You don't need to be an 'investor' to invest in Singletrack: 6 days left: 95% of target - Find out more
Are low BBs a thing that comes with the geometry of short travel full sus 29ers? I'm riding a Trance 2. Much pedal striking on Eastern Dartmoor.
Any frame/bike options out there for loftier BBs ?
Can you get shorter cranks or lower profile pedals?
It might be an option...........
45mm BB drop on my http://www.carbonda.com/mountain/full-suspension/98.html (Vitus Rapide FS) no pedal strikes to note using 170mm cranks in the Shire.
Is this the same @trailmonkey from Dartmoor way who shared a trip to the Lakes with a Londoner, slugwash & Si many years ago on a Hemlock? If so how's things?
Shorter cranks? I’m running 165’s on my smuggler.
As above, 165s
If you need to run shorter cranks to compensate for the bb hight… does that mean that the bb drop has been designed too low? By using short cranks the seat ends up higher anyway. Or are they designed low bb for better handling with pedals level?
What's the quoted BB drop on your Trance OP?
Shorter cranks will certainly help, but do you feel you've got the right kind of shock tune? It's not wallowing in the travel is it?
Is this the same @trailmonkey from Dartmoor way who shared a trip to the Lakes with a Londoner, slugwash & Si many years ago on a Hemlock? If so how’s things?
The very same, all good here how’s things with you?
Bb drop is 55mm. I’m sure the design is deliberate. My local trails are notorious for pedal strikes though so I guess not every bike suits every terrain?
Cranks are 175 so going to 165 would make a difference. Wouldn’t I end up just raising the seat post though and altering the reach to the bars?
Geometry geeks have the trance 29 at 35mm drop, same as my smuggler. Not smashed any pedals in a while….
@jam-bo my mistake, 35 is correct. Wishful thinking on my part 😁
35mm drop is pretty standard. Same as my bikes.
I think a combination of shorter cranks and revised technique was how I stopped smashing my pedals so much.
Well worth trying less sag. £free. All too easy to set bikes up with incorrect/unsuitable sag.
And 165 cranks are great for everything anyway. Win-win.
If your shock has it, it might be an idea to use a firmer compression setting too.
Wouldn’t I end up just raising the seat post though and altering the reach to the bars?
Reach (bb to top of head tube, horizontally) isn’t effected. Do you mean the distance from saddle to bars as a result of a higher seat? If so, a tiny nudge forward on the saddle would correct any change (and it would be tiny)
My Aether 9 has a 40mm drop, so 5mm lower than yours. I'm getting along ok with 170mm cranks and 18mm thick Unite pedals. Had some issues at first, mostly solved by technique and running a bit less sag (27% vs. 30% of 130mm, which is around 4mm). This does mean that on some natural rides the shock is a bit harder than it needs to be, but I don't notice it as much as I would with the fork.
I'm happy enough with it, but it was the main factor in me just having ordered 165mm cranks. And on my next bike I'll certainly be looking for a higher BB. Not a fault of the bike, just the terrain bias it was designed for, it's 3mm lower sagged than the AM9.
My local trails are notorious for pedal strikes though so I guess not every bike suits every terrain?
IIRC Cotic said they design higher BBs than most, for their local terrain. The Jeht has 27mm drop, the FlareMAX has 32mm. At the same sag %, that should give both roughly the same BB height despite the difference in travel (140mm vs 125mm). Not much in it against your 35mm drop on a 115mm travel I'd think - maybe 3mm.
Reach (bb to top of head tube, horizontally) isn’t effected. Do you mean the distance from saddle to bars as a result of a higher seat? If so, a tiny nudge forward on the saddle would correct any change (and it would be tiny)
If he raised the bars by an equal amount as the saddle, the effective reach will be slightly shorter (a few mm). This is the horizontal distance from the BB axle to the steering axis at the level of the bars (rather than the headset bearing). This is separate from the position of the saddle. To maintain the same distance from saddle to bars, you would actually need to slide the saddle back fractionally.
👋 @trailmonkey 👋 we left London in 2011 aiming for South Devon but settled halfway in Stroud, Gloucestershire which I really like (think: affluent, chavvy & hippy all rolled into one. Totnes/Hebden etc). Did some DIY on a bungalow and then got back to riding. Lots of short sharp hills around here, keeps my lungs alive, XC only riding for me nothing too rad. Turned 50 in December! Left my old employer and now in the same role but an alternative SEN educational setting, loving no nights, weekends and Christmases. Last saw Si in 2017 I think, follow slugwash on IG. Don't tend to travel far these days, all ridings from my doorstep.
@qwerty my sis is in Purton, not too far from you I guess? Let’s catch up for a ride next time I’m up that way 😎
Thanks all for the advice so far. I’ve ridden these trails for a while so I’m pretty aware of the technique for riding them. I’ll certainly try more air in the can and reduce the sag a tad. I’ve got a feeling that I’m right on the edge of my saddle height as is so I don’t think I could go to 165 cranks, maybe 170?
Let’s catch up for a ride next time I’m up that way 😎
Sure, DM me via STW or via IG cyclesofmartin when your over this way 👍