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After a strong start the Genesis has sadly remain mothballed for the past three years.
The bike was displaced by the Fuji Touring whose utilitarian prowess served to keep me riding in an environment that offered precious little incentive to ride for the sake of it, and whose components opened the door to a whole new world of comfort I'd not previously experienced.
The Fuji exposed or reinforced a number of significant issues with the Genesis, all revolving around its crankset - namely (in descending order of severity):
- Q-factor / pedal spacing too narrow - feeling uncomfortably so and causing knee and hip pain
- Ratios b*llocks - 50/34 is simply too high for me and I found constantly shifting between rings
- Crank arms longer than ideal (impacting joints and toe overlap with front wheel)
Q-Factor
Q-factor can be increased with pedal spacers although these aren't ideal for a number of reasons. MTB cranksets tend to have a much wider Q-factor than road equivalents (typically 165-180mm between pedal mounting faces versus IIRC about 146mm on road cranks). Unfortunately Shimano's compatability between these two sets of components is extremely limited; adding to an already significant list of potential issues when hunting for viable replacements.
Gearing - Triples
Gearing could be resolved with a horrendously unfashionable triple chainset; the 48/36/26 on the Fuji feeling perfect; with the middle ring doing 95% of the work and the other two only bothered at the extremes of usage.
Road triples were out on their narrow Q-factor and typically higher ratios; this option being killed stone-dead by the inability to run them with hydro brakes - the only triple shifters available being to suit cable brakes.
While MTB triples were much better in terms of Q and ratios the shifter problem persisted, while this was added to by the difference in cable pull ratios between the non-existant, hypothetical road shifters and MTB FDs.
I did look at the potential to modify a hydro road 2x shifter to work with a triple MTB FD; however achieving this was beyond my abilities (while in any case I now know the FD wouldn't have physically fitted the bike due to insufficient clearance with the mudguard), so the triple idea was abandoned in favour of the next best thing - a sub-compact double.
Gearing - Sub-Compact Doubles
This potential route was also fraught with problems. The road compact double ftted is 50/34t; which I'd wager is far larger than ideal for the bulk of recreational riders. Shimano push as low as 46/30 on their GRX RX600 crank however IMO this still isn't low enough for rougher terrain / my preferences... This was confirmed by the unit on my ill-fated CdF 20 flat bar; where the 46t ring still seemed far too high to be much of the time.
Due to the bolt-circle-diameters of the chainring fixings you can't go much lower than what's available out of the box, while not a whole lot of aftermarket rings are available for Shimano's propriatory assymetric 4x bolt patterns in any case.
On top of all that these road / road adjacent cranksets still have the same narrow Q-factor.
An MTB-double perhaps looked a bit better - wider Q-factor and ratios that were tantalisingly close, if never quite high enough to be comfortable - with one or two few-and-far-between models offering 40/28t but most being down in the 36/38t range on the top ring. While this was ideal as a middle ring on the Fuji I was concerned by that lack of range at the top end's effect on faster runs.
Truth be told the 48t ring on the Fuji was very rarely bothered, however such a bike - intended for sedately lugging stuff around - isn't necessarily a perfect model for a lighter leisure bike intended to be ridden more "enthusiastically".
I also looked at many different offerings from different manufacturers, but an acceptable solution remained elusive.
The last chance saloon was to build something up from parts. After sifting through the specs of pretty much every MTB / MTB-adjacent crankset Shimano have made for the past decade and taking into account chainlines, axle spacing, ring BCDs, compatable components and myriad other stuff I think I finally reached an acceptable conclusion; and some weeks ago (years after casually starting to look for suitable gear) I finally had "everything" necessary:
We have:
Shimano Deore XT FC-T8000 crankset: MTB-derived touring/ "trekking" triple; 176mm Q-factor, 170mm cranks, 47mm-ish chainline (when setup as a double using inner and middle positions) and venerable 104/64mm BCD standard used to mount the original 48/36/26 rings. Originally quite a pricey bit of kit, however not silly money in the post-covid crash, as an old and unfashionable format to suit an old and unfashionable type of bike.
