Ask the experts

[hick]

[emoji638]][emoji640][emoji639]][emoji638][emoji638][emoji[emoji6[emoji640][emoji638]][emoji640][emoji6[emoji640][emoji638]]][emoji637][emoji638][emoji6[emoji640][emoji637]]]Hick, did you get the large or extra-large Sentinel frame? I prefer a frame to not feel too large


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I went XL. But, I have long arms and inseam. I’d say downsize to a large if you don’t want to long. Maybe someone has one you can sit on. The XL is more maneuverable than I thought it would be though.


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[Dantheman]

Dammit - now I am thinking about buying a Mara Pro for my Trance, which is 185 x 52.5. Hayes has them on sale right now for $252.

Do it. Do it now. That's barely more than doing a full service on your current shock. A lot of people here have bought the Mara Pro and I can't think of one person who didn't love it. Check that they have the right tune, though.

Just to add, shock spec rarely changes with frame size, but shock clearance sometimes will. With transitions, you'd mostly just need to worry about large piggybacks running into the downtube on smaller sizes at full bottom out. I've heard of issues with certain shocks on the Spur. Don't recall hearing about issues on any other tranny frames, but they may exist.

Water bottles can also be a problem. My frame technically holds a full size bottle, but not with a piggyback shock.

[east or bust]

This reminds me, isn’t there a slightly shorter (~12mm) PB for the Mara Pro?

They just have one listed in the parts section on their website but doesn’t clarify if it’s the short or long one.


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[skaredshtles]

Do it. Do it now. That's barely more than doing a full service on your current shock. A lot of people here have bought the Mara Pro and I can't think of one person who didn't love it. Check that they have the right tune, though. Water bottles can also be a problem. My frame technically holds a full size bottle, but not with a piggyback shock.

The only remaining size they had was 185x50, which is a shorter stroke than my bike came with stock. Fortunately, I was informed that the 50 is the same as the 52.5 and 55 except with a couple volume reducers installed. So I've ordered the 50 and will crack it open and remove one... perhaps both of the added spacers.
Thanks alot, Dan, for prompting me to spend more money. My wife will be annoyed.

[g_man80]

How annoying is the chain angle/cross angle with 55mm chainline cranks with normal 148mm rear end and 12-spd cassette. Specifically, shimano m8120 cranks, 30t chainring, 10-51 cassette, 440 chainstay. CS clearance is just a bit too tight to go with the 8100 cranks. I’m removing a sram transmission which we all know is designed around 55mm with the cassette just smidge pushed out.
I do spend a lot of time in 1st and 2nd gear. Will backpedaling be a problem? I feel like we're back in time to the 1x conversion era.

[toast2266]

How annoying is the chain angle/cross angle with 55mm chainline cranks with normal 148mm rear end and 12-spd cassette. Specifically, shimano m8120 cranks, 30t chainring, 10-51 cassette, 440 chainstay. CS clearance is just a bit too tight to go with the 8100 cranks. I’m removing a sram transmission which we all know is designed around 55mm with the cassette just smidge pushed out.
I do spend a lot of time in 1st and 2nd gear. Will backpedaling be a problem? I feel like we're back in time to the 1x conversion era.

Realistically fine, but depending on your bb width, I think there's a 2.5 mm spacer that goes on the crank spindle on the drive side. You could shift that to the non drive and see if the chainring still clears. If it doesn't, you can get thin spacers (wheels manufacturing makes them) to mix and match to dial in your chainline.

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[Spencer123]

I did this for awhile with a sram setup. Backpedaling in first is rough, but as long as it was tuned well 2nd was no problem. It wasn’t bad enough to bother changing it up until I wanted shorter cranks anyways. Not totally ideal but can for sure live with it.

[g_man80]

Thanks. BB is 73mm, so there will be one 2.5mm spacer on the drive side between the frame and BB. If I go with M8100, no additional spacers, so no additional adjustments. If I go M8120, I'll have two 3mm spindle spacers (one on each side). As mentioned, I could use the Wheels Mfg. thin spacers to bring the drive side crank back towards center a smidge (e.g., 2mm spacer on DS and 4mm spacer on non-DS, resulting in a 54mm chainline).

