 though I do also have a bike with a 13/29 set up.  I have rarely ever needed my top gear of 50/13.

[Oxford_Guy]

I normally use a 13/26 cassette with my compact chainset of 34/50 though I do also have a bike with a 13/29 set up.  I have rarely ever needed my top gear of 50/13.

Nice tight ratios on the 13-26 all the way up to 19T, I think, but 50/13 is only about 100 gear inches I think, which I think I would spin out of quite easily on not that steep downhills - I certainly used to on 42/11 which is similar. Am on 46/11 now on that bike, which I find better, though 44/11 probably would have been more useful

[Phil W]

Never understood what people have against triples. Difference in weight between a triple and compact, taking SPA chain sets for instance is only 65g.  So neither here nor there.  Whole range of lower gears you can have with a close ratio rear cassette if you want, or keep a wide range cassette for super low gears for touring or fatigued on long rides.

[Oxford_Guy]

Never understood what people have against triples. Difference in weight between a triple and compact, taking SPA chain sets for instance is only 65g.  So neither here nor there.  Whole range of lower gears you can have with a close ratio rear cassette if you want, or keep a wide range cassette for super low gears for touring or fatigued on long rides.

The weight difference is a bit more comparing Square Taper BB Campag with Campag UltraTorque BB, as well as a somewhat stiffer BB spindle. Smaller Q-factor too. Not saying triples are a bad thing, far from it, but there are some advantages to an UT Compact.

If I was running a triple I'd probably put a 12-25 cassette on it for a road bike

[Brucey]

re triples, I don't understand it either. 

 Only serious objection (which matters more to some than others) is that of Q value, but that can be overcome by careful design on road bikes; one of my bikes has a triple chainset  and by using carefully chosen parts the Q value is appreciably less than you might get on a modern compact double, and the chainline is about the same (or better) on the bigger chainrings as would be had on a compact double too.

Given that so many folk only use top gear when running downhill, yet might use bottom gear for considerably longer (both in time and pedal revolutions) there is much to be said for road bikes with

- at least 135mm OLN hubs
- 8/9/10s cassette (centre chainline of ~46mm to 47mm on 135mm OLN) or shortened cassette on a 7s freehub body
- chainrings set at ~34, 42, 50mm chainlines (won't fit on every frame since inner chainring is centred on the end of a 68mm BB shell)

Whilst on the bigger rings his gives freedom to use the sprockets as if you were riding a double setup (more or less) and leaves the inside chainring for emergencies, during which time you would only use it with the larger 2/3rds of the sprockets anyway. The chainline onto the smallest sprocket isn't great but that is no big deal given that you would only ever use it going down hills.

So for example even a 7s cassette gives a good range of gears on a triple this way, e.g. 13,15,17,19,21,24,28 and chainrings of 30,42,52 gives me enough gears for every (unladen) circumstance and on the big ring the 17 and 19T sprockets give near-perfect chainlines and are good gears (for me) to ride briskly on, being both measurably more efficient (than I'd use with smaller chainrings) and more hard-wearing.

 The same freehub body will accept up to nine 10s sprockets if seven isn't enough for some reason.  A 135mm/7s wheel has almost no dish which means that you can have a very strong and lightweight wheel indeed.

Contrast that with a compact double (2x11 or 2x10) with 130mm OLN wheels and you have at least as much weight in the sprockets/chainrings etc, a rear wheel that is weaker, heavier (or both), lower efficiency (because the chainrings/sprockets are smaller for any given gear ratio)  and worse chainlines more of the time.


Sod fashion, I reckon a triple (set thusly) works better for me and a lot of other riders too.

BTW re chainset weight; I think a third chainring could be added to a campag UT double chainset (using a tripleizer ring and a very slight offset to the cups in the BB) and the 'extra weight' would be 100g, tops, to be traded against lighter/fewer sprockets.

cheers

[Ian gaggiaport]

I miss the ' half step +granny' on my Audax Bike
It's the sourcing of shifters that made me switch in the end. I liked the old micro shift campag ones.
So now I run a double but don't use the 11t.
I didn't like the big step from outer to inner.
So I've lowered the outer to 46 and increased the inner to 36.
But if I have a hilly ride I can fit a 34 inner.
Maybe I should get 3 chainset options from spa cycles and fit as required.

[guidon]

On my Mercian audax special which was meant to be a custom build - due to the delays in production I ended up getting an off the peg and seeing what adjustments had to be made to fit me re stem length, seatpost and saddle height - I find that the band-on adaptor doesnt work well with triples (getting into the smallest chainring is sketchy at times) so maybe a band on is advantageous. Also that the frame had a 1 inch threadless fork which pretty much limits you to a campag record headset....23mm tyres with mudguards, 25 without (the specs at the time of purchase some 8 years ago) however limits the choice of tyre and comfort factor now...
These niggles aside it still is the most comfortable bike I own for over 200km, and I'll never part with it