Specialites TA Chinook chainrings - 42 and 28t: While the 104/64mm BCD standard of the crank has been around forever and probably boasts the largest selection of aftermarket rings for any standard, very little existed in the sizes I wanted; with the nebulous differences between those intended for 8/9 speed and 10/11 speed proving particularly problematic. Despite being ostensibly avaible in many places in the UK, these (well, the 42t item) proved particulary difficult to source - the bigger ring especially; taking the fat end of six months to get hold of.
Thorn 44t chainguard: Arguably unnecessary on a gravel bike, however the most elegant and aesthetically acceptable means I could find of filling the gap left by the now-absent outer chainring.
BB-MT801 bottom bracket: Mid-teir MTB BB to suit the longer crank axle length of associated cranks; correspondingly intended to fit wider 73mm BB shells instead of the 68mm road standard of the unit on the bike. In a rare spasm of fortune MTB BBs have enough thread on them to be fitted to the smaller road BB shells if installed with spacers.
FD-RX810 front derailleur and band on adaptor: Compatable with the road shifters and spaced out by an additional 2.5mm compared to the existing 105 item to accommodate the wider 47mm chainline of gravel cranksets; which this build should be very close to. Band-on adaptor required since the mount isn't integral as it is on the fitted 105 FD.
Pedal Washers: Fitted in the interest primarly of protecting the pedal register faces on the cranks from damage, also adding a few precious millimetres to the pedal spacing.
Race Face crank boots, small: While I don't do anything particularly hardcore, I do recall damage occurring to the ends of the 105 cranks not long after I’d bought the bike; so these seemed like a sensible addition.
While I’d done my best to pre-empt and mitigate all possible problems, assembly didn’t go according to plan due to a few oversights on my part and arguable balls-dropped by manufacturers.
It all started off nicely enough; the crankset coming apart sufficeintly easily to receive its new chainrings – thanks partially to the proprietary crank nuts that restrain themselves against rotation rather than needing one of those crappy little pressed steel tools to engage, and inevitably slip out of, the crappy little slots in normal chainring nuts.
The first apparant problem was that the chain guard wouldn't sit flush against the mounting tabs on the crankset, thanks to the latter having chamfers in their corners where joined to the main crank body; which fouled the square edges on the back of the guard.
While spacing it out was an option this would destroy the seamless transition between the crank body and chainring nuts; the whole point of fitting the guard being to preserve this; so that was out. So, I set to work with the files..
Many hours later I was largely satisfied with my work, although had to tidy up some innocent edges I'd nicked with the file with some gloss black paint.
I resented having to do this at all since this is likely to be an issue on most cranks (although my inability to space the ring out with impunity isn't). I can appreciate why these aren't supplied like this though as it would require a totally different, additional operation to the otherwise entirely drilled / profile cut manufacture of the guard... although if it's in a CNC mill anyway for the holes..
That hurdle overcome the next problem was with the middle chainring nuts; which take the form of threaded aluminium inserts with a larger, mult-faceted plastic head molded onto them via a splined interface. What was at worst intitally lost on me / at best considered but unable to be quantified was the load-bearing area of the nuts.
Turns out the splines are approximately the same diameter as the counterbores in the front of the guard (against which they're intended to register) meaning that moulded interface between the plastic nut head and aluminium splines would have to react the axial load of tightening the bolts; rather than the ends of the splines themselves.
Thankfully for once monkey brain took notice of what lizard brain had noticed and I stopped tightening these before it was too late.
This issue was resolve courtesy of some M10x12mm shims in various thicknesses - sourced dirt cheap from Ali Express when I couldn't even find any over here at any price. Typically the travelled from China to the UK in good time; with the process being dragged out thanks to Evri losing them..
In addition I had to dress down some sharp edges of the mating face of the 42t ring; which I thought had damaged the surface of the crank although I also found exactly the same sheared-burrs on the original ring; so we'll let the chainring off on this occasion.
In terms of quality the 28t ring was really nice - with few sharp edges and a nice, even matt media-blasted finish. The 42t ring was less nice with a more variable gloss finish and a load of sharp edges; although it wasn't going back given how long I'd waited..
Relatively minor quality issues aside, the rings were geometrically very nice - the 28t being pretty basic and uniform, the 42t however having the numerous cutouts, pins and varying tooth profiles you'd find on any decent OEM rings in the interest of clean and consistant shifting.
