Cannondale TOPSTONE 2019 is released

Especially for light weight issues concerning cyclocross / touring bikes & parts.

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frogtape777
Posts: 116
Joined: Thu Dec 20, 2018 9:35 pm

by frogtape777

Thanks Tom,

I want my power meter i'm so used to on my MTB more than anything, and was trying to convince myself of Shimano 105s earlier, (As stages 105 power meter left crank arms are so cheap) but the 34 small chainring on the 105, would mean my rear 34T casette, would effectively become a 30T casette.

Rode up Holmes Moss yesterday and the Sky road, and 34T got me out of the hurt locker, with a full on headwind, at the steepest parts, so i'm loathe to lose it!

Not done a test ride on the GK 38s yet, but will get out one day next week :)

tomh79
Posts: 103
Joined: Thu Dec 27, 2018 9:50 pm

by tomh79

OK. Why don't you buy a new 105 crank or even better: used Ultegra 6800/r8000 crank 46/36 --> swap the 36 for a 34 ring and install a SRAM 11-36 cassette instead of your Shimano 11-34. Lowest gear would be: 0.994 instead of 0.882 but still less than 1:1

EDIT: if you install one of those cranks you might have to work with spacers to achieve a 45mm chainline to work with your current setup. of course a normal 43.5 would work as well - depends which cogs you use the most...

by Weenie


frogtape777
Posts: 116
Joined: Thu Dec 20, 2018 9:35 pm

by frogtape777

tomh79 wrote:
Sun Aug 18, 2019 12:18 pm
OK. Why don't you buy a new 105 crank or even better: used Ultegra 6800/r8000 crank 46/36 --> swap the 36 for a 34 ring and install a SRAM 11-36 cassette instead of your Shimano 11-34. Lowest gear would be: 0.994 instead of 0.882 but still less than 1:1

EDIT: if you install one of those cranks you might have to work with spacers to achieve a 45mm chainline to work with your current setup. of course a normal 43.5 would work as well - depends which cogs you use the most...

Would the Stones default front mech work with the above, or need major fettle/new mech? and rear mech handle a 36?

Talk to me about the chainline bit, always confuses the hell out of me! :shock:

Ps I wouldn't mind a 48/50 bigger ring, as do spin the 46 out on roads, but again would probably need new mech?

tomh79
Posts: 103
Joined: Thu Dec 27, 2018 9:50 pm

by tomh79

Image

The Topstone has a 142mm rear hub spacing (afaik) --> optimal chainline: 46mm --> that's about what I measured on my Topstone 105. Optimal chainline meaning --> a straight chain (no crosschaining) so it runs smoothly. "Optimal" is of course subjective. Manufacturers always define the center of the cassette as optimal. If you would ride on your small cogs most of the time, your optimal chainline would be further out --> maybe 47/48mm? if you ride on your 28t, 30t or 34t most of the time --> 43mm would be better.

Since the crank chainline is defined by the manufacturer you have to be careful what crank you want to buy. Although you could correct it with spacers (somebody please correct me if I'm wrong). Here's a table with common hub spacings: https://pubwheels.com/blogs/news/know-y ... -standards --> road quick release (rim brake) has a narrower spacing, resulting in cranks with narrower chainlines (road cranks by Shimano have a 43.5 chainline, GRX crank has 46.9 I think).

your 105 r7000 front mech would probably work easily with a 11-36 cassette (people push it to 11-40). 45mm chainline seems to work as well, and by shimming the front mech even 47mm could work?

frogtape777
Posts: 116
Joined: Thu Dec 20, 2018 9:35 pm

by frogtape777

tomh79 wrote:
Sun Aug 18, 2019 6:38 pm
Image

The Topstone has a 142mm rear hub spacing (afaik) --> optimal chainline: 46mm --> that's about what I measured on my Topstone 105. Optimal chainline meaning --> a straight chain (no crosschaining) so it runs smoothly. "Optimal" is of course subjective. Manufacturers always define the center of the cassette as optimal. If you would ride on your small cogs most of the time, your optimal chainline would be further out --> maybe 47/48mm? if you ride on your 28t, 30t or 34t most of the time --> 43mm would be better.