Honestly, I am probably over thinking it. Last night I installed a regular mechanical SRAM eagle drivetrain with normal DUB cranks (not DUB wide) and a 32t chainring. The chainring clears okay, but what is giving me pause is how close the chain is to the chainstay where it swoops up toward the main pivot. It does have a nice rubber plastic protector, so I do not think it will get chewed up as the chain bounces around. Of course dropping down to the 30t will lower the chain a bit closer to the chainstay. I would share pic, but the forum is fussy right now.

It is worth nothing that the manufacturer specs the M8120, 30t cranks on their Shimano builds. It would appear they prefer to protect the chainstay and get by with a less than ideal chain angle. There are plenty of other manufactures doing the same (e.g., Ibis Ripley V4S shimano builds have 20 series cranks with 55mm chainline and 148 rear, and those have a very short chainstay).

[Dee Hubbs]

Anyone in the SLC area able to help a Mag with the wife's bike? Carbon MTB frame, I've been through 4 BBs in 18mos. I'm guessing the BB cups in the frame are a smidge too small, so need the BB area reamed (Park Tools makes one). I can pull the crank and BB, just need the tool thru thru it to rule that problem out.Mucho appreciated.

This is a job where you will need to call all the shops to see who has the tools.
The tools needed are expensive, and are usually in old school shops that faced and chased bottom brackets and head tubes on metal bikes back in the day.
And you need a PF92 (41mm) reaming tool, which was not a common standard when these old school shops bought these tools. Many shops have not bought the modern fittings/cutters for their tools to fix the modern BB standards.
To put it in perspective they need the main tool ($500), and specific to your BB size reamer ($153) facer ($175) centering cone ($35) reamer stop ($14) pilot ($10).
Only 1 or 2 of those cheaper parts translates to multiple BB sizes, so that $200-325 per BB standard that needs to be reamed (6 sizes).

AND then you need to find a mechanic you trust performing a non reversible reaming (cutting material out) process.
Good luck, choose wisely.

[beaterdit]

I’ve got my preferences on local shops and it’s usually not Contender but for this I would try them. I had them face my rear brake posts down on two bikes and am happy with the results. They’re the only shop I contacted who had the tools and didn’t flinch at the job. It was routed to their chief mechanic who’s been around for along time. They also have the money to be able to potentially have these tools on hand.

[SJG]

thanks Mags

[Dantheman]

This reminds me, isn’t there a slightly shorter (~12mm) PB for the Mara Pro?

They just have one listed in the parts section on their website but doesn’t clarify if it’s the short or long one.

Yes, there's a short PB option.

The only remaining size they had was 185x50, which is a shorter stroke than my bike came with stock. Fortunately, I was informed that the 50 is the same as the 52.5 and 55 except with a couple volume reducers installed. So I've ordered the 50 and will crack it open and remove one... perhaps both of the added spacers.
Thanks alot, Dan, for prompting me to spend more money. My wife will be annoyed.

I'm pretty sure that changing the stroke on the Mara Pro is not a DIY job.

[jamal]

Yeah, travel spacers and volume spacers are two different things.

Volume spacers - easy, in air can, generally clip on.

travel spacers,-inside damper between seal head and piston, what top out happens against. So all that has to come apart to get to them.

[toast2266]

I'm pretty sure that changing the stroke on the Mara Pro is not a DIY job.

That's my understanding as well. That said, he's increasing stroke, which means removing the spacers. The spacers aren't hard to get at - its just a matter of opening the air can. Assuming he's going for full stroke, he can just cut the spacer out without going through the full disassembly procedure. Gotta be careful to not scratch up the internals though.

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[frorider]

^ good point.

Re: Chainlines - the 55 mm CL / 148 rear history is complicated https://theradavist.com/55mm_chainline/ and kinda lame. It reflected a period when 27.5+ and short CS were considered important. Fortunately today there are some options to unfuck things. I encourage you to experiment with thin spacers to see how much you can decrease your CL. Not only will it make backpedaling robust rather than barely acceptable, it will of course increase drivetrain life since it’s the steeep climbing that sees your greatest torque.