While these evidently start out as a bit of stamped ally, it seems they're also subject to some pretty trick multi-axis machining.
The rings seemed pretty hard which I hope bodes well for wear resistance..
The non-trivial assembly of the crankset finally complete, it sat for a few weeks while I mustered the determination to actually sling it on the bike, which was going to require another significant investment of time.
While I'm not overly sold on the aesthetic of the guard, it's the least-worst solution I could come up with and I think it all looks pretty cohesive together:
The bike was displaced by the Fuji Touring whose utilitarian prowess served to keep me riding in an environment that offered precious little incentive to ride for the sake of it, and whose components opened the door to a whole new world of comfort I'd not previously experienced.
The Fuji exposed or reinforced a number of significant issues with the Genesis, all revolving around its crankset - namely (in descending order of severity):
- Q-factor / pedal spacing too narrow - feeling uncomfortably so and causing knee and hip pain
- Ratios b*llocks - 50/34 is simply too high for me and I found constantly shifting between rings
- Crank arms longer than ideal (impacting joints and toe overlap with front wheel)
Q-Factor
Q-factor can be increased with pedal spacers although these aren't ideal for a number of reasons. MTB cranksets tend to have a much wider Q-factor than road equivalents (typically 165-180mm between pedal mounting faces versus IIRC about 146mm on road cranks). Unfortunately Shimano's compatability between these two sets of components is extremely limited; adding to an already significant list of potential issues when hunting for viable replacements.
Gearing - Triples
Gearing could be resolved with a horrendously unfashionable triple chainset; the 48/36/26 on the Fuji feeling perfect; with the middle ring doing 95% of the work and the other two only bothered at the extremes of usage.
Road triples were out on their narrow Q-factor and typically higher ratios; this option being killed stone-dead by the inability to run them with hydro brakes - the only triple shifters available being to suit cable brakes.
While MTB triples were much better in terms of Q and ratios the shifter problem persisted, while this was added to by the difference in cable pull ratios between the non-existant, hypothetical road shifters and MTB FDs.
I did look at the potential to modify a hydro road 2x shifter to work with a triple MTB FD; however achieving this was beyond my abilities (while in any case I now know the FD wouldn't have physically fitted the bike due to insufficient clearance with the mudguard), so the triple idea was abandoned in favour of the next best thing - a sub-compact double.
Gearing - Sub-Compact Doubles
This potential route was also fraught with problems. The road compact double ftted is 50/34t; which I'd wager is far larger than ideal for the bulk of recreational riders. Shimano push as low as 46/30 on their GRX RX600 crank however IMO this still isn't low enough for rougher terrain / my preferences... This was confirmed by the unit on my ill-fated CdF 20 flat bar; where the 46t ring still seemed far too high to be much of the time.
Due to the bolt-circle-diameters of the chainring fixings you can't go much lower than what's available out of the box, while not a whole lot of aftermarket rings are available for Shimano's propriatory assymetric 4x bolt patterns in any case.
On top of all that these road / road adjacent cranksets still have the same narrow Q-factor.
An MTB-double perhaps looked a bit better - wider Q-factor and ratios that were tantalisingly close, if never quite high enough to be comfortable - with one or two few-and-far-between models offering 40/28t but most being down in the 36/38t range on the top ring. While this was ideal as a middle ring on the Fuji I was concerned by that lack of range at the top end's effect on faster runs.
Truth be told the 48t ring on the Fuji was very rarely bothered, however such a bike - intended for sedately lugging stuff around - isn't necessarily a perfect model for a lighter leisure bike intended to be ridden more "enthusiastically".
I also looked at many different offerings from different manufacturers, but an acceptable solution remained elusive.
The last chance saloon was to build something up from parts. After sifting through the specs of pretty much every MTB / MTB-adjacent crankset Shimano have made for the past decade and taking into account chainlines, axle spacing, ring BCDs, compatable components and myriad other stuff I think I finally reached an acceptable conclusion; and some weeks ago (years after casually starting to look for suitable gear) I finally had "everything" necessary:
We have:
Shimano Deore XT FC-T8000 crankset: MTB-derived touring/ "trekking" triple; 176mm Q-factor, 170mm cranks, 47mm-ish chainline (when setup as a double using inner and middle positions) and venerable 104/64mm BCD standard used to mount the original 48/36/26 rings. Originally quite a pricey bit of kit, however not silly money in the post-covid crash, as an old and unfashionable format to suit an old and unfashionable type of bike.
