You don't need to be an 'investor' to invest in Singletrack: 6 days left: 95% of target - Find out more
Looking at going back to 2 rings from a single ring setup on my Ti Hardtail. The reason's not important, but looking at the bike, I was wondering something...
Are 2x10 setups (say a 26/39 SRAM crank) spaced further over than a 3 ring setup? I'm looking at my M760 Shimano XT crank (came with a 22/32/44 setup on it) and the 32T clears the chainstay OK, but only just clears a 36T ring if I put that in the middle position. If I put a 26/39 SRAM crank on, is it going to clear the chainstays ok?
Frame is a 2009 (I think) Genesis Altitude Ti for what it's worth.
add another spacer?
add another spacer?
No can do
It's a 73mm BB
the frame will have been designed with a specific chainset in mind
i personally wouldnt be comfortable overspacing the BB to compensate
The outer ring on a double Chainset will be slightly further out than the middle ring on a triple
Not sure it's completely true but think of the 2x chainrings as occupying the spaces between the 3x chainrings. No need to space the BB, the crank offset/chainline is different.
Put on a triple BUT and here is the clever part PRETEND the outer chainring is a bash guard UNTIL you need a higher gear THEN you can use it. JOB'S A GOOD 'UN
............to be slightly more helpful....I think you will struggle....BUT phone the distributor/maker of the frame and ask them. They make the stuff so they should help you out
Don't Madison do Genesis...if so then they have an email question service which I've used before
Yes a true double crankset has a narrower Qfactor or tread than a tripple ring crank.
Hang on!! weren't you telling everyone in no uncertain terms that more than one chainring is unnecessary a short while back?? 😕
"the frame will have been designed with a specific chainset in mind"
.. pre-2x10 anyway. 26-39 on a proper double crank should be ok. A triple's middle ring usually sits in the position between the 2 rings on a double - both about 48~50mm chainline. It's the earlier / larger 30-42 2x10 combos that don't fit a lot of pre-2010 bikes.
Not sure it's completely true but think of the 2x chainrings as occupying the spaces between the 3x chainrings. No need to space the BB, the crank offset/chainline is different.
That's kinda what I was hoping...
............to be slightly more helpful....I think you will struggle....BUT phone the distributor/maker of the frame and ask them. They make the stuff so they should help you out
Don't Madison do Genesis...if so then they have an email question service which I've used before
Yes but... I'd have to wait til Monday for that...
"the frame will have been designed with a specific chainset in mind"
.. pre-2x10 anyway. 26-39 on a proper double crank should be ok. A triple's middle ring usually sits in the position between the 2 rings on a double - both about 48~50mm chainline. It's the earlier / larger 30-42 2x10 combos that don't fit a lot of pre-2010 bikes.
Posting it on here is way better as the guy who designed the frame answered the question for me late on a Friday night (cheers James!)
Hang on!! weren't you telling everyone in no uncertain terms that more than one chainring is unnecessary a short while back??
Haha Kev, you ok mate?
To be fair I still maintain for offroad a single ring with an 11-36 cassette is pretty much all you need, but I'll now put a caveat on that. It's not ideal for "social" riding. Without a low low gear, you've got to grunt up the climbs which invariably means riding at your own pace on group rides. Also, whilst a 32 is plenty for me offroad, having to do a bit more on road now (GF has just started riding) its a touch low for on road use. Hence thinking of going to a new style XC double chainset.
All good cheers fella, must admit I did try the single chain ring thingy but found I was getting dropped on the fast bits and not making the steep climbs, so I went back to the old faithful 2×9. 🙂
ie I've not got the drawings anymore so I can't say for sure, if you're about to buy one..[u]should[/u] be ok.
Kev, not found a climb I can't make yet on 32/36 bottom gear. That said, its not easy and does require some grunt! Said climb I've tried climbing it on a bike with a triple chainset before, sitting trying to spin in the granny, and ended up either wheelieing or spinning the back tyre up the whole time. I've run the single with a 36T ring before and found the spread of gears pretty much ideal, except for the 1:1 bottom ratio was a struggle on anything really steep.
Cheers James, whatever I do I'll keep the receipt in case anything needs to be returned. 36T fits fine in the normal middle ring position though, so if a double is slightly further spaced out than a normal triple middle ring, it should just about fit I reckon.