Since the crank chainline is defined by the manufacturer you have to be careful what crank you want to buy. Although you could correct it with spacers (somebody please correct me if I'm wrong). Here's a table with common hub spacings: https://pubwheels.com/blogs/news/know-y ... -standards --> road quick release (rim brake) has a narrower spacing, resulting in cranks with narrower chainlines (road cranks by Shimano have a 43.5 chainline, GRX crank has 46.9 I think).

your 105 r7000 front mech would probably work easily with a 11-36 cassette (people push it to 11-40). 45mm chainline seems to work as well, and by shimming the front mech even 47mm could work?
Thanks Tom, see all this shimming, and spacers etc makes me want to source a bolt on power meter, be it pedals, chainring, bb etc,

I'll revisit all this info once i've done more research though, fantastic help!

Thedude74
Posts: 3
Joined: Mon Jun 10, 2019 8:09 pm

by Thedude74

Hi all - is it possible to keep the existing crank set and thus bottom bracket and change to a single chain ring (narrow wide)?

If so what would be the ideal front chain ring from a gearing perspective? Ideally I would like to keep the gearing as close to stock as possible as this works fine for me.

Thank you in advance

yinzerniner
Posts: 49
Joined: Tue Jun 13, 2017 8:54 pm

by yinzerniner

Thedude74 wrote:
Tue Aug 27, 2019 8:59 pm
Hi all - is it possible to keep the existing crank set and thus bottom bracket and change to a single chain ring (narrow wide)?

If so what would be the ideal front chain ring from a gearing perspective? Ideally I would like to keep the gearing as close to stock as possible as this works fine for me.

Thank you in advance
Cannondale makes direct mount 1x Narrow Wide chainrings for their cranks. See here:
https://www.cannondalespares.com/produc ... =61&b=&s=n

As for gearing, use this to calculate what you'll need to keep existing gearing:
http://ritzelrechner.de/

frogtape777
Posts: 116
Joined: Thu Dec 20, 2018 9:35 pm

by frogtape777

Hey Tom,

I'm about to pull the trigger on new crankset etc

Which of these would I need

https://www.bike24.com/1.php?content=8; ... =1000,4,23

frogtape777
Posts: 116
Joined: Thu Dec 20, 2018 9:35 pm

by frogtape777

PS This is what i'm going for pending correct BB

This

https://store.stagescycling.com/GEN-3-S ... =5&color=2


and



Image

tomh79
Posts: 103
Joined: Thu Dec 27, 2018 9:50 pm

by tomh79

Hey! You need BSA. So you’ve decided on a road 50/34? I have that (Ultegra) on my Synapse with an 11-32 cassette. Works well also in hilly areas but I would not want to climb steep gravel with it.

frogtape777
Posts: 116
Joined: Thu Dec 20, 2018 9:35 pm

by frogtape777

tomh79 wrote:
Sun Sep 15, 2019 7:05 am
Hey! You need BSA. So you’ve decided on a road 50/34? I have that (Ultegra) on my Synapse with an 11-32 cassette. Works well also in hilly areas but I would not want to climb steep gravel with it.
Amazing help, added a BSA.

The crank alone will save 0.3 lbs, I know theres better options, but I just can't find a stages power meter on any of them.

https://store.stagescycling.com/Single- ... wer-Meters


I'm hoping the 11-36 will give me as close as damn it a good enough steep gravel and road gear.

They do have a GRX power meter but you have to post the crank arm to USA, and its an aftermarket fit.

Other wise i'd be all over this

https://www.bike24.com/p2322754.html?q=shimano+grx

tomh79
Posts: 103
Joined: Thu Dec 27, 2018 9:50 pm

by tomh79

Good point about the power meter. Did you buy the 11-36 sram cassette? Tell me how it works then! 34/36 should be good enough if you don‘t plan to do bike packing trips.

frogtape777
Posts: 116
Joined: Thu Dec 20, 2018 9:35 pm

by frogtape777

Yeah bought the 11-36 too.

Can't see whether it needs a spacer behind it, like the Shimano 11-34 does?

The 1130 seems to mention a spacer as its a 8/9/10 speed compatible one

https://www.rosebikes.co.uk/sram-pg-113 ... tte-852203


The 1170 looks like it might be 11 speed road only?

https://r2-bike.com/SRAM-Force-22-Casse ... ed-PG-1170

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