Specialites TA Chinook chainrings - 42 and 28t: While the 104/64mm BCD standard of the crank has been around forever and probably boasts the largest selection of aftermarket rings for any standard, very little existed in the sizes I wanted; with the nebulous differences between those intended for 8/9 speed and 10/11 speed proving particularly problematic. Despite being ostensibly avaible in many places in the UK, these (well, the 42t item) proved particulary difficult to source - the bigger ring especially; taking the fat end of six months to get hold of.
Thorn 44t chainguard: Arguably unnecessary on a gravel bike, however the most elegant and aesthetically acceptable means I could find of filling the gap left by the now-absent outer chainring.
BB-MT801 bottom bracket: Mid-teir MTB BB to suit the longer crank axle length of associated cranks; correspondingly intended to fit wider 73mm BB shells instead of the 68mm road standard of the unit on the bike. In a rare spasm of fortune MTB BBs have enough thread on them to be fitted to the smaller road BB shells if installed with spacers.
FD-RX810 front derailleur and band on adaptor: Compatable with the road shifters and spaced out by an additional 2.5mm compared to the existing 105 item to accommodate the wider 47mm chainline of gravel cranksets; which this build should be very close to. Band-on adaptor required since the mount isn't integral as it is on the fitted 105 FD.
Pedal Washers: Fitted in the interest primarly of protecting the pedal register faces on the cranks from damage, also adding a few precious millimetres to the pedal spacing.
Race Face crank boots, small: While I don't do anything particularly hardcore, I do recall damage occurring to the ends of the 105 cranks not long after I’d bought the bike; so these seemed like a sensible addition.
While I’d done my best to pre-empt and mitigate all possible problems, assembly didn’t go according to plan due to a few oversights on my part and arguable balls-dropped by manufacturers.
It all started off nicely enough; the crankset coming apart sufficeintly easily to receive its new chainrings – thanks partially to the proprietary crank nuts that restrain themselves against rotation rather than needing one of those crappy little pressed steel tools to engage, and inevitably slip out of, the crappy little slots in normal chainring nuts.
The first apparant problem was that the chain guard wouldn't sit flush against the mounting tabs on the crankset, thanks to the latter having chamfers in their corners where joined to the main crank body; which fouled the square edges on the back of the guard.
While spacing it out was an option this would destroy the seamless transition between the crank body and chainring nuts; the whole point of fitting the guard being to preserve this; so that was out. So, I set to work with the files..
Many hours later I was largely satisfied with my work, although had to tidy up some innocent edges I'd nicked with the file with some gloss black paint.
I resented having to do this at all since this is likely to be an issue on most cranks (although my inability to space the ring out with impunity isn't). I can appreciate why these aren't supplied like this though as it would require a totally different, additional operation to the otherwise entirely drilled / profile cut manufacture of the guard... although if it's in a CNC mill anyway for the holes..
That hurdle overcome the next problem was with the middle chainring nuts; which take the form of threaded aluminium inserts with a larger, mult-faceted plastic head molded onto them via a splined interface. What was at worst intitally lost on me / at best considered but unable to be quantified was the load-bearing area of the nuts.
Turns out the splines are approximately the same diameter as the counterbores in the front of the guard (against which they're intended to register) meaning that moulded interface between the plastic nut head and aluminium splines would have to react the axial load of tightening the bolts; rather than the ends of the splines themselves.
Thankfully for once monkey brain took notice of what lizard brain had noticed and I stopped tightening these before it was too late.
This issue was resolve courtesy of some M10x12mm shims in various thicknesses - sourced dirt cheap from Ali Express when I couldn't even find any over here at any price. Typically the travelled from China to the UK in good time; with the process being dragged out thanks to Evri losing them..
In addition I had to dress down some sharp edges of the mating face of the 42t ring; which I thought had damaged the surface of the crank although I also found exactly the same sheared-burrs on the original ring; so we'll let the chainring off on this occasion.
