[Closed] 38t chainring too big?

1 x is all about compromise (IMHO), so long as you can maintain the 47 -50mm chainline and your legs can take it a 38 chainring should work without hitting the chainstay, so long as it is an older P7 that was designed with 2 x or 3 x drivetrain.

Alternatively, go 2 x and go 42/36 or similar and suffer less spinning out.

It’s a 2017 model that was set up as 1x in the first place

Might need a new chain.

Check chain ring clearance to the chainstays.

Learn to spin properly if you're spinning out a 34t with 11 at the back, over 50kph is easily doable on 32/11 on a 29er

I’m still spinning out on slight inclines.

You sir, need sponsorship! I've certainly never span out on an incline, that's for sure...

OP currently has a 34t chainring - that's not exactly difficult to spin out even on an incline. I run a 36t on most of mine for exactly that reason. My FS is an exception because I don't tend to push on smooth trails with it, and the 36 I fitted would have cut through the carbon stays if I'd ridden with it 😀 The FS is also a 27.5 plus bus so the larger wheel makes up for the smaller 34t gear. The XC and Fattie though are both awesome on singletrack going flat out, and I still spin out with a 36x11 sometimes. Those are 26x4.8 and 27.5x2.2 so not quite as large a wheel circumference hence the bigger gear. On a 26er I'd go 38 at least and a 29er 34 minimum.

38 42 low gear is too big for most people who ride cross country unless you ride somewhere really flat or is this a brag of look how big a gear I can push ?

lustyd

Member
OP currently has a 34t chainring – that’s not exactly difficult to spin out even on an incline.

Speak for yourself,I can only begin to dream of doing that.lol

Yeah, I'm not the fittest of riders though. That might explain why.😁

34/11 at 100rpm is 41km/h...uphill. good for the op, thats impressive.
Into the 800w ballpark? Nino's 745 over 1 minute apparently

38 42 low gear is too big for most people who ride cross country unless you ride somewhere really flat or is this a brag of look how big a gear I can push ?

I had an MTB a couple of months ago for a few months and found that I never used 32/42 that I had even on slow seated climbs but do live in relatively flat New Forest. A 38/42 would get me up everything. I also found the 32/11 too low for going downhill so again a 38 would have been better for me too. And as for being able to spin I have ridden fixed for almost 20 years and can spin at over 180rpm on fixed downhill but wouldn't choose to on a geared bike.

do we even know if this "slight incline" is up or down ?

"34/11 at 100rpm is 41km/h…uphill."

Nobody is doing 100rpm out of the saddle offroad. This isn't a road bike and we're not talking about riding on roads. On a mountain bike you need enough resistance to maintain pace out of the saddle for fast sections. Using arbitary wattage figures is pointless since power and weight are very closely related (but not to speed!). I can certainly maintain 800W for a while, but I weight a good deal more than Nino.

@Klunk I was certainly talking about false flats, so up. Not sure about the OP.

Well the OP hasn't said where they live but they did say:

(I) want to take a few local downhill Strava segments.
I’m still spinning out on slight inclines.

Which implies that the "inclines" are downhill.

What each of us regards as "spinning out" being a problem is different as well. If I'm going along the flat in my biggest ratio and there's a short descent and I spin out temporarily that's not a problem, I can just coast for a few seconds and get my breath back. If I was spinning out on the flat then it does become a potential problem. If however you need to get to 88mph for the flux capacitors to work then you are going to need a bigger gear.

do we even know if this “slight incline” is up or down ?

I believe, though of course I may be wrong, that an incline can be both up and down at the same time. I think it's one of those mind blowing things like a single photon of light passing through 2 separate slits at exactly the same time!The universe really is far more weird than you can ever imagine.

Sorry for the confusion chaps, I meant going down an incline, maybe I should’ve called it a decline.

I can assure you all, there is no way I will be breaking any records going uphill, I have made my peace with this and just enjoy going down as quickly as possible and occasionally worrying the odd Strava leaderboard if the conditions are fair and the incline/decline if favourable too!

I’ve just ordered a 38T oval chainring from Superstar Components. I’m not sure whether oval was a good idea, but I’ve never used one before so thought I’d give it a go. Cheers for the replies!

Just bear in mind that an oval needs even more clearance than a regular 38t - it's probably 40t at wides points, and 36t at narrowest

I see the OP’s need, I used to run 38/26 2x10 for exactly this reason.

It’s all about available gear range and it’s one of the big reasons I prefer a 10T top in 1x.

OP, I’d agree with the earlier comments that you may be heading for clearance issues. I’d check carefully and cleanly before bolting anything...

OP currently has a 34t chainring – that’s not exactly difficult to spin out even on an incline. I run a 36t on most of mine for exactly that reason

I can certainly maintain 800W for a while,

You Sir are a climbing god worthy of competing at a seriously high level. That is of course unless you already are!!

I bought a 38T oval from superstar and it has a larger tooth pcd on widest sections than the 41T round ring I was taking off, so watch that clearance on swingarm!!!

Cheeky comment, but I have a 38T Hope N/W I've just taken off my retired singlespeed….

Thanks Martin, it has to be cinch direct mount. The 38t Superstar Oval arrived today.. I’ll report back

Quick update, thanks for all the helpful comments.

The oval 38T chainring went on today.

I want to use this bike for XC in the my local Hertfordshire are, so not too hilly. I managed to blast down the slight DECLINES 🙂 that my local route takes in without spinning out at the top end and could climb the steepest inclines with plenty in the tank. Grabbed a place on a Strava leaderboard tonight, not that bigger deal unless you're a middle aged fatty like myself!

Overall I'm very happy. I had to take the top guard off, but the ring is narrow wide and didn't have any problems there. I'm not sure if I need a guard or if anyone does one that fits a 40T.. I'm guessing thats what my 38T would be at the highest point of the oval?

The oval ring suits my pedalling action I'm more of a stomper, might be worth noting if you're more of a spin the pedals type of person.

Screenshot the strava profile for these downhill ups! 😆 These we have to see!