The inward angled teeth on the transmission big cog is moderately helpful but frankly it’s lipstick on a pig.

[Whiteroom_Guardian]

Best way to carry an 18" chainsaw on MTB? Best electric chain saws?

I got my saw cert from USFS so I can help our local MTB association clear trail. I don't have a fatbike or E-bike so will be grinding on my Enduro bike. I have an 18" stihl, but man it would be nice to have one of the good electrics. The FS dude seemed to really like the Husky electric that the FS has purchased some of the last year.

[toast2266]

Best way to carry an 18" chainsaw on MTB? Best electric chain saws?

I got my saw cert from USFS so I can help our local MTB association clear trail. I don't have a fatbike or E-bike so will be grinding on my Enduro bike. I have an 18" stihl, but man it would be nice to have one of the good electrics. The FS dude seemed to really like the Husky electric that the FS has purchased some of the last year.

Either the Evoc or Dakine saw pack. Dakine is a bit bigger and can hold more shit, but realistically, unless you're not going very far, you're not gonna want to ride with a bunch of extra crap in the pack.

Riding flat or downhill with the saw in a pack is fairly do-able. I find that doing significant climbs on an analog bike with the saw pack is pretty miserable. It's my last resort.

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[hick]

I have the Dakine and an old Mystery Ranch I use when going light. Keep in mind with the battery saws, you don’t lose weight when the battery goes dead. A small gas saw, you’ll use your fuel and lighten your load. I have a Makita battery saw I like for low profile missions, but mostly use a Husky [emoji639][emoji640][emoji6[emoji640][emoji638]] xp for pedaling. Husky [emoji6[emoji640][emoji637]][emoji640][emoji6[emoji640][emoji637]]xp is a great current option that’s fairly light and durable. Props man! We need more saws out and about especially with the FS trail crews gutted recently from doge.


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[evasive_MT]

The Evoc saw packs look great, but they’ve been out of stock for a while. I’d like to get a few for our nonprofit to add to the Dakines we have.

[jackstraw]

I use an old Lowe pack. It's a substantial internal frame backpack. I forget the liters. My entire Milwaukee saw fits inside so I can be stealthy heading into the woods...kinda sorta I guess [emoji16]

[evdog]

I have the dakine builder pack. I wouldn't say its great for carrying a saw but I make it work. I have a 12" ryobi that is kinda fat - seems like small gas saws have a smaller profile. It is a pretty comfortable pack even when loaded down. I carried a saw 3 miles in to a work site yesterday. When riding in I have strapped it down to the old man mountain rack. That worked fine for a long climb up. Descending back down I put it in the pack. That combo seemed to work well.

[XXX-er]

I got the Dakine was hard to find on-line , even with an E-bike it was a slog up into the bluff

[toast2266]

The Evoc saw packs look great, but they’ve been out of stock for a while. I’d like to get a few for our nonprofit to add to the Dakines we have.

I have the evoc. It carries the saw about as well as I think a pack can. My only real complaint is that the back panel doesn't have much rigidity to it, so it you have oddly shaped stuff in the pack and a saw in the holster, the saw presses everything into your back in a non-optimal way. But on the whole I like the pack a lot and use it quite a bit.

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[Whiteroom_Guardian]

Half tempted to jam the saw into a contractor bag and stick it in my carbon frame hunting pack. Though I REALLY don't want to get any gas/saw smell on that pack.

This looks pretty nifty. https://www.enduroeng.com/p148232-mtb-bike-chainsaw

[XXX-er]

I do not think I want all that weight on the front end of an mtn bike^^ and then try to ride it


A cutting buddy would just take the bar off and stuff his saw in a pack to hike it around the hill when we were cutting runs without no bikes


but yeah you are gona get oil and gas all over it so maybe find a well used pack somebody is selling off. Getting oil and gas allover my a brand newDakine builders pack just felt wrong but that what I bought it for



I used a forestry cruising vest to carry oil/ gas/ tools/ chains food water in all the pockets but i don't remeber riding with it