In terms of quality the 28t ring was really nice - with few sharp edges and a nice, even matt media-blasted finish. The 42t ring was less nice with a more variable gloss finish and a load of sharp edges; although it wasn't going back given how long I'd waited..
Relatively minor quality issues aside, the rings were geometrically very nice - the 28t being pretty basic and uniform, the 42t however having the numerous cutouts, pins and varying tooth profiles you'd find on any decent OEM rings in the interest of clean and consistant shifting.
While these evidently start out as a bit of stamped ally, it seems they're also subject to some pretty trick multi-axis machining.
The rings seemed pretty hard which I hope bodes well for wear resistance..
The non-trivial assembly of the crankset finally complete, it sat for a few weeks while I mustered the determination to actually sling it on the bike, which was going to require another significant investment of time.
While I'm not overly sold on the aesthetic of the guard, it's the least-worst solution I could come up with and I think it all looks pretty cohesive together:
Last edited:
Since I had many more important obligations for others to fulfil, I spent most of this weekend up to my eyeballs in this project..
While anyone with more skill / less OCD would have had this job done in an hour or two, it was an opportunity to get a few more bits sorted; while as usual unforseen issues served to drag everything out longer.
To begin, the bike was chucked on the workstand on the patio and the wheels, crankset and BB removed before being thoroughly washed, dried and waxed.
As usual I gave the final rinse with a 5l bottle of distilled water (harvested from the condenser drier) to avoid water marks - administering such a dousing always reminds me of the petrol scene from Reservoir Dogs with Tim Roth and Michael Madsen (RIP!).. thankfully I rarely feel like torching any of my bikes; well - except the Brompton.
While waxing the rims I found the cause of the front tyre's slow leak - pulling a 1/2" hawthorn from the tyre prompting it to expel all its air in short order.. while the tyre was off for the puncture to be sorted I also noticed a pretty large ding in the rim edge. This was dressed out as well as possible with a punch and bit of fibreboard to protect the surface; before some corrseponding outward deformation was found deeper into the rim - which received the same treatment.
While it's far better than it was, this area remains imperfect - as ally seems to since it work-hardens and often cracks before you can get it back to exactly where it is..
Once clean and shiny the BB shell was degreased with paraffin and a toothbrush and dried before the build could commence; beginning with the fitment of the new bottom bracket with plenty of copper grease, torqued to the lowest recommended value of 35Nm.
Old and new BB assemblies - SM-BBR60 (road) and BB-MT801 (MTB). These are equivalent in terms of quality (Ultegra / Deore XT) and share many extenal dims and finish, although the cups aren't directly interchangeable as the major-diameter sections are thicker on the road variant and threaded length is a little different.
I was impressed by Shimano's almost commendably quaint, minimal, recyclable packaging as well as the aluminunium spacers (to allow fitment to a 68mm BB shell) - as I've only ever previously encountered lower-spec BBs that come with placcy spacers.
The BB went in without issue; thanks partially to the use of a Shimano plastic reducer insert that fits into the socket for the lower-spec / larger OD BBs; thus minimising the potential for damage during fitting / if anything slips.
The crankset was a similar story with the ever-reliable Hollowtech standard going together as nicely as ever and everything again being torqued to the lower end of the stated values. Old and new cranksets - Despite being larger the 105 item is significantly lighter at 733g versus the modified XT's portly 855g - although most of this difference is down to the 3mm thick guard.
Stark difference in Q-factor illustrated:
Before the front derailleur could be properly fitted cable routing had to be taken care of. By default the shifter cables run down the same side of the bike as the shifter is located upon - the consequence of this being that the cables are forced into a tighter than necessary loop; increasing drag, compromising cable entry angle to the barrel adjustors on the head tube and influencing the steering when the front wheel is unloaded (such as when the bike is in a stand)... as well as looking shite.
The solution to this is to swap the cables to the barrel adjustors on the opposite sides and cross them under the down tube as I've already done on the Fuji. Unfortunately on the CdF this is complicated by the two bottle cage mounting bolts near the bottom bracket. Of course these can be removed but we don't want the vacant holes hoovering up all the crap thrown up off the ground, so the were blanked with very low profile wafer-head bolts:
While the cable were out the barrel adjustors were stripped, cleaned and greased; while the ends of their springs were dressed on a stone to remove sharp edges in the interest of improved operation and reduced damage to the paint on the frame.
Once fitted the front derailleur proved to be its own can of worms.. Most concerningly when set at the correct height it fouled the chainguard (since this is intended for 44t rings and I have 42 - with no way to tell for sure if it'd fit I chanced it). Thankfully this turned out to not be an issue in use - the gap between the outer cage and tooth top on the big ring being more like 5-6mm rather than Shimano's stated 1-3mm.
Ideally I'd like a smaller chain guard but I'm not holding my breath..
Secondly cable retention proved to be a pig - due to a combination of limited instructions, jammed bits and my own ineptitude. Seems I wasn't alone as the cable was reet chewed in the same area on the similarly designed original fitment 105 FD; which I managed to correct to some extent..
I also had issues with the cable tensioner on the FD seizing - apparently after the rotating base into which the retainer plate bolts had somehow become elevated in the FD housing; causing it to jam. Took a while to work that out as I'm not particularly familar with working on these.
Both the outgoing R7000 105 and new RX810 GRX items are very similar - seemingly well-thought-out and well-featured; especially being offset outboard of the seatpost tube to give more tyre / guard clerance. Main differences are that the GRX item sits 2.5mm more outboard, and is bolt-on rather than band-on.
Despite being touted as suitable for differing chainring sizes, the cages look identical and I suspect they only have different part numbers because of the branding.
FD finally setup it was on to the RD; the original GRD RX810 being retained but the cable requiring refitting after being re-routed. As some bellends do, the cable had been bent hard after the clamp; making it difficult to pull through the housing and requiring straightening as best as possible before refitting.
Finally a chain could be fitted and the new configuration set up and tested. Of course with six or eight teeth missing from the new rings the original was slack and sloppy, but only in the highly-ill-advised small / small combination and was fine otherwise; proving that (on the stand at least) shifting was good and there were no obvious issues.
A ten mile test ride was had and a few adjustments made before I committed to shortening one of the spare chains I had waxed and ready.
Since I appear to have misplaced my chain holder, Ideal chain length was determined by using the quicklink pliers to create a loop of excess chain; effectively shortening it. Turns out the chain was only slack on the 28/11t combination and two links / one link-pair was removed; leaving a chain of 112 links.
While the original chain has lasted admirably, it's now looking about 70% through its life (despite seeming immortal at the beginning) so I thought it best to start with a much lower mileage effort..
28/11 with the original chain:
With two links "removed"; bringing some tension to the RD / chain:
While anyone with more skill / less OCD would have had this job done in an hour or two, it was an opportunity to get a few more bits sorted; while as usual unforseen issues served to drag everything out longer.
To begin, the bike was chucked on the workstand on the patio and the wheels, crankset and BB removed before being thoroughly washed, dried and waxed.
As usual I gave the final rinse with a 5l bottle of distilled water (harvested from the condenser drier) to avoid water marks - administering such a dousing always reminds me of the petrol scene from Reservoir Dogs with Tim Roth and Michael Madsen (RIP!).. thankfully I rarely feel like torching any of my bikes; well - except the Brompton.
While waxing the rims I found the cause of the front tyre's slow leak - pulling a 1/2" hawthorn from the tyre prompting it to expel all its air in short order.. while the tyre was off for the puncture to be sorted I also noticed a pretty large ding in the rim edge. This was dressed out as well as possible with a punch and bit of fibreboard to protect the surface; before some corrseponding outward deformation was found deeper into the rim - which received the same treatment.
While it's far better than it was, this area remains imperfect - as ally seems to since it work-hardens and often cracks before you can get it back to exactly where it is..
Once clean and shiny the BB shell was degreased with paraffin and a toothbrush and dried before the build could commence; beginning with the fitment of the new bottom bracket with plenty of copper grease, torqued to the lowest recommended value of 35Nm.
Old and new BB assemblies - SM-BBR60 (road) and BB-MT801 (MTB). These are equivalent in terms of quality (Ultegra / Deore XT) and share many extenal dims and finish, although the cups aren't directly interchangeable as the major-diameter sections are thicker on the road variant and threaded length is a little different.
I was impressed by Shimano's almost commendably quaint, minimal, recyclable packaging as well as the aluminunium spacers (to allow fitment to a 68mm BB shell) - as I've only ever previously encountered lower-spec BBs that come with placcy spacers.
The BB went in without issue; thanks partially to the use of a Shimano plastic reducer insert that fits into the socket for the lower-spec / larger OD BBs; thus minimising the potential for damage during fitting / if anything slips.
The crankset was a similar story with the ever-reliable Hollowtech standard going together as nicely as ever and everything again being torqued to the lower end of the stated values. Old and new cranksets - Despite being larger the 105 item is significantly lighter at 733g versus the modified XT's portly 855g - although most of this difference is down to the 3mm thick guard.
Stark difference in Q-factor illustrated:
Before the front derailleur could be properly fitted cable routing had to be taken care of. By default the shifter cables run down the same side of the bike as the shifter is located upon - the consequence of this being that the cables are forced into a tighter than necessary loop; increasing drag, compromising cable entry angle to the barrel adjustors on the head tube and influencing the steering when the front wheel is unloaded (such as when the bike is in a stand)... as well as looking shite.
The solution to this is to swap the cables to the barrel adjustors on the opposite sides and cross them under the down tube as I've already done on the Fuji. Unfortunately on the CdF this is complicated by the two bottle cage mounting bolts near the bottom bracket. Of course these can be removed but we don't want the vacant holes hoovering up all the crap thrown up off the ground, so the were blanked with very low profile wafer-head bolts:
While the cable were out the barrel adjustors were stripped, cleaned and greased; while the ends of their springs were dressed on a stone to remove sharp edges in the interest of improved operation and reduced damage to the paint on the frame.
Once fitted the front derailleur proved to be its own can of worms.. Most concerningly when set at the correct height it fouled the chainguard (since this is intended for 44t rings and I have 42 - with no way to tell for sure if it'd fit I chanced it). Thankfully this turned out to not be an issue in use - the gap between the outer cage and tooth top on the big ring being more like 5-6mm rather than Shimano's stated 1-3mm.
Ideally I'd like a smaller chain guard but I'm not holding my breath..
Secondly cable retention proved to be a pig - due to a combination of limited instructions, jammed bits and my own ineptitude. Seems I wasn't alone as the cable was reet chewed in the same area on the similarly designed original fitment 105 FD; which I managed to correct to some extent..
I also had issues with the cable tensioner on the FD seizing - apparently after the rotating base into which the retainer plate bolts had somehow become elevated in the FD housing; causing it to jam. Took a while to work that out as I'm not particularly familar with working on these.
Both the outgoing R7000 105 and new RX810 GRX items are very similar - seemingly well-thought-out and well-featured; especially being offset outboard of the seatpost tube to give more tyre / guard clerance. Main differences are that the GRX item sits 2.5mm more outboard, and is bolt-on rather than band-on.
Despite being touted as suitable for differing chainring sizes, the cages look identical and I suspect they only have different part numbers because of the branding.
FD finally setup it was on to the RD; the original GRD RX810 being retained but the cable requiring refitting after being re-routed. As some bellends do, the cable had been bent hard after the clamp; making it difficult to pull through the housing and requiring straightening as best as possible before refitting.
Finally a chain could be fitted and the new configuration set up and tested. Of course with six or eight teeth missing from the new rings the original was slack and sloppy, but only in the highly-ill-advised small / small combination and was fine otherwise; proving that (on the stand at least) shifting was good and there were no obvious issues.
A ten mile test ride was had and a few adjustments made before I committed to shortening one of the spare chains I had waxed and ready.
Since I appear to have misplaced my chain holder, Ideal chain length was determined by using the quicklink pliers to create a loop of excess chain; effectively shortening it. Turns out the chain was only slack on the 28/11t combination and two links / one link-pair was removed; leaving a chain of 112 links.
While the original chain has lasted admirably, it's now looking about 70% through its life (despite seeming immortal at the beginning) so I thought it best to start with a much lower mileage effort..
28/11 with the original chain:
With two links "removed"; bringing some tension to the RD